FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE
Specification
(See section 10 and rule 13)
LiBr Vapor Absorption Heat Pump
THERMAX LIMITED
an Indian Company
of D-13, MIDC Industrial Area, R. D. Aga Road, Chinehwad, Pune 411019,
Maharashtra, India
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

This invention relates to a LiBr Vapor Absorption Heat Pump.
PRIOR ART
Vapour absorption heat pumps are thermally driven, which means that heat rather than mechanical energy is supplied to drive the cycle. Absorption heat pumps for space conditioning are often gas fired, while industrial installations are usually driven by high pressure steam or waste heat. The industrial heat pumps are mainly used for space heating and cooling of process streams, steam production, drying, evaporation and distillation.
Absorption systems utilize the ability of liquids or salts to absorb the vapour of the working fluid. The most common working pairs for absorption systems are:
• Water (working fluid) and lithium bromide (absorbent);
• Ammonia (working fluid) and water (absorbent).
A refrigeration system using a vapour absorption cycle typically has the following components:
1. An evaporator, containing refrigerant (such as water) for extracting heat from the environment to be refrigerated and converting refrigerant to vapour.
2. An absorber, containing an absorbent such as concentrated LiBr solution in which vapours of refrigerant are absorbed.
3. A pump for pumping the refrigerant bearing absorbent to a high
temperature generator.
4. A high temperature generator in which the refrigerant separates from the
absorbent.


5. A condenser for receiving the refrigerant vapours and transmitting condensed refrigerant to an evaporator via an expansion valve.
6. Another expansion valve for transmitting concentrated LiBr from the generator to the absorber.
Lithium bromide vapor absorption heat pumps (LiBr VAHP) are used for producing cooling effect by utilizing heat as an energy source. The performance of a LiBr VAHP is dependent on number of factors such as heat source temperature, design of absorption system, LiBr solution circulation rate and the like .
In the prior art LiBr Vapor Absorption Heat Pumps are of two types:
1. Double effect units which accept heat at a temperature level generally greater than 140°C
2. Singe effect units which accept heat at a temperature level generally greater than 90°C .
The above-mentioned units fail to produce cooling effect (generally required at 5°C or above) if the heat source temperature is less than that mentioned above.
DRAWBACKS
1. The main limitation of conventional LiBr Vapor Absorption Heat Pump is that it is unable to generate cooling effect with waste heat available at temperatures less than 75°C


2. Considerable de-rating of the units occurs at lower heat source temperatures resulting in higher capital costs.
3. Lower heat source temperatures also require lower cooling water temperatures for the rejection of heat, typically less than 28°C which are impossible to get under hot climatic conditions.
OBJECT OF THE INVENTION
It is therefore a primary object of this invention to provide an LiBr Vapor Absorption Heat Pump for utilizing waste heat from sources, which are at low temperatures like 75°C (or lower).
It is another object of this invention to propose a new cycle of operation, which is different from conventional single, and double effect cycles.
It is also another object of this invention to propose a new system which will produce cooling effect at temperatures as low as 3°C while using heat from low temperature heat sources such as waste heat sources. ( and at cooling water temperatures normally available in hot climatic conditions.
It is a further object of this invention to provide a generator for LiBr VAHP, which is not of the pool boiling type.
BRIEF STATEMENT OF THE INVENTION
According to this invention there is provided a low temperature LiBr vapour absorption apparatus comprising


