330
MODERN GASWORKS PRACTICE
veyed from the retort house. and lowered into a tank of water for quenching purposes. When quenching is complete the skip is raised from the tank, and the coke is deposited at the required spot in the store-yard ; or, if required for water-gas manufacture, it is tipped direct into the generator without quenching. When quenching coke by dipping the skip into a tank of water it is advantageous to permit as much. of the cooling as possible to be performed by the escaping steam or by top spraying ; hcnce only the lower portions of the skip should be immersed.
The method of quenching by simply plunging the incandescent coke into water
Fig. 243.—Standard Tblehbb with Coke Skip.
is usually found too severe, and considerable improvement has followed the practice x>f top-spraying in conjunction with the submersion of the base of the skip. An effective automatic spray has recently been introduced by means of which. a large volume of water is spread uniformly over the top of the coke at the moment the skip is lowered into the tank, the water being turned on and the sprays brought into position by the descent of the skip. As the skip is hoisted the sprays are automatically lifted clear and the water is turned off.
The average telpher macliine as designed for dealing with coke handles a gross load of two tons with a hoisting speed of 80 feet to 100 feet a minute, while a travelling