Sheet 4343-4 Page 2
REAR
FRONT
Bed Cover
Drop Gate Screws
Drop Gate Rear Plenum Cover
PROCEDURE
Step 3: After the initial vertical lift, the cover may be moved horizontally away from the stationary section. It is important to keep the cover centered until it has cleared the internal sidewalls to prevent damage to the cover refractory. Consideration of cover placement during the remainder of the bed cleaning is extremely important. Keep in mind that a knife edge male seal protrudes from the flange area and that it must be protected from damage. If the cover refractories have been sufficiently cooled, it can be set down on a wood pallet or platform. If the refractory is too hot for this, it should be placed on a heat resistant surface. Be careful not to damage the knife edge or refractory.
After burner(s) have fired direct for sufficient time to properly cool the regenerator beds: • Turn off the burner to be cleaned. • Lock out the controls so the burner cannot be turned on. • Close the individual burner manual gas valves to burner gas, to injector gas, and to the individual burner manual pilot gas valve for the respective burner. • Place the furnace flue damper control into the manual mode and drive open.
BURNER BED REMOVAL
Step 4: With the cover removed and properly stored, move into place the container that will accept the fouled bed material.
WARNING: Maintain a negative pressure within the furnace to protect personnel cleaning the beds from contact with hot furnace gases. Under positive or neutral furnace pressures, furnace gases could exit through an open burner hatch. Lifting lugs are positioned at each corner of the bed cover on its top surface. Each facility usually provides removal hardware suitable to their installation requirements. A suggested arrangement is the use of a spreader bar with four lifting chains and hooks for connection to four lifting lugs on the cover. The other side of the spreader bar is connected to an overhead crane or a chain hoist fastened to an overhead rail, gantry, or the forks of a lift truck.
After removing all air plenum cover bolts, the cover is now ready to be removed. The rear plenum cover has no refractory lining but large sizes are heavy. WARNING: Keep hands away from rear of the regen- erator when loosening the two drop gate screws because the support plate drops with considerable force. Simultaneously loosen the two drop gate screws holding the rear half of the bed support plate until the plate drops into the air plenum. WARNING: Keep clear of the rear of the regenerator. The fouled bed media will pour out immediately and could be very hot if cooling on direct fire operation is inadequate. Step 5: A portion of the bed media will fall out as the bed support plate drops. The remainder is raked out. Most of the fouled media will be loose, however, some areas may have agglomerated and will require breaking up.
Step 1: Connect the lifting device to the bed cover, but keep off tension.
Step 2: After removing all bed cover bolts, the cover is now ready to be removed. The cover gasket arrangement consists of a knife edge around the perimeter of the removable section and a rope gasket housed in a channel around the perimeter of the stationary bed section. It is important for the refractory construction that the lifting device be centered such that at least the first few inches of lift be true vertical.
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