Railroad Car Thawing Equipment. When high moisture coal
is shipped in freezing temperatures, unloading the cars becomes a major
problem. The need for special equipment to unload frozen coal will depend on
the location and size of the plant. In a plant where below-freezing
temperatures are infrequent, manual operation to break the coal out of the
cars will be sufficient. In regions where frozen coal is a regular
occurrence, thawing sheds or pits are often necessary. Top mounted car
shakers which transmit a vibratory action to the railroad car can be used with
the thawing units or used independently in milder climates.
Railroad Car Pullers. Car pullers are usually of either a
capstan type or drum type. A capstan type puller is satisfactory for handling
rail cars on level grade provided the pulling capacity is not exceeded. For
higher pulling capabilities and locations where rails are not on level grade,
the drum type puller should be used. In some cases a driven rail spotter
vehicle is justified in lieu of the above. In making a choice, consider
weight to be pulled, grade, radius of curvature (should be straight), track
condition and operating temperature.
Railroad Car Scales. Railroad scales are optional for
large plants if their use can be justified.
Unloading Hoppers. A double hopper arrangement,
approximately 14 ft (4.27 m) wide and 28 ft (8.53 m) long should normally be
provided. Bar grating protects against personnel and vehicles falling into
the hopper. Hopper slope should be at least 60 degrees from horizontal. All
hoppers, chutes and surfaces on which coal flows should be stainless steel for
long life and good coal flow.
c) Truck Delivery. Transportation by truck is the most economical
over short distances. The effective range is approximately 150 miles (242
km). Although it is the most flexible mode of transportation, it can also be
highly dependent on the weather. Unloading equipment for truck delivery is
similar to that required for rail delivery but is much less extensive. Truck
scales are optional subject to economics and use justification. Truck hoppers
are a minimum of 10 ft (3.05 m) by 10 ft (3.05 m) with steel grating and
hinged or removable covers.
Coal Handling Equipment. Extensive equipment is required to
transport coal from unloading hoppers to the furnace or storage area. Typical
handling systems could include a combination of various elevators, crushers,