USACE / NAVFAC / AFCESA / NASA UFGS-23 51 43.01 20 (April 2006)
------------------------------
Preparing Activity: NAVFAC Replacing without change
UFGS-15861N (September 1999)
UNIFIED FACILITIES GUIDE SPECIFICATIONS
References are in agreement with UMRL dated January 2009
SECTION 23 51 43.01 20
MECHANICAL CYCLONE DUST COLLECTOR OF FLUE GAS PARTICULATES
04/06
NOTE: This guide specification covers the requirements for furnishing, installing,
adjusting, and testing of mechanical cyclone-type dust collector(s).
Edit this guide specification for project specific requirements by adding, deleting,
or revising text. For bracketed items, choose applicable items(s) or insert
appropriate information.
Remove information and requirements not required in respective project, whether
or not brackets are present.
Comments and suggestions on this guide specification are welcome and should
be directed to the technical proponent of the specification. A listing of technical
proponents, including their organization designation and telephone number, is
on the Internet.
Recommended changes to a UFGS should be submitted as a Criteria Change Request
(CCR).
NOTE: The dust collectors are intended to be used for flue gas particulate
removal and collection associated with coal-fired or oil-fired boilers and refuse-fired
waste disposal incinerators. Coal-fired boilers applicable to this specification
are those designed for pulverized coal firing, spreader stoker firing, or underfeed
stoker firing with capacities ranging between 3.78 and 44 kilogram of steam
per second 30,000 and 350,000 pounds of steam per hour. The incinerators applicable
to this specification are those designed for burning municipal-type waste having
firing capacities between 454 kilogram per hour 1,000 pounds per hour and 182
Mg 200 tons per day.
NOTE: The following information shall be shown on the project drawings:
1. The physical geometry of the cyclone relative to the plant.
2. The manner in which the cyclone is connected to the ductwork.
3. The means of physical support of the cyclone.
4. The amount of clearance between the hopper and floor.
PART 1 GENERAL
1.1 REFERENCES
NOTE: This paragraph is used to list the publications cited in the text of
the guide specification. The publications are referred to in the text by basic
designation only and listed in this paragraph by organization, designation,
date, and title.
Use the Reference Wizard's Check Reference feature when you add a RID outside
of the Section's Reference Article to automatically place the reference in the
Reference Article. Also use the Reference Wizard's Check Reference feature
to update the issue dates.
References not used in the text will automatically be deleted from this section
of the project specification when you choose to reconcile references in the
publish print process.
The publications listed below form a part of this specification to the extent referenced. The publications are
referred to within the text by the basic designation only.
[ASTM INTERNATIONAL (ASTM)ASTM A 123/A 123M(2008) Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel ProductsASTM A 139/A 139M(2004) Standard Specification for Electric-Fusion (ARC)-Welded Steel Pipe (NPS 4 and over)ASTM A 167(1999; R 2004) Standard Specification for Stainless and Heat-Resisting Chromium-Nickel Steel Plate, Sheet, and StripASTM A 240/A 240M(2008) Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General ApplicationsASTM A 242/A 242M(2004e1) Standard Specification for High-Strength Low-Alloy Structural SteelASTM A 36/A 36M(2008) Standard Specification for Carbon Structural SteelASTM A 532/A 532M(1993a; R 2008) Standard Specification for Abrasion-Resistant Cast IronsASTM A 580/A 580M(2008) Standard Specification for Stainless Steel WireASTM A 667/A 667M(1987; R 2008) Standard Specification for Centrifugally Cast Dual Metal (Gray and White Cast Iron) CylindersASTM B 209(2007) Standard Specification for Aluminum and Aluminum-Alloy Sheet and PlateASTM B 209M(2007) Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate (Metric)ASTM C 401(1991; R 2005) Alumina and Alumina-Silicate Castable RefractoriesASTM C 592(2008a) Standard Specification for Mineral Fiber Blanket Insulation and Blanket-Type Pipe Insulation (Metal-Mesh Covered) (Industrial Type)ASTM C 612(2004e1) Mineral Fiber Block and Board Thermal Insulation][INSTITUTE OF CLEAN AIR COMPANIES (ICAC)ICAC M-2(1969) Cyclonic Mechanical Dust Collector CriteriaICAC M-4(1973) Information Required for the Preparation of Bidding Specifications for Large Diameter Cyclones and Tubular Centrifugal CollectorsICAC M-5(1975) Standardized Method of Particle Size Determination and Collection EfficiencyICAC M-6(1981) Simplified Method of Efficiency Calculations from Fractional Efficiency Curves][NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)NEMA ICS 6(1993; R 2006) Standard for Industrial Controls and Systems Enclosures][SHEET METAL AND AIR CONDITIONING CONTRACTORS' NATIONAL ASSOCIATION (SMACNA)SMACNA 1403(1975, 1st Ed) Accepted Industry Practice for Industrial Duct Construction][THE SOCIETY FOR PROTECTIVE COATINGS (SSPC)SSPC SP 6(7) Commercial Blast CleaningSSPC SSPM(2000) SSPC Painting Manual, Volume 2, Systems and Specifications][U.S. GENERAL SERVICES ADMINISTRATION (GSA)FS TT-P-28(Rev G) Paint, Aluminum, Heat Resisting (1200 Degrees F.)][U.S. NATIONAL ARCHIVES AND RECORDS ADMINISTRATION (NARA)29 CFR 1910-SUBPART DWalking - Working Surfaces40 CFR 60Standards of Performance for New Stationary Sources]1.2 SYSTEM DESCRIPTION
NOTE: Select the applicable paragraph(s) from the following:
NOTE: Use these paragraphs for multitube collectors 150 mm 6 inch diameter
collecting tubes may cause a plugging problem. Designer must investigate flue
gas particulate size, distribution and tendency of particulates to adhere to
each other for the specific project before selecting diameter of collector tubes.
NOTE: The third sentence of this paragraph shall be used only when dust collector
is used with spreader stoker-fired boiler.
[Dust collector(s) shall be multitube, mechanical cyclone type, having collector tubes in accordance with ICAC M-2
, ICAC M-4, ICAC M-5, and ICAC M-6. Collector(s) shall remove fly-ash from flue gas produced by a [pulverized
coal-fired boiler] [spreader stoker-fired boiler] [underfeed stoker-fired boiler] [No. 6 fuel oil fired boiler]
[refuse fired waste disposal incinerator of water wall furnace design]. [There shall not be any reinjection
from dust collector hopper(s) into spreader stoker-fired boiler.] Collector(s) shall be designed for [indoor]
[outdoor] installation and located in the flue-gas system between [_____] outlet and [_____] inlet [existing]
locations. Provide necessary gas distribution devices in the ductwork ahead of and at the entrance of the dust
collector(s) to ensure even gas flow into the dust collector(s).]
NOTE: Use this paragraph for 600 mm 24 inch or larger diameter cyclone collectors.
A choice of diameter is dependent upon design parameters that must be analyzed.
[Dust collector(s) shall be high-efficiency, mechanical cyclone-type, [600 mm] [24 inch] [_____] diameter centrifugal
cyclone body with tangential entry having arrangements of one, two, four, or more parallel unit combinations
in accordance with ICAC M-2, ICAC M-4, ICAC M-5, and ICAC M-6. Collector(s) shall remove fly ash from flue gas
produced by a refuse fired waste disposal incinerator of the no-boiler furnace design. Collector(s) shall be
designed for [indoor] [outdoor] installation and located in the flue gas system between [_____] outlet and [_____]
inlet [existing] locations. Provide necessary gas distribution devices in the ductwork ahead of and at the entrance
of the dust collector(s) to ensure even gas flow into the dust collector(s).]
1.3 PERFORMANCE
NOTE:
1. The stack emission or efficiency requirement must comply with either (a)
weight emission standards: (b) opacity regulations; or (c) community standards
for visible emissions. Compliance with existing emission codes may not satisfy
the opacity regulation. Similarly opacity regulations may not be as demanding
as community standards. A specific quantitative emission rate must be selected
on the basis of the goals established.
2. Stack opacity is influenced by particle size makeup. For example, with
pulverized coal-fired boilers, about 45 percent of ash particles are below 10
microns in size; for a cyclone-fired boiler, about 70 percent are below 10 microns;
for a stoker-fired boiler, about 25 percent are below 10 microns. A visually
acceptable stack for these three options might require residuals of 0.046 g/m3
0.02 gr per cf, 0.023 g/m3 0.01 gr per cf, and 0.0929 g/m3 0.04 gr per cf,
respectively.
