FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
TITLE OF THE INVENTION
A SYSTEM FOR DRY PROCESSING OF AIR IN PNEUMATIC OPERATION
APPLICANT
CEAT LIMITED
An Indian Company having its registered office at
RPG House, 463
Dr. Annie Besant Road
Worli, Mumbai 400 030,
Maharashtra, INDIA
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the
manner in which it is to be performed

FIELD OF INVENTION
The present invention relates to a pneumatic system and more specifically a
system for dry processing of air in pneumatic operations.
BACKGROUND OF THE INVENTION
A pneumatic system is a system that uses compressed air to transmit and
control energy. The pneumatic system uses air as the medium which is
abundantly available and can be exhausted into the atmosphere after
completion of the assigned task. The word ‘Pneuma’ means air. Pneumatics
is all about using compressed air to do the work. Compressed air is the air
from the atmosphere which is reduced in volume by compression thus
increasing its pressure. The pneumatic systems are used extensively in
various industries. Most pneumatic systems rely on a constant supply of
compressed air to make them work. This is provided by an air compressor.
The compressor sucks in air from the atmosphere and stores it in a high
pressure tank called a receiver. This compressed air is then supplied to the
system through a series of pipes and valves. The compressed air is mainly
used to do work by acting on a piston or vane.
The pneumatic systems are widely used in different industries (such as steel
industry) for the driving of automatic machines. The pneumatic systems
have a lot of advantages, such as
•High effectiveness – There is an unlimited supply of air in the
atmosphere to produce compressed air. Also there is the possibility of
easy storage in large volumes. The use of compressed air is not restricted
by distance, as it can easily be transported through pipes. After use,
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compressed air can be released directly into the atmosphere without the
need of processing.
•High durability and reliability – The pneumatic system components are
extremely durable and cannot be damaged easily. Compared to
electromotive components, pneumatic components are more durable and
reliable.
•Simple design – The designs of pneumatic system components are
relatively simple. They are thus more suitable for use in simple
automatic control systems. There is choice of movement such as linear
movement or angular rotational movement with simple and continuously
variable operational speeds.
•Safety aspects – The pneumatic systems are safer than electromotive
systems because they can work in inflammable environment without
causing fire or explosion. Apart from that, overloading in pneumatic
system only leads to sliding or cessation of operation. Unlike
components of electromotive system, pneumatic system components do
not burn or get overheated when overloaded.
•Easy selection of speed and pressure – The speeds of rectilinear and
oscillating movement of pneumatic systems are easy to adjust and
subject to few limitations. The pressure and the volume of the
compressed air can easily be adjusted by a pressure regulator.
•Environmental friendly – The operation of pneumatic systems do not
produce pollutants. The pneumatic systems are environmentally clean
and with proper exhaust air treatment can be installed to clean room
standards. Therefore, pneumatic systems can work in environments that
demand high level of cleanliness.
•Economical – As the pneumatic system components are not expensive,
the costs of pneumatic systems are quite low. Moreover, as pneumatic
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systems are very durable, the cost of maintenance is significantly lower
than that of other systems.
Although pneumatic systems possess a lot of advantages, they are also
subject to several limitations. For satisfactory operation of the pneumatic
system the compressed air needs to be cleaned and dried. Atmospheric air is
contaminated with dust, smoke and is humid. These particles can cause
wear of the system components and presence of moisture causes corrosion.
Hence it is essential to treat the air to get rid of these impurities. The
moisture content in the air is considered to the main culprit for the operation
of the pneumatic system, and causing heavy and severe problems in the
components of the pneumatic system. The problems caused due to moisture
content in the air are as follow:
•Corrosion in pipes or valves carrying air
•Solenoid valves malfunction due to moisture content
•Sluggish operation of air cylinder due to moisture content.
•Manual efforts are required to drain out moisture at several locations
frequently
•Breakdowns due to moisture as seal were not performing as air contains
moisture.
•Processing required before use – Compressed air must be processed
before use to ensure the absence of water vapour or dust. Otherwise, the
moving parts of the pneumatic components wear out quickly due to
friction.
