Rush candle

Besides cattails, a few plants have been effectively used as torches and fuel for specialized lamps. The rushlight or rush candle is made from rushes common in wet fields or bogs. These plants have a tall pithy stem and few or no... 

Not at the end. The rector came often. Something had happened to Mrs. Gill s face. It was blurred and wet. We stared at each other. There was a rushing in my head and I thought I d faint, so I walked away very straight-backed, got myself into the laboratory, set my candle down, and locked the doors. 

Candles can be sluiced or backwashed from the insides of the cylinders. A useful option with the cylindrical geometry is to apply a pressure pulse to dislodge the cake. With the fabric-covered version, this might be an air pulse. To avoid a sudden drop in pressure in the air header when this is done, an air tank is usually mounted on the unit. This can be filled by line pressure or by a small compressor dedicated to the service. When air is released, the pressure in the tank drops, but not so drastically as would the pressure at the end of a pipeline. With the porous carbon elements, the pressure pulse is applied to lines still filled with filtrate. This produces a sudden rush of fluid back through the elements. This so-called flashwashing is a very efficient form of backwash. 

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