3. A 90 percent overall collection efficiency may be attainable with most coals
burned in underfeed or gravity feed stoker-fired boilers. Mechanical cyclones
must be viewed as a part of an air pollution system on boilers or incinerators.
When used as precleaners in conjunction with electrostatic precipitators (ESP)
or baghouses, a high efficiency cyclone is not necessary and may even adversely
affect the high efficiencies of the ESP or baghouse. In addition, 90 percent
efficiency is dependent upon particle size, distribution and concentration as
well as the collector being or not being used in conjunction with higher efficiency
ESP or baghouse collectors. The large diameter cyclones do have a low pressure
drop, but the high efficient multitube collectors operate in a range from 747
to 1992 Pa 3 to 8 inches water gage.
[Multitube] [Centrifugal cyclone] collector shall operate with a minimum overall collection efficiency of [_____]
percent at a maximum draft loss of [1992] [249] Pa [8] [1] [_____] inch water gage when operating at maximum
[continuous] [peak] rating of flue gas flow conditions, dust loading, and dust particle size distribution specified
in paragraph entitled "Inlet Gas Conditions."
1.4 DESIGN REQUIREMENTS
1.4.1 Mechanical Cyclone Dust Collector System
Indicate the kind, size, collector arrangement with duct gas distribution devices, duct transitions, hopper access,
walkways, housing access, damper and damper controls, draft gage and sample portal connections, weight of each
component, and breakdown for shipment. When detail drawings are submitted without statements describing sectional
shipments, it will be understood that no field assembly of the equipment will be required. Indicate the arrangement
of platforms, walkways, stairways, and fixed ladders that are required for operation, examination, testing and
maintenance of each dust collector. Indicate the external connections, location of local controls and remote
control panels, anchorages, and supports required; the dimensions needed for installation and correlation with
other materials and equipment; and foundation and loading information. Submit the layout drawings for each component
showing design and assembly. Layout drawings shall show each hopper face with all arrangement including control
zones. Submit wiring diagrams and control schematics of all electrical and pneumatic circuits used.
1.5 OPERATING EXPERIENCE REQUIREMENTS
1.5.1 Equipment
Provide only [a] dust collector[s] which meet[s] all of the operating experience requirements listed below.
1.5.2 Operating Experience
Manufacturer shall certify that the manufacturer has constructed not less than three mechanical cyclone type
dust collectors of the [multitube mechanical type] [high-efficiency; large-diameter centrifugal cyclone type]
treating flue gas from [an incinerator] [a boiler] with [automatic] [manual] combustion control. Each collector
shall have performed satisfactorily, normal maintenance or downtime of the associated [boiler] [incinerator]
included, for a period of not less than 2 years treating at least [_____] L/s acfm of inlet gas at a temperature
of at least [_____] degrees C F, with inlet dust loading of at least [_____] grams per liter grains per acf and
outlet dust loading of at most [_____] grams per liter grains per acf. In determining this experience:
a. Only collection of fly ash as produced by [coal-fired boilers] [oil-fired boilers] [refuse-fired
waste disposal incinerator] is considered as equivalent experience.
b. Only experience at the approximate flow gas volume, flue gas temperature and inlet dust
loading is acceptable.
1.6 MANUFACTURER'S FIELD REPRESENTATIVE
Furnish the services of [a] field representative(s) specifically trained by the manufacturer to assist installers
of their equipment. Field representative(s) shall be at the erection site during all phases of the installation
including unloading, hauling, storing, cleaning, erecting, and testing. It is the responsibility of the field
representative(s) to assist the installer during the erection of [the] dust collector(s) and to assure both parties
that dust collector(s) [is] [are] being installed in accordance with the dust collector manufacturer's recommendations.
The field representative(s) shall certify in writing to the Contracting Officer that dust collector(s) [has]
[have] been installed as recommended by the manufacturer. The field representative(s) shall supervise the adjustment
of all controls, control devices, and components supplied with dust collector(s) as necessary to place dust collector(s)
in successful operation. Field representative(s) shall instruct plant operators in operation, care, and maintenance
of the dust collector(s). Written notice from the Contracting Officer shall be received prior to scheduling
these instructions. The field representative[s] services will be required for approximately [3] [_____] days
and will include [2] [_____] round trips to the job site.
1.7 RELATED REQUIREMENTS
Section 23 03 00.00 20 BASIC MECHANICAL MATERIALS AND METHODS, shall apply.
1.8 SUBMITTALS
NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL
PROCEDURES and edit the following list to reflect only the submittals required
for the project. Submittals should be kept to the minimum required for adequate
quality control.
A “G” following a submittal item indicates that the submittal requires Government
approval. Some submittals are already marked with a “G”. Only delete an existing
“G” if the submittal item is not complex and can be reviewed through the Contractor’s
Quality Control system. Only add a “G” if the submittal is sufficiently important
or complex in context of the project.
For submittals requiring Government approval on Army projects, a code of up
to three characters within the submittal tags may be used following the "G"
designation to indicate the approving authority. Codes for Army projects using
the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO"
for District Office (Engineering Division or other organization in the District
Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project
Office. Codes following the "G" typically are not used for Navy, Air Force,
and NASA projects.
Choose the first bracketed item for Navy, Air Force and NASA projects, or choose
the second bracketed item for Army projects.
Government approval is required for submittals with a "G" designation; submittals not having a "G" designation
are [for Contractor Quality Control approval.][for information only. When used, a designation following the
"G" designation identifies the office that will review the submittal for the Government.] The following shall
be submitted in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:
SD-03 Product Data
[Centrifugal cyclone collector]
[Multitube collector]
Submit performance curves consisting of particle size distribution and fractional efficiency
curves.
SD-02 Shop Drawings
Mechanical cyclone dust collector system
SD-07 Certificates
Lists of prior installations
Certification of testing capability
SD-06 Test Reports
Voltage testing certificate
Post-installation inspection of dust collectors
Performance test of dust collectors
Particulate tests of dust collectors
Submit post installation inspection report within 15 calendar days after inspection stating
the findings including a statement that [the] mechanical dust collector(s) [are] [are not] acceptable
for field performance tests. Perform dust collector tests in conjunction with boiler or incinerator.
For each performance test, including cycling test and 100 percent load testing, submit data
specified in paragraph entitled "Inlet Gas Conditions" and paragraph entitled "Dust Collector
Data." Depict deficiencies and failures of components in test reports. Test reports for particulators
tests shall certify that instruments were calibrated and readings indicated are true, that computations
required for testing are accurate, that acceptable methods were used, and that the equipment
performed in accordance with the requirements or performed with depicted failures or deficiencies.
Results of additional tests shall be recorded and submitted in a written report to the Contracting
Officer.
SD-10 Operation and Maintenance Data
Centrifugal cyclone collector, Data Package 3
Multitube collector, Data Package 3
Submit in accordance with Section 01 78 23 OPERATION AND MAINTENANCE DATA. Include complete
installation, operation and maintenance instructions and data including models and serial numbers
and part lists for the equipment.
1.9 QUALITY ASSURANCE
1.9.1 Lists of Prior Installations
Submit within 30 days after award and prior to commencement of installation, a certificate containing the following
information:
a. A list of at least three installations meeting requirements set forth in paragraph entitled
"Operating Experience."
b. Owner and location of each installation.
c. Date of owner acceptance of each installation.
d. Collector model number.
e. Design inlet gas volume, L/s acfm.
f. Design inlet gas temperature, degrees C F.
g. Design inlet dust loading, grams per liter grains per acf.
h. Design outlet dust loading grams per liter grains per acf.
i. Type of [coal-fired] [oil-fired] [boiler] [refuse-fired waste disposal incinerator].
1.9.2 Certification of Testing Capability
Certify that the factory is capable of performing electrical integrity tests of 1000 volts for hopper heater
modules, blanket or tape.
1.9.3 Voltage Testing Certificate
Submit test.
1.10 BID FORMS
ICAC M-4 evaluation bid forms.
1.11 DELIVERY AND ASSEMBLY
Ship equipment completely factory-assembled, except when physical size, arrangement, or configuration of the
equipment, or shipping limitations, makes the shipment of completely assembled equipment impracticable, in which
case assemble equipment and ship as shown on the approved shop drawings. The Contractor is responsible for all
costs encountered in the field for assembly of sections, accessories, or appurtenances not listed in the proposal
as requiring field assembly.