•Due to moisture, failure of rate of seal was very high. Very frequently
seal fails. Failure of seal means: passing (wastage) of air through the
same.
With a view, therefore, to overcome the limitations associated with the
conventional pneumatic system. The inventor has modified or improved the
existing pneumatic system by introducing the refrigerated air dryer which
extract the moisture content of the air and provide clean and dried air for
effective pneumatic operations with high efficiency. The inventor faces
certain technical problem while installing the refrigerated air dryer in the
pneumatic system which he overcome effectively and succeeded in
installing the refrigerated air dryer in the pneumatic system. Such as system
was operational, air pressure, starting of new air drier was difficult. With
the help of Isolation valve the inventor manage remedial action. Also,
managing space in between operating set up for air drier was a challenge.
The inventor has created space by putting a platform to have space exactly
near the existing air compressor. Seasonal variations in ambient
temperatures, made standard operating procedure for same. As same set
point( Dew point ) is not give quality output in all seasons. Water drain was
creating mess around the air drier, made a drain chamber to collect water
from & diverted to appropriate drain chamber. As requirement of dried (
moisture free) air was huge & continuous, satisfying the need was difficult.
Capacity finalization was also challenge. The introduction of the
refrigerated air dryer also increases life and durability of the components of
the pneumatic system and facilitate smooth working of the pneumatic
system. Also, it helps to fulfill basic air hygiene recommended by all
Original Equipment Manufacturer OEM and helps to reduce breakdown
hours by 47%. The solenoid sluggish phenomenon is reduced to zero from
three incidents per month and breakdown in Band building machines (total
119 Pneumatic cylinders) reduced to zero from 14 per month. Also, the
present invention helps to reduce the store consumption by Rs. 90220 per
annum due to seal kit and solenoid valves and thus, it is cost effective.
It aims for reduction of seal failure. Due to unplanned breakdown of any of
the component, it was hectic to arrange & carry out the breakdown.
Hampering production activity. As pneumatic operation is directly getting
affected & machine operation gets stopped. It started increasing the Muri
(fatigue) of carrying out maintenance job.
OBJECT OF THE INVENTION
The principal object of the invention is to remove the moisture content from
the compressed air for effective pneumatic operation.
Another object of the invention is to protect the air carrying pipes from the
corrosion and enhance the life and durability of the components of the
pneumatic system.
Yet another object of the invention is to avoid frequent malfunctioning of
the solenoid valves due to moisture content and to protect wear of the
moving parts of the pneumatic components due to friction.
Still another object of the invention is to provide a system which enhances
the operation of the air cylinder and provide smooth working in pneumatic
operation.
SUMMARY OF THE INVENTION
The present invention mainly relates to a refrigerated air dryer system
wherein atleast one air dryer is installed with the compressor to remove the
moisture content of the compressed air. The refrigerated air dryer is
disposed in-between the compressor and the air receiver tank. The receiver
tank collects the dry air released from the dryer. The compressed air from
the air receiver tank is processed further to obtain required movement of the
mechanical elements of the pneumatic system.
According to one aspect of the present invention, a system for dry
processing of air in pneumatic operation comprising: at least one
compressor for generating compressed air received from surroundings; an
air storage means for storing compressed dry air released from said
compressor; and at least one refrigerated air dryer operatively connected
between said compressor and said air storage means, said refrigerated air
dryer is configured to extract moisture contents of said compressed air and
produce dry compressed air which is stored in said air storage means for the
pneumatic operation.
According to another aspect of the present invention, a being disposed in
between said compressor and said refrigerated air dryer to reduce the
temperature of the compressed air.
According to another aspect of the present invention, a separator being
disposed in between said compressor and said refrigerated air dryer,
preferably in between said cooler and said refrigerated air dryer to removes
dust and impurities from compressed air.
According to yet another aspect of the present invention, a wet receiver tank
being disposed in between said compressor and said refrigerated air dryer,
preferably in between said separator and said refrigerated air dryer to
collect compressed air containing moisture in order to remove excess air
when required.
According to yet another aspect of the present invention, an optional bypass
valve and a filter being connected in between said wet receiver tank
and said refrigerated air dryer.