i. a high pressure shell maintained at between 30 to 60 mm of Hg;
ii. a low pressure shell maintained at between 4 to 10 mm of Hg;
iii. an intermediate pressure shell maintained at between 15 to 30 mm of
Hg;
iv. a first closed loop LiBr solution cycle provided between the low
pressure shell and the intermediate pressure shell;
v. a second closed loop LiBr solution cycle provided between the high
pressure shell and the intermediate pressure shell;
vi. a heat source providing heat in the range of 55 to 90 degrees C to
drive both cycles;
vii. a solution pump for ( pumping solution in ) the first and second
closed loop solution cycle; and
viii. a refrigerant cycle cooperating with the first and second closed
loop solution cycles provided in all three shells to provide
refrigeration at the low pressure shell and heat absorption at the
high pressure and the intermediate pressure shell.
Particularly, the high pressure shell comprises
i. a high pressure tube bank connected to a heating source to receive hot
fluid in the temperature range of 90 to 55 degrees C and a warm water
outlet, a first sprayer and a first trough being part of the second closed
loop LiBr solution cycle and the refrigerant cycle;
ii. a condenser tube bank connected to a coldwater source, and a second
trough forming part of the refrigerant cycle; and
iii a first baffle separating the first trough and the second trough and a
plurality of inverted V or S shaped separator/eliminator plates fitted
between the high pressure tube bank and the condenser tube bank.


Particularly, the low pressure shell comprises
i. an evaporator tube bank having a chilled water inlet and a chilled
water outlet , a second sprayer and a third trough having means to
receive refrigerant from the second trough; a refrigerant pump to pump
refrigerant from the third trough to the second sprayer; said evaporator
tube bank being part of the refrigerant cycle;
ii. a Low pressure absorber tube bank connected to a coldwater source ,
a fourth trough and a third sprayer forming part of first closed loop LiBr
solution cycle and the refrigerant cycle; and
iii a second baffle separating the third trough and the fourth trough and a
plurality of inverted V or S shaped separator/eliminator plates fitted
between the evaporator tube bank and the Low pressure absorber tube
bank
Particularly, the intermediate pressure shell comprises i. a low pressure generator tube bank receiving warm water from the warm water outlet of the high pressure tube bank and an outlet to lead relatively less warm water out of the apparatus, a fourth sprayer connected to the fourth trough via a solution pump and a low pressure heat exchanger and a fifth trough supplying LiBr solution to the third sprayer via the low pressure heat exchanger said evaporator tube bank being part of the first closed loop LiBr solution cycle and the refrigerant cycle;
ii. a high pressure absorber tube bank connected to a coldwater source , a sixth trough and a fifth sprayer receiving LiBr solution from the first trough via a high pressure heat exchanger forming part of second closed loop LiBr solution cycle and the refrigerant cycle;


iii a third baffle separating the fifth trough and the sixth trough and a
plurality of inverted separator/eliminator plates fitted between the low
pressure generator tube bank and the high pressure absorber tube bank;
and
iv a second solution pump for pumping LiBr solution from the sixth
trough to the first sprayer via the said high pressure heat exchanger.
Particularly, the refrigerant is water.
Particularly, the heat source is a heat source selected from a group of heat sources consisting of fluid heated by waste heat; fluid heated while cooling any part of any machine or prime mover; fluid heated by solar energy; fluid heated by exhaust heat; fluid heated by a solid fuel fired boiler; fluid heated by a liquid fuel fired boiler; fluid heated by a heat exchanger; fluid heated by exothermic reaction of any process and fluid directly heated by a burner.
Particularly, the tubes in the tube bank are of a material selected from a group of materials consisting of stainless steel, copper, aluminium; mild steel; a polymeric material and a metal alloy.
DETAILED DESCRIPTION OF THE DRAWING.
The invention will now be described with reference to the accompanying drawings, in which Figure 1 is a schematic drawing of the low temperature LiBr vapour absorption apparatus in accordance with this invention,