1.11.1 Coordination
Contractor shall ensure that design parameters of collector are coordinated by dust collector manufacturer with
manufacturers of system equipment and installing contractor of ductwork with gas distribution devices which will
interface with, and optimize system operation.
1.12 DATA AND CONDITIONS
1.12.1 Boiler Data
NOTE: Select the applicable paragraph(s) from the following:
NOTE: Depending on air pollution emission regulations, mechanical cyclone-type
dust collectors should not be used alone on pulverized coal-fired boilers.
They should be used with, and ahead of, electrostatic precipitators. Specify
range of properties for coal. If other air pollution equipment exists or is
proposed, list: description, type, rating, performance, condition, expected
life and how to be used with new equipment.
NOTE: Insert appropriate Section number and title in the blanks below using
format per UFC 1-300-02.
Design mechanical cyclone-type dust collectors for operation with [the boiler(s) specified in [_____]] [boiler(s)
manufactured by [_____], Type [_____], Model No. [_____]]. The boiler is a [new] [existing] [pulverized coal-fired]
[spreader stoker-fired] [underfeed stoker-fired] [No. 6 fuel oil fired] boiler rated [_____] kilogram per second
of steam at [_____] kPa pounds per hour of steam at [_____] psi, having a gross heat input of [_____] kilowatt
million Btu per hour, and utilizing coal with the following approximate properties:
a. Proximate analysis, as received, percent by weight:
Range
Moisture [_____]
Ash [_____]
Volatile Matter [_____]
Fixed Carbon [_____]
Sulfur, percent by weight [_____]
Heating Value, Btu per pound [_____]
b. Ultimate analysis, as received, percent by weight
Range
Moisture [_____]
Carbon [_____]
Hydrogen [_____]
Sulfur [_____]
Nitrogen [_____]
Oxygen [_____]
Ash [_____]
Expected range of boiler steam output will be between [_____] and [_____] pounds per hour with peak loads only
between [_____] and [_____] hours. Proposed or other existing gas cleaning equipment includes [_____]. Boiler
combustion is controlled [manually] [automatically]. The standby fuel is [_____].
[Incinerator Data
NOTE:
1. The standard classification of wastes is as follows:
CLASSIFICATION
Noncom-
bustible
Solids Moisture Heating
(Max. Content Value
Percent (Max. (kJ per
Type Description Principle Components by Weight Percent) kg)
0 Trash Highly combustible 5 10 19,805
waste, paper, wood,
cardboard cartons,
including up to 10%
treated paper, plastic
or rubber scrap,
commercial and
industrial sources
1 Rubbish Combustible waste 10 25 15,145
paper, cartons, rags,
wood scraps,
combustible floor
sweepings, domestic,
commercial, and
industrial sources
2 Refuse Rubbish and garbage; 7 50 10,019
residential sources
3 Garbage Animal and vegetable 5 70 5825
waste, restaurants,
hotels, markets;
institutional,
commercial, and
industrial sources
4 Animal solids Carcasses, organs, 5 85 2330
and organic solid organic wastes;
wastes hospital, laboratory,
abattoirs, animal
pounds, and similar
sources
Loose - - 23,300 Paper
Loose
Wood - - 23,300
Classified Highly-combustible
Material waste, paper,
cardboard cartons
including up to 10% - - 16,310
plastics and treated to
paper - - 23,300
CLASSIFICATION
Noncom-
bustible
Solids Moisture Heating
(Max. Content Value
Percent (Max. (Btu per
Type Description Principle Components by Weight Percent) Pound)
0 Trash Highly combustible 5 10 8,500
waste, paper, wood,
cardboard cartons,
including up to 10%
treated paper, plastic
or rubber scrap,
commercial and
industrial sources
1 Rubbish Combustible waste 10 25 6,500
paper, cartons, rags,
wood scraps,
combustible floor
sweepings, domestic,
commercial, and
industrial sources
2 Refuse Rubbish and garbage; 7 50 4,300
residential sources
3 Garbage Animal and vegetable 5 70 2,500
waste, restaurants,
hotels, markets;
institutional,
commercial, and
industrial sources
4 Animal Carcasses, organs, 5 85 1,000
solids and solid organic wastes;
organic hospital, laboratory,
wastes abattoirs, animal
pounds, and similar
sources
Loose - - 10,000 Paper
Loose
Wood - - 10,000
Classified Highly-combustible
Material waste, paper,
cardboard cartons
including up to 10%
plastics and treated
paper - - 7,000 to
10,000
2. Include ash analysis if available. Classified material contents description
may change as plastic use increases. Check Incinerator Institute of America
for latest information.
NOTE: Insert appropriate Section number and title in the blanks below using
format per UFC 1-300-02.
Design mechanical cyclone-type dust collector(s) for operation with [the incinerator(s) specified in [_____]]
[incinerator(s) manufactured by [_____], Type [_____], Model No. [_____]]. The incinerator is a [new] [existing]
installation capable of burning [_____] [kilogrampounds] per hour [Mgtons per day] of type [0], [1], [2], [3],
[4], [loose paper] [loose wood] [classified material] wastes. The expected range of incinerator operation will
be between [_____] and [_____] [kilogrampounds] per hour [Mgtons per day] of wastes. Incinerator combustion
is controlled [manually] [automatically]. Auxiliary fuel is [______]. Proposed or other existing gas cleaning
equipment includes [______].]
1.12.2 Inlet Gas Conditions
NOTE:
1. To properly apply their equipment, the dust collector manufacturer must
know the expected inlet gas conditions. This information can best be supplied
by the boiler or incinerator manufacturer.
2. In determining the inlet gas conditions for existing installations, source
testing should be performed to determine the gas flow and contents. Gas volume
determinations should be made using a Pitot tube in accordance with ICAC "Test
Procedure," Bulletin 101. This publication incorporates ASME techniques as
called for in ASME PTC 38 "Determining the Concentration of Particulate Matter
in a Gas Stream." For particulate loading an actual sample should be taken
and analyzed in accordance with ASME PTC 28, "Determining the Properties of
Fine Particulate Matter" or in accordance with EPA 40 CFR 60, Appendix A, Method
5 or Method 17 or applicable local standard.
3. If off-design conditions exist, the following relationships are available
for estimation purposes:
For Variable Gas Flow Rate:
100 - Eff (1) = [Q(2)] 0.5
100 - Eff (2) [Q(1)] 0.5
For Constant Gas Flow Rate:
100 - Eff (1) = [U(2)] 0.5
100 - Eff (2) [U(1)] 0.5
For Variations in Gas Density:
100 - Eff (1) = [Pp-Pg(2)] 0.5
100 - Eff (2) [Pp-Pg(1)] 0.5
For Moderate Changes In Gas Particulate Loadings:
100 - Eff (1) = [C(2)] 0.183
100 - Eff (2) [C(1)] 0.183
Eff: Collector Efficiency
Pp: Particulate Density
Q: Volume Flow Rate
Pg: Gas Density
U: Gas Viscosity
C: Particulate Concentration
1,2: Operating Conditions (Mass Per Unit Volume)
4. Mechanical cyclone type dust collectors should be able to handle up to 120
percent of inlet flue gas volume.
5. For new installations, the inlet gas conditions should be obtained from
the boiler or incinerator manufacturer. If this is not possible, the gas contents
must be estimated. When estimates are made, the emission factors and handbook
data should be taken from U.S. Environmental Protection Agency publication No.
AP-42, "Compilation of Air Pollutant Emission Factors" with the latest supplements.
NOTE: Supply excess air percentage for incinerator applications.
