Appendix_D_-_Lime_Storage_Silo_(Leg_Support_Type)_and_Accesory_Equipment.pdf

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SECTION 11292

Appendix D

LIME STORAGE SILO

(LEG SUPPORTED TYPE) AND

ACCESSORY EQUIPMENT

PART 1-GENERAL

1.01 DESCRIPTION

A. Scope of Work:

1. Furnish all labor, materials, equipment, and incidentals required, and install and field test complete and ready for operation, one (1) lime storage silo suitable for storage of pebble quicklime with accessories as shown on the Drawings and as specified herein.

2. Furnish the lime storage silo system, including silo, level indicators, bin vibrators, dust control systems, ladders, bulk pneumatic truck unloading equipment, controls, and all piping and other appurtenances necessary for a complete system.

B. Related Work Described Elsewhere:

1. Division 5: Metals

1.02 QUALIFICATIONS

A. The equipment shall be products of manufacturers who are fully experienced, reputable and qualified in the manufacture of the equipment to be furnished.

The system components shall be designed, constructed, delivered and installed in accordance with the best practices and methods.

B. The supplier/manufacturer of the lime silo shall have the required financial capability to produce and deliver the specified equipment. The supplier/manufacturer shall carry a minimum of $500,000 in product liability insurance for all products furnished.

C. The system shall be furnished by a single supplier who shall be responsible for the coordination of the system design and who shall assume complete responsibilities for the proper operation of each system. The lime storage silo

11292-2 shall be as specified herein and as manufactured by Nosun Engineering Sales, Daco, or an equal approved by the Engineer.

D. The equipment design, layout sizes and configuration, and electrical wiring shown on the Drawings are based on equipment furnished through Nosun Engineering Sales. If equipment is supplied through another manufacturer, it is the Contractor's responsibility to confirm or revise all required equipment and wiring interface.

E. The supplier/manufacturer shall have successfully provided a minimum of ten

(10) installations of similar design or scope over a minimum of five (5) years. The supplier/manufacturer shall provide a list of a minimum of five (5) references including locations, contact names, and phone numbers and cost of equipment furnished.

1.03 SUBMITTALS

A. Copies of all materials required to establish compliance with these Specifications shall be submitted in accordance with the provisions of Section 01340.

Submittals shall include at least the following:

1. Certified shop and erection drawings showing all important details of construction, dimensions and anchor bolt locations. Shop drawings shall also show complete information regarding location, size, type and length of all welds in accordance with "Standard Welding Symbols" AWS A2.0 of the American Welding Society. Special conditions shall be fully explained by notes or details.

2. Descriptive literature, bulletins, and/or catalog cut sheets of each item of equipment.

3. All information required by Section 01340.

4. The empty weight and the maximum operating weight of each major item of equipment.

5. AWS certificates for welders fabricating the lime silos.

6. A complete total bill of materials for all equipment.

7. A list of the manufacturer's recommended spare parts. Include gaskets, packing and other parts on the list.

8. List of lubricants and grades for all equipment requiring lubrication.

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9. Complete motor data.

10. Structural drawings and calculations for the storage silo and leg supports.

Drawings and calculations for the storage silo shall be signed and sealed by a Registered Professional Engineer, registered in the State of Florida.

11. Complete wiring diagrams and schematics of each control panel, controller(s), control device(s) and operator's station(s) furnished under this Section.

12. Complete wiring diagrams and schematics of all power and control systems showing wiring requirements between all system components, motors, sensors, control panels, etc., including connections to Work of other Sections.

B. Prepare the above information as a single packaged or grouped shop drawing submittal.

1.04 PRODUCT DELIVERY, STORAGE AND HANDLING

A. All equipment and parts shall be properly protected so that no damage or deterioration will occur during a prolonged delay from the time of shipment until installation is completed and the equipment is ready for operation.

B. All equipment and parts must be properly protected against any damage during a prolonged period at the site.

C. Factory assembled parts and components shall not be dismantled for shipment unless permission is received in writing from the Engineer.

D. Finished iron or steel surfaces not painted shall be properly protected to prevent rust and corrosion.

E. Each box, crate or package shall be properly marked to show its net weight in addition to its contents.

F. Handle during delivery, storage and installation in a manner to prevent damage of any nature in accordance with the manufacturer's approved instructions.

1.05 WARRANTY AND GUARANTEES

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A. All equipment supplied under this Section shall be warranted for a period of one

(1) year by the manufacturer and Contractor. Warranty period shall commence upon Owner acceptance as outlined in the General Conditions.

B. The equipment shall be warranted to be free from defects in workmanship, design and materials. If any part of the equipment should fail during the warranty period, it shall be replaced at no expense to the Owner.

C. The manufacturer's warranty period shall run concurrently with the Contractor's warranty period. No exception to this provision shall be allowed.

D. Refer to the General Conditions and Section 01740 for additional guarantee and warranty requirements.

PART 2 - PRODUCTS

2.01 MATERIALS AND EQUIPMENT - GENERAL

A. These Specifications are intended to give a general description of what is required but do not cover details of construction which may vary in accordance with the exact requirements of the equipment as offered.

B. All necessary accessory equipment and auxiliaries required for the proper functioning of the lime silo system installation incorporating the highest degree of standards for the specified type of service shall be furnished by the system supplier whether or not specifically mentioned in these Specifications or shown on the Drawings.

C. The materials covered by these specifications are intended to be standard equipment of proven ability and as manufactured by reputable concerns, having experience in the production of such equipment. The equipment furnished shall be designed, constructed, and installed in accordance with the best practices and methods and shall operate satisfactorily.

