36C25218B0230-00005001.pdf

Cleaver‐ Brooks Rentech

2.1.A Factory‐assembled, packaged water tube, industrial‐class, high pressure steam boiler. Two drum, "D‐type" furnace tube configuration, two pass. Designed for natural gas and fuel oil firing and constructed in accordance with Section 1 of the ASME Boiler and Pressure Vessel Code for the specified design pressure and shall bear the ASME standard symbol.

x x

2.1.B Service Designed to continuously receive feedwater at a minimum of 212 °F and generate steam at pressures and quantities shown x x

2.1.C Performance Steam output quality, 99 percent minimum at all steam flow rates. Based on water quality in boiler of 3500 ppm maximum total solids, 15 ppm maximum suspended solids, 700 ppm maximum alkalinity.

x x

2.1.C.1 Minimum Efficiency at Required Maximum Output (Natural Gas Fuel 1000 Btu/cubic foot)

78 percent at 15 percent excess air or 80 percent at 5 percent excess air.

x x

2.1.C.2 Minimum Efficiency at Required Maximum Output (Fuel Oil (ASTM D396 Grade 2))

83 percent at 15 percent excess air or 81.5 percent at 5 percent excess air.

x x

2.1.D.1 Heating Surface Area Provide surface area necessary to obtain required performance, however surface area shall not be less than shown on the drawings. Heating surface is defined as flat projected tube surface, including fins, in combustion space, whether or not covered by refractory, plus outside (gas side) circumferential area of all convection tubes.

x x

2.1.D.2 Furnace (Combustion) Volume

Heat release at full load shall not exceed 50,000 Btu per hour, per cubic foot. Combustion volume limits shall not extend beyond first plane of entry into convection tubes. Screen tubes, when used, shall be considered the first plane of entry. x x

2.1.E Minimum Design Pressure

200 psi x x

2.1.F.3 Construction The furnace side walls, roof, floor, front & rear walls shall be 100% water‐cooled membrane surface. Membrane design will consist of 2" OD tubes on 4" centerlines, with membrane fins between tubes. The adjacent fins of each outboard furnace and convection tube shall be continuously seal‐welded together, forming a water‐cooled, gas‐tight inner seal. The inboard row of finned tubes between the furnace and convection zone shall be seal‐welded together to prevent short circuiting of flue gas from the furnace to the boiler flue gas outlet. Boiler shall be designed for minimum refractory. Burner throat shall be refractory‐free. No element of the boiler or accessories shall be overstressed, displaced, or have cracks, broken welds or excessive deflection. All vertical elements of the boiler and accessories shall be plumb and all horizontal elements shall be level.

x x

2.1.F.4 Elements No element of the boiler or accessories shall be overstressed, displaced, or have cracks, broken welds or excessive deflection. All vertical elements of the boiler and accessories shall be plumb and all horizontal elements shall be level. x x

2.1.F.5 Base Frame Design for mounting on flat concrete base. All elements shall be level and square. Provide attachments for anchorage to concrete foundation.

x x

2.1.F.6 Lifting Lugs and Jacking Pads shall be provided x x

Salient Characteristics for D‐Type Water Tube Boiler

Salient Characteristics for D‐Type Water Tube Boiler

2.1.F.7 Drums Steam drum shall be minimum 36 inch diameter. Bottom drum shall be minimum 24 inch diameter. Equip steam drum with elliptical side‐hinged manway on each end. Equip bottom drum with non‐hinged elliptical manways at each end. Equip all manways with properly fitted forged steel yokes, bolts, nuts, and non‐asbestos gaskets. Drums shall be fusion welded, radio‐graphed and stress‐relieved. They shall be complete with all necessary connections, a 12" x 16" manway opening in each head with cover and yokes, internal piping for feedwater, chemical feed, and continuous blowdown. The upper drum shall include adequate steam separating equipment to assure the specified steam quality. The lower drum shall include a slotted inverted channel to assure uniform blowoff. All internal fittings and pipe must be adequately supported and removable for maintenance purposes Manway covers shall have bolt slots forged integral with covers. Provide access to all manways clear of piping, valves. All tube holes shall be grooved and sized for 2 inch tubes and shall be radial and properly located to permit proper alignment of tubes. Swaged tubes with reduced drum openings will not be permitted. Intermediate header for water wall or convection tubes will not be permitted. No part of the boiler drums shall be directly exposed to furnace radiation. Refractory shall be utilized to protect from radiant heat. Each water drum shall be equipped with a flanged blowoff connection.