Design mechanical cyclone-type dust collector(s) for inlet gas conditions from the [boiler(s)] [incinerator(s)]
specified above. Dust collector manufacturer shall coordinate the application of his equipment with the [boiler]
[incinerator] manufacturer to assure that the collection efficiency specified herein is attained. The inlet
gas conditions are:
Design Data Percent of Boiler Load
25 50 75 100
a. Inlet gas volume, L/s: [_____] [_____] [_____] [_____]
b. Inlet gas temperature, degrees C: [_____] [_____] [_____] [_____]
c. Inlet gas density, kilogram per cubic [_____] [_____] [_____] [_____]
meter:
d. Inlet gas moisture, percent by weight: [_____] [_____] [_____] [_____]
e. Inlet dust loading, grams per liter [_____] [_____] [_____] [_____]
(kg per kJ)
f. Altitude above sea level, m: [_____]
g. Particle size distribution:
Design Data Percent of Boiler Load
25 50 75 100
a. Inlet gas volume, acfm: [_____] [_____] [_____] [_____]
b. Inlet gas temperature, degrees F: [_____] [_____] [_____] [_____]
c. Inlet gas density, pounds per acf: [_____] [_____] [_____] [_____]
d. Inlet gas moisture, percent by weight: [_____] [_____] [_____] [_____]
e. Inlet dust loading, grains per acf [_____] [_____] [_____] [_____]
(lbs per MMBTU)
f. Altitude above sea level, ft: [_____]
g. Particle size distribution:
Maximum Percent by Weight Less
Size, Microns (Diameter) Than Particle Size
60 and Over [_____]
40 [_____]
30 [_____]
20 [_____]
15 [_____]
10 [_____]
7.5 [_____]
1.0 [_____]
0 to 1.0 [_____]
Total 100.0
h. Fly ash density for hopper volume design kilogram per cubic meter pounds per cubic foot:
[640] [40] [_____]
i. Fly ash density for weight determination, kilogram per cubic meter pounds per cubic foot
: [1440] [90] [_____]
j. Fly ash specific gravity: [_____]
k. Excess air (range): [_____]
Contractor shall verify data in the field and shall design the dust collector(s) to operate efficiently over
the possible range of inlet gas conditions.
1.12.3 Dust Collector Data
The following design criteria shall apply to [each of] the dust collector(s). Applicable criteria shall be based
on flow conditions at maximum continuous rating.
a. Minimum collection efficiency, percent [_____].
b. Gas velocity range through dust collector, m/s fps[_____].
c. Maximum pressure drop through dust collector at design condition of flue gas flow and inlet
dust loading, Pa inches watergage [_____].
d. Maximum hopper storage capacity, each hopper, hours [_____].
e. Minimum hopper storage capacity, each hopper, cubic meter feet [_____].
f. Minimum hopper valley angle degrees from horizontal, [57] [_____].
g. Minimum hopper side slope angle degrees from horizontal, [60] [_____].
h. Minimum casing design pressure at [260 degrees C] [500 degrees F] [_____], Pa inches water
gage [+3735+15] [_____].
i. Minimum casing design vacuum at [21 degrees C] [70 degrees C] [_____], Pa inches water gage
[-6225-25] [_____].
j. Minimum casing design temperature, degrees C F [_____].
PART 2 PRODUCTS
2.1 MATERIALS
NOTE: Select the applicable paragraph(s) from the following:
NOTE: Use these paragraphs for multitube collectors 150 mm 6 inch diameter
collecting tubes may cause a plugging problem. Designer must investigate flue
gas particulate size, distribution and tendency of particulates to adhere to
each other for the specific project before selecting diameter of collector tubes.
Multitube collector parts exposed to flue gas shall have a multilayer internal lining having physical characteristics
suitable for the service and able to withstand abrasive and chemical action of flue gas and fly ash. Insulating
properties of lining shall be such that metal skin temperature shall not exceed 343 degrees C 650 degrees F.
All parts subject to deterioration shall be accessible for inspection, maintenance or replacement. Materials
used shall conform to the following requirements:
NOTE: Use ASTM A 242/A 242M steel when material is subjected to continuous
temperatures of 204 degrees C 400 degrees F or higher.
a. Exterior shell: [ASTM A 242/A 242M Type 1] [or] [ASTM A 36/A 36M] 6 mm 1/4 inch minimum
thickness.
b. Hoppers: [ASTM A 240/A 240M] 6 mm 1/4 inch minimum thickness.
NOTE: Use ASTM A 242/A 242M steel when material is subjected to continuous
temperatures of 204 degrees C 400 degrees F or higher.
c. Collecting and outlet tube sheets: [ASTM A 242/A 242M Type 1] [or] [ASTM A 36/A 36M].
d. Outlet tube: [ASTM A 139/A 139M Steel] [or] [ASTM A 667/A 667MCentrifugally Cast Iron]
[or] [ASTM A 532/A 532M, Abrasion Resistant Cast Iron].
e. Collecting tube: [ASTM A 667/A 667M Centrifugally Cast Iron] [or] [ASTM A 532/A 532M, Abrasion
Resistant Cast Iron].
f. Inlet vanes: [ASTM A 667/A 667M Centrifugally Cast Iron] [or] [ASTM A 532/A 532M, Abrasion
Resistant Cast Iron].
g. Gaskets: Type E, fiberglass suitable for service temperatures up to 371 degrees C 700 degrees
F.
NOTE: Use ASTM A 242/A 242M steel when material is subjected to continuous
temperatures of 204 degrees C 400 degrees F or higher.
h. Inlet manifold: [ASTM A 242/A 242M Type 1] [or] [ASTM A 36/A 36M] 6 mm 1/4 inch minimum
thickness.
NOTE: Use ASTM A 242/A 242M steel when material is subjected to continuous
temperatures of 204 degrees C 400 degrees F or higher.
i. Structural and miscellaneous steel: [ASTM A 242/A 242M Type 1] [or] [ASTM A 36/A 36M].
NOTE: Use these paragraphs for 600 mm 24 inch or larger diameter cyclone collectors.
A choice of diameter is dependent upon design parameters that must be analyzed
(See paragraph entitled "SD-81, Operation and Maintenance Instructions, parts
and Testing") and satisfied for each specific project.
[Centrifugal cyclone collector parts exposed to flue gas shall be of materials having physical characteristics
suitable for the service and able to withstand abrasive and chemical action of flue gas and fly ash. Materials
used shall conform to the following requirements:
a. Cone: ASTM A 36/A 36M, 6 mm 1/4 inch minimum thickness.
NOTE: Use ASTM A 242/A 242M steel when material is subjected to continuous
temperatures of 204 degrees C 400 degrees F or higher.
b. Body: [ASTM A 242/A 242M Type 1] [or] [ASTM A 36/A 36M] 6 mm 1/4 inch minimum thickness.
c. Hoppers: [ASTM A 240/A 240M] 6 mm 1/4 inch minimum thickness.
NOTE: Use ASTM A 242/A 242M steel when material is subjected to continuous
temperatures of 204 degrees C 400 degrees F or higher.
d. Inlet manifold: [ASTM A 242/A 242M Type 1] [or] [ASTM A 36/A 36M].
e. Dense castable abrasion resistant lining: ASTM C 401, Class B.
NOTE: Use ASTM A 242/A 242M steel when material is subjected to continuous
temperatures of 204 degrees C 400 degrees F or higher.
f. Structural and miscellaneous steel: [ASTM A 242/A 242M Type 1] [or] [ASTM A 36/A 36M].]
2.2 FABRICATION
NOTE: Select the applicable paragraph(s) from the following:
NOTE: Use these paragraphs for multitube collectors. 150 mm 6 inch diameter
collecting tubes may cause a plugging problem. Designer must investigate flue
gas particulate size, distribution and tendency of particulates to adhere to
each other for the specific project before selecting diameter of collector tubes.
[Fabricate multitube type mechanical dust collector(s) of welded and flanged steel with structural steel supporting
framework. Arrange internal inlet tubes so that no tube is more than one row away from alleyway with a minimum
width of 460 mm 18 inches that will allow total accessibility for inspection and cleaning of tubes. Recovery
vanes are not required and shall not be provided on dust collectors that receive the gases from oil burning [boilers]
[incinerators]. Stresses due to draft differential and thermal expansion shall not cause excessive deflection
of plates or members. Joints between tubes and tube sheets shall be gas tight; dust collector housings shall
be gas tight and dust tight. Flange flue gas inlet and outlet connections and arrange to accommodate connecting
breeching as shown on drawings. Arrange tubes in outlet and hopper sections so that no tube is more than two
rows from physical access from an alleyway with a minimum width of 600 mm 24 inches.]
NOTE: Use this and associated paragraphs for 600 mm 24 inch or larger diameter
cyclone collectors. A choice of diameter is dependent upon design parameters
that must be analyzed (See paragraph entitled "SD-81, Operation and Maintenance
Instructions, Parts and Testing") and satisfied for each specific project.