D. All equipment shall be designed and fabricated to have liberal strength, stability, and stiffness and to be especially adapted for the intended service.

E. All bolts, nuts, washers, plates, clamps and other mounting hardware shall be

Type 316 stainless steel. All equipment and piping shall be rigidly and accurately anchored into position and all necessary mounting hardware shall be furnished and installed.

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F. All electrical material and equipment furnished shall be equal to that specified in Division 16: Electrical.

G. All motor couplings, V-belt drives and similar exposed rotating equipment shall be provided with removable, all metal guards in conformance with OSHA requirements. Guards shall be fabricated of steel and shall be hot-dip galvanized, after fabrication.

H. When completed, the lime storage silo system shall be completely dust-tight.

Equipment shall be weathertight and suitable for outdoor operation.

I. All motors furnished under this Section shall be in accordance with Section

16150: Motors, and in addition to the following requirements:

1. Motors shall have totally enclosed fan-cooled enclosures.

2. Motors shall have a maximum speed of 1,800 rpm, unless noted otherwise herein.

3. Motor horsepower required shall be as determined by the system supplier and as approved by the Engineer. Motors shall be designed for operation on a power supply as specified below in this Section.

J. All equipment and motors shall be provided with a stainless steel nameplate, fastened with non-tamper stainless steel screws or pins. Nameplates shall include the name of the manufacturer, model number, serial number, flow rate, horsepower, speed, voltage, phase, amperes, and other pertinent information.

2.02 DESIGN REQUIREMENTS

A. The system shall be proportioned and designed to resist all loads and stresses caused by the material stored, especially during lime loading operations, as well as local wind and seismic conditions. The lime silo shall be designed for a super imposed roof live load of 50 PSF, a wind load of 120 MPH and Earthquake Zone 1.

B. For the purpose of stress design calculations, all vertical design loads shall be considered both acting alone and in combination with lateral wind and seismic loadings. Stress design calculations shall be completed for the storage silo considering both full and empty conditions. The maximum allowable stress in any structural member shall not exceed those permitted in the latest AISC Design Specifications for the Design, Fabrication and Erection of Structural Steel for Buildings.

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C. All welds to construct the silo shall be in accordance with the latest edition of the American Welding Society (AWS) standards. All welding shall be by qualified welders certified in accordance with the AWS requirements.

D. All electrical equipment and wiring shall conform to the applicable NEMA and

NEC Standards, and the Standard Building Code.

2.03 LIME STORAGE SILO SYSTEM

A. The lime storage silo system shall consist of, but not be limited to, the following components:

1. Storage Silo

2. Silo Level Indicator Switches

3. Silo Vibrator

4. Silo Dust Filter

3. Hollow Steel Doors and Frames

4. Ventilation Fan and Damper

5. Fixed Aluminum Stormproof Louver

6. Access Ladder/Platforms

7. Aluminum Handrailing

8. Silo Roof Access Manhole

9. Fill Pipe

10. Truck Fill Panel

11. Interior Electrical and Lighting

2.04 LIME STORAGE SILO

A. Each storage silo shall be approximately 65'-0" overall height, 20 ft. diameter, dual compartment bins, with conical hopper bottoms, four (4) support legs, and weather skirt constructed of structural carbon steel plates and shapes. Structural steel plates, except for the weather skirt, shall be minimum 1/4-inch thick and in accordance with ASTM A36. The silo shall incorporate dual 60° cone bottoms terminating with 1/2-inch thick, minimum, flanged bottom opening/connections.

Each flanged bottom opening/connection shall be sized and drilled to connect to an inlet knife gate valve to be provided by the supplier of the lime feeder/slaker equipment. The silo manufacturer shall coordinate with the feeder/slaker equipment manufacturer for sizing and dimensions for the silo opening/connection flange bolting pattern to accommodate the inlet knife gate valves to be provided. Mounting pads shall be provided for the silo vibrators.

Connection and interior paddle guards shall be provided, near the roof access ladder, for intermediate and low silo level indicator switches. A weather skirt shall extend from the bottom of the straight side wall section at the silo storage compartment to the bottom of the silo support leg flanges. The skirt shall be

11292-7 fabricated of 1/8-inch thick minimum carbon steel plate and shall terminate to a welded 3-inch x 3-inch x 1/4-inch angle. The steel angle shall be rolled to the same diameter as the skirt and shall be drilled for anchor bolts.

B. The elevation of the bottom of the hopper discharge shall be as indicated on the

Drawings. The lime storage silo shall be designed with a usable storage volume of 9,580 cubic feet, not including the silo cone (straight wall silo volume). The lime storage silo shall be designed to accommodate all dead and live loads anticipated, including vibrations from silo vibrating devices and a total full live load of 704,500 pounds of pebble quicklime with a bulk density of 65 pounds per cubic foot. The interior of the silo storage compartment shall be smooth with no inward projecting members, except protection plates for silo level indicators.

The lime storage silo shall be completely dust-tight and weatherproof. All connections to the storage compartment shall be by flanged and gasketed connections. Gaskets for flanged connections shall be neoprene, full faced type.

All nuts, bolts, washers and other hardware for bolted, flanged connections shall be Type 316 stainless steel.

C. Each lime silo shall be supported with four (4) support legs fabricated of standard carbon steel pipe. Pipe used to fabricate the support legs shall be steel pipe Class XS, with a minimum pipe wall thickness of 0.500 inches, in accordance with ASTM A53, latest revision. The pipe diameter used for the legs shall be as required based on the structural design calculations for the anticipated loads of the silo. Support legs shall be of adequate length to provide the minimum dimension from the bottom of the cone flange to the concrete floor of the lime silo as shown on the Drawings. The clearance dimension shall include allowances for heights of the concrete support pads.

