Note: Descriptions are shown in the official language in which they were submitted.
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HYDR~ULIC SYSTEM FOR RECOVERING REFPIGERANTS
Field of the Invention
This invention relates primarily to refrigerant reclamation
systems and more particularly to such systems, and a method for use
thereor, which includes hydraulic apparatus for moving a
refrigerant liquid or vapor.
Backqround of the Invention
Normally, pneumatic systems are provided to move refrigerant
for purposes such as recovery thereof. In such pneumatic systems,
both a li~uid and vapor refrigerant is moved for purposes of
recovery thereof. However, it has been found that a major limiting
factor for the pneumatic system is the maximum attainable air
pressure, which is in the range of one hundred seventy five pounds
per square inch.
In hydraulic technology used for various purposes, it is
common to develop as much as three thousand pounds per square inch
in order to move a much larger piston, than was and is the case
with pneumatic technology. Transmitting such factors to a system
for pumping liquid refrigerant, it is the result that large
pneumatic systems claim a pumping rate of thirty pounds per minute
for such refrigerant liquid.
With hydraulic technology, however, upwards of four hundre~
pounds per minute of liquid refrigerant is achieved, with the only
limiting factor ~eing the size of the inlet line. Furthermore,
2~ speed limitations imposed upon pneumatic systems are not a major
concern -~ith hydraulic technology.
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Obiects and SummarY of the Invention
Accordingly, a primary object of the present invention is to
make use of hydraulic technology in a svstem for moving liquid or
vapor refrigerant.
A further, and more particular object of the present invention
is to provide a hydraulic system and method for moving liquid or
vapor refrigerant with a high pump rate by moving a larger piston
and operating with larger speed of movement than previously
possible wlth a pneumatic unit.
These and other objects of the present invention are provided
with apparatus in a system, and using that system in a method, for
moving large amounts of refrigerant for recovery or reclamation in
a shorter time period than with previously available pneumatic
technology. The hydraulic system and apparatus comprise
hydraulic pump, an oil reservoir for operating the pump, a
hydraulic cylinder, whose motion is controlled by a remote switch
sensing the position of the piston therein, and a spool valve for
controlling the flow of hydraulic oil. The hydraulic system
supplies control oil from the oil reservoir through a variable flow
hydraulic pump, which oil is used to drive the hydraulic cylinder
as directed by the spool valve and remote switch assembly. The
hydraulic cylinder includes the refrigerant pump pistons whish move
from a first side to a second side, and at this time vapor and/or
liquid refrigerant is drawn in the first side from a first inlet
through a first check valve, as a secona check valve is held shut
by back pressure. The second side of the refrigerant p-ston pu~p
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is discharging vapor and/or liquid refrigerant to a regulating
outlet valve through a fourth check valve, while the third check
valve on the second side of the refrigerant pump pistons is held
shut by inner cylinder pressure. At the end of the stroke, the
5 remote switch assembly reverses the hydraulic oil flow through the
spool valve and thereby drives the refrigerant pump pistons in the
opposite direction. The process is reversed from the second side
to the first side.
At this time, vapor and/or liquid refrigerant is drawn into
the second side of the refrigerant pump from the first inlet
through the third check valve, as the fourth check valve is held
shut by means of downstream pressure. The first side of the piston
pump is now discharging vapor and/or liquid refrigerant to an
outlet regulating valve, through the second check valve. The first
check valve is held shut by irner cylinder pressure.
At all times, the hydraulic oil from the retracting side of
the power hydraulic cylinder is returning oil to the hydraulic
reservoir through the hydraulic spool valve.
The limit switch assembly controls the direction of the
hydraulic oil according to its sensing of the piston position. At
the end of each stroke, the limit switch assembly reverses the
directicn of the refrigerant pump piston.
