GB1598098A

GB1598098A - Absorption refrigeration unit

Info

Publication number: GB1598098A
Application number: GB2107680A
Authority: GB
Original assignee: Benteler Deustchland GmbH
Current assignee: Benteler Deustchland GmbH
Priority date: 1977-12-19
Filing date: 1977-12-19
Publication date: 1981-09-16

Description

(54) ABSORPTION REFRIGERATION UNIT (71) We, BENTELER-WERKE AKTIEN GESELLSCHAFT, a Company of the Federal Republic of Germany, of 4794 Schloss Neuhaus, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement This invention relates to a continuously operable absorption refrigeration unit for cooling water, drinks and draught beer, the unit comprising a metal container for receiving the material to be cooled and an evaporator tube associated with the metal container.

Absorption refrigeration units of this kind are known and operate quietly.

An object of the invention is to improve the efficiency of the aforementioned continuously operable absorption units for cooling water, drinks and draught beer.

Accordingly, the present invention provides a continuously operable absorption refrigeration unit for cooling water, drinks and draught beer, the unit comprising a metal container for receiving the material to be cooled and an associated evaporator tube for cooling the container, in which unit the container is double-walled, the space between the walls contains a cold transmitting and storing medium and evaporator tube is coiled and has a flat oval cross-section presenting a flat portion which operatively engages the container wall.

In an advantageous embodiment of the invention, the evaporator tube and/or an absorber tube of the unit is provided with steel wire gauze adjacent the inner surface of the tube. This capillary-forming means enhances evaporation in the evaporator tube and/or condensation in the absorber tube.

Cold-storage means in the form of a eutectic solution may be contained in the space between the walls of the container. The eutectic point of the solution is slightly below the lowest temperature at which the cooled material is withdrawn.

According to another preferred feature of the invention, a condenser of the absorption unit extends approximately at right angles to a boiler of the unit or to a gas and vapour tube extending from the boiler. The condenser may be in the form of a finned tube, such as a Trufin (Registered Trade Mark) tube having aluminium tube walls and fins.

Alternatively, the condenser may be a coiled tube which, in the upper region of the container, is separated therefrom by thermally insulating material and is accessible to a flow of external air. Advantageously, a cooling plate is provided, and surrounds the sides of the coiled condenser tube.

An absorption unit embodying the invention is compact and light-weight.

In order that the invention may be readily understood, embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: FIGURE 1 showsanabsorptionunithaving a single-walled container (shown in vertical section) for holding a material to be cooled; FIGURE 2 is a front view of the absorption refrigeration unit of Figure 1, without the container; FIGURE 3 shows, in cross-section, a container and evaporator arrangement which in an embodiment of the invention is incorporated in the absorption refrigeration unit of Figures 1 and 2; FIGURE 4 is an enlarged cross-sectional view showing in detail the engagement beween and evaporator tube of flat oval cross-section and an associated wall of the container; FIGURE 5 shows in cross-section the sump of a gas heat exchanger of the unit which drains into a storage tank;; FIGURE 6 is a section along line X-X in Figure 5; FIGURE 7 shows an absorber tube, partly in section and FIGURE 8 is a view in the direction of arrows XII-XII in Figure 7.

Figure 1 shows an absorption refrigeration unit comprising a boiler 1, a gas and vapour pipe 2, a condenser 3, a coiled evaporator tube 4, an absorber 5 and a storage tank 6.

Tank 6 is connected to boiler 1 by a pipe 7.

Boiler 1 can be heated electrically or be LP gas or kerosene.

The material to be cooled is held in a vessel 8 which is made of metal, preferably aluminium, and is surrounded by thermal insulation 9, covering the side wall and the bottom of container 8. The insulation also partly screens from the container the heatradiating parts of the absorption unit, i.e.

condenser 3 and absorption 5, but allows the necessary heat exchange to occur between the condenser and absorber and the external air.