The apparatus in accordance with this invention can be described as follows with reference to figure 1 of the accompanying drawings.
The apparatus generally indicated by the reference numeral 100 consists of three shells placed one on top of the other or adjacent to each other. The three shells are the high pressure shell [HPS] the low pressure shell [LPS] and the intermediate pressure shell [IPS]. The atmosphere in all three shells is evacuated, the relative pressures in each of the shells being as under: in the high pressure shell [HPS] the pressure is maintained between 30 to 60 mm of Hg, in the Low pressure shell [LPS] the pressure is maintained between 4 to 10 mm of Hg and in the intermediate pressure shell [IPS] the pressure is maintained at between 15 to 30 mm of Hg. The high pressure shell HPS contains a high pressure generator tube bank HPGTB comprising a bank of tubes, typically of stainless steel having an inlet for hot water HWI1 at a temperature of between 55 to 90 degrees C and an out let HWOl. The shell HPS also has a second bank of tubes being a condenser tube bank CTB having an inlet for cold water CWI1 and an outlet for cold water CW02. The condenser tube bank CTB has an array of tubes, typically of copper for better heat transference. The tube banks HPGTB and CTB are separated by an array of inverted V or S shaped eliminators El which are basically separators and by a baffle Bl at the base. Collecting troughs Tl and T2 are provided tube banks HPGTB and CTB respectively. The troughs Tl and T2 have respective outlets 01 and 02 respectively. A sprayer SI is provided over the tube bank HPGTB. Dilute Lithium bromide solution having a concentration of 44 to 50% and a temperature ranging between 46 and 78 degrees C is sprayed by means of the sprayer SI on the high pressure generator tube bank HPGTB. As the spray contacts the tubes of the bank


HPGTB, the water in the LiBr solution vaporizes and concentrated LiBr solution having a concentration in the range of 46 to 57% and a temperature between 52 and 85 degree C is collected in the trough Tl. The water vapour passes through the eliminators El. Any liquid droplets trapped in the vapour strike the inverted V plate eliminators El and fall into the trough Tl. The water vapour strikes the condenser tube bank CTB and the vapour gives away heat to the cold water introduced through cold water inlet CWI1 and condenses to water and is collected in the trough T2. This water is led through outlet 02 of the trough T2 to the Low pressure Shell LPS where it is collected in the trough T3 through inlet I. The trough T3 has an outlet 03 which is connected to a refrigerant pump PI. The low pressure shell LPS is fitted internally with an evaporator tube bank ETB having a chilled water inlet CHWIN and a chilled water outlet CHWOUT. A sprayer S2 is fitted operatively above the evaporator tube bank ETB. The low pressure shell is also fitted with a Low pressure absorber tube bank LPATB. A sprayer S3 is fitted operatively above the low pressure absorber tube bank LPATB. The low pressure absorber tube bank has a cold water inlet CWI2 and a cold water outlet CW02. A set of eliminator separators E2 are fitted between the evaporator tube bank ETB and the Low pressure absorber tube bank LPATB. A trough T4 is fitted operatively below the Low pressure absorber tube bank LPATB having an outlet 04. The troughs T3 and T4 are separated by a baffle B2. The refrigerant pump PI pumps water from trough T3 through its outlet 03 to the sprayer S2. The water sprayed through sprayer S2 is reduced to vapour as a result of the low pressure in the shell LPS. While turning to vapour, the water absorbs heat from the chilled water circulating in the evaporator tubes ETB. The temperature of the water emanating from the outlet CHWO of the evaporator tube bank ETB thus


drops and useable refrigerated water between 4 and 10 degrees C is collected from the outlet CHWO. Meanwhile the vapour formed on the evaporator tube bank ETB of the low pressure shell LPS passes through the eliminator separator plates E2 and passes to the low pressure absorber tube bank LPATB side of the low pressure shell LPS, Concentrated LiBr solution of concentration 58 to 63 percent and temperature 38 to 45 degrees C is sprayed through sprayer S3 on the low pressure absorber tube bank LPATB. On contacting the incoming vapours from the evaporator tube bank side, the LiBr concentrated solution is diluted to 54 to 59% and loses temperature . This diluted LiBr solution of concentration 54 to 59% and temperature in the range of 30 to 40 degrees Celsius is collected in the trough T4. Water at a temperature between 25 and 35 degrees C is circulated through the low pressure absorber tube bank LPATB and the water coming out of the outlet CW02 is in the range of 27 to 40 degrees C. The pump P2 is fitted to the outlet 04 of the trough T4. The diluted LiBr solution of concentration 54 to 59% and temperature 30 to 40 degrees C from trough T4 is pumped through a low pressure heat exchanger LPHE where it takes up heat from incoming concentrated LiBr solution. The dilute LiBr solution exiting the Low pressure heat exchanger LPHE has a concentration of 54 to 59% and a temperature of 45 to 55 degrees C. This dilute partially heated LiBr solution is passed to a sprayer S4 in the intermediate pressure shell IPS over a low pressure generator tube bank LPGTB. The low pressure generator tube bank LPGTB is supplied with hot water at its hot water inlet HWI2 at 53 to 75 degrees C which is coming from the hot water outlet HWOl emanating from the High pressure generator tube bank HPGTB fitted in the high pressure shell HPS. The low pressure generator tube bank LPGTB has a hot water outlet HWO3 and water at a temperature of 50 to 55 degrees C