Brief Description of the Drawinqs
Other objects, features and advantages of the present
invention will become apparant by reference to the following
description of a preferred, but nonetheless illustrative,
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embodiment, with reference to the accompanying drawing, wherein:
FIG. 1 shows a schematic representation of a system method and
apparatus according to the present invention.
Detailed Description of the Preferred Embodiment
The drawing of the invention illustrates schematically the
various elements and interrelationships thereof of the present
invention, showing elements of a hydraulic system for driving a
piston in a hydraulic cylinder in order to move refrigerant liquid
or vapor for purposes of reclamation or recovery. The elements
include an inlet port 10 for admitting refrigerant in a direction
depicted by arrow 12, a hydraulic pump 14, a hydraulic oil
reservoir 16, the pump 14 controlling the flow of oil from oil
reservoir 16. Pump 14 is of the variable flow hydraulic type.
The hydraulic oil is used to drive a hydraulic piston 18 in a
1~ hydraulic cylinder 20, and cylinder 20 is connected to spool valve
22, which controls the flow of hydraulic ~il to and from hydraulic
reservoir 16. Drain lines ~g are also provided.
A limit switch assembly 24 is used to sense the position of
piston 18, so that at the end of each stroke the direction of the
piston is reversed.
A series of check valves control the flow of refrigerant
through the system. First check valve 26 controls the flow of
vapor refrigerant and/or liquid refrigerant from inlet 1~ in a
direction depicted by arrow 12' at ~'he left or first side of the
system in the orientation of the drawing. In the nomenclature of
this application and/or patent, the motion of piston 18 from the
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- left side to the right side shall be considered a first direction;
and the motion of the piston from the right side to the left side,
or from the second side to the first side, shall be considered a
second direction.
A second chec~ valve 28 is located on the fir5t side of the
system, whereas the second side of the piston and cylinder includes
third and fourth check valves 30, 32. Regulating outlet valve 34
is located to enable refrigerant to flow in a controlled manner
through condenser 36 to a condensed refrigerant outlet 38, for
enabling outlet flow in a direction decpited by arrow 40.
Thus, in operation of the system, the operation begins with
motion of the piston from the left side to the right side, or from
a first side to a second side. At this time, refrigerant vapor
and/or liquid refrigerant is drawn in through inlet 10, in
direct on 12', and through check valve 26, as check valve 28 is
held shut by back pressure. The right or second side of the
refrigerant piston is discharging vapor and/or liquid refrigerant
to regulating valve 34, through check valve 32, in a direction
depicted by arrow 12a, while check valve 30 is held shut by inner
cy'-..d_~ pressure.
At the end of that stroke of piston 18, the limit switch
assembly 24 reverses hydraulic oil through spool valve 22 to drive
the refrigerant piston in the opposite direction, so that
refrigerant liquid or vapor is drawn into the right or the second
2, side of the refrigerant piston 18 from inlet 10 in a direction
depicted by arrow 12", through check valve 30, as check valve 32 is
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held shut due to downstream pressure. The left or first cide of
the refrigerant piston pump is now discharging vapor and/or li~uid
refrigerant in a direction depicted by arrow 12b to regulating
valve 34 through check valve 28. Check valve 26 is held shut by
inner cylinder pressure.
At all times, the hydraulic oil from the retracting side of
hydraulic cylinder 20 is returning oil to the hydraulic reservoir
16 through hydraulic spool valve 22.
The limit switch assembly 24 controls the direction of the
hydraulic oil, according to its sensing of the piston position; and
at the end of each stroke the limit switcn a~sembly 24 reverses the
direction of the refrigerant pump.
In this manner, a method for reclaiming, recovering or
otherwise treating refrigerant li~uid and/or vapor is provided in
connection with an air or water-cooled condenser step, through a
condensed refrigerant outlet 38 in a direction depicted ~y arrow
40.
While operation of the various elements of the system
apparatus has beer. described, and thereby the steps of the method
taught, the limits of the present invention method and system are
to be imposed only by the following claims:
