Modern Gasworks Practice

440 MODERN GASWORKS PRACTICE The battery condenser (Fig. 269) is of somewhat novel construction. It con-sists of a long and narrow box divided internally by baffle-plates which cause the gas to take a circuitous course. The width. of the box is usually about 2 feet, and small tubes passing from side to side form the chief cooling surface. The ends of these tubes are left open, so that a current of air readily passes through. In addition, the obstruction caused by the tubes has some effect in breaking up and throwing down the tarry vesicles suspended in the gas. So far as capacity of condenser plant is concerned, the most reliable rule from which to form an estimate is that which provides an allowance of 5 square feet of superficial area per 1,000 cubic feet of gas made per diem. This is sufficient (but not extravagantly so) when cast-iron mains and apparatus are employed, and may Gas Outlet r JT n |L_ _J 0 OOO o o o o o o O 0 o OOO o o o o c o o o o o o o 0 o o ooo 1° ool o o o o o o o o o o o o o o o o o o ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo o © o ooo ooo ooo ooo ooo ooo o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o ooo o o o o o o/ o o o o o o o o o ooo OOO OOO OOO OOO : OOO o © o ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo ooo 1 Gas Inlet Fig. 269.— Batteky Condensek. be slightly reduced wlien wrought iron or mild steel is used. It must be borne in mind that the figure given by this rule includes (in addition to the areas exposed by the actual condenser) the area of all piping between the outlet of the liydraulic main and the miet of the condenser. This is readily calculated. The following relate to pipes commonly in use as foul mains :— 6-in.ch pipe. Each foot run exposes an area of 1-57 square feet. 9-inch ,, >> JJ 2-35 12-inch ,, >> >> >> 3-14 15-inch „ >> >> 3-92 18-ineh „ »> ?? » 4-71 24-inch „ ,, »> >> 6-28