D. The silo manufacturer shall install rolled angle stiffening rings on each silo assembly, to provide structural integrity. A silo roof angle stiffening ring shall be a minimum 2 1/2-inch x 2 1/2-inch x 1/4-inch angle, continuously welded outside the silo shell and to the roof plates. Where the silo straight wall intersects the silo cone, a minimum 4-inch x 4-inch x 1/4-inch angle stiffening ring shall be continuously welded to the silo wall to prevent cone separation from the silo straight wall. Top surface of angle leg shall be welded to the silo storage compartment wall, the bottom of the angle shall be welded to the silo skirt, and the cone section shall be welded to the inner portion of the ring.

E. The silo manufacturer shall provide an intermediate access platform in the skirt section of the silo, constructed between the steel support legs, for access to each lime feeder and slaker. The access platform shall span the entire area within the silo skirt interior. The dimension of the top of the platform grating to the cone flanges shall be as shown on the Drawings. Support beams and members for the platform and support beams for the lime feeder/slaker shall be

11292-8 fabricated of heavy duty structural steel beams and channels. All structural members shall be sized such that the maximum deflection of the platform supporting the operating weight of the feeder/slaker and operating personnel shall not exceed 1:360 of the maximum span. Platform support beams shall be attached to the silo columns using bolted connections. All support members for the platform assembly shall have bolted connections so that the platform may be disassembled for removal and replacement of the lime slaker. All bolts, nuts and lockwashers for bolted connections of the platform and the support beams shall be Type 316 stainless steel. An angle support ring shall be provided on the silo skirt interior to provide added support for the intermediate platform floor grating. The angle support ring shall be fabricated of 2 1/2-inch x 2 1/2-inch x 1/4-inch steel angle continuously seal welded to the inside of the steel skirt. The floor of the platform shall be fabricated of 1 1/2-inch minimum fiberglass grating. Fiberglass grating used for the platform flooring shall be in accordance with Section 06600 - Fiberglass Grating and Structural Shapes. Flooring shall be continuous across the entire silo area within the steel skirt and shall be clipped in place with stainless steel hardware.

F. The support system for the gravimetric lime feeder and the paste lime slaker shall be accurately designed for precise location and rigidity for anchoring of the lime feeder/slaker combination into the proper position on the operating platform. All supports for the lime feeder/slaker shall be fabricated of Type 316 stainless steel square tube and plate for mounting flanges. All bolts, nuts, washers and plates for mounting and anchoring the lime feeder/slaker, shall be Type 316 stainless steel. The lime silo manufacturer shall coordinate with the lime feeder/slaker manufacturer for accurate locations, sizes and bolting patterns for the support system. The lime silo manufacturer shall install the lime feeder/slaker support system and the lime feeder/slaker on the lime silo discharge flange, at the Project site, following field assembly and welding of the lime silo. All coordination required for shipment and mounting of the lime feeder/slaker to the lime silo shall be coordinated between the Contractor, the lime silo supplier, and the lime feeder/slaker supplier.

G. The silo roof shall be constructed of 1/4-inch structural steel plate and shall be pitched 1:12 for drainage purposes. The silo roof shall be reinforced such that the deflection will be less than 1/240. Where applicable, all flanges shall be a minimum of 125 lb connections unless noted otherwise within these specifications. The roof shall be designed to support all roof appurtenances and shall have the following appurtenances and connections:

1. Flanged connection for a 24-inch diameter combination manhole-pressure/vacuum relief valve.

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2. Flanged nozzle type connection of 1/4-inch steel plate suitable to support the silo dust filter.

3. Flanged nozzle connection for a material inlet turbulence (target) box with screw cap clean out.

4. Flanged nozzle connection for high silo level indicator switch.

H. The storage silo, skirt and support legs shall be of all welded construction. All welding for the silo shall be continuous or seal welded throughout shop fabrication. All welded joints for the silo shall be full penetration butt welds, both on the interior and exterior. Single pass welding on the exterior only shall be rejected. The lime silo shall be shipped in the minimum number of pieces required for final field assembly and welding at the Project site.

2.05 SILO LEVEL INDICATOR SWITCHES

A. One set of silo level indicators shall be provided for the lime storage silo. Silo level indicator switches shall be electric motor operated with a stainless steel paddle. One (1) indicator switch shall be provided for high level in the storage silo. The high level indicator switch shall include a 2 ft. shaft extension and guard, and mount on the silo roof. Two (2) indicator switches shall be provided for side mounting on the storage silo. One (1) indicator switch shall be provided for an intermediate level and one (1) indicator switch shall be provided for low level. The intermediate and low level indicator switches shall mount in the wall of the storage area at the levels shown on the Drawings, near the silo roof access ladder. Side mounted indicator switches shall be provided with angle shields inside the silo. All indicator switches shall be field mounted and wired. Mounting hardware, nuts, bolts and the like shall be Type 316 stainless steel.

2.06 SILO VIBRATOR

A. A 115 volt, 60 hertz, 1 phase electric impact vibrator shall be provided for each silo cone section (two silo vibrators required for the silo). Each vibrator shall be capable of 3,600 vibrations per minute, adjustable impact. Controllers to be housed in a NEMA 4X stainless steel enclosure. The unit to be field mounted and wired. Silo vibrator shall be Syntron Model V-86 with adjustable vibrating frequency and timer controls. The vibrator controls shall be furnished in a NEMA 4X Type 316 stainless steel control panel, mounted as shown on the Drawings.