According to yet another aspect of the present invention, an optional filters
and bypass valve being connected in between said refrigerated air dryer and
said air storage means to further remove dust and other unwanted foreign
particles.
According to a further aspect of the present invention, an optional by-pass
valve arrangement to connect said wet air receiver tank and said air storage
means.
According to a further aspect of the present invention, said refrigerated air
dryer is installed at pressure band of 6.1 Kg/cm2 -6.8 Kg/cm2.
According to a further aspect of the present invention, the wet air receiver
tank and said air storage means being provided with auto-drain valve to
drain out the excess compressed air.
According to still further aspect of the present invention, a method for
processing dry air in pneumatic operation comprising steps of: receiving air
from surrounding through an air inlet of a compressor; generating and
releasing compressed air from an outlet of the compressor to a cooler;
cooling temperature of the compressed air by the cooler and thereupon
passing the compressed air to a separator; separating dust and impurities
from the compressed air by the separator and thereupon passing the
compressed air to a wet air receiver tank; draining out the excess of
compressed air through the auto-drain valve of said wet air receiver tank
and thereupon passing the compressed air to a refrigerated air dryer
through an optional filter; removing the moisture contents of the
compressed air by the refrigerated air dryer and thereupon passing it to an
air storage means through an optional filters which further removes dirt and
other foreign particles from the compressed dry air; and processing the
compressed dry air from the air storage means for pneumatic operations.

BRIEF DESCRIPTION OF DRAWINGS
The foregoing summary, as well as the following detailed description of the
present invention, will be better understood when read in conjunction with
the appended drawings. For the purpose of assisting in the explanation of
the invention, there are shown in the drawings embodiments which are
presently preferred and considered illustrative. It should be understood,
however, that the invention is not limited to the precise arrangements and
instrumentalities shown therein. In the drawings:
Figure 1 (Prior art) shows the conventional pneumatic system with all its
components.
Figure 2 shows the block diagram of the pneumatic system in accordance
with the present invention.
Figure 3 shows the dry process air Schematic arrangement of the pneumatic
system in accordance with the present invention.
Figure 4 shows that internal components arrangement of the refrigerated air
drier used in the present invention.
Description of reference numbers for the major components of the present
invention in the drawings are mention below:
In Figure 1,
2 - Intake filter
4 - Compressor
6 - Cooler
8 - Separator
10 - Air Receiver
12 - Motor Control Centre
14 - Pressure Switch
16 - Secondary air treatment
18 - Control valve
20 - Actuator
100 - Conventional Pneumatic System
In Figure 2,
200 - Invented Refrigeration Air Dryer Pneumatic system.
202, 204, 206, 208 - Air Compressor
210, 212, 214, 216 - Air Dryer
220 - Pipeline
218 - Air Receiver Tank
In Figure – 3,
302 - Compressor
304 - Cooler
306 - Separator
308 - Wet Air receiver tank
310 - HF 9 Filter
312 - Refrigerated Air Dryer
314 - HF 7 filter
316 - HF 5 filter
318 - Dry Air receiver tank
320 - Auto-drain valve
322 - By pass Valve
In Figure 4,
402 - Refrigeration Compressor
404 - Condenser
406 - Filter Dryer
408 - Thermostatic Expansion Valve
410 - Thermal Reservoir
412 - Circulator pump
414 - Moisture Separator
416 - Pre cooler / Re heater
418 - Outlet for Dry Air Exists
420 - Inlet for moisture – laden Air entry
DETAILED DESCRIPTION
In describing and claiming the invention, the following terminology will be
used in accordance with the definitions set forth below. Unless defined
otherwise, all technical and scientific terms used herein have the same
meaning as commonly understood by one of ordinary skill in the art to
which this invention belongs. Although any sensing device, methods,
system and materials similar or equivalent to those described herein can be
used in the practice or testing of the present invention, the preferred sensing
device, methods, system and materials are described herein. As used herein,
each of the following terms has the meaning associated with it in this
section. Specific and preferred values listed below for individual
components, substituents, and ranges are for illustration only; they do not
exclude other defined values or other values within defined ranges for the
components and substituents.
The terms “preferred” and “preferably” refer to embodiments of the
invention that may afford certain benefits, under certain circumstances.