[Fabricate [600 mm] [24 inch] [_____] diameter centrifugal dust cyclone collector(s) of welded steel. Provide
all portions of collector(s) subjected to high temperature flue gas flow with a multilayer internal lining having
specified insulating and abrasion resistant properties suitable for service intended. In addition, provide inside
surfaces of outlet manifold with ASTM C 401, Class B abrasion resistant lining. Lining shall be suitable for
maximum 343 degrees C 650 degrees Fof metal skin temperatures. Apply and reinforce lining in accordance with
lining manufacturer's recommendations to resist cracking, spalling, and blistering. Provide each hopper with
a flanged fly ash outlet connection to accept fly ash transportation system valves. Flange flue gas inlet and
outlet connections and arrange to accommodate connecting breeching as shown on drawings.]
2.2.1 Structural Supports
NOTE: Delete 1st sentence if project is not located in seismic Zone 3 and 4
of the Uniform Building Code. Use 6 mm 1/4 inch thick steel for temperatures
over 260 degrees C 500 degrees F. Detail structural supports on the drawings.
Obtain from manufacturer and provide collector operating pressure and design
pressure (PaWC negative-positive) and design temperature (degrees C F) on drawings.
[Specify support for dust collector(s) for seismic probability zone [3] [4] in accordance with Section
22 05 48.00 20 MECHANICAL SOUND VIBRATION AND SEISMIC CONTROL.] Design dust collector(s) to support its own
dead weight plus insulation, maximum weight of accumulated fly ash, and the following external loads based upon
flue gas flow at maximum continuous [boiler] [incinerator] load rating and maximum pressure drop across the dust
collector.
a. Snow load, kilogram per square meter pounds per square foot[_____]
b. Wind load, kilogram per square meter pounds per square foot[_____]
c. Live load, kilogram per square meter pounds per square foot[_____]
2.2.2 Hoppers
NOTE: Specify access door for clean gas side of collector(s) if such access
door is not provided in the clean gas ductwork.
Provide dust hopper(s) with dust collector(s). Provide a minimum of one pyramid hopper for each collector.
Fabricate all hopper plates of 6 mm 1/4 inch thick ASTM A 240/A 240M, Type 316 stainless steel. Provide hopper(s)
with untapered fillet sheets, fabricated of cold rolled 10 gage ASTM A 167 Type 316 stainless steel in each corner.
Extend fillet sheets the full length of the corner. Seal weld the fillet sheets to the hopper walls. Provide
closure sheets at the top of the hopper at each corner to prevent flow into the area between the fillet sheet
and the hopper corner. Steel reinforcements not in contact with the gas or ash may be either [ASTM A 167] [ASTM A 240/A 240M
] Type 316 stainless steel or ASTM A 242/A 242M Type 1 structural steel. Welding rods shall be specifically
selected to be compatible with the base metal and shall be submitted to the Contracting Officer for approval.
Provide protection of rods against moisture whether for factory or field assembly.
2.2.2.1 Hopper Accessories
Provide at least one key interlocked hinged inspection cleanout and access door on each hopper with gas tight
seals. Each lock shall have a key unique for this installation. Keys shall not be able to be removed from the
locks when access doors are opened. Access doors shall be a minimum opening size of 460 by 600 mm 18 by 24 inches
for rectangular openings and 600 mm 24 inches inside diameter for round openings. Hoppers with gas baffles
shall have access doors on both sides of the hopper. Provide each hopper with provisions for attachment of vibrators.
Hoppers shall have adequate flexibility for vibrating. Provide each hopper with two 100 mm 4 inch poke holes
with a tee wash connection and screwed caps. Position poke holes to permit only downward thrusts into the hopper.
A special reinforced "pounding area" plate shall be provided on each hopper face for external manual vibrating.
Each pounding plate shall be 300 by 300 by 25 mm 12 by 12 by 1 inch thick ASTM A 36/A 36Mplate steel. Provide
a work platform with fixed stairs and railing and toe board to each pounding area for units with pounding areas
more than 1.50 meters five feet above ground. Pounding plate shall not be insulated. Insulation shall be neatly
finished at this discontinuity. Provide a flanged fly ash outlet connection on each hopper to accept the fly
ash transportation system equipment. Provide access hatch not less than 200 by 200 mm 8 by 8 inches for cleanout
within 200 mm 8 inches above flange on opposite sides. Bolt down type hatches are acceptable for the cleanout
hatch.
2.2.2.2 Hopper Vibrators
Provide each hopper with 2 vibrators set at the mid-height and on opposite sides. Vibrator controls shall be
interfaced with ash collection system to provide vibrator operation only at the inception and during an evacuation
cycle. Operation shall be automatic. Provide manual override control for hopper vibrators and evacuation system
in the hopper area. Enclose override control(s) in [a] case(s) to prevent accidental energization of systems.
Place a warning over the vibrator manual control with the following inscription: "WARNING: VIBRATOR CONTROL.
DO NOT ACTIVATE UNLESS HOPPER EVACUATION SYSTEM IS OPERATING."
2.2.3 Multitube Collector Collecting and Outlet Tubes
NOTE: Use these paragraphs for multitube collectors. 150 mm 6 inch diameter
collecting tubes may cause a plugging problem. Designer must investigate flue
gas particulate size, distribution and tendency of particulates to adhere to
each other for the specific project before selecting diameter of collector tubes.
Fabricate multitube collector collecting tubes of material specified in paragraph entitled "Materials." Material
shall have a Brinell hardness of not less than 400. Attach collecting tubes to tube sheet so that tubes may
be readily removable and replaceable. Collecting tube diameter shall be not less than [150 mm] [6 inches] [_____].
Fabricate multitube collector outlet tubes, to convey clean gases out of collector, of material specified in
paragraph entitled "Materials," and vary length with longest row at flue gas inlet to collector. Provide steel
wear angles not less than 100 by 100 by 10 mm 4 by 4 by 3/8 inch vertically tack welded in 5 or 6 places onto
the exterior surface of the inlet row of the outlet tubes. Locate each angle so that each leg faces the inlet
flue gas and deflects the flue gas by protecting the exterior surfaces of each outlet tube along the inlet row
from abrasive particles contained in the incoming flue gas. These vertical wear angles shall extend between
the top of the bottom header sheet and the bottom of the top header sheet on the inlet row of the outlet tubes.
2.2.4 Hopper Heating Systems
NOTE: Use this paragraph when units are operated where incoming gases may be
cooled below dew point.
Provide a hopper heating system for each cyclone hopper as specified herein.
2.2.4.1 Hopper Heater System Design
The system shall be furnished by the collector manufacturer with all material required for mounting and shall
be designed to provide a 66 degrees C 150 degree F rise in temperature in the hopper, in the vicinity of the
heaters, during offline and startup conditions. The system shall be sized to provide a hopper skin temperature
of not less than 121 degrees C 250 degrees F when insulation specified herein is in place during minimum equipment
operating temperatures. Design system with a minimum heating safety factor of 1.1 and a minimum wind heat loss
factor of 1.12. Provide system with maximum heater coverage between hopper stiffeners utilizing modular heaters
and flexible blanket or tape heaters for the hopper throat heating. Heater modules shall cover at least 33 percent
of the hopper area, shall cover the bottom portion of the hopper to the maximum extent possible, and shall extend
at least 70 percent up the hopper height. Use flexible electric heating blankets or tapes, capable of withstanding
427 degrees C 800 degrees F, where modular equipment will not fit. Design all equipment to withstand natural
and induced vibrations, plus shock loadings normally experienced during operation of the dust collector and ancillary
equipment including manual rapping of the strike plates. The hopper heater system shall be individually, thermostatically
controlled with adjustable setpoint and shall be furnished and installed complete including all power, control,
and alarm components. Locate the low temperature and control thermocouples in the lower portion of each heater
zone. Heater power voltage shall be 480 volts AC. Heater control voltage shall be 120 volts AC.
a. Hopper Heater Module Design: Heater modules shall be self-contained and each modular heater
shall be furnished complete. The modules shall have a flexible heating face to conform to the
irregularities of the hopper surface, providing intimate contact between the heaters and the
hopper, and providing maximum heat transfer. Hopper heater modules shall be of low watt density
design (maximum of 0.0047 watts per square mm 3 watts per square inch of resistance element)
with a minimum of 6 parallel resistance paths per heater (continuous blanket type elements shall
be deemed to meet the multipath requirement). Heating element in the module shall be capable
of being operated at and shall be rated at 2690 watts per square meter 250 watts per square
foot, but shall be designed to operate at 2152 watts per square meter 200 watts per square foot
. Size all wiring, circuits, and controls for 2690 watts per square meter 250 watts per square
foot. Total power density shall not be less than 4304 watts per square meter 400 watts per
square foot of heater module surface. Provide hopper throat blanket heater with a single heating
element. Blanket element shall remain on during startup, offline, and online operating conditions.