The silo vibrator controls shall be interconnected with the lime feeder/slaker controls such that the appropriate vibrator shall operate only when the corresponding lime feeder/slaker is in operation.

2.07 SILO DUST FILTER

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A. A silo dust filter shall be flange mounted on the lime storage silo roof. The unit shall be pre-wired and functionally checked prior to shipment. Unit shall be mounted by the silo manufacturer. Unit shall be an open bottom, flanged mounted, mechanical shaker-type dust collector, designed to shake retained dust off the filter elements(s), directly into the lime storage silo during shaker operation. The silo dust filter shall have a minimum of 360 square feet of dacron felt, filter cloth area, with a minimum capacity of 1,200 scfm at 7.0 inch w.c.

based on a maximum air to filter area ratio of 3:1. The silo dust filter shall be fabricated of weatherproof and drip-proof construction, with self contained filter shaker and exhaust fan assemblies.

B. The silo dust filter housing shall be fabricated of not less than 14 gauge carbon steel. The housing shall be of one (1) piece construction with all seams continuously welded. Spot welding or skip welding shall not be acceptable. The housing shall have two (2) access doors which shall be totally removable, or be able to open on a swing hinge assembly for quick inspection. The doors shall give complete access to the filter element compartment and to the shaker compartment. The unit shall be designed so that an operator may be able to open the inspection doors during operation, without allowing dust to escape while the unit is in operation.

C. Filter element(s) shall be removable without the use of any tooling. The filter element shall pivot on a filter element retainer and hang from the shaker mechanism with an automatic self tensioning spring. All filter element(s) shall be installed in the unit at the factory. The filter element(s) manifold shall be constructed to prevent filter element(s) from falling into the lime storage silo.

D. All parts of the unit subject to service or maintenance, shall not be more than five feet above the mounting flange, and shall be accessible without the use of any service platforms or ladders.

E. An electrically operated mechanical filter element shaking mechanism shall be provided as an integral part of the silo dust filter. Shaker assembly shall be operated by a minimum 1/3 hp, 230/460 volt, 3 phase, 1,725 rpm TEFC motor.

Unit shall contain a mechanical oscillator assembly with a sealed lubrication system, and shall be enclosed in a weatherproof enclosure. Oscillator assembly shall be directly connected to a free floating filter element holding manifold which shall shake the dust collector filter element(s) during operation. Shaking mechanism shall not contain any belts. It shall be a direct gear driven unit.

F. An exhaust fan shall be included as an integral part of the silo dust filter assembly. The fan shall be a squirrel cage type, operating at 3,450 rpm. The unit shall provide a negative pressure within the storage silo during truck unloading

11292-11 operation, and shall be operated by a minimum 5 hp, 230/460 volt, 3 phase, TEFC motor.

G. Motor starters and safety disconnect switches shall be provided for the shaker mechanism and exhaust fan motors. Motor starters shall be mounted in the Truck Fill Control Panel, and safety disconnect switches shall be mounted on the filter unit, adjacent to each motor. Motor starters and safety disconnect switches shall be furnished with a NEMA 4X stainless steel enclosure. Provide a NEMA 4X stainless steel junction box for electrical feeder connections.

H. The silo dust filter shall be a Sternvent VibraClean Model as manufactured by the

Sternvent Company or an approved equal.

2.08 HOLLOW METAL DOORS AND FRAMES AND HARDWARE

A. The lime silo manufacturer shall furnish and install galvanized hollow metal frames and doors at the locations shown on the Drawings. A single door with opening size of 3-feet 0-inches wide by 7-feet 0-inches high shall be installed at the second level lime slaker operating platform. A double door with a total opening size of 6-feet 0-inches wide by 7-feet 0-inches high shall be installed at the ground level grit collection/lime slurry operating area of the silo. Hollow metal frames and doors shall be in accordance with Section 08112, Hollow Metal Doors and Frames, with the following additions and/or modifications.

1. Each door leaf shall be provided with a 6-inch wide by 36-inch high vision panel. Glass for the vision panel shall be safety glass provided and installed in accordance with Section 08800, Glazing.

2. Hardware for the single door shall be in accordance with the Exterior

Door Hardware Description specified in Section 08710, Finish Hardware including the following items:

a. Butt Hinges

b. Mortise Lockset

c. Door Closer

d. Overhead Door Holder

e. Continuous Threshold

f. Door Bottom Seal

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g. Silencers

3. Hardware for the double doors shall be in accordance with the Exterior Door Hardware Description specified in Section 08710, Finish Hardware including the following items:

a. Butt Hinges

b. Mortise Lockset

c. Door Closer for the Active Leaf

d. Overhead Door Holder for Both Leafs

e. Flush Bolts for the Fixed Leaf

f. Double Door Bottom Seals

4. Following installation the galvanized hollow metal frames and doors shall be field painted with the rest of the lime silo as specified below in Part 3

– EXECUTION.

2.09 SILO AIR VENTILATION FIXED STORMPROOF LOUVER

A. Louver Standards:

1. Comply with Aluminum Association, Architectural Aluminum Manufacturers' Association, and SMACNA, "Architectural Sheet Metal Manual" recommendations for design, fabrication, construction details, and installation procedures, except as otherwise shown or specified.

2. All louvers shall be designed to meet all wind load requirements of

Section 1205 of the Standard Building Code, but in no case shall they be designed for a wind load less than 40 pounds per square foot.