emanates through the outlet HWO3 and is led to the system . The dilute LiBr solution which is sprayed via sprayer S4 on the tube bank LPGTB takes up heat from the hot water in the tubes of low pressure generator tube bank LPGTB and water in the solution is vaporized. Concentrated relatively hot LiBr solution of concentration 58 to 63 % and temperature 48 to 70 degrees C collects in trough T5 and is passed through outlet 05 to the Low pressure heat exchanger LPHE. As stated earlier in the low pressure heat exchanger LPHE, exchange of heat takes place with the incoming dilute LiBr solution from the low pressure absorber tube bank LPATB which is at a temperature of 30 to 40 degrees C. In the Low pressure heat exchanger the concentrated LiBr solution loses heat and from the Low pressure heat exchanger LPHE and the concentrated LiBr solution flows out a temperature of 35 to 46 degrees C and a concentration of 58 to 63 %. This concentrated LiBr solution is sprayed by means of sprayer S3 over the low pressure absorber tube bank LPATB in the low pressure shell LPS. Thus a first closed loop cycle of LiBr solution is maintained between the Low pressure absorber tube bank LPATB section of the low pressure shell LPS and the low pressure generator tube bank LPGTB section of the intermediate pressure shell IPS. In the Low pressure absorber tube bank LPATB section of the low pressure shell LPS the LiBr solution is diluted and cooled and in the low pressure generator tube bank LPGTB of the intermediate pressure shell IPS the diluted LiBr solution is concentrated and heated on a continuous basis. Hot water received in the High pressure generator tube bank HPGTB at HWI 1 in the high pressure shell HPS, at 55 to 90 degrees C is converted to warm water through the warm water outlet HWO2 from the low pressure generator tube bank LPGTB in the intermediate pressure shell IPS in the temperature range of 50 to 55 degrees C. The vapour


extracted from the LiBr solution in the Low pressure generator tube bank LPGTB section of the intermediate pressure shell IPS passes through the eliminator wall E3 and passes to the adjacent chamber of the intermediate pressure shell IPS where a high pressure absorber tube bank HPATB is resident. A sprayer S5 is fitted above the high pressure absorber tube bank HPATB. Through this sprayer S5, partially concentrated LiBr solution having a concentration of 46 to 57% and a temperature of 35 to 50 degrees C is sprayed on the high pressure absorber tube bank HPATB. Cold water at a temperature of 25 to 35 degrees C is introduced into the high pressure absorber tube bank HPATB through the cold water inlet CWI3. Water coming out through the cold water outlet CWO3 is typically at a temperature ranging from 27 to 40 degrees C. The partially concentrated LiBr solution takes in the incoming water vapour from the Low pressure generator tube bank side of the intermediate pressure shell IPS , gets diluted to a concentration of 50 to 55% and a temperature of 30 to 37 degrees of C and is collected in trough T6. Trough T6 is separated from the trough T5 by a baffle B3. The diluted LiBr solution at a concentration of 44 to 50% and a temperature of 30 to 40 degrees of C in the trough T6, is pumped through outlet 06 via solution pump P3 to a high pressure heat exchanger HPHE where its temperature is increases to 46 to 78 degrees C. This diluted LiBr solution having a concentration of 44 to 50%) and a temperature of 46 to 78 degrees C is sprayed through sprayer S1 on the high pressure generator tube bank HPGTB & where the hot water circulating in the high pressure generator tube bank HPGTB increases the temperature of the diluted LiBr solution sprayed by sprayer SI on the high pressure generator tube bank HPGTB from 46 to 78 degrees C to 52 to 85 degrees C at the same time the water in the LiBr solution is converted to vapour by the combined action of


