The tilting working chamber is connected with the stationary ports L and L' by means of the loose water-cooled joint W in Campbell's system, which is here shown.
This is prevented by the water-cooled damper S, which always closes the air-blast when the gas-pipe is open and vice versa.
Condensers are either air-cooled or water-cooled, or both.
D, Water-cooled pipe on which J, The incoming gas.
7, is to set in the brick-work walls several horizontal rows of flat water-cooled bronze boxes, RR', extending nearly to the interior of the furnace, and tapered so that they can readily be withdrawn and replaced in case they burn through.
The positive carbon was in some cases replaced by a water-cooled metal tube, or ferrule, closed, of course, at the end inserted in the crucible.
A combined brickand water-cooled furnace has been adopted by the Iron Mountain Company at Keswick, Cal., for matte concentration.
In water-cooled condensers it is usual to arrange that the water passes through a large number of small pipes contained in a larger one through which the gas flows, and as it constantly happened that condenser pipes became choked by naphthalene, the so-called reversible condenser, in which the stream of gas may be altered from time to time and the walls of the pipes cleaned by pumping tar over them, is a decided advance.
In the more recent form of the hearth process the blocks of cast iron forming the sides and back of the Scottish furnace are now generally replaced in the United States by water-cooled shells (waterjackets) of cast iron.
Borchers endeavoured to contend against the first difficulty by employing an iron cathode vessel and a chamotte (fire-clay) anode chamber united by a specially constructed water-cooled joint.