However, other embodiments may also be preferred, under the same or
other circumstances. Furthermore, the recitation of one or more preferred
embodiments does not imply that other embodiments are not useful, and is
not intended to exclude other embodiments from the scope of the invention.
As used herein, the terms “comprising,” “including,” “having,”
“containing,” “involving,” and the like are to be understood to be openended,
i.e. to mean including but not limited to.
Thus, before describing the present invention in detail, it is to be understood
that this invention is not limited to particularly exemplified systems or
process parameters that may of course, vary. It is also to be understood that
the terminology used herein is for the purpose of describing particular
embodiments of the invention only, and is not intended to limit the scope of
the invention in any manner.
Figure 1 shows the basic components arrangement of the existing
pneumatic system. An intake filter (2) also known as air filter is used to
filter out the contaminants from the air. An air compressor (4) converts the
mechanical energy of an electric or combustion motor into the potential
energy of compressed air. There are several types of compressors which are
used in the compressed air systems. The compressor (4) used for
generation of compressed air is selected on the basis of desired maximum
delivery pressure and the required flow rate of the air. An Electric motor
(12) transforms electrical energy into mechanical energy. It is used to drive
the air compressor (4). The compressed air coming from the compressor (4)
is stored in an air receiver (10). The purpose of the air receiver (10) is to
smooth the pulsating flow from the compressor (4). It also helps the air to
cool and condense the moisture present. The air receiver (10) is large
enough to hold all the air delivered by the compressor (4). The pressure in
the receiver (10) is held higher than the system operating pressure to
compensate pressure loss in the pipes. Also the large surface area of the
receiver (10) helps in dissipating the heat from the compressed air. For
satisfactory operation of the pneumatic system the compressed air needs to
be cleaned and dried. Atmospheric air is contaminated with dust, smoke and
is humid. These particles can cause wear of the system components and
presence of moisture cause corrosion. Hence it is essential to treat the air to
get rid of these impurities. Further during compression operation, air
temperature increases. Therefore a cooler (6) is used to reduce the
temperature of the compressed air. A control valve (18) is e used to
regulate, control and monitor for control of direction flow, pressure etc. and
an air actuator (i.e. air cylinders) is used to obtain the required movements
of mechanical elements of pneumatic system. The compressed air is used
as a working medium normally at a pressure of 6 kg/sq cm to 8 kg/sq cm.
For using pneumatic systems, maximum force up to 50 kN can be
developed. The inventor has installed a refrigerated drier in between
compressor and the air receiver to remove the moisture content from the
compressed air operating in the air pressure band of 6.1 Kg/cm2 to 6.8
Kg/cm2. The mean value of for this range of pressure band is 6.5 Kg/cm2.
At pressure band 6.1 Kg/cm2 is loading , in case of air demand for process,
compressor turns ON; and at 6.8 Kg/cm2 is unloading , if pressure (
Demand) is less, compressor goes NO LOAD. The installation of the
refrigerated air drier at pressure band 6.5 Kg/cm2 for removal of moisture
from compressed air for giving quality air to machine operation. No such
installation is carried out in the prior art at this air pressure band. Thus, this
arrangement helps to carry out all the moisture content from the compressed
air which creates problems or corrosion to piping & related machines
during the operation. Hence, the installation of the refrigerated air dryer in
this arrangement reduces the problems & heavy breakdowns.
Figure 2 shows a refrigerated air dryer system (200) in accordance with the
present invention. An individual air dryer (210, 212, 214, 216) is installed
with each of air compressor (202, 204, 206, 208). The air dryers (210, 212,
214, 216) are disposed in between air compressors (202, 204, 206, 208) and
the air receiver tank (218). The plurality of air dryers is set on the plurality
of platforms exactly near plurality of air compressors to manage the space
in the refrigerated air dryer system (200). The capacity of each dryer is
1500 Cubic Feet Minute CFM and the capacity of the Compressor is
1000CFM. The ambient air is applied to the compressor (202, 204, 206,
208) which compress the air to the required pressure band and then air is
fed to the dryer (210, 212, 214, 216) to extract the moisture from it. The
moisture content present in the ambient air is around at the rate of 4 particle
per million (PPM); and the operating dew point is 3 to 4oC. at which all the
moisture in air is collected ( Air drier) and separated out. The operating dew
point may vary according to the seasonal variation in temperature of the
place. The moisture free air (i.e. dry air) is fed to main pipeline (220) from
where it is collected in an air receiver tank (218). The air from the receiver
tank (218) is used for further processing. The compressed air from the air
receiver tank is used to obtain required movement of the mechanical
elements of the pneumatic system. The capacity of the air receiver tank
(218) used in the present invention is 10 m3. However, the capacity of the
air tank receiver is not limited to this value only.
