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FORM 2
The Patents Act 1970
(39 of 1970)
&
The Patent Rules 2003
COMPLETE SPECIFICATION
(See Section 10 and rule 13)
TITLE OF THE INVENTION:
COOLING APPARATUS FOR CONDESATE WATER IN A COMPRESSOR
APPLICANT:
a) Name: KIRLOSKAR PNEUMATIC COMPANY LIMITED
b) Nationality: Indian
c) Address: HADAPSAR INDUSTRIAL ESTATE, PUNE 411013
PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS PERFORMED
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A) TECHNICAL FIELD
[001] The present invention generally relates to mechanical apparatus and
particularly relates to a cooling apparatus using a condensate water to cool an air-
oil separator pipe to reduce an energy required by the air cooler.
B) BACKGROUND OF INVENTION
[002] Gas compressors typically comprise a kinetic energy source, such as an
electrical motor, diesel engine, gasoline engine, and/or the like and a suitable
mechanism which uses the kinetic energy to compress and pressurize gas. There are
a variety of types of known compressors having different types of mechanisms for
using the kinetic energy of the energy source to compress and pressurize gas. One
class of gas compressors is a liquid-injected gas compressor.
[003] Liquid-injected gas compressors involve the injection of liquids, such as
lubrication oil, into the mechanism used to compress and pressurize the gas. Like
gas compressors generally, liquid-injected gas compressors may have a variety of
mechanisms for compressing and pressurizing the gas. As the gas is compressed in
a liquid-injected gas compressor, the gas and the injected liquid heat up, forming a
mixture of hot gas and liquid. In some applications, there is a desire to cool the
heated mixture. In some applications, there is a desire to separate the mixture (i.e.
to separate the gas from the liquid). For example, where the liquid-injected gas
compressor is an air compressor, there can be a desire to separate the compressed
air from the lubricating oil prior to using the compressed air, to cool the lubricating
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oil prior to re-using the lubricating oil in the compression and/or to cool the
compressed air prior to using the compressed air.
[004] In prior art systems, the moisture is separated from a compressed air and is
discarded or not utilized optimally through a feedback mechanism. Also, the energy
required for after cooler and oil cooler operation is very high which influences
overall energy requirement of the compressor.
[005] Hence, there is a need for a cooling system to utilize the condensate water
for reducing an operational temperature of the air-oil mixture. Also, there is a need
for a cooling system to cool the air-oil mixture during transit before air coolers and
oil coolers in order to lower the energy required for after cooler and oil cooler.
[006] The above-mentioned shortcomings, disadvantages and problems are
addressed herein, as detailed below.
C) OBJECT OF INVENTION
[007] The primary objective of the present invention is to provide a cooling
system to utilize the condensate water for reducing an operational temperature of
the air-oil mixture.
[008] Another objective of the present invention is to provide a cooling system to
cool the air-oil mixture during transit before air coolers and oil cooler in order to
lower the energy required for the cooling process.
[009] These and other objects and advantages of the embodiments herein will
become readily apparent from the following detailed description taken in
conjunction with the accompanying drawings.
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D) SUMMARY OF INVENTION
[0010] The embodiments of the present invention provide a condensate cooling
apparatus for a compressor to improve an air-oil mixture cooling. The apparatus
comprises a condensate housing, a condensate pipe and a flow monitor. The
condensate housing encompasses an air-oil mixture pipe. The condensate housing
comprises an inlet port, an outlet port and a drain pipe. The condensate pipe is
connected to a moisture separator on a first end and the inlet port of the condensate
housing on a second end. The flow monitor is connected to the inlet port and the
outlet port of the condensate housing. The moisture separator is connected to outlet
of the after cooler for separating the condensate formed during cooling process of
compressed air The excess moisture is transferred to the condensate housing
through a condensate tank.
[0011] According to one embodiment of the present invention, the condensate
temperature is maintained in a range of 10-60°C leading to a temperature gradient
of 50°C with respect to temperature of air-oil mixture.
[0012] According to one embodiment of the present invention, a parallel flow of
the condensate is maintained in the condensate housing leading to a reduction of
temperature of the condensate by a range of 2-5°C.
[0013] According to one embodiment of the present invention, a same condensate
flow is regulated until a temperature gradient of 50°C is maintained. The
temperature of the condensate is monitored by a temperature sensor attached with
the condensate housing. On lowering of the temperature gradient below 50°C, the
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hot condensate is continuously replaced by the fresh cold condensate from the
moisture separator. According to one embodiment of the present invention, a
cooling mechanism provided by the condensate housing lower an energy
requirement to the after cooler by 1-2%.
[0014] These and other aspects of the embodiments herein will be better
appreciated and understood when considered in conjunction with the following
description and the accompanying drawings. It should be understood, however, that
the following descriptions, while indicating preferred embodiments and numerous
specific details thereof, are given by way of illustration and not of limitation. Many
changes and modifications may be made within the scope of the embodiments
herein without departing from the spirit thereof, and the embodiments herein
include all such modifications.
E) BRIEF DESCRIPTION OF DRAWINGS
[0015] The other objects, features and advantages will occur to those skilled in the
art from the following description of the preferred embodiment and the
accompanying drawings in which:
[0016] FIG. 1a and 1b illustrates a perspective view of a condensate cooling
apparatus connected to a condensate tank, according to one embodiment of the
present invention.
[0017] FIG. 2a and 2b illustrates a perspective view of various pipes and position
for fitment of the condensate cooling apparatus in a compressor, according to one
embodiment of the present invention.
