Improvements in and relating to the Construction and Operation of Refrigerating Apparatus.
Year: 1893

page_text: Date of Application, 20th Oct., 1893
Complete Specification Left, 20th July, 1894-Accepted, 25th Aug., 1894
Improvements in and relating to the Construction and Operation of
Refrigerating Apparatus.
I, FREDERICK NOEL MACKAY, of 242 York Road, King's Cross, in the
County of Middlesex, Engineer, do hereby declare the nature of this invention to
be as follows:-
My invention relates to improvements in the construction and operation of
refrigerating-apparatus.
The object of my said invention is to construct for refrigerating-apparatus
improved compression-pumps, and improved oil-apparatus for use therewith com-
prising an oil "rectifier," and other means hereinafter fully described, by which
devices the working of the compression-pump is made more efficient and satisfactory
than heretofore, and the use of oil therein is economized and made particularly
convenient and advantageous.
According to my invention I jacket the barrel of the pump and lead the gas or
vapour from the cooler into the jacket and thence to the suction-valves of the
pump. Further, it is an important feature of my invention that I inject or draw,
through suitable channels, a certain quantity of condensed gas or condensed vapour,
into the jacket from the condenser to maintain the pump at the desired low
temperature, that is to say, the temperature which the gas should have as it leaves
the refrigerator. By the use of the condensed medium, heating of the pump is
prevented, and it is properly filled with gas at each stroke, which would not happen
if it were allowed to get warm.
By passing the condensed gas or condensed vapour first into the jacket, instead
of directly into the pump as heretofore, the condensed medium cools the jacket and
pump by evaporation in the jacket, and finally enters the pump cylinder in gaseous
form and not as a liquid; hence the wear of the piston and pump barrel, which
would otherwise be excessive, is obviated.
In connection with the aforesaid apparatus I provide an oil pump or equivalent
device, to draw oil from a suitable source of supply, and deliver it through pipes,
into the piston-rod gland and thence, by a suitable pipe, on to the rod so that it
keeps the said gland tight and the packing lubricated.
In the discharge passage from the pump to the condenser I use a separator or
oil trap, to intercept any oil which comes through the said passage. From the
bottom of the said separator or trap a pipe is led to a closed chamber hereinafter
termed an "oil rectifier," and from the top of the rectifier another pipe is led into
any convenient channel in communication with the suction passages of the pump.
Cocks are provided in the several pipe connections of the rectifier and when the
connection from the trap to the rectifier is opened, oil and gas pass into the
rectifier, and by opening the aforesaid pipe-connection between the rectifier and
the suction side of the pump pressure in the rectifier is reduced by the latter,
whereupon the gas in the oil evaporates therefrom, and the oil cools, thus becoming
ready for further use in the pump without the intervention of other cooling-
apparatus which has heretofore been necessary.
At the bottom of the rectifier is a drain and a steam heating-coil, heating-pocket,
or equivalent device, for purposes hereinafter specified. Such oil as may collect
in the condenser and cooler is delivered into the rectifier through suitable pipes and
valves..
The evaporation of the gas from the oil drawn from the cooler or condenser can
he readily accelerated when necessary by the use of the steam-heating device in the

page_text: rectifier, for when it is desired to withdraw the oil from the machine the use of the
steam heater entirely frees it from gas and permits of the oil being withdrawn
without loss of gas.
I provide a connection with suitable regulating-valve, between the rectifier and
the pump gland and another pipe from the top of the gland to the back suction-
valve chamber, so that oil may pass back into the machine from the rectifier by
way of the gland, so that the packing of same may be maintained tight and the
piston and valve seats be lubricated and clearance lessened between the piston ends
and the pump covers.
A charging cock is provided on the rectifier, so that fresh oil can be drawn
therethrough into the apparatus.
The construction of the glands hereinbefore referred to is preferably similar to
that described in the Specification of Letters Patent No. 4645 of A.D. 1888,
granted to me.
7
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to the Construction and Operation of
Refrigerating Apparatus.
I, FREDERICK NOEL MACKAY, of 242 York Road, King's Cross, in the
County of Middlesex, Engineer, do hereby declare the nature of this invention,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :—
My invention relates to improvements in the construction and operation of
refrigerating-apparatus.
The object of my said invention is to construct for refrigerating-apparatus an
improved compression-pump, and improved oil-apparatus for use therewith com-
prising an oil "rectifier," and other means hereinafter fully described, by which
devices the working of the compression-pump is made more efficient and satisfactory
than heretofore, and the use of oil therein is economized and made particularly
convenient and advantageous.
My improved compression-pump is constructed with a jacketed barrel the gas or
vapour from the cooler being led into the jacket and thence to the suction-valves of
the pump. Further, it is an important feature of my invention that I inject or
draw, through suitable channels, a certain quantity of condensed gas or condensed
vapour from the condenser into the jacket which condensed gas or vapour
evaporating in the jacket cools the same and so maintains the pump at the desired
low temperature, that is to say, the temperature which the gas should have as it
leaves the refrigerator.
In order that my invention may be clearly understood I will now proceed to
describe the same with reference to the accompanying drawing which shews
somewhat diagrammatically an improved compression-pump and oil apparatus for
use therewith constructed according to my invention.
A is a pipe leading from the cooler to the jacket B of the compression pump.
Said jacket is connected by pipes B¹, B' to the suction valve of the pump. The
delivery valves of the pump are connected by pipes C, C to a pipe C₁ which leads
to an oil trap D from whence the gas after being purified from oil is led by a
pipe D' to the condenser. F is a pipe fitted with a suitable cock F¹ leading from
the condenser to the pump jacket B.
G is what I call an "oil rectifier" which is connected by a pipe G¹ having a
cock G³ to the bottom of the oil-trap D, and is connected at the top by a pipe H