Heating elements shall be made of 600 series stainless steel alloy or nickel-chrome alloy encased
in a minimum 20 gage aluminum or aluminized-steel mounting pan or casing. Two sets of heater
pigtails shall exit each module, one set of pigtail for each element and circuit. Heater pigtail
wires and interconnecting wires shall be multi-strand copper wire with high temperature (454
degrees C 850 degrees F) insulation. Provide heater pigtails with strain relief fabricated
in such a manner as to prevent damage to the heater modules due to rough handling. Pigtails
shall be of sufficient length to reach the terminal box. Splices shall not be permitted in
pigtails from modules, tapes, or blankets to the terminal box. Test each module, blanket, or
tape for electrical integrity at 1,000 volts prior to installation. Heating units supplied shall
have metal labels firmly attached to the unit listing the wattage and voltage of the unit.
Heating units and mounting hardware shall be fabricated of high temperature materials capable
of withstanding 454 degrees C 850 degrees F. Insulate heating units with high temperature
woven glass cloth or mineral fiber. Mica or magnesium oxide insulated heaters shall not be
provided.
2.2.4.2 Hopper Heater Controls
Each hopper heater shall be thermostatically controlled with adjustable set point and shall be furnished and
installed complete including all power, control, and alarm components. The thermostats for monitoring temperature
shall be 120 volt AC adjustable type mounted in NEMA ICS 6, Type 4 enclosures. For thermostatic control of the
hopper heater system, the Contractor shall provide a Master Hopper Heater Control Panel for the Plant, a Local
Hopper Heater Control Panel for the [boiler] [incinerator], and a Local Hopper Heater Terminal Box at the hopper(s).
The Contractor shall furnish all materials, tools, and labor required for connections of circuits and wiring
between local hopper heater terminal boxes, local hopper heater control panel(s), and the master hopper heater
control panel(s).
a. Local Hopper Heater Terminal Box: On each hopper, provide hot-dipped galvanized NEMA ICS 6
Type 4 hopper heater terminal boxes with terminal blocks for connection of heater pigtails
and thermostat leads. Terminal blocks in each terminal box shall contain a sufficient number
of terminals to connect heater pigtails and thermocouples.
b. Local Hopper Heater Control Panel: Provide each [boiler] [incinerator] with a local hopper
heater control panel located in the control room. Each local hopper heater control panel shall
contain: terminal blocks for power, control, and alarm circuits, one control temperature thermostat,
one low temperature alarm thermostat, magnetic contactor and alarm relay with two normally open
contacts, and auxiliary relays for automatic operation of the heater system. Provide a 3-pole
fused switched main disconnect device and a fused control transformer having a 120-volt AC secondary
for connection to the [boiler] [incinerator] local hopper heater control panel. Provide thermostats
with a set point range of 38 to 260 degrees C 100 to 500 degrees F. Thermostats shall measure
hopper skin temperature using ungrounded, Type J thermocouples. The local hopper heater control
panel cover shall contain the following devices.
(1) "START UP," "ON LINE," "OFF," "AUTO" selector switch.
(2) 120 V "ON" red light with integral transformer.
(3) 120 V "LO TEMP" alarm white light with integral transformer.
(4) Device and enclosure nameplates.
Wire the selector switch for the following system operation:
(1) "START UP": All elements on (includes throat heater).
(2) "ON LINE": All elements on (includes throat heater).
(3) "OFF": All elements off.
(4) "AUTO": Control functions transfer to Master Hopper Heater Control Panel.
c. Master Hopper Heater Control Panel: Provide panel(s) containing relays, contactors, circuit
breakers, control transformers, and other devices required for complete control of [each] hopper
heater system. Locate Master Hopper Heater Control Panel(s) in the control room. Panel components
shall be factory installed and wired in a NEMA ICS 6, type 4 enclosure and shall include the
following:
(1) A main circuit breaker.
(2) A circuit breaker and contactor alarm relay with two normally open contacts. The contactor
shall have a 120-volt operating coil.
(3) "START UP," "ON LINE," "OFF," selector switch for each hopper.
(4) 120 V red "ON" light and 120 V white "LO TEMP" alarm light with integral transformers.
(5) Auxiliary relays and equipment required for operation of the heating alarm systems.
(6) Device and enclosure nameplates.
(7) Fused control transformer having a 120 volt AC secondary.
2.2.5 Fly Ash Level Alarms
NOTE: The nuclear detector radiation should not exceed 6x10-7 sievert per hour
0.06 mR/Hr. The designer must contact the safety department of the using activity
to coordinate the limit of the surface radiation and edit into this paragraph
that limit for the specific project.
Provide each hopper with a fly ash level alarm utilizing factory installed lead shielded nuclear type detectors.
The detectors shall be single-point gamma source and detection units. Provide lead shielding to cover the detector
and surrounding mounting surfaces and additional lead shielding required around the source housing to limit the
maximum measured surface radiation at any surface accessible to personnel during normal operation to [6x10-7
sievert/hr] [0.06 mR/hr] [_____] above ground radiation. Provide manufacturer's standard nuclear warning sign.
Provide detectors complete with separately mounted electronic units which shall include a local high level indicating
light and relays for use with annunciation system herein specified. Relays shall be rated 10 amperes, 120 volts
AC, or 125 volts DC continuous duty. Switch housing for all hoppers shall be dustproof and shall be mounted at
one easily accessible location. Locate all detector and source electronics at the hopper control panel. Detector
shall be explosion proof and have waterjacketing. Alarm shall be able to withstand vibration and temperatures
up to 427 degrees C 800 degrees F. Provide the source with a lockable shutter mechanism operated by an external
handle to totally isolate the beam when in the closed position. Electrical supply shall be 120 volts, single
phase, 60 hertz. Locate alarm at the 50 percent hopper capacity level. Provide each hopper with two sensors--one
at the alarm level, and one at the empty level. Level reproductivity shall be within one inch. All outdoor
components shall operate between minus 40 and 93 degrees C 40 and 200 degrees F.
2.2.5.1 Hopper Source and Access Door
Source for each hopper shall be Cesium 137. Design source head with a spring return off system in the event
of remote cable actuator failure. Interlock source with hopper access door(s) to prevent entry into hopper unless
source has been secured. Hopper access door key shall only be able to open one pair of hopper doors.
2.2.5.2 Hopper Level Signals
Hopper level signals, based on hopper level status indicator system, shall report to a microprocessor through
a coaxial cable system. Provide each hopper with two indicators, one for full and one for empty. A flashing
light shall indicate a wall buildup. Loss of power for any period of time shall not require a recalibration.
Provide microprocessor with a NEMA ICS 6, Type 4 enclosure.
2.2.6 Ductwork
Section 23 35 19.00 20 INDUSTRIAL VENTILATION AND EXHAUST, and SMACNA 1403, for [Class III] [Class IV] duct construction
suitable for system operating pressures and temperatures indicated. Provide duct materials, fittings, hangers,
supports, flanges, gaskets, expansion joints, connections, relief vents, reinforcements, [and corrosion protection]
for the [existing] flue gases [to be] encountered in accordance with SMACNA 1403.
2.2.6.1 Ductwork to Cyclones
Design all ductwork between [boilers] [incinerator(s)] and cyclone(s) to be self-cleaning. Ductwork meeting
the following requirements will be considered to be self-cleaning.
a. A duct at an angle greater than 45 degrees to the horizontal plane with gas flowing downward.
b. A duct at an angle greater than 60 degrees to the horizontal plane with gas flowing upward.
c. A duct with hopper-shaped bottom and a conveyor[ specified in Section 23 51 43.03 20 FABRIC
FILTER DUST COLLECTOR OF FLYASH PARTICLES IN FLUE GAS to remove the settled dust].
2.2.6.2 Flue Gas Velocity
Flue gas design velocities in ductwork shall be calculated at the design flow range specified in paragraph, "Dust
Collector Data." The design velocities in self-cleaning ducts shall be between 1372 and 1524 m/s 4,500 and 5,000
fpm. Where a possibility of dust settling exists, the design velocity shall be 1676 to 1829 m/s 5,500 to 6,000
fpm. The design velocity of clean gas shall be greater than 1219 m/s 4,000 fpm.
