Sludge flushing

Nevertheless, even if phosphate is added directly to the boiler, if this sludge is not removed by BD it eventually settles and acts as a foulant to impede flow in the boiler waterways. Furthermore, without adequate dispersants during boiler operation, or if the boiler is not flushed out when drained down, the sludge may bake onto a heat exchange surface and generate an adherent, heat transfer-resisting deposit. 

Where serious problems develop, typically the waterside chemistry is poor and iron corrosion debris, sludges, and general deposition are evident. Perhaps there is no softener or the water treatment program is unsuitable for actual operating conditions. Possibly the protocol for BD is inappropriate (either too much or too little, or it is unrelated to steam demands) or flushing, cleaning, and boil-out programs have not been properly instituted. 

Polymeric sludges and tars can be removed by heating a 1 % caustic and 0.7% potassium permanganate (KMn04) solution for 12 to 24 hours at 150 to 175 °F, followed by draining and flushing. 

The scrubber design implies that the excess sludge be regularly removed from the packed section. This sludge settles in the lower zone and reduces the air throughput. For cleaning, the blocks of the packed tower are removed (Fig. 6), flushed out or dried and knocked out. The cleaning must take place every 3 months and 2 to 3 hours. 

Cleaning. If the drained coolant is rust-colored or the radiator, as viewed through the filler neck, is rusty, the system should be cleaned. A flush type product will facilitate removal of sludge and loosely adherent rust. However, if the system is badly rusted, a heavy-duty cooling system cleaner will be required. In either case, the manufacturer s directions should be carefully followed. 

B16A 71845 1 xl) Connection parts for flushing device (Only for partial sludge discharge) Elbow... 

On hard-to-handle services, such as the fluidized-bed level measurement in combustion processes, there is little choice but to use radiation gauges. On slurry and sludge services, d/p units with extended diaphragms eliminate the dead-ended cavity and bring the sensing diaphragm flush with the inner surface of the tank. Other level transmitters that can be considered for hard-to-handle services include the capacitance/RF, laser, radar, sonic, and TDR types. 

The tar and liquor plant handles the flushing liquor that circulates between the byproduct plant and the primary cooler. It also processes the wastewater that results from recovery of the coal moisture and chemically bound water in the coal. The flushing liquor flows into tar decanters, where the tar separates from the water and is pumped to storage for later sale. Heavier solid particles separate from the tar and are removed as tar decanter sludge. After withdrawal of a bleed stream that contains ammonia, the aqueous liquor is pumped back to the primary cooler. Following removal of tar particles, the wastewater stream is steam stripped. An alkali, such as sodium hydroxide, is added to decompose ammonia compounds dissolved in the liquor. The ammonia vapor is recovered and combined with the rest of the ammonia recovered from the coke-oven gas. 

Anaerobic Methods. Strict anaerobic procedures were used throughout this investigation. Sludge samples were flushed with 02-free 70% N2-30% CO2 (2) whenever handling was necessary. 

Back flushing is used to remove the sludge from the activated charcoal filter. Thermal reactivation of the filters under similar conditions to activated charcoal production has to be performed periodically to avoid break-through of pollutants. This can be carried out either at the waterworks or by the manufacturer of the activated charcoal. 

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