2.9
COAL HANDLING EQUIPMENT
2.9.1
Railroad Hopper Car Thawing System
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NOTE: Pit type railcar thawing system is capable of
operating on natural gas, liquified petroleum gas or
No. 2 fuel oil. The radiant heat (infrared) type
railcar thawing system can only burn natural gas or
liquified petroleum gas or use electric resistance
heaters. The radiant heat (infrared) type provides
a slower method of thawing but causes less damage to
the railroad car finish and is preferred provided
natural gas or liquified petroleum gas or electrical
power is economically available and permitted by
current D.O.D. policy.
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Hopper car thawing system shall be pit-type or prefabricated surface
mounted enclosed type [or electric radiant type] hopper car thawing unit
and shall include burners, controls, combustion air blowers, fuel storage
and handling, and related work. Design system to thaw 56 Mg 55 ton, 71 Mg
70 ton and 102 Mg 100 ton capacity coal cars.
System shall be capable of
thawing [_____] bottom hopper unloading coal cars simultaneously. Railroad
hopper car thawing system shall utilize [No. 2 fuel oil] [natural gas]
[liquified petroleum gas] as a fuel. Provide a sufficient number of
heaters to have a minimum heat input of 2198 kW 7,500,000 Btu/hr per car
station, with heaters distributed under hopper car, or under and beside
hopper car, such that the entire car is heated.
Locate burner pits or
heater units for even heating of the hopper cars without subjecting air
hoses, air brake equipment, and bearings to excessive heat.
2.9.1.1
Pit-type Railroad Hopper Car Thawing System
a.
Pit-type Thawing Unit: Pit-type hopper car thawing unit shall be
complete with a refractory lined steel box, burner assemblies,
steel burner enclosure with cover, valves, piping, and hinged main
pit protective covers. Each pit shall have the capacity to
generate 366 kW 1,250,000 Btu/hr when burning [No. 2 fuel oil]
[natural gas] [liquified petroleum gas]. Burners shall fire
horizontally and tangentially into the pit from opposite sides to
heat the refractory lined pit up to radiant temperature. Heat
shall be transferred to the hopper car by radiation from hot
refractory surfaces and by convection from exhaust gases and
evaporated moisture to rail car bottom and sides. Construct pit
outer shell of not less than 6 mm 1/4 inch thick corrosion
resistant steel plate, with the end plates of 10 gage (3.42 mm
0.1345 inch) steel. Provide supporting flanges and handling loops
on both ends and provide cap strips on top of both sides.
Place
cast iron heat deflecting plates with overlapping edges on pit
sides and bottom supported off the ledge on the outer shell.
Provide a minimum 25 mm one inch air space between plates and
outer shell. Pit side walls and bottom shall have a minimum 65 mm
2 1/2 inch thickness of standard firebrick with one course of
standard end skew brick along the top of the side walls.
Firebrick shall be easily replaceable. End section shall have not
less than 114 mm 4 1/2 inch thick precast high temperature
refractory panels. Provide burner refractory ignition tiles with
steel jacket casings having mounting lugs for bolting to end
SECTION 15502N
Page 94