Improvements in and relating to a System of Underground Distri- bution and Recovery of Anhydrous Ammonia when employed as a Refrigerating Agent.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to a System of Underground Distri-
bution and Recovery of Anhydrous Ammonia when employed as
a Refrigerating Agent.
We, DAVID BRANSON, ROBERT DENNY THORNBURGH and JOHN EDWIN
STARR, citizens of the United States of America, residing respectively at
No. 1315 South Broad Street, in the City and County of Philadelphia and State
of Pennsylvania, No. 2814 Washington Avenue, in the City and County of
St. Louis and State of Missouri, and No. 3137 Morgan Street, in said City and
County of St. Louis and State of Missouri, United States of America, Gentlemen,
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 :-
This invention relates to a system of underground distribution and recovery
of anhydrous ammonia when employed as a refrigerating agent, and consists in
the construction and arrangement of the apparatus, piping and devices used in
carrying it out, which will be more fully hereinafter described and particularly
pointed out in the claims.
The principal object of the invention is to provide simple and practical means
by which anhydrous ammonia may be conveyed under pressure from a central
or convenient building where it is produced and held in suitable reservoirs, to
any required number of buildings or places of business, however distant, for use in
refrigerators, boxes, or rooms, and after such use, to return such ammonia in its
expanded form to the place from which it was originally taken and there recover
the same and distil it over for use again.
A further object of this invention is to provide means by which to regulate
and control the flow of the ammonia from the reservoir through the pipes, to
keep the pipes free from foreign matter and retarding substances, and in case of
the bursting and leakage of the pipes to have notice of such leakage automatically
communicated at once to the central office.
A further object of the invention is to provide means by which, in case of the
bursting or leakage of the pipes through which such ammonia is conveyed, or the
disarrangement or destruction of any of the devices or appliances used and
employed in the system, to at once. cut out from the entire system the part or
section of it so affected until it is repaired, without disturbing the operation of
the system at any other point.
A further object of the invention is to secure with certainty and safety, and with
greater économy than it has heretofore been done, the distribution and recovery of
the ammonia used as a refrigerating agent.
These objects are attained with the devices, appliances and apparatus illustrated
in the accompanying drawings, forming a part of this application.
Figures 1 and 2, when taken together, represent a longitudinal vertical section
of the invention on the line - of Figure 3.
Figure 3 is a plan view of the invention with the cover of the conduit removed.
Figure 4 is an enlarged broken plan view of the conduit showing the means by
which street connections are made.
Figure 5 is a vertical cross section of the conduit showing the manner of
arranging the pipes and electric wires therein.
Figure 6 is an elevation of a refrigerator, partly in section, showing the cooling
coil and its connections.
Referring to Figure 1 of the drawings, A, A, represent anhydrous ammonia
receivers erected within a building where such ammonia is produced. The

page_text: ma suit and apparatus are пOL SHOWn in the drawings, as they do not form
a part of the invention herein claimed.
B represents the supply pipe, having branch pipes B', B', connecting it with the
receivers A, A, and also with the cooling coils C, through valves E on the
refrigerators set up in buildings along the line, as D, in Figure 2. This pipe B is
arranged and secured in a conduit in the street, as shown in Figure 4, and may be
of any required length extending in a straight line but conforming to the grade of
the street, as shown in Figures 1 and 2, or it may extend around a square or block,
as shown in Figure 3.
B2 is the return pipe or main, of equal length but of greater diameter than B, to
convey the expanded gas from the cooling coils C, in the refrigerator D, along the
line back to the absorber F, and is also secured in the conduit, as shown in
Figure 4.
In constructing or laying the conduits containing said pipes the grades are
established for as long distances as possible, and at the lowest point of each
grade, a is placed in the return main, which is connected to a suitable trap,
as G, in a manhole. These traps are for the purpose of collecting any water or
liquid which may accumulate in the coils of the refrigerators and flow down into
the return main. The traps have suitable outlets with cocks, so they can be
connected with a portable vessel, and when filled, or partly filled, the trap is con-
nected to such vessel, the cock is opened, and the pressure in the return main
forces any aqueous fluid which may have accumulated therein into the portable
vessel, which is then carried away for further use. In this way the return pipes
are kept free from obstructions and the ammonia collected in the traps is saved.
The
13 is a vacuum pipe secured in the conduit, as shown in Figure 4, and extends
from the vacuum pump H the entire length of the conduit, the same as pipes B
and B². It has a branch B' connecting it with the discharge end of the cooling
coil just before its connection with return pipe B2, as shown in Figure 2.
principal object of this pipe B is to provide for making repairs or changes in any
of the refrigerators along the line without the loss or escape of any gas, or
occasioning any smell in the vicinity of the works. We will now explain how this
can be accomplished.
Normally, the cock which connects the vacuum pipe to the discharge end of the
cooling coil is closed, but should occasion arise to make any changes in the
refrigerator box, the supply of ammonia to the expansion valve is cut off by turning
cock 1, the return of the expanded gas through pipe B³ is cut off by turning the
cock 2, and cock 3 is opened, thus connecting the cooling coil of said refrigerator
with the vacuum pipe B³. Vacuum pump H being now started, all of the ammonia
and ammoniacal vapor remaining in said coil is drawn out and forced, by means of
connecting pipes into pipe B2, as shown, near absorber F, and thence into the
absorber. By keeping the vacuum pump constantly running, refrigerators at
different points in the line may be repaired at the same time if necessary, as the
vacuum pump will keep a constant current of air in the pipe, thus preventing any
smell of ammonia.
This vacuum line may also be connected at intervals with the liquid supply line,
so that any break, in any section of it, may be repaired, or the ammonia may be
diverted into the vacuum line and run around any break in the main line until
repairs can be made. It may also be used to operate the electric and the expansion
valves by means of compressed air.
In the systems of automatic refrigeration now in use, valves for supplying the
anhydrous ammonia to the coils or coolers are sometimes operated by thermostats,
which make and break electric circuits connected through armatures to the valves,
and thus let on or shut off the supply of ammonia, and so regulate the temperature
of the room or box within which the thermostat is situated. When valves are
so regulated they are termed "electric valves," or "electric. expansion valves."
An expansion valve may also be operated by hand, as any hand valve is operated,
and then they are called simply, ""expansion valves."