As shown in Figures 1 and 2, the device is compact and the heat-radiating parts of the absorption unit are at the back of the unit, so that heat can be radiated outwards when the device is incorporated in a housing with an open back.

In Figures I and 2, the condenser 3 extends approximately at right angles to the boiler 1 and the gas and vapour pipe 2. The condenser tubes may be Trufin (Registered Trade Mark) tubes equipped with aluminium tube walls and fins. Container 8 has an outlet 10 for withdrawing cooled material from the bottom 11 of container 8. A second outlet 12 is associated with an internal feed pipe 13. A supply bottle (not shown) is placed upsidedown at the top end of pipe 13, so that drinks can be withdrawn through the outlet 12 from the bottle.

Figure 3 shows a container and evaporator arrangement which in an embodiment of the invention is incorporated in the absorption refrigeration unit and in which the container 8b double-walled, the turns of the evaporator tube 15 being disposed in the space 17 between the walls of container 8b. The details of the engagement between the evaporator tube 15 and the container walk 14 are shown in Figure 4.

The space 17 contains a cold transmitting and storing medium which may, for example, be a eutectic solution for cold storage.

The eutectic point of the solution is slightly below the lowest temperature at which cooled material is withdrawn.

Figures 5 and 6 show means whereby a sump of the gas heat exchanger is drained into the storage tank.

A gas heat exchanger 26 surrounds the descending portion of an evaporator tube 25 extending from evaporator 4 or 15 to the storage tank 6. A drainage tube 27 is sealingly disposed between the external wall of the tube 25 and the internal wall of the tube of the gas-heat exchanger 26, and the portion of the gas heat exchanger tube surrounding the evaporator and drainage tubes is sealed off so that the sump of the gas heat exchanger can drain into the storage tank. As shown in Figures 5 and 6, the end portion of the tube 25 is compressed in order to accommodate the tube 27.

Figures 7 and 8 show an absorber tube in which steel wire gauze 28 is inserted adjacent the inner wall to form a capillary means which enhances condensation. The same feature can be applied to the evaporator tube, to enhance evaporation therein.

Attention is hereby drawn to our Copending Patent Application No. 52825/77 (Serial No. 1598097) which also relates to an absorption refrigeration unit and from which the present Application was divided.

WHAT WE CLAIM IS 1. A continuously operable absorption refrigeration unit for cooling water, drinks and draught beer, the unit comprising a metal container for receiving the material to be cooled and an associated evaporator tube for cooling the container, in which unit the container is double-walled, the space between the walls contains a cold transmitting and storing medium and the evaporator tube is coiled and has a flat oval cross-section presenting a flat portion which operatively engages the container wall.

2. A refrigeration unit according to claim 1, wherein the evaporator tube is disposed in the internal space containing the cold-transmitting and storing medium.

3. A refrigeration unit according to claim 1 or 2, wherein the cold storage medium comprises a eutectic solution, the eutectic point of which is slightly below the lowest temperature at which the cooled material is withdrawn.

4. A refrigeration unit according to any one of claims 1 to 3, wherein the evaporator tube and/or an absorber tube is or are provided with steel wire gauze adjacent the inner surface of the tube.

5. A refrigeration unit according to any preceding claim, wherein an end portion of the evaporator tube extending to a storage tank of the unit is surrounded by a gas heat exchanger tube and a drainage tube for draining off the sump into the storage tank is disposed between the exterior wall of the evaporator tube and the interior wall of the gas heat exchanger tube.

6. A refrigeration unit according to claim 5, wherein the end portion of the evaporator tube is compressed to accommodate the drain tube and the portion of the gas heat exchanger tube surrounding the evaporator and drainage tubes is sealed off.

7. A refrigeration unit according to any preceding claim, wherein a condenser of the refrigeration unit extends approximately at right angles to a boiler of the unit or to a gas and vapour tube extending from the boiler.

