IMPROVEMENTS IN ICE MAKING OR REFRIGERATING MACHINES OR APPARATUS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left-by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 29th March 1883. Com-
municated to him from Thomas Rose a person resident at the City County and
State of New York in the United States of America
46
JOHN HENRY JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex,
Gentleman IMPROVEMENTS IN ICE MAKING OR REFRIGERATING MACHINES OR
APPARATUS," a communication to me from Thomas Rose a person resident at the
City County and State of New York in the United States of America.
Machinery or apparatus constructed according to this Invention consists of the
following main parts vizt.-An absorber or condenser; a transmitter; a vacuum
pump with a cold water jacket and a gas delivery chamber; a force pump for
circulating ammoniacal Liquor and another for circulating brine when used; a
refrigerator and a valve to retain and regulate the pressure in the absorber or
condenser and an engine for driving the pumps which may be conveniently com-
posed of a steam cylinder mounted on the transmitter the piston rod being fastened
to one end of a beam rocking upon centres carried by the condenser or absorber a
fly wheel and crank may be provided for controlling. the stroke of the vacuuin
pump. A gas inlet pipe communicates with the vacuum pump and a gas outlet
pipe leads from the gas chamber of the said pump to an upper chamber of the
condenser or absorber A pipe for conveying the saturated ammoniacal solution
from the absorber to the refrigerator leads from the lower chamber of the absorber
and passes in a coil through the transmitter and thence through the before
mentioned valve to the refrigerator. A pipe is provided for conveying the spent
liquor from the force pump through the transmitter to the absorber and there is
also a pipe for conveying the refrigerating liquor to the freezing tanks or other
refrigerating devices. A spent liquor tank is provided for receiving the overflow
from the freezing tanks and from the said spent liquor tank it is conveyed by a
pipe to the force pump. In working the apparatus the absorber, the transmitter
and the freezing plates immersed in the ice tank and also the small spent liquor
tank are filled with a solution of Hydrate of Ammonia of about 880 specific
gravity and the machine is set in motion: the force pump will then pump
I Price 1

page_text: ammoniacal solution from the spent liquor tank and force it into the transmitter.
This will obviously displace a corresponding amount sending it through the com-
municating pipe into the lower chamber of the absorber and this again displaces a
like quantity sending it through the communicating pipes into the refrigerator where
it will come under the action of the vacuum pump which will extract sufficient gas
therefrom to reduce the solution to about half its original strength;' and the
temperature to nearly zero of Fahrenheits thermometer. The flow of solution to
the refrigerator and the pressure in the absorber is controlled by adjusting the
valve. Of course the less the flow of solution admitted to the refrigerator the
greater will be the degree of cold obtained. This cold solution now flows by virtue
of its own gravity, through the pipe from the refrigerator and is distributed
amongst the freezing plates in the ice tank by suitable pipes, and causes a corres-
ponding quantity of spent liquor to overflow therefrom into the small spent liquor
tank and thus maintains a supply to the force pump. As this spent liquor enters
the absorber near the bottom thereof, it meets the gas coming from the vacuum
pump which is also being forced into the upper chamber of the absorber and there-
from through a central pipe passing down nearly to the bottom of the absorber the
lower portion of the said pipe being perforated to facilitate the distribution of the
gas. The gas is here reabsorbed by the spent liquor and therefore a fresh concen-
trated solution is constantly being formed. Heat generated by absorption of the
gas is carried off by means of cold water running through a coil of pipes which
traverses the whole length of the lower chamber of the absorber. Hence it will be
seen that two complete circulations are continually going on: One of gas through
the vacuum pump: the other of solution through the force pump. these two
currents meeting at the bottom of the absorber in such relative proportions as to
reform a saturated solution: and so to perpetuate the process as long as the
machine is kept in motion. The object of the transmitter is to lower. the tem-
perature of the saturated solution on its way to the refrigerator; this it will
readily do, because, although the spent liquor which is being pumped into the
transmitter has before its work for the time being still its temperature will not
exceed 30° Fahrenheit whereas the solution passing through the coil in the said
transmitter immersed therein may be as high as 90° Fahrenheit or even somewhat
higher where cooling water is not abundant.
:-
The vacuum pump is arranged as follows:-
The gas. enters the cylinder through a series of small holes bored through it at or
about the centre of its length and communicating with a space or chamber formed
around the exterior of the cylinder into, which chamber the gas enters, through a
valve from a chamber beneath into which the gas pipe opens. The outlet from the
pump is through the piston rod, which is hollow. The piston is double and each
portion is free to move for the space of about a quarter of an inch upon the piston
rod the pistons are kept apart, within certain limits, by springs and collars upon
the piston rod. Just below the upper collar and just above the under collar are a
number of holes bored through the hollow piston rod for allowing the gas to pass
through the piston rod into the gas chamber which it does by way of a perforated
coupling on the piston rod.
Suppose the piston to be travelling upwards then the pressure of the gas upon
the upper portion will force it down upon the mid collar between the two parts of
the piston leaving the holes under the upper collar uncovered and so permitting the
gas to enter the hollow piston rod and thence pass to the gas chamber. But this
pressure upon the upper part of the piston is also communicated to the lower by
reason of the springs and thereby presses it down tightly upon the lower collar and
shuts off the holes above the same. When the pump is on the opposite stroke the
action upon the pistons is reversed. Packing rings are provided at the bearing of
the parts of the piston on the cylinder, and on the piston rod.
The object of the gas chamber is to prevent air entering the
the pump: it is provided with packing glands at top and bottom.
apparatus through
As the pressure

page_text: in this chamber is a little in excess of the atmosphere at all times if there were any
escape it must necessarily be gas out of, and not air into the machine.
It is proposed to construct small machines suitable for domestic use, and in that
case the freezing tank would be placed inside an ice box, taking the place of ice ns
now employed. In this manner advantage can be taken of the cold solution.
remaining in the said freezing tank after ice has been made. Or it can be cooled
down at any time to serve as a refrigerator whether ice has been produced or not.
A modification of this process may be employed by using two refrigerating tanks
worked alternately.