3. All louvers shall be AMCA licensed and certified.

B. Approved Manufacturers: The louvers shall be designed, constructed and installed following the best current practices and methods of the industry.

Provide louvers as manufactured by Airolite, Marietta, Ohio; All-Lite Metal Company, Levittown, PA; Construction Specialties Louvers, Crawford, N.J.; or approved equal.

C. Materials of Construction:

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1. Aluminum Extrusions: ASTM B 221, Alloy 6063-T52.

2. Fasteners: Fasteners shall be stainless steel and shall be vandalproof type. Provide types, gages, and lengths to suit unit installation conditions. Use Phillips flat-head machine screws for exposed fasteners, unless otherwise shown, with finish to match louver.

D. Fixed Stormproof Louver:

1. Manufacture: Fixed louvers shall be high efficiency, stationary, extruded aluminum with horizontal blades. The louvers shall be fixed louvers, drainable, with 51 percent free area, and maximum free air velocity of 940 fpm at the point of beginning water penetration at 0.01 oz/sq ft (for 15 minute test period). Louver assemblies shall be four (4) inches deep.

2. Furnish louvers with frames and blades fabricated of not less than 0.125-inch thick extruded aluminum or profile depth with reinforcing bosses, and sizes indicated.

3. Heads, sills, and jambs shall be one piece structural members and shall have integral caulking slots and retaining beads. Frames shall be fabricated to suite adjacent construction.

4. Slidable, interlocked mullions shall have provision for expansion and contraction.

5. Closed cell PVC compression gaskets shall be provided for expansion and contraction.

6. Assemble louvers and provide all supports, anchorages, and accessories for complete installation.

E. Louver Finish:

1. Finish designations prefixed by AA comply with system established by the Aluminum Association for designating aluminum finishes.

2. Preparation: After fabrication, prepare all aluminum surfaces for finishing in accordance with the aluminum producer's recommendations and standards of the finisher or processor. Process all components simultaneously to obtain complete uniformity of color.

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3. Clear Anodized Finish: NAAMM AA-M21C22A21, Architectural Class 1, clear coating (minimum thickness 0.018 mm) complying with AAMA 607.1.

F. Louver Screens:

1. Provide removable insect screens for all louvers.

2. Insect Screens: Rolled or extruded aluminum frame with mitered corners;

18 x 14 aluminum mesh, 0.0123-inch diameter wire. Color shall match color of louver. Provide insect screens for all louvers.

3. Locate screens on inside face of louvers. Secure screens to louver frames with stainless steel clips or stainless steel sheet metal screws, spaced at each corner and at 12 inches o.c. between.

2.10 SILO VENTILATION FAN AND DAMPER

A. The silo exhaust ventilator shall be a direct driven, propeller type exhaust fan.

Exhaust fan shall be a Model "F" as manufactured by New York Blower Company or an approved equal. Wall panel and venturi for the fan shall be fabricated of heavy duty steel with a gray acrylic-epoxy finish. The fan blades shall be fabricated of aluminum. The exhaust fan shall be non-overloading type, shall have a minimum diameter of 16-inches and shall be capable of exhausting 2,700 cfm with a static pressure of 1/4-inch w.c. The fan motor shall be 1/3 hp, 230/460 volt, 3 phase, 1,760 rpm with a TEFC enclosure. The motor bearings shall be permanently lubricated. The motor shall be supported by a vibration isolator-type mounting on a rigid frame. The fan shall be provided with a galvanized wire guard. All nuts, bolts, washers and other fasteners, used to mount the fan housing to a steel mounting flange on the interior of the silo skirt, shall be Type 316 stainless steel.

B. The exhaust fan shall be controlled by a thermostat with a scale range of 35ºF to

100ºF, visible on the front cover. The exhaust fan shall operate whenever the temperature in the silo reaches the predetermined set point. The thermostat shall have a 2ºF switch differential utilizing sealed switches and shall operate on 120 volt, 1 phase, 60 Hz power. The thermostat shall have an integral wall mounting base and an on-off-auto control switch. The thermostat shall be as manufactured by Honeywell or an approved equal.

C. A backdraft damper shall be provided for exterior mounting to a steel mounting flange on the silo skirt. Backdraft damper shall have a frame fabricated of extruded aluminum sections. Blades shall be fabricated from 0.025 inch thick aluminum with felt on the closing edge. Each blade shall be hinged with

11292-15 continuous 3/16 inch stainless steel rod which pivots on nylon bushings. Damper shall be color anodized or Kynar finished with a gray color finish. Backdraft damper shall be manufactured by Swartwout, Penn Ventilator Company, Greenheck Fan Corporation or an approved equal. All nuts, bolts, washers and other fasteners used to mount the backdraft damper to the silo shall be Type 316 stainless steel.

2.11 ACCESS LADDER/CAGE/PLATFORMS AND HANDRAILING

A. Silo roof access shall be by means of a ladder/cage with necessary intermediate transfer platforms as required to comply with OSHA safety requirements and the Standard Building Code. The ladder and cage shall be constructed of structural aluminum, Alloy 6061-T6. The intermediate transfer platforms shall be positioned such that the access ladder run intervals do not exceed 20 feet in height. The intermediate transfer platforms shall be constructed of structural aluminum shapes conforming to ASTM B209 or ASTM B308, Alloy 6063-T6 and shall be provided with 1 1/2 inch aluminum bar grating and aluminum handrailing with a 4-inch aluminum toe plate. Structural steel supports shall be provided by the silo manufacturer for bolting of the fabricated sections of the access caged ladder and intermediate transfer platforms to the silo and skirt exterior wall. All ladder, cage and intermediate transfer platforms shall be fabricated in major sections and shipped loose for field assembly and installation. All hardware, nuts, bolts, and the like, for mounting of the aluminum ladder, cage and intermediate transfer platforms, shall be Type 316 stainless steel.