2.2.7 Draft Connections
Provide a 25 mm one inch capped connection in flue gas inlet and outlet breech of dust collector(s) for determining
differential pressure across collector(s). Orient these connections so as to be accessible from access platform
or walkway specified herein.
2.2.8 Inlet Manifold and Dampers
NOTE: Specify or indicate air pressure available for pneumatic operators or
electrical characteristics available for electric operators.
Provide, specially made for the dust collector, a steel plate flue gas inlet manifold to provide single, flanged
inlet connection. Furnish this manifold with sectionalizing dampers with [pneumatic] [electric motor] operators
suitable for remote-manual operation. Dampers shall be guillotine type not louver type.
2.2.9 Access
2.2.9.1 Access Structures and Fixtures
Platforms, Walkways, Stairways, Handrails, Kickplates and Fixed Ladders: that are required for operation, examination,
testing and maintenance of each dust collector and shall be provided with each dust collector. Platforms, walkways,
stairways, handrails, kickplates and fixed ladders shall be factory or shop fabricated, shall provide suitable
access to all openings in the hopper, and shall meet OSHA 29 CFR 1910-SUBPART D for safety of maintenance and
operating personnel. Walkways shall be provided for maintenance and inspection of maintenance points. Walkways
shall be located not more than 1.22 meters 4 feet directly below the centerline of collector striker plates and
the centerline of [the] [each] access door to [the] [each] hopper. Walkways and platforms shall be connected
by stairways or fixed ladders. Supporting steel for platforms, fixed ladders and walkways shall be designed
for the live load specified herein. Platforms shall be designed to support a 488 kilogram per square meter 100
pound per square foot live load. Walking surfaces of walkways and platforms shall be fabricated of ASTM A 242/A 242M
raised pattern floor plate minimum 5 mm 3/16 inch thickness. Platforms, walkways, stairways, fixed ladders,
handrails and kickplates shall be hot dipped galvanized after fabrication in accordance with ASTM A 123/A 123M
. Minimum galvanized coating weight per surface shall be not less than 0.70 kilogram per square meter 2.3 ounces
per square foot.
2.2.9.2 Access Doors
Access doors to hoppers and mechanical or electrical components shall be accessible from walkways or be provided
with a permanent steel ladder or stairway to facilitate maintenance. Provide internal and external handholes
at all access doors to facilitate entry. Provide access doors to hoppers and to inlet plenums and to outlet
plenums. Provide fixed industrial stairs or fixed ladders that meet OSHA 29 CFR 1910-SUBPART Dto connect access
doors. Access doors shall be permanently hinged or be completely removable by guide-action fastening devices.
Key interlocks are required only on hinged doors.
2.2.10 Insulation and Casing
Insulate and case the collector shell [including flue gas inlet manifold] and hoppers. Insulation shall be asbestos
free. Provide a walking surface on all top surfaces hereinafter specified, where periodic equipment maintenance
or inspection of equipment located in that area is required.
2.2.10.1 Insulation Material
NOTE:
1. For multitube collector(s) use minimum thickness of 65 mm 2 1/2 inches for
operating temperature range of 94 to 260 degrees C 201 to 500 degrees F, and
minimum thickness of 140 mm 5 1/2 inches for operating temperatures above 261
degrees C 501 degrees F.
2. For 300 mm 12 inch or larger diameter centrifugal cyclone collector(s) use
minimum thickness of 140 mm 5 1/2 inches.
3. For ductwork with an operating temperatures 94 to 260 degrees C 201 to 250
degrees F, use minimum insulation thickness of 65 mm 2 1/2 inches; for operating
temperatures 261 to 190 degrees C 251 to 375 degrees F, use minimum insulation
thickness of 100 mm 4 inches; for operating temperature range 191 to 260 degrees
C 376 to 500 degrees F, use minimum insulation thickness of 125 mm 5 inches
for operating temperatures above 260 degrees C 500 degrees F, use minimum insulation
thickness of 140 mm 5 1/2 inches.
Externally insulate shell, hoppers, and ductwork. Mineral fiber block and board insulation shall conform to
ASTM C 612 and mineral fiber blanket insulation shall conform to ASTM C 592. Minimum insulation thicknesses
shall be as follows:
a. Shell: [_____] mm inches
b. Hoppers: [_____] mm inches
c. Ductwork: [_____] mm inches.
2.2.10.2 Casing Materials
ASTM B 209M ASTM B 209 aluminum. Casing, except the top surface which might serve as personnel walking surface,
shall be 1.27 mm 0.050 inch thick stucco embossed, 100 mm 4 inch rib unpainted aluminum panel. Top surface
ductwork casing shall be flat aluminum sheet having a minimum thickness of 2.03 mm 0.080 inch and be suitably
reinforced to support a 122 kilogram per square meter 25 pound per square foot live load.
2.3 SAMPLING PORTALS
Provide minimum 100 mm 4 inch inside diameter x minimum 6 mm 1/4 inch thick wall sampling portals for fly ash
particulate sample testing on inlet breech and outlet breech of dust collector. Sampling portal material shall
conform to ASTM A 36/A 36M and shall be insulated as specified elsewhere in this section. Locate sampling portals
in accordance with EPA 40 CFR 60, Appendix A, Method 1 - "Sample and Velocity Traverses for Stationary Sources."
Provide two portals 90 degrees apart on round inlet breech and two portals 90 degrees apart on round outlet breech.
For rectangular breeching apply EPA 40 CFR 60, Appendix A, Method 1. Portals shall extend above the exterior
surface of breech insulation at least 150 mm 6 inches. Exposed end of each portal outside of breech insulation
shall be NPT threaded and closed with a NPT threaded, removable screw cap or plug. ASTM A 36/A 36M exterior
surface areas of portal and cap or plug shall be painted as specified in paragraph entitled "Painting." Cap
or plug when detached from portal shall be secured to portal by a galvanized or stainless steel chain welded
at one end to the top of the cap or plug and welded to the side of the portal. Portal shall be continuously
welded where it contacts breech and not extend inside the breech more than 15 mm 1/2 inch. In EPA 40 CFR 60,
Appendix A, Method 1 the term "administrator" and "stack" or the word "duct" shall mean "Contracting Officer"
and "breech" in that order, respectively.
PART 3 EXECUTION
3.1 INSTALLATION
NOTE: Revise this paragraph as necessary when it is desired to have the collector
manufacturer install the equipment furnished.
Install equipment specified herein on foundations or structural-steel framework shown on the drawings, or as
specified herein. Install in accordance with manufacturer's recommendations as shown on manufacturer's detailed
drawings. Furnish the services of [a] field representative(s) of the dust collector manufacturer as hereinafter
specified.
3.2 INSULATION INSTALLATION
Apply insulation in order to permit access doors, inspection doors, flanges, sampling portals and other special
features to be opened, or removed for inspection or maintenance, without disturbing insulation. Provide boxouts
around code stamping symbols and nameplates. Install double thickness insulation with joints of the two layers
staggered. Fill cracks, voids, and depressions in layers of insulation with suitable insulating cements before
application of another layer of insulation or jacket application. Provide expansion joints in insulation as
required to allow for thermal expansion movements which might cause cracks or tears in the insulation. Install
insulation between and over stiffeners in such a manner that stiffeners are completely insulated. Install additional
insulation or casing spacers between stiffeners so that a level surface is achieved. The intent of this insulating
procedure is to prevent a direct metal path between the collector inside and ambient air. Securely wire insulation
and lace in place using No. 14 dead soft Type 302 stainless steel wire conforming to ASTM A 580/A 580M.
3.2.1 Block and Mineral Fiberboard Insulation Installation
Hold block and mineral fiberboard insulation in place with insulation lugs spaced on not greater than 300 to
460 mm 12 to 18 inch centers. Lugs shall be stud-type welded in place. Reinforce blocks on exterior face with
expanded metal, if necessary, to prevent sagging or cutting of insulation by lacing wire. Securely wire block
and mineral fiberboard insulation of specified thickness in place over entire surface by means of wire threaded
through lugs both ways, pulled tight with ends of wire loops twisted together with pliers, bent over, and carefully
pressed into surface of insulation.
3.2.2 Mineral Fiber Blanket Insulation
Hold mineral fiber blanket insulation in place with speed washers and impaling pins spaced on centers not exceeding
300 mm 12 inches. Provide mineral fiber blanket insulation with expanded metal reinforcement on the outer surface
and wire mesh or expanded metal on the inner surface. Tightly butt sections of blankets, jam together, and securely
tie for maximum sealing at joints and edges. Take care in applying speed washers so that designed thickness
of insulation is not reduced when washers are installed.