page_text: having a cock H' to the pipe A. I is a pipe by which oil freed from gas is drained
out of the oil rectifier, is a steam heating coil furnished with inlet pipe J' and
outlet pipe J', for heating the oil in the rectifier when desired. The oil rectifier is
also connected by a pipe K with the stuffing box B2 on the pump. Said stuffing
box is also connected by a pipe K¹ to the suction valve of the pump.
I provide an oil pump L preferably operated as shewn by a tappet L' on the
piston rod M of the pump, said oil pump being for the purpose of pumping oil from
the oil tank N to the stuffing box B³ where the packing is lubricated. From
thence the oil passes by the pipe N₁ to the piston rod M which is also thoroughly
lubricated thereby and finally is drawn by the piston rod into the pump cylinder.
G' is a charging cock through which oil may be supplied to the rectifier G so that
fresh oil may be drawn therethrough into the apparatus. G₁, is a cock through
which any oil accumulating in the condenser may be discharged into the rectifier
and G is a similar cock through which oil from the cooler may be discharged into
the rectifier in a similar manner.
The operation of my improved apparatus will now be described the arrows in the
drawing shewing the direction of the flow of gas and oil in the apparatus. When
the pump is worked gas is drawn from the cooler through the pipe A and cock A¹
into the jacket B of the pump from thence the gas passes to the suction valves by
the pipes B¹ B. A small quantity of the condensed gas or vapour is supplied from
the condenser by the pipe F to the jacket B, the quantity being regulated by the
valve F. This liquid gas evaporates in the jacket and prevents the pump heating
so that it is properly filled with gas at each stroke which would not happen if it
were allowed to get warm. Moreover the condensed liquid enters the pump
cylinder in a gaseous form and not as a liquid; hence the wear of the piston and
pump barrel which would otherwise be excessive is obviated.
The gas from the delivery valves of the pump is led by the pipe C¹ to an oil
trap D of any suitable description wherein the gas is separated to a very large
extent from the oil which is brought with it from the pump cylinder. The purified
gas finally passes to the condenser by the pipe D'. It will be observed that the oil
trap D is in direct communication with the condenser therefore the pressure in said
oil trap is approximately the same as that in the condenser, this pressure drives the
oil out of the oil trap through the regulating cock G² and pipe G¹ into the oil
rectifier G where the pressure is much lower. Any gas carried over by the oil will
here evaporate and pass by the pipe H through the cock H' to the pipe A. The
evaporation of the gas cools the oil and thus renders it ready for use again in the
pump. I prefer to so adjust the cock H' that the pressure in the rectifier G is a
little above that in the pipe A and the jacket B for a purpose hereinafter specified.
The oil which collects in the rectifier passes through the pipe K to the stuffing
box B and after lubricating the packing therein passes through the pipe K' to the
suction valve of the pump. There is preferably as above described a small
difference in pressure between the jacket or suction and the oil rectifier so that oil
will always tend to flow up the pipe K to the stuffing box B².
The evaporation of the gas from the oil drawn from the cooler or condenser can
be readily accelerated when necessary by the use of the steam-heating coil J in the
rectifier G, for when it is desired to withdraw the oil from the machine the use of
the steam heater entirely frees it from gas and permits of the oil being withdrawn
through the drain I for example, without loss of gas.
The construction of the stuffing boxes on the pump hereinbefore referred to is
preferably similar to that described in the Specification of Letters Patent No. 4645
of A.D. 1888 or of Letters Patent No. 1851893 granted to me.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim it :-
1. In a refrigerating apparatus, a pump having a jacket into which gas is drawn
from the cooler before said gas passes to the suction valve of the pump, with a pipe

page_text: through which liquid gas from the condenser may be injected into said jacket, for
the purpose specified.
2. In a refrigerating apparatus the combination of a pump, an oil trap, and a
closed vessel forming an oil rectifier, so connected and arranged that the oil and gas
collecting in the oil trap pass into the rectifier, being there separated the gas
returning into the low pressure side of the apparatus while the oil passes through
the piston rod stuffing-box into the suction side of the pump, substantially as and
for the purpose set forth.
3. In a refrigerating apparatus, a closed vessel G into which oil contaminated
with gas passes from an oil interceptor placed in the delivery pipe or condenser,
said vessel being connected by the pipe H to the suction pipe, and by the pipes K
to.the gland which is in connection with the suction, and with or without a heating
device, substantially as and for the purposes specified.
4. In a refrigerating apparatus, a pump and oiling apparatus constructed
substantially as described with reference to the accompanying drawing, and
operating as specified.
Dated this 19th day of July 1894
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.