Figure 3 shows the schematic arrangement of the complete refrigerated air
dryer system in accordance with the present invention. Ambient air is
supplied to a compressor (302) which compressed the air to the required
pressure band (i.e. 6.1 Kg/cm2 to 6.8 Kg/cm2) and more preferably to a
pressure of 6.5 Kg/cm2. The air temperature increased during compression
is reduced by using a cooler (304) connected to the compressor (302). The
compressed air from the cooler (304) is fed to the separator to remove dust
and impurities from it. The output of the separator (306) is connected to the
wet air receiver tank (308) which collects the compressed air containing
water moisture. An auto-drain valve is provided to the air receiver tank
(308) to drain out the excess air when required. The output of the air
receiver tank (308) is connect a refrigerated air dryer (312) which removes
the moisture content of the compressed air through a by-pass valve (323)
and HF9 filter. An isolation valve is provided to keep the air pressure 6.1
Kg/cm2 to 6.8 Kg/cm2 in the refrigerated air dryer (312) to start
functioning with respect to the air compressor (302). The output of the
refrigerated air dryer (312) is connected to an air storage means or dry air
receiver tank (318) via two gauge (i.e. HF7 filter and HF5 filter) and by
pass valve (324). A separate by pass valve (322) is provided in this
arrangement which connects the wet air receiver tank (308) and the dry air
receiver tank (318). An auto-drain valve is provided to the dry air receiver
tank (318) to drain out the excess air when required. The compressed air
from the dry air receiver tank (318) is processed to the factory for working.
The function of all HF filter is to remove dirt (Dust & other unwanted
foreign particles) present in compressed air. (Its Optional). If required can
be installed.
Figure 4 shows a schematic arrangement of components the refrigeration
drier which is used in the present invented refrigerated air dryer system.
The refrigerated air dryer comprises of refrigeration compressor (402),
condenser (404), filter dryer (406), thermostatic expansion valve (408),
thermal reservoir (410), circulator pump (412), moisture separator (414),
precooler/reheater (416), inlet for moisture laden air entry and outlet for dry
air exits. The refrigerated compressed air dryer (400) is one of the most
common used types of air dryers. It is simple in design, need very little
maintenance and relatively cheaper than other dryer. The refrigerated
compressed air dryer is the standard choice and do not have special
requirements, like an ultra-low dew point. It does not need much or any
special maintenance and if good quality refrigerated air dryer is installed
properly in this invented system, then no maintenance cost is required. It is
basically set-and-forget. The refrigerated air dryer (400) works by cooling
down the air (like a refrigerator). The warm wet air enters the dryer (400),
where it is cooled down to about 3 to 4 degrees Celsius. All the water
vapour present in the air condenses into water. The liquid water is then
removed from the compressed air by a water-trap. After that, the cold air is
re-heated to room temperature. Since a lot of water has condensed into
water, the air is now much dryer. In a separate circuit, liquid refrigerant is
evaporated in the evaporator, to cool down the warm compressed air. The
air is cooled, while the refrigerant gets warmer. The refrigerant is
compressed by a small compressor and cooled again in the condenser. The
evaporator (where the refrigerant cools down the compressed air) is located
at the top of the dryer.