B. A three-rail type roof handrail with 4-inch aluminum toe plate shall also be provided. Handrailing shall be constructed of 1 1/2-inch (1.9" o.d.), Schedule 40, aluminum pipe, Alloy 6063-T6. The handrails shall be fabricated in major sections for installation in the field. Structural steel supports shall be provided by the silo manufacturer for bolting of the fabricated sections to the silo exterior wall and roof. All items to be shipped loose for field assembly and installation. All hardware, nuts, bolts, and the like, for mounting the aluminum handrails shall be Type 316 stainless steel.

2.12 SILO ROOF ACCESS MANHOLE HATCH

A. The silo manufacturer shall provide a 24-inch diameter, combination manhole hatch-pressure/vacuum relief valve to be mounted on the silo roof. The hatch shall be of all aluminum construction and flanged for bolted installation. The pressure relief shall be set for 2.0 ounces per square inch and the vacuum setting shall be set for 0.5 ounces per square inch. The hatch shall be a Model HH as manufactured by the Knappco Corporation, or an approved equal.

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B. The flanged connection on the tank shall be gasketed. All nuts, bolts, washers and other hardware for bolted, flanged connections shall be Type 316 stainless steel.

2.13 FILL PIPE

A. Provide one (1) complete fill pipe arrangement for the lime storage silo. The fill pipe arrangement for the truck unloading station shall include one (1) set of 4-inch dia., Schedule 40, ASTM A53, steel pipe with one (1), hardened steel 45° short radius elbow, one (1) hardened steel 90° long radius elbow, turbulence box, Type 316 stainless steel camlock-type adapter coupling with chained Type 316 stainless steel dust cap, and limit switch on end of pipe. The pipe arrangement and location shall be as shown on the Drawings. Provide eleven

(11) equally spaced structural steel fill pipe supports welded to the silo shell. All hardware for anchoring pipe to the supports including U-bolts, nuts, washers and the like shall be Type 316 stainless steel. The pipe shall terminate approximately 3 1/2 ft. above the finished grade. The pipe, fittings and turbulence box to be shipped loose for field installation.

B. The fill pipe shall be fabricated and trial fit at the shop to ensure proper fit and then disassembled for shipment to the job site. The fill pipe shall be designed for grooved-type (Victaulic) pipe connections for flexibility and ease of installation.

The long radius 90° bend for the fill pipe shall have minimum radius' of 4 feet.

The 45° and 90° bends shall be fabricated of a hardened steel material and shall have grooved-type pipe connections.

C. A heavy duty inlet target box shall be mounted on the storage silo roof flanged connection. This target box shall be complete with a grooved-type pipe connection for adapting to the 90° long radius elbow. The target box shall be designed to reduce the velocity of the pebble quicklime being conveyed, and allow it to drop into the storage silo in an even pattern. The target box shall be provided with a removable end cap to facilitate cleaning of the silo fill system.

D. The limit switch shall be mounted on the adapter coupling to provide automatic operation of the silo dust filter during and after the truck unloading cycle. The limit switch assembly shall be NEMA 4X, adjustable and secured with a heavy duty, Type 316 stainless steel mounting bracket for dependable operation. The limit switch shall include two sets of normally open (N.O.) and normally closed (N.C.) contacts wired to the truck fill control panel. The dust cap for the adapter coupling shall be provided with a milled slot opening to prevent actuation of the limit switch, while the truck fill system is not in use.

2.14 ANCHOR BOLTS

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A. Bolts and nuts to anchor bolt the lime silo support leg anchor bolt plates and the lime silo skirt anchoring flange to the concrete foundation shall be furnished by the lime silo manufacturer. The quantity of bolts required and the bolt diameters shall be as required by the lime silo manufacturer for the anticipated loads. Hook bolts shall be provided for concrete anchor bolts for the lime silo support leg bolting plates with hex nuts. Concrete wedge-type or adhesive-type anchor bolts shall be used to anchor the lime silo skirt anchoring flange to the concrete curb foundation. The wedge-type or adhesive-type anchor bolts shall also be furnished by the lime silo manufacturer.

All threads for nuts and bolts shall be in accordance with ANSI B1.1, Class 2A fit, 8 pitch thread series. Hook anchor bolts and nuts for concrete anchor bolts shall be manufactured of Type 316 stainless steel (Grade B8M), in accordance with ASTM A320, Class 2 for high strength stainless steel bolts. Wedge-type or adhesive-type anchor bolts to anchor the lime silo skirt shall be manufactured of Type 316 stainless steel, Alloy Group 2, Condition "A" in accordance with ASTM F 593 for bolts and studs and ASTM F 594 for nuts.

The nuts for all anchor bolts shall have a hardness that is lower than that of the anchor bolts by at least a difference of 50 Brinnell hardness to prevent galling during installation. Washers shall be the same material as the anchor bolts and nuts.

2.15 SHOP COATINGS

A. Surface Preparation: After fabrication all surfaces of the lime silo and all accessories shall be prepared for shop coating as follows:

• Remove all weld spatter and slag by grinding smooth. All sharp edges and corners shall be rounded to a smooth contour by grinding.

