It often happens in towns and where manufactories are crowded
together, that the supply of water for condensing purposes is very
small, and consequently that it attains an inconveniently high
temperature under unfavorable conditions of weather, resulting in the
deterioration of the vacuum and a consequent increase in the
consumption of fuel. To remedy or to diminish this difficulty, Messrs.
Boase and Miller, of London, have brought out the water cooler
illustrated above. This consists, says _Engineering_, of a revolving
basket of wire gauze surrounding an inner stationary vessel pierced
with numerous small holes, through which the heated water discharged
by the air pump finds its way into the basket, to be thrown out in the
form of fine spray to a distance of 20 ft. at each side. The drops are
received in the tank or pond, and in their rapid passage through the
air are sufficiently cooled to be again injected into the condenser.
The illustration shows a cooler having a basket three feet in
diameter, revolving at 300 revolutions per minute, and discharging
into a tank 40 ft. square. It requires 3 to 4 indicated horse-power to
drive it, and will cool 300 gallons per minute. The following decrease
of temperature has been observed in actual practice: Water entering at
95 deg. fell 20 deg. in temperature; water entering at 100 deg. to 110
deg. fell 25 deg.; and water entering at 110 deg. to 120 deg. fell 30
deg. The machine with which these trials were made was so placed that
the top of the basket was four ft. from the surface of the water in
the pond. With a greater elevation, as shown in the engraving, better
results can be obtained.
[Illustration: IMPROVED WATER COOLING APPARATUS.]
The advantages claimed for the cooler are that by its means the
temperature of the injection water can be reduced, the cost and size
of cooling ponds can be diminished, and condensing engines can be
employed where hitherto they have not been possible. The apparatus has
been for two years in operation at several large factories, and there
is every reason to believe that its use will extend, as it supplies a
real want in a very simple and ingenious manner. Messrs. Duncan
Brothers, of Dundee and 32 Queen Victoria Street, E.C., are the
manufacturers.
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