The Scranton tribune. [volume] (Scranton, Pa.) 1891-1910, 1902-03-11
Theory and Principles of Pumps.

Editor of The Tribune.
Sir: have been approached by perplexed in
quirer in regard to the theory, principles and
workings of pumps; but still my intelligent friend
will not give in that lie is entirely wrong in his
arguments Probably he might understand it bet
ter in print, and / guess the Scranton Tribune
will not have the slightest objection to its pub
lication The forms of construction OF pumps,
and the modes in which they are applied, are
necessarily very numerous, yet, so far as their
principles concerned, all are clearly referabe
to one OF four classes: The sucking pump, the
forcing pump, the lifting pump and the centri-
fugal pump.
The sucking pump suction or lift pump, con-
sists OF a cylinder, called the barrel, with pipe
at the bottom, communicating with the water to
be raised, and pipe at the top to receive the
water raised. There are two valves in the barrel,
one at the bottom and another at the top. This
opens into the piston, which is moved up and
down by means OF rod connected with the han
die, whenever the requisite power is applied.
When the piston is raised, the air in the barrel
between the valves is expanded and becoming
rarfed eXerts less pressure on the lower valve,
which opens, and the whole air in the pipe and
barrel becomes less dense.
The atmospheric pressure on the surface of the
water, about fifteen pounds 10 every square inch,
causes IL to rise in the pipe until the tension OF
the confined air becomes equal TO the pressure of
the atmosphere On again depressing the piston,
its valve opens, and the air passes through it
from the barrel as it descends; but the lower
valve being closed by the downward pressure the
volume OF water which has risen into the pipe
remains On again raising the piston similar
process takes place. an additional quantity OF
water entering the pipe, Thus, by the alternate
motion OF the piston, column OF water is raised
or lifted in the pipe until il reaches the piston
when at the bottom OF the barrel, and all the air
below it has been excluded. On raising the pis'
ton when the water has reached it, the fluid will
necessarily follow il, owing TO the atmospheric
pressure on the surface OF the brook OF well from
which it rises.
When the piston is again lowered, the water
pours through its opened valve, and rises into the
barrel and by successive strokes is lifted up until
it reaches and pours out OF the spout. The at
mospherc pressure balances column OF water
thirty-three feet in height, but owing to the dif'
fculy of making the pump perfectly air-tight, il
Is seldom that n greater height Is attained III
working than twenty-five to thirty feet
To he brief about it, In all kinds OF pumps,
the total effort required 10 work the machines,
independently OF friction, may be described as
equal to the weight OF column OF water whose
base is equal to the area OF section of the
working cylinder, while the altitude will CORES.
pond to the distance between the surface of the
water in the reservoir and the point TO which ii
is raised Have argued the question fairly, per-
picked inquirer, am ! right or wrongg
Daniel Gegory, Elmhurst