3.3 CASING INSTALLATION
3.3.1 Structural Steel Grid System
Install casings on an aluminized structural steel grid system of subgirts. Provide subgirts of sufficient size,
gage, and depth to provide adequate support and a smooth exterior surface. Subgirts shall be welded to equipment
and structural support surfaces. Subgirts shall be of sufficient depth to provide for application of full thickness
of insulation over the stiffeners, access doors, flanges, ribs, and other surfaces having uneven contours to
provide a smooth finished surface. Subgirts on vertical and bottom surfaces shall be at a maximum spacing of
1.22 meters 4 feeton centers. Subgirts on top surfaces shall be at a maximum spacing of 610 mm 2 feet on centers.
Design so as to transmit an external 114 kg 250 pound walking load from aluminum casing to structural steel
grid system without compression of insulation material.
3.3.2 Access Openings
Access doors and other penetrations through the insulation shall have insulation fitted closely to the hinges
and fasteners and shall be neatly framed and flashed to be weather tight and create a pleasing appearance. Provide
hinged or lift off doors designed for convenient opening at nameplates, code stampings, non-projecting connections,
and access openings. Flash and weatherproof openings. Pitch all horizontal access openings for water runoff.
Provide all vertical access doors with flashing above door head and flash to prevent wind driven rain from seeping
under the aluminum casing.
3.3.3 Weatherproofing
Install casings with proper overlap to make the installation weather tight. Carefully fabricate and fit casing
to ensure a neat appearance; furnish required closures, flashings, and seals. Provide open ends of fluted sections
with tight-fitting closure pieces. Form and install flashing so that water cannot enter and wet the insulation,
and design and install flashing to readily drain any water that might enter. Weatherproof joints or openings
in casing, which cannot be effectively sealed from entry of moisture by flashings or laps by application of an
aluminum pigmented sealer manufactured for this type of service.
3.3.4 Convection Stops
Furnish and install convection stops on vertical surfaces over 3.66 meters 12 feet tall; maximum interval between
convection stops shall be 3.66 meters 12 feet. Convection stops shall consist of steel channel of Z-girt, covered
with 80 mm 3 inch thickness of insulation.
3.3.5 Casing Attachment
NOTE: If a separate insulation section is part of this specification, add note
to that section to indicate that insulation of the collector is covered by this
section.
Attach aluminum casing to structural steel grid system by means of No. 14 stainless steel, Series 300, self-tapping
screws on 300 mm 12 inchcenters. Fasten vertical laps and flashings by means of 20 mm 3/4 inch No. 14 stainless
steel, Series 300, sheet-metal screws on 300 mm 12 inch centers. Exposed screws shall have aluminum or stainless-steel
backed neoprene washers preassembled to screws. Install insulation so that it is not compressed below nominal
thickness.
3.4 HOPPER HEATER SYSTEM
Deliver system components to the job site in containers designed to protect the components from adverse handling,
weather, and storage conditions. Store components in their original shipping containers, unless the containers
are damaged, or under protective weatherproof covering until installation. Clean hopper surfaces of dust, grease,
oil and rust thoroughly prior to installation of any heater. Heater modules shall be installed to provide maximum
contact between the heaters and the hopper wall. Furnish heaters with mounting hardware, channels, and brackets.
Throat heaters shall not overlap and shall be held in place with high temperature (454 degrees C850 degrees F
) glass tape or other means approved by the Contracting Officer. Cover the throat heater with insulation material
prior to application of jacketing.
3.5 GALVANIC CORROSION
To prevent galvanic corrosion, avoid permanent contact of aluminum casing with copper, copper alloy, tin, lead,
nickel, or nickel alloy including monel metal. Where it is necessary to attach casing to carbon steel or low
alloy steel, first prime steel with zinc chromate, and then paint with aluminum paint conforming to FS TT-P-28
suitable for surface temperatures encountered. Use of lead base paint is prohibited.
3.6 PROTECTION FROM INSULATION MATERIALS
Protect equipment and structures from damage from insulation materials. After completion of work, clean, repair,
and restore equipment and structure to their original state. Repair any casing that becomes corroded, discolored,
or damaged or replace casing if beyond repair as determined by the Contracting Officer.
3.7 INSPECTIONS AND TESTS
3.7.1 Factory Inspection
The right is reserved by the Government to inspect the equipment at the manufacturer's plant, during or after
manufacture. Acceptance at the factory shall not constitute final acceptance.
3.7.2 Field Inspection and Tests
3.7.2.1 Delivery Inspection
Upon delivery to the jobsite, materials and equipment will be inspected to assure that equipment and installation
comply with local and Government requirements for equipment and safety.
3.7.2.2 Post-Installation Inspection of Dust Collectors
Dust collector manufacturer's field representative shall inspect mechanical dust collector after installation
is completed and prior to start of testing to verify that the unit is installed in conformance with the manufacturer's
recommendations.
3.7.2.3 Performance Test of Dust Collectors
NOTE:
1. If provision for operation at partial loads is included, specify that test
shall also be conducted at the desired part-load conditions.
2. If Government operating personnel are available for operation of the associated
equipment required to perform the tests, revise this paragraph accordingly.
For installation in which a new boiler or incinerator is being installed, the
Government operating personnel should be under the supervision of the Contractor.
3. Specifying inlet and outlet tests to determine efficiency or performance
guarantees for cyclones can cause problems in retrofits and some new units.
Cyclones with very short or angled inlet and outlet ducts can cause inaccurate
test data to be collected. Therefore, specifying cyclone outlet grain loading
requirements may be more appropriate than an efficiency requirement.
Field performance tests shall be performed by a testing laboratory with experience in EPA's test methods and
approved by the Contracting Officer.Furnish a schedule of tests in writing to the Contracting Officer at least
10 calendar days before scheduled test(s) start date. Dust collector(s) field performance test shall be conducted
with [its] [their] respective [boiler] [incinerator]. Operate each dust collector and its [boiler] [incinerator]
for at least 45 calendar days at approximately 25, 50, 75 and 100 percent loads and cycle [boiler] [incinerator]
not less than two complete cycles between 100 percent load and each partial load and back to 100 percent load.
A trial run of 7 days minimum witnessed by the Government, shall be performed before the 45 day test to ensure
that all associated systems required for the test are ready. The Contractor and the dust collector manufacturer's
field representative shall witness the trial run and all tests. The testing laboratory shall furnish equipment,
tools and personnel necessary for testing, data gathering, and recording test results.
a. Particulate Tests of Dust Collectors: Simultaneous inlet and outlet particulate tests on
all mechanical dust collector(s) shall be performed in accordance with EPA 40 CFR 60, Appendix
A, methods 1 through 5 and 17. Method 17, in stack filtration, may be performed as an alternate
test to Method 5. Tests shall be performed at maximum and partial load conditions herein specified
and report submitted to the Contracting Officer.
b. Additional Tests: In the event that the mechanical dust collector(s) do not meet performance
requirements, failures and deficiencies shall be resolved and additional tests shall be performed
by the testing laboratory as required to demonstrate that the resolutions used permitted acceptable
performance of the mechanical dust collectors.
3.8 IDENTIFICATION
Provide an aluminum, brass, or type 304 or 316 stainless steel nameplate and fasten to equipment in a visible
location by means of rivets or sheet metal screws of the same material as the nameplate material. Nameplate
shall contain data that consists of the manufacturer's name, model or series number, and serial number. Indent
or emboss the information in the metal. Offset the nameplate a sufficient amount to avoid being covered by insulation.
3.9 PAINTING
Clean the non-insulated exterior surfaces of equipment being furnished to base metal in accordance with SSPC SP 6
and paint at the factory with two coats of paint conforming to FS TT-P-28. Performed painting in accordance
with SSPC SSPM. Power clean to bare materal and touch up exterior surfaces damaged during field installation
or during shipment with two coats of FS TT-P-28 high temperature (up to 650 degrees C 1200 degrees F) heat resistant
paint.
3.10 SCHEDULE
Some metric measurements in this section are based on mathematical conversion of inch-pound measurements, and
not on metric measurements commonly agreed on by the manufacturers or other parties. The inch-pound and metric
measurements shown are as follows:
Products Inch-Pound Metric
a. [_____ _____ _____]