The present invention also discloses a method for processing dry air in
pneumatic operation, which comprises of following steps: receiving air
from surrounding through an air inlet of a compressor (302); generating and
releasing compressed air from an outlet of the compressor (302) to the
cooler (304); cooling temperature of the compressed air by the cooler (304)
and thereupon passing the compressed air to the separator (306);
separating dust and impurities from the compressed air by the separator
(306) and thereupon passing the compressed air to the wet air receiver tank
(308); draining out the excess of compressed air through the auto-drain
valve of said wet air receiver tank (308) and thereupon passing the
compressed air to a refrigerated air dryer (312) through an optional filter
(310); removing the moisture contents of the compressed air by the
refrigerated air dryer (312) and thereupon passing it to the air storage means
(318) or dry air receiver tank through an optional filters (314, 316) which
further removes dirt and other foreign particles from the compressed dry
air; and processing the compressed dry air from the air storage means (318)
for pneumatic operations.
While specific embodiments of the invention have been described in detail,
it will be appreciated by those skilled in the art that various modifications
and alternatives to those details could be developed in light of the overall
teachings of the disclosure. Accordingly, the particular arrangements
disclosed are meant to be illustrative only and not limiting as to the scope of
the invention which is to be given the full breadth of the appended claims
and any and all equivalents thereof.

We claim:
1. A system (300) for dry processing of air in pneumatic operation
comprising:
- at least one compressor (302) for generating compressed air
received from surroundings;
- an air storage means (318) for storing compressed dry air
released from said compressor (302); and
- at least one refrigerated air dryer (312) operatively connected
between said compressor (302) and said air storage means
(318), said refrigerated air dryer (312) is configured to extract
moisture contents of said compressed air and produce dry
compressed air which is stored in said air storage means (318)
for the pneumatic operation.
2. The system (300) as claimed in claim 1, further comprising a
cooler (304) being disposed in between said compressor (302)
and said refrigerated air dryer (312) to reduce the temperature
of the compressed air.
3. The system (300) as claimed in claim 1 or 2, further
comprising a separator (306) being disposed in between said
compressor (302) and said refrigerated air dryer (312),
preferably in between said cooler (304) and said refrigerated air
dryer (312) to removes dust and impurities from compressed
air.
4. The system (300) as claimed in any one of claims 1 to 3, further
comprising a wet receiver tank (308) being disposed in between
said compressor (302) and said refrigerated air dryer (312),
preferably in between said separator (306) and said refrigerated
air dryer (312) to collect compressed air containing moisture in
order to remove excess air when required.
5. The system (300) as claimed in any one of claims 1 to 4, further
comprising an optional by-pass valve and a filter (310) being
connected in between said wet receiver tank (308) and said
refrigerated air dryer (312).
6. The system (300) as claimed in any one of claims 1 to 5, further
comprising an optional filters (314, 316) and bypass valve
being connected in between said refrigerated air dryer (312) and
said air storage means (318) to further remove dust and other
unwanted foreign particles.
7. The system (300) as claimed in any one of claims 1 to 6, further
comprising an optional by-pass valve (322) arrangement to
connect said wet air receiver tank (308) and said air storage
means (318).
8. The system (300) as claimed in any one of claims 1 to 6,
wherein said refrigerated air dryer (312/400) is installed at
pressure band of 6.1 Kg/cm2 - 6.8 Kg/cm2.
9. The system (300) as claimed in claim 1, wherein said wet air
receiver tank (308) and said air storage means (318) being
provided with auto-drain valve to drain out the excess
compressed air.
10. A method for processing dry air in pneumatic operation
comprising steps of:
- receiving air from surrounding through an air inlet of a
compressor (302);
- generating and releasing compressed air from an outlet of
the compressor (302) to a cooler (304);
- cooling temperature of the compressed air by the cooler
(304) and thereupon passing the compressed air to a
separator (306);
- separating dust and impurities from the compressed air by
the separator (306) and thereupon passing the compressed air
to a wet air receiver tank (303);
- draining out the excess of compressed air through the
auto-drain valve of said wet air receiver tank (303) and
thereupon passing the compressed air to a refrigerated air
dryer (312) through an optional filter;
- removing the moisture contents of the compressed air by
the refrigerated air dryer (312) and thereupon passing it to an
air storage means (318) through an optional filters which
further removes dirt and other foreign particles from the
compressed dry air; and
- processing the compressed dry air from the air storage
means (318) for pneumatic operations.