the high pressure in the shell HPS and the temperature of the water circulating in the tubes of the high pressure generator tube bank HPGTB. LiBr solution concentrated to a concentration of 46 to 57% and a temperature of 52 to 85 degrees C is collected in trough Tl and flows to the sprayer S5 located in the intermediate shell IPS over the high pressure absorber tube bank HPATB. Thus a second closed loop cycle of the LiBr solution is maintained between the high pressure generator tube bank HPGTB high pressure shell HPS of where diluted comparatively cooler LiBr solution is heated and concentrated and the High pressure absorber tube bank HPATB of the intermediate shell IPS where the concentrated LiBr solution is diluted and cooled continuously. Hot water at a temperature 55 to 90 degrees C introduced through the Hot water inlet HWI1 of the High pressure generator tube bank HPGTB in the high pressure shell HPS is therefore let out through the Heat pump via the Hot water outlet HWO2 of the Low pressure generator tube bank LPGTB in the Intermediate pressure shell IPS at a temperature of 50 to 55 degrees C. A the same time cold water introduced through the cold water inlet CWI1 of the condenser tube bank CTB and the cold water inlet CWI2 of the low pressure absorber tube bank LPATB and the cold water inlet CWI3 of the high pressure absorber tube bank HPATB is warmed whereas chilled water for refrigeration is obtained through the chilled water outlet CHWO. Thus the LiBr heat pump in accordance with this invention can be worked at a comparatively low temperature incoming hot water at the high pressure generator tube bank HPGTB. The cycle of the refrigerant [water] in the cycle is as follows: water is extracted from dilute LiBr solution at the High pressure generator tube bank HPGTB turn to vapour and is passed to the condenser tube bank CTB. This water is led to the evaporator tube section ETB in the low pressure shell


LPS. In the evaporator tube section the water is converted to vapour. This vapour is passed through the eliminator separating walls and passes through to the high pressure absorber section of the IPS. This vapour condenses and is used to dilute LiBr solution and this dilute LiBr solution is returned to the High pressure generator tube bank HPGTB to start the cycle once again. Thus the low temperature heat pump of this invention operates via two LiBr cycles and a refrigerant [water] cycle traversing through both LiBr cycles.
The invention will now be described with reference to the accompanying examples:
Example 1
In one experiment, jacket water from DG set was used as heat source to
drive the low temperature LiBr Vapor Absorption system designed to deliver
40 USRT refrigeration capacity.
The jacket water flow was around 34 m3/hr and inlet temperature was 72°C.
This water was first fed to HPGTB. The temperature of water from the outlet
of HPGTB was 67°C. This water was then introduced at the inlet of LPGTB.
The temperature of water at the outlet of LPGTB was 62 °C. The water was
then recycled back to the DG set for the cooling of engine jacket.
Cooling water at the rate of around 65 m3/hr and 32°C was introduced first
to LPATB. The outlet of LPATB was obtained at 34°C which was fed to
HPATB. The outlet of HPATB was obtained at 36.8°C which was fed to
CTB. The outlet of CTB was obtained at 39°C which was sent to cooling
tower for cooling it back to 32°C.
In the vapor absorption machine, the dilute solution pumped by solution
pump P2 was at around 57% concentration and at around 36°C. The dilute