page_text: The vacuum line may be used to operate these electric expansion valves, or the
hand valves by connecting it to the reservoir of an air compressing pump.
I, I, represent electrical wires, arranged in the conduit, as shown in Figure 4.
These wires are for the purpose of operating the electric valves, alarm bells, and
danger signals, and in cases where large storehouses are refrigerated, for electric
lighting.
The wires 1, 1, in the conduit may be used throughout the entire system of
underground distribution and recovery, to open and close the electric expansion
valves by means of an electric current, as above set forth, also to operate alarm
bells, and danger signals, by any of the well known means, appliances, and
connections used, and for this reason the. means have not been described or
illustrated, as such description was deemed unnecessary.
The source of electricity may be a dynamo-electric machine or a battery, as the
circumstances may require, preferably the former.
In the drawings,
Figure 1, a dynamo-electric machine is indicated, as it has thus far been found to
produce the best results.
The flow of the ammonia through the supply pipe B is controlled by a pressure
reducer and by check-valves, as P, and P¹. The pressure reducer and check-valves
may be of any well-known construction and are so set as to maintain a uniform
flow of the ammonia.
The pressure reducer is set so as to remain stationary under ordinary pressure.
It is electrically connected, however, with an alarm bell in the central office, so
that in case of unusual pressure by reason of breakage of the pipe and the escape
of the gas, contact will be made, the bell rung, and the superintendent of the works
admonished to shut off the supply of ammonia and proceed at once to ascertain
where the break is and repair it.
In Figures 4 and 5 the construction of the conduit is shown. It consists, simply,
of a rectangular box with supports for the pipes and wires as shown.
In Figure 6 is shown a refrigerator box with a suitable coil and pipes connecting
it with the system herein described. No claim is made to any of the patentable
features shown therein in this application, as such features, so far as patentable,
are the subject matter of other applications.
It is well known that scale is formed on the inside of iron pipes, and owing to
the searching nature of anhydrous ammonia, this scale is disengaged from the pipes
and in time partially fills up the pipes and greatly injures the action of the valves.
To remove this difficulty as far as possible, scale traps, as K, are placed wherever
the ammonia is caused to flow in a vertical line, but more particularly in connection
with each refrigerator box. These scale traps require attention only at long
intervals, but they practically remove all the difficulties which would otherwise
result from the deposit of the scale in the pipes and valves.
The operation of this system is so obvious, in view of the state of the art and
the explanations herein given as not to require further description.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. In a system of underground distribution and recovery of anhydrous ammonia,
the combination of an ammonia receiver, a liquid supply pipe provided with
branches, refrigerator boxes provided with cooling coils, a return pipe for the
expanded gas provided with fluid traps, and an absorber, substantially as described.
2. In a system of underground distribution and recovery of anhydrous ammonia,
the combination of au ammonia receiver, a liquid supply pipe provided with
branches and having scale traps with each branch, cooling coils within chambers, a
return main provided with branches corresponding in number to the branches from
the liquid supply pipe, fluid traps connected to the return main, and an absorber,
substantially as described.

page_text: 3. In a system of underground distribution and recovery of anhydrous ammonia,
the combination of an ammonia receiver, a liquid supply pipe provided with
branches, cooling coils in chambers, a return main with branches, a vacuum pipe
with branches connected to each cooling coil and a vacuum pump connected to
the vacuum pipe and discharging into the return main at or near the absorber,
substantially as described.
4. In a system of underground distribution and recovery of anhydrous ammonia,
the combination with the supply pipe, the cooling coils and the return pipe, of a
vacuum pipe and a vacuum pump for exhausting the ammonia from said pipes and
coils, substantially as described.
5. In a system of underground distribution and recovery of anhydrous ammonia,
the combination, with an ammonia receiver, a liquid supply pipe provided with
branches, refrigerating boxes provided with cooling coils, a return pipe for the
expanded gas, and an absorber, of a pressure reducer situated in the supply pipe,
and an alarm bell electrically connected to said pressure reducer, substantially as
described.
Dated this 10th day of January 1893.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.