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F) DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] In the following detailed description, a reference is made to the
accompanying drawings that form a part hereof, and in which the specific
embodiments that may be practiced is shown by way of illustration. The
embodiments are described in sufficient detail to enable those skilled in the art to
practice the embodiments and it is to be understood that the logical, mechanical and
other changes may be made without departing from the scope of the embodiments.
The following detailed description is therefore not to be taken in a limiting sense.
[0019] In every screw compressor, a moisture separator (also called as bulk water
separator or a condensate separator). The moisture separator removes a condensed
water coming from the after cooler in liquid form. This condensed water is removed
through various air – liquid separation process. The removed water is collected in a
container and drained through a tube mostly thrown away to the waste water tanks.
The temperature of the condensed water is 10°C above the atmospheric temperature
and maximum temperature of the condensate can go up to 60°C. At the same time,
the air-oil separator (AOS) tank temperature is averagely 60°C above the
atmospheric temperature, while a maximum temperature of the air oil separator
tank can go up to 110°C. So, the temperature difference between the condensate
and an AOS tank inlet pipe (connected to the AOS tank) is always 50°C. Hence,
there is a potential of pre-cooling the AOS tank inlet pipe, so the heat load on the
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after coolers and oil coolers are reduced, a total oil temperature in the compressor is
reduced and an application temperature is also reduced.
[0020] To achieve this goal, the present condensate cooling apparatus is
implemented (as shown in FIG. 1a and 1b) which comprises a condensate housing
101, a condensate pipe 102 and a flow monitor 103. The condensate housing 101
encompasses an air-oil mixture pipe (AOS tank inlet pipe) 104. The condensate
housing 101 comprises an inlet port 105, an outlet port 106 and a drain pipe 107.
The condensate pipe 101 is connected to a moisture separator 108 on a first end and
the inlet port 105 of the condensate housing on a second end. The flow monitor 103
is connected to the inlet port 105 and the outlet port 106 of the condensate housing.
After flowing through a condensate housing in a parallel manner i.e. the
arrangement of the condensate housing is parallel to the AOS tank inlet pipe 105 to
perform maximum heat transfer from the AOS tank inlet pipe 105 to the
condensate, the condensate leaves the condensate housing 101 through the outlet
port 106. The outlet port is connected to the drain pipe 107 for draining out the hot
condensate. The moisture separator 108 is connected to an after cooler outlet for
collection of excess moisture (condensate) from the compressed air. The
condensate is transferred to the condensate housing 101 through a condensate tank
108 which is integrated part of moisture separator.
[0021] According to one embodiment of the present invention, a same condensate
flow is regulated until a temperature gradient of 50°C is maintained. The
temperature of the condensate is monitored by a temperature sensor attached with
the condensate housing. On lowering of the temperature gradient below 50°C, the
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condensate is discarded and a fresh condensate to transferred from a condensate
tank to the condensate housing.
[0022] According to one embodiment of the present invention, a cooling
mechanism provided by the condensate housing lower an energy requirement to the
after cooler by 1-2%.
[0023] According to one embodiment of the present invention, the condensate
cooling apparatus is modular in nature and can be connected to different pipes
where temperature gradient between the condensate and the pipe is higher than
20°C (as shown in FIG. 2a and 2b).
[0024] According to an exemplar embodiment of the present invention, the
condensate apparatus operates at normal pressure with little hot water. The amount
of condensate also depends on the moisture content (relative humidity) of the area
where the compressor is operating. In average considering 50% relative humidity,
the amount of condensate collected per minute, per m3 of air is 10grams
continuously. This may increase as the RH increases and decreases as the RH
reduced. There is a sleeve like structure (condensate housing) surrounding the steel
pipe which carries the air and oil mixture from the compression element to air oil
separator tank. The sleeve is also called cooling jacket. This sleeve will have 2
openings, one will be the inlet and the other will be the outlet. The condensate
collected from the moisture separator is connected to the inlet of the sleeve and the
outlet of the sleeve is connected to the drainage line of the compressor. The free
flow of condensate is ensured, so that no water is carried away during the transfer
to and from the condensate housing. The flow pattern is a parallel flow. The cold
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condensate enters on the hot side of the AOS tank pipe and exits at the cold side of
the AOS tank pipe similar to the below picture.
[0025] The average condensate formed in a screw compressor with moisture
separator is 0.01Kg/min/m3 of air. i.e. 10 gram/ml of water per min per cubic meter
of air. This is the specific condensate removed from a compressor. For a
compressor having capacity of 30m3/min of air will be able deliver 300g or ml of
water in a minute. The amount of condensate is almost proportional in all screw
compressor due to same design philosophy of the cooling system. So, for a
compressor having 15m3/min of air will produce 150g or ml of water in a minute,
hence, 150ml of water per min interms of a 24hours is minimum 200Litres per day.
This 200litres of water is used to pre-cool the hot air oil mixture entering AOS
tank. For a 1meter length schedule 40 pipe of 3”, a heat of 150w can be extracted
based on the said calculation for a 75kW screw compressor. An amount of the heat
energy extracted or reduced from the compressor would be 150 x 24 = 3600w/day.
G) ADVANTAGES OF THE INVENTION
[0026] The present invention allows to use the condensate (a throwaway feature in
prior art systems) to cool primarily but not limited to the AOS tank inlet pipe
leading to a cost effective to lower the operation temperature of the compressor.
The cooling of the AOS tank inlet pipe also allows an improved oil carry-over ratio
in comparison to the prior arts.
[0027] It is to be understood that the phraseology or terminology employed herein
is for the purpose of description and not of limitation. Therefore, while the
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embodiments herein have been described in terms of preferred embodiments, those
skilled in the art will recognize that the embodiments herein can be practiced with
modification within the spirit and scope of the claims.