solution pumped by solution pump P3 was at around 45% concentration and at around 40°C. The strong solution sprayed on the LPATB was at around 61.5% concentration and at around 44°C. The strong solution sprayed on the HPATB was at around 51.5% concentration and at around 46°C. The chilled water, used for air conditioning purpose, was received from cooling coils at flow rate of around 24 m3/hr and 12°C and fed to inlet of ETB. It was observed that on operation of the unit it gets cooled down to 7°C. The unit delivered around 39.7 TR capacity at COP of around 0.355
Example 2
In another experiment, cooling water from process fluid condenser of one of
the process industry was used as heat source to drive the low temperature
LiBr Vapor Absorption system designed to deliver 40 USRT refrigeration
capacity at nominal condition.
The hot water flow was around 63 m3/hr and inlet temperature was 66°C.
This water was first fed to HPGTB. The temperature of water from the outlet
of HPGTB was 63.5°C. This water was then introduced at the inlet of
LPGTB. The temperature of water at the outlet of LPGTB was 61°C. The
water was then recycled back to the condenser as cooling water fro process
fluid condenser.
Cooling water at the rate of around 70 m3/hr and 33°C was introduced first
to LPATB. The outlet of LPATB was obtained at 35°C which was fed to
HPATB. The outlet of HPATB was obtained at 37°C which was fed to CTB.
The outlet of CTB was obtained at 39°C which was sent to cooling tower for
cooling it back to 33 °C.
The chilled water, used for process fluid chilling purpose, was received from
chilling coils at flow rate of around 21.5 m3/hr and 15°C and fed to inlet of


ETB. It was observed that on operation of the unit it gets cooled down to 10°C. The unit delivered around 35.7 TR capacity at COP of around 0.34
Example 3
In one more experiment, hot effluent water from one of the process industry
was used as heat source to drive the low temperature LiBr Vapor Absorption
system designed to deliver 40 USRT refrigeration capacity at nominal
condition.
The hot water flow was around 17.5 m3/hr and inlet temperature was 69°C.
This water was first fed to HPGTB. The temperature of water from the outlet
of HPGTB was 60°C. This water was then introduced at the inlet of LPGTB.
The temperature of water at the outlet of LPGTB was 51°C. The effluent
water was then sent to common drain system since it is not possible to
recycle this water in the process.
Cooling water at the rate of around 65 m3/hr and 29.4°C was divided in to
three equal streams and introduced simultaneously to LPATB, HPATB and
CTB. The outlet of LPATB, HPATB and CTB were obtained at 36.2°C,
36.4°C and 36°C respectively. The three streams were combined again and
sent to cooling tower for cooling it back to 29.4°C.
The chilled water, used for process fluid chilling purpose, was received from
chilling coils at flow rate of around 20.5 m3/hr and 14°C and fed to inlet of
ETB. It was observed that on operation of the unit it gets cooled down to
8°C. The unit delivered around 40.5 TR capacity at COP of around 0.39.
While considerable emphasis has been placed herein on the particular features of the preferred embodiment and the improvisation with regards to


it, it will be appreciated the various modifications can be made in the preferred embodiments without departing from the principles of the invention. These and the other modifications in the nature of the invention will be apparent to those skilled in art from disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to interpreted merely as illustrative of the invention and not as a limitation.


We Claim:
[1] A low temperature LiBr vapour absorption apparatus comprising
i. a high pressure shell maintained at between 30 to 60 mm
of Hg;
ii. a low pressure shell maintained at between 4 to 10 mm of
Hg;
iii. an intermediate pressure shell maintained at between 15
to 30 mm of Hg;
iv. a first closed loop LiBr solution cycle provided between
the low pressure shell and the intermediate pressure shell; v. a second closed loop LiBr solution cycle provided
between the high pressure shell and the intermediate
pressure shell;
vi. a heat source providing heat in the range of 55 to 90
degrees C to drive the cycles;
vii. solution pumps for pumping solution to both cycles; and viii. a refrigerant cycle cooperating with the first and second
closed loop solution cycles provided in all three shells to
provide refrigeration at the low pressure shell and heat
absorption at the high pressure and the intermediate
pressure shell.
[2] A low temperature LiBr vapour absorption apparatus as claimed in claim 1, wherein the high pressure shell comprises