x x

2.1.F.8 Drum Piping Connections

All connections larger than 2" shall be flanged. Threaded connections are permitted for pipe size under 2 inches. Steam nozzle shall be 300 psi ANSI flanged. Design nozzle and drum assembly to withstand forces and moments imposed by connected piping. Studding nozzle will not be permitted. Locate boiler manual steam vent to permit access to gate valve from platform located above boiler. Soot blower outlets. Locate safety valve outlets to permit straight run of vents through roof and to permit valve handle access from platform located above boiler. Separate connections for water column and auxiliary low water cutoff. Connections for boiler feedwater, chemical admission, combined continuous blow down and water sampling. Locate as shown on the drawings. Bottom drum blowoff. Water level sensor connections (for incoming feedwater control). Pressure gage and pressure switch connections. Two 2 inch piping connections on rear head of bottom drum for steam heater for keeping boiler warm in standby mode. Also, connection for temperature sensor for temperature control valve.

x x

2.1.F.9 Drum Internals Steam purification equipment, including dry pan separators, plate‐type baffles and other devices as necessary, to meet steam quality requirements and provide proper water levels in the boiler steam drum. Boiler feedwater admission system to properly distribute feedwater. Chemical feed piping to permit infusion of mixture of water treatment compounds along entire length of drum by continuous feed system. Continuous blowdown and water sampling system as combined unit designed to collect water along entire length of drum. Bottom drum blowoff system to properly collect sediment from bottom drum and to permit complete collection of sediment and drainage. Steam heating pipes in bottom drum to keep boiler warm on standby. Cap for future connections of steam supply and condensate return. Drum internal fittings shall be provided, securely mounted and easily removable for boiler internal access for inspections and cleaning.

Salient Characteristics for D‐Type Water Tube Boiler

2.1.F.10 Tubes All tubes shall be ASTM A178 Grade A, 2" O.D., electric resistance welded, and shall be designed and arranged to provide for natural circulation in the proper direction at all loads. Tubes of variable diameter, such as swaged tubes, shall not be permitted.

No tube shall enter the lower drum below the horizontal drum centerline or enter the steam drum above the minimum water level.

Tubes shall not have any reverse bends or "pockets" which would prevent complete drainage of the boiler through the lower blowoff opening. All tubes are to be rolled in holes drilled true and radially, to afford full parallel bearing in the drum plate. Each tube hole shall be serrated to assure the tightest possible mechanical joint. All tubes shall be a minimum of 0.105" wall thickness.

Uniform internal area, not swaged at drum connections, bend radii permitting turbine cleaning by mechanical tube cleaner.

Arrange convection tubes in alternate narrow and wide rows or in‐line arrangement to permit tube removal without removing adjacent tubes. Align tubes to prevent impingement of soot blower steam jet directly on tube surface Front furnace tubes (if provided) shall be completely clear of burner throat and bullring and arranged to permit maintenance of front wall refractory system without tube removal. Provide rear water wall tubes covering a minimum of 80 percent of the rear wall area. Arrange tubes to permit unobstructed view through observation ports in the rear wall and to permit maintenance of rear wall refractory without removing tubes. Tubes separating the furnace from the convection area shall have continuous fins welded to each side of the tubes and to each other to form a pressure‐tight membrane wall to prevent flue gas bypass of the furnace and convection spaces. Soot blower and baffle supports from tubes shall be properly arranged to eliminate excessive stress on tubes.

x x

2.1.F.11 Refractory Refractory quality and temperature characteristics shall be suitable for long‐term service at the maximum operating conditions and shall be the boiler manufacturer’s experience proven selection. Incorporate refractory systems in the front and rear walls, and seal interface between combustion and convection areas. Repair and replacement of refractory shall be possible without alteration to pressure parts of boiler. Front and Rear Walls: Construct of shiplap firebrick arranged to permit expansion and contraction. Do not use castable refractory except to seal locations where bricks cannot be used. Provide bullring constructed of firebrick to protect burner throat refractory from forces generated within front wall. Provide expansion joint between bullring and burner throat.

Incorporate openings in rear wall for observation ports, and for access to furnace as specified under paragraph "Casing." Access opening shall include a removable refractory plug.

x x

2.1.F.12 Casing, Setting, and Insulation

Provide double wall casing system with insulation between the walls. Inner casing can be a welded finned‐tube inner wall. The inner casing or welded fin tube construction shall be sealed to prevent the combustion gases from coming in contact with the outer casing. Design casing at the combustion gas outlet to receive approved stack or breeching transition section as shown. Refer to plans for details of gas outlet arrangement. Provide furnace access door located near the furnace floor. Use of burner throat as access is not permitted. Equip furnace access door opening with refractory, backed up by insulation and airtight cover system.

Provide three 1.5 inch (minimum) diameter observation ports in rear wall of furnace located to permit observation of each sidewall of furnace and full area of burner throat and bullring. Furnish each port with clear and tinted interchangeable glass; gas tight sliding metal closure between glass and furnace, forced air‐cooling.