O
MODERN GASWORKS PRACTICE
(a) Lower initial cost.
(&) Increased safety, owing to the elimination of the water seal, which is liable to evaporate, thus lessening the seal.
(c) They will not “ blow ” in the event of a temporary excess of back-pressure.
(<Z) Greater durability.
(e) Tliere is no risk of frozen. lutes in winter, with the consequent absence of anxiety.
(f) Owing to the lighter construction of the lids, the lif ting apparatus is not so cumbersome.
There are several types of jointing material made use of with luteless purifiers. A gas-tight joint is ensured by a strip of rubber or tallowed liemp inserted between the flanges of the cover and side plates. The two flanges are then pulled together by
6'
Fig. 365.—Milboubne’s Jointing for Dby Lutes.
ordinary bolts and nuts inserted at a pitch of about twelve inches. The most effective arrangement, ]i owe ver. is an automatic catch attached to a sliaft running throughout the length of the side of the box. By means of an eccentric movement the holding-down catches can then be released simultaneously along the whole side. Milbourne’s fastener is illustrated in Figs. 361 and 362. In this case the complete cover is released from one point, about thirty seconds being required for the operation. Special fastener clutches, spaced at intervals of about three feet, are actuated by eccentric discs attached to square steel rods running along the edge of the cover and comiected at the corners by bevel gearing. When a cover is unfastened the first portion of the stroke of the operating lever imparts a downward vertical motion to the fastener clutch, whilst the second portion of the stroke swings the clutches out of position. When a lid is tightened up the reverse occurs. The “ Eclipse ” fastener is shown in Fig. 363. In this case the fastener is fixed to the side of the purifier, the steel shaft running beneath a raised cast-iron flange. When the cover is released the whole of the catches fall clear, and leave the cover a free passage for lifting.