Sheet 4343-4 Page 3
MEDIA CLEANING
WARNING: Stay clear of the back of the regenerator. The container should be large enough to hold all the balls but some may still fall out and roll around. Before continuing with bed removal, pick up all balls on floor. Use shovel or other device as balls may still be hot.
The heat transfer media can be cleaned by tumbling to separate the contaminants or by washing the media with a water spray. DRY METHOD The contaminated ¾ " diameter balls are placed into a perforated rotating drum, or onto a stationary perforated flat plate. The rotating drum will separate the dust and small pieces automatically while the charge is manually raked when the flat plate is used. A vibratory finishing mill such as those of SWECO Corp. will make the process automatic. These machines can be totally enclosed to contain all the dust, and can be fitted with discharge classifying screens and dust separators. WET METHOD Similar to the dry method, but with the addition of a water spray or jet. Disposal of the spent water has to be considered for environmental reasons, since it will contain dissolved salts. Glass – volatiles are usually Na 2 SO 4 which is very soluble in water, but batch carryover is not water soluble. Aluminum – fluxing salts are water soluble. Aluminum oxide or dross is not. Note: A wet media charge should not be placed into the regenerators. Sufficiently air dry prior to placing in the regenerator or run burners in direct fire for sufficient time to ensure a dry charge. SIZING MEDIA There will be some breakage of the balls because of splitting or shelling. These smaller pieces should not be put back into the regenerators, since they could plug the holes in the perforated support plate. They will also cause higher bed pressure drops and may contribute to accelerated plugging.
Step 6: Rake out balls from front of regenerator.
Note: Use care during the removal process to prevent damage to the regenerator refractory. INSPECTION
When all the bed media has been extracted, inspect the following:
• Remove the rear perforated support plate, check for plugging of the perforations, clean as required using a wire brush. If a wire brush dœs not clean the perforations, use a 5⁄16 " drill to open holes. • Clean the front stationary perforated support plate as described for the rear plate (burner sizes -10, -12A and -12B only). • Remove (vacuum or brush) any small particles, dust, etc. that may have fallen through the perforations into the plenum chamber. Check for and remove any obstructions on the wire screens located in the air and exhaust connections.
• Inspect all refractory for damage or degradation. If required, make repairs.
• Inspect and clean seals and sealing surfaces. Replace any damaged seals.
Note: It is very important to maintain the integrity of the bed cover and air plenum cover gaskets. RE-ASSEMBLY Step 1: Replace the perforated bed support plate. Slide the plate onto inclined rails at the center of the plenum. Push the plate up the incline until it drops into the grooved holder. Lift bed plate and lock into position with drop gate screws. Step 2: Carefully replace the rear air plenum cover making sure the gasket seating surfaces are clear of all dirt and debris. When the retainer is satisfactorily seated, install all bolts back into position and tighten fully. Step 3: Fill the regenerator with clean ¾ " diameter alumina balls to a level depth of 12". Be careful not to damage the burner refractories. Step 4: Replace the bed cover by reversing the removal procedure. Make sure all gasket surfaces are clear of dirt and debris. Install and tighten all bolts. Step 5: Open the manual gas line valves and return the furnace and furnace pressure control system to normal operation.
REAR
FRONT
Fixed Front Bed Support Plate (TBII sizes -10, -12A, and -12B only)
Rear Bed Support Plate (all sizes TBII)
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