i. a high pressure tube bank connected to a heating source to receive hot
fluid in the temperature range of 90 to 55 degrees C and a warm water
outlet, a first sprayer and a first trough being part of the second closed
loop LiBr solution cycle and the refrigerant cycle;
ii. a condenser tube bank connected to a coldwater source, and a second
trough forming part of the refrigerant cycle; and
iii a first baffle separating the first trough and the second trough and a
plurality of inverted V or S shaped separator/eliminator plates fitted
between the high pressure tube bank and the condenser tube bank.
3. A low temperature LiBr vapour absorption apparatus as claimed in
claim 1, wherein the low pressure shell comprises
i. an evaporator tube bank having a chilled water inlet and a chilled water outlet , a second sprayer and a third trough having means to receive refrigerant from the second trough; a first solution pump to pump refrigerant from the third trough to the second sprayer; said evaporator tube bank being part of the refrigerant cycle;
ii. a Low pressure absorber tube bank connected to a coldwater source , a fourth trough and a third sprayer forming part of first closed loop LiBr solution cycle and the refrigerant cycle; and
iii a second baffle separating the third trough and the fourth trough and a plurality of inverted V or S shaped separator/eliminator plates fitted between the evaporator tube bank and the Low pressure absorber tube bank.
4. A low temperature LiBr vapour absorption apparatus as claimed in
claim 1, wherein the intermediate pressure shell comprises


i. a low pressure generator tube bank receiving warm water from the
warm water outlet of the high pressure tube bank and an outlet to lead
relatively less warm water out of the apparatus, a fourth sprayer
connected to the fourth trough via a solution pump and a low pressure
heat exchanger and a fifth trough supplying LiBr solution to the third
sprayer via the low pressure heat exchanger said evaporator tube bank
being part of the first closed loop LiBr solution cycle and the refrigerant
cycle;
ii. a high pressure absorber tube bank connected to a coldwater source ,
a sixth trough and a fifth sprayer receiving LiBr solution from the first
trough via a high pressure heat exchanger forming part of second closed
loop LiBr solution cycle and the refrigerant cycle;
iii a third baffle separating the fifth trough and the sixth trough and a
plurality of inverted V or S shaped separator/eliminator plates fitted
between the low pressure generator tube bank and the high pressure
absorber tube bank; and
iv a second solution pump for pumping LiBr solution from the sixth
trough to the first sprayer via the said high pressure heat exchanger.
5. A low temperature LiBr vapour absorption apparatus as claimed in any of the preceding claims, wherein the refrigerant is water.
6. A low temperature LiBr vapour absorption apparatus as claimed in claim 1, wherein the heat source is a heat source selected from a group of heat sources consisting of fluid heated by waste heat; fluid heated while cooling any part of any machine or prime mover; fluid heated by solar energy; fluid heated by exhaust heat; fluid heated by a solid fuel fired


boiler; fluid heated by a liquid fuel fired boiler; fluid heated by a heat exchanger; fluid heated by exothermic reaction of any process and fluid directly heated by a burner.
7. A low temperature LiBr vapour absorption apparatus as claimed in
claim 1, wherein the tubes in the tube bank are of a material selected
from a group of materials consisting of stainless steel , copper,
aluminium; mild steel; a polymeric material and a metal alloy.
8. A low temperature LiBr vapour absorption apparatus as described
herein with reference to the accompanying drawing.


ABSTRACT
A low temperature LiBr vapour absorption apparatus comprising a high pressure shell, a low pressure shell and an intermediate pressure shell; a first closed loop LiBr solution cycle provided between the low pressure shell and the intermediate pressure shell; a second closed loop LiBr solution cycle provided between the high pressure shell and the intermediate pressure shell; a heat source providing heat in the range of 55 to 90 degrees C to drive both cycles; a solution pump for driving the first closed loop solution cycle; and a refrigerant cycle cooperating with the first and second closed loop solution cycles provided in all three shells to provide refrigeration at the low pressure shell and heat absorption at the high pressure and the intermediate pressure shell.