• All ferrous surfaces shall be white metal abrasive blast cleaned to SSPC-

SP5 to remove all visible oil, grease, dirt, dust, mill scale, rust, oxides, corrosion products and other foreign matter. Blast profile shall be 1 to 3 mils.

B. Interior/Exterior Surface Coatings: All interior storage surfaces of the lime silo and accessories, shall be coated with an NSF approved epoxy coating system.

• Primer - 1 coat, 5.0 mils DFT/coat Primer shall be equal to Tnemec Series 66, Hi-Build Epoxoline, Color: red

• Finish Coats - 2 coats, 6.0 mils DFT/coat

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Finish coating shall be equal to Tnemec Series 66, Hi-Build Epoxoline, Color: white

C. Exterior Primer: All exterior surfaces of the lime silo, cones, support legs, skirt and accessories shall be coated with a rust-inhibitive, polyamide epoxy primer.

Shop primer shall be applied in one or more coats to achieve a minimum dry film thickness of 4 mils, DFT. Shop primer shall be equal to Tnemec Series 65, Poxiprime; Color: gray. Shop primer used shall be compatible with the intended finish coats to be applied in the field.

2.16 TRUCK FILL CONTROL PANEL

A. General:

1. Provide a truck fill control panel for the lime storage silo in materials and rating noted below. Panel shall be sized to adequately dissipate heat generated by equipment mounted inside or on the panel face with minimum dimensions as shown on the Drawings.

Panel Name Rating Qty Material Power

Feed Truck Fill Control Panel NEMA 4X 1 316 SST 480 V

2. All electrical equipment and materials required to control the lime silo dust control fan and shaker for the lime silo shall be installed in a single control panel. Dust controls shall be provided to control either dust control system from the exterior of the panel.

3. Panel control layout and wiring interface shall be shown on the electrical shop drawings for the control panel. Exceptions to these specifications and wiring requirements shall be noted in the shop drawing review and brought to the attention of the electrical subcontractor.

4. Changes to the field wiring requirements shall be fully coordinated by the

Contractor and all modifications to field wiring shown on the Drawings, as a result of these changes, shall be provided by the Contractor at no additional cost to the Owner.

B. Finish:

1. Smoothly finish panel face openings for panel-mounted equipment. Cut with counter boring, and provide with trim strips as required to give a neat finished appearance.

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2. Stainless steel surfaces shall not be painted. Finish interior steel back plate with two coats of baked enamel, white, ANSI No. 51.

C. Access and Identification:

1. Provide a continuous piano hinge door for ease of access on all control panels. Expose a minimum of 80% of the panel interior for door openings.

Panel door openings shall be sealed and fully gasketed. Provide print pockets on each door. Panel doors shall be equipped with three point, quick-release latches.

2. All components and terminals shall be accessible without removing other components except for covers.

3. Panels shall have conduit entry from the bottom only.

4. Provide laminated, engraved plastic nameplates for all front-face panel mounted controls to completely define their use.

5. Provide plastic, permanent identification tags and wire number tags for all internal components, wires, and terminals.

D. Corrosion Control: Protect all panels from internal corrosion by the use Of corrosion - inhibiting vapor capsules, Hoffman, Model A-HCI, or approved equal.

Provide panels with combination drain/breathers, Crouse-Hinds model ECD18; or approved equal.

E. Temperature Control: Provide panels with thermostatically controlled space heaters to maintain internal temperatures above dew point.

F. Construction: All panels shall be manufactured items, Hoffman Engineering, or approved equal. Panel shall be constructed of Type 316 stainless steel sheet metal with a minimum metal thickness of 14-gauge. Provide stiffeners as required to prevent deflection under instrument loading and permit lifting without racking or distortion.

G. Electrical:

1. Provide a main circuit breaker and internal branch circuit breaker for each branch circuit as required to distribute power within each panel from the main power feed. Provide terminal board for termination of all wiring. Provide access to the branch breakers when the panel door is open. Do not exceed an amp capacity of 12 amps for any branch circuit.

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Panel heater, filter exhaust fan power feed, filter shaker power feed, and controls shall be on separate branch circuits. The panel shall include motor starters for the filter exhaust fan and filter shaker motors.

2. Design, furnish and install all interior wiring within the control panel and furnish complete wiring diagrams showing the electrical circuits inside the panel and interconnections between the panel and the external instruments and components. Identify and number all terminals and wires. Attach plastic, heat-shrink type numbered tags to each panel wire for identification. Inside each panel, provide a copy of the panel wiring diagram. No power shall be applied until the supplier has approved the installation.

3. Wiring within panels shall meet the following requirements:

a) Discrete wiring shall be 600-volt, type TFF/MTW stranded copper, sized for the current carried, but not smaller than No. 16 AWG.

b) Power wiring shall be 600-volt, type TFF/MTW stranded copper, No. 12 AWG size, for 120V service.

c) Analog signal wiring shall be 300-volt, stranded copper in twisted shielded pairs, no smaller than No. 16 AWG.

d) Restrain wiring with plastic ties or ducts. Hinge wiring shall be secured at each end with bend area protected with a plastic sleeve.

e) Separate analog or dc circuits at least six inches from any ac power or control wiring.

4. All relays shall be the compact, general-purpose, plug-in type. Contacts shall be rated for not less than 10 amperes at 120V. Provide relays with neon status lights and test buttons. Time delay relays shall have an integral adjustment knob or dip switches and rangeability of at least 10:1.

All relays shall have permanent, legible identification.

5. Terminal blocks shall meet the following requirements:

a) Provide unused spare terminals as indicated on the Drawings.

b) Provide terminal blocks for dc and analog signals separate from ac circuit terminal blocks.

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c) Screw-type terminal connections shall have locking, fork-tongue or ring-tongue lugs crimped with proper sized anvil. Terminate no more the two lugs per terminal with no more than one wire per lug.

d) Compression clamp terminal connections shall be stripped and prepared per manufacturer's recommendations. Terminate no more than one wire per screw and yoke.

6. Provide all panels with an isolated copper grounding bus or grounding terminals to ground all signal and shield connections. Ground analog signal shielding. Properly ground all surge and transient protection devices. Coordinate grounding system with Division 16, Electrical.

H. Front-Face Panel Instrument Components

1. Indicators, Digital Panel, Watertight: Units shall be watertight NEMA 4X

(gasketed). Units shall surface mount as noted and indicate process variable value in engineering units on digital LED, sunlight readable, backlit display. Display color shall be blue/green. Process indicators shall be horizontal digital indicators nominally 2.0 inches high by 4.0 inches wide with an eight digit display, digits nominally 0.5 inch in height. These indicators shall accept a 4 to 20 mA dc input signal from the silo weight indicator display for each silo weighing system and shall display the value of the represented digital variable in engineering units with scale range as noted. Decimal point shall be field selectable. Unit shall be provided with a permanent service legend to display the engineering units of the process variable. Unit shall operate loop power or on 120V line power.

Digital panel indicators shall be mounted to the panel mounting front face. Units shall be Crompton Modutec Series 2000, or approved equal.

2. Indicating Lights, Watertight: Units shall be heavy duty, watertight, push-to-test industrial-type with integral transformer for 120V AC application.

The lights shall be rated for NEMA 4X service. Units shall have screwed-on flat-faced lenses in colors shown and factory-engraved legend plates as noted. Units shall be single hole mounted in panel thicknesses of 1/16-to 1/4-inch. Units shall be Square D Type SK, Allen Bradley Type 800H, Cutler Hammer Type E34, or approved equal.

3. Switches, Maintained Contact, Watertight: Units shall be heavy duty, watertight, industrial type selector switches with contacts rated for 120-volt AC service at 10 amperes continuous. The switches shall be rated for NEMA 4X service. Units shall have factory-engraved legend plates indicating position definition. Operators shall be black knob type.

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Units shall have the number of positions and contact arrangements as required. Units shall be single hole mounting in panel thicknesses of 1/16- to 1/4-inch. Units shall be Square D Class 9001, Type SK; Allen Bradley Type 800H, Cutler Hammer Type E34, or approved equal.

4. Switches, Momentary Contact, Watertight: Units shall be heavy duty, watertight, industrial type pushbuttons with momentary contact rated for 120 volt AC service at 10 amperes continuous. The pushbuttons shall be rated for NEMA 4X service. Units shall have factory-engraved legend plates indicating service definition. Units shall have contact arrangements as required in colors as shown. Units shall be single hole mounted in panel thicknesses of 1/16- to 1/4-inch. Units shall be Square D Type SK, Allen Bradley Type 800H, Cutler Hammer Type E34, or approved equal.

5. Alarm, Audible Horn: Provide audible horn that generates a loud audible alarm when activated by 115V AC power. The horn shall surface mount remotely as noted, suitable for outdoor use. Outdoor units with sealed conduit entry, shall be Ronan Model 350W, or approved equal.

6. Alarm, Visual Strobe Beacon: Alarm lights shall be strobe type units that produce 360-degree beams of colored light. Flashing rate shall be 60 to 80 flashes per minute. Unit shall use a solid state strobe source. Light color shall be red and unit shall have simple technique for relamping.

Unit shall be suitable for panel mounting and shall operate on 120V AC power, unless otherwise noted or shown. Housing shall be weatherproof, suitable for use in outdoor environments without other protection. General purpose units shall be Benjamin Electric Manufacturing, Series KL-4000; or approved equal.

I. Indicating lights shall be provided for the silo level indicator switches on the silo fill control panel. The high and low level indicator switch lights shall be red in color. The intermediate level indicator switch shall have an amber indicating light on the panel. The panel audible and visual alarms shall be activated when either the high or low level silo indicator switches are tripped. The high and low level indicator switches shall include an extra set of contacts that will be wired to the silo fill control panel terminal strip for use as remote alarms to the Plant computer control system.

J. Automatic Operation:

1. Move the dust filter shaker selector to the "auto" position. When the truck hose is connected, a limit switch on the end of the fill pipe shall be actuated. When the limit switch is actuated, the silo exhaust fan shall be energized. The exhaust fan shall continue to run as long as the truck fill

11292-23 hose is connected. When the truck hose is disconnected, the limit switch deactivates, the exhaust fan is de-energized and the dust filter shaker is started. The shaker running time shall be controlled by an adjustable timer (0-15 minutes). The system shall be sequence wired to prevent operation of the exhaust fan and the bag shaker at the same time.

2. If material in the silo reaches the high level indicator, the "high level" indicating light will come on, the alarm horn will sound, the alarm strobe beacon will be activated, and the remote alarm contact will be actuated.

3. If material in the silo reaches the low level indicator, the "low level" indicating light will come on, the alarm horn will sound, the alarm strobe beacon will be activated, and the remote alarm contact will be actuated.

4. The panel shall be field mounted and wired. Field connection to panel, level indicators, dust filter shaker and fill pipe limit switch is required.

5. The auxiliary contacts on the limit switch, mounted to the truck fill pipe, shall be wired to a terminal strip in the truck fill control panel.