8. A refrigeration unit according to claim 7, wherein the condenser is in the form of a finned tube.

9. A refrigeration unit according to any one of claims 1 to 6, wherein a condenser of the refrigeration unit is in the form of a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. gas or kerosene. The material to be cooled is held in a vessel 8 which is made of metal, preferably aluminium, and is surrounded by thermal insulation 9, covering the side wall and the bottom of container 8. The insulation also partly screens from the container the heatradiating parts of the absorption unit, i.e. condenser 3 and absorption 5, but allows the necessary heat exchange to occur between the condenser and absorber and the external air. As shown in Figures 1 and 2, the device is compact and the heat-radiating parts of the absorption unit are at the back of the unit, so that heat can be radiated outwards when the device is incorporated in a housing with an open back. In Figures I and 2, the condenser 3 extends approximately at right angles to the boiler 1 and the gas and vapour pipe 2. The condenser tubes may be Trufin (Registered Trade Mark) tubes equipped with aluminium tube walls and fins. Container 8 has an outlet 10 for withdrawing cooled material from the bottom 11 of container 8. A second outlet 12 is associated with an internal feed pipe 13. A supply bottle (not shown) is placed upsidedown at the top end of pipe 13, so that drinks can be withdrawn through the outlet 12 from the bottle. Figure 3 shows a container and evaporator arrangement which in an embodiment of the invention is incorporated in the absorption refrigeration unit and in which the container 8b double-walled, the turns of the evaporator tube 15 being disposed in the space 17 between the walls of container 8b. The details of the engagement between the evaporator tube 15 and the container walk 14 are shown in Figure 4. The space 17 contains a cold transmitting and storing medium which may, for example, be a eutectic solution for cold storage. The eutectic point of the solution is slightly below the lowest temperature at which cooled material is withdrawn. Figures 5 and 6 show means whereby a sump of the gas heat exchanger is drained into the storage tank. A gas heat exchanger 26 surrounds the descending portion of an evaporator tube 25 extending from evaporator 4 or 15 to the storage tank 6. A drainage tube 27 is sealingly disposed between the external wall of the tube 25 and the internal wall of the tube of the gas-heat exchanger 26, and the portion of the gas heat exchanger tube surrounding the evaporator and drainage tubes is sealed off so that the sump of the gas heat exchanger can drain into the storage tank. As shown in Figures 5 and 6, the end portion of the tube 25 is compressed in order to accommodate the tube 27. Figures 7 and 8 show an absorber tube in which steel wire gauze 28 is inserted adjacent the inner wall to form a capillary means which enhances condensation. The same feature can be applied to the evaporator tube, to enhance evaporation therein. Attention is hereby drawn to our Copending Patent Application No. 52825/77 (Serial No. 1598097) which also relates to an absorption refrigeration unit and from which the present Application was divided. WHAT WE CLAIM IS

1. A continuously operable absorption refrigeration unit for cooling water, drinks and draught beer, the unit comprising a metal container for receiving the material to be cooled and an associated evaporator tube for cooling the container, in which unit the container is double-walled, the space between the walls contains a cold transmitting and storing medium and the evaporator tube is coiled and has a flat oval cross-section presenting a flat portion which operatively engages the container wall.

coiled tube which is located at the top edge of the container and is separated therefrom by thermal insulating material whilst being accessible to a flow of external air

10. A refrigeration unit according to cllim 9, wherein a heat conducting plate extends around the periphery of the condenser tube and is accessible to a flow of external air.

11. A refrigeration unit according to any preceding claims, wherein the container has an outlet means for withdrawing cooled material at the bottom and a second outlet means connected to an internal feed pipe associated with a storage bottle for withdrawing water or drinks from the bottle through the second outlet means.

12. An absorption refrigeration unit substantially as hereinbefore described with reference to Figures 1, 2 and 3 of the accompanying drawings.

13. An absorption refrigeration unit according to claim 12, having an evaporator tube draining arrangement substantially as hereinbefore described with reference to Figures 5 and 6 of the accompanying drawings.

14. An absorption refrigeration unit according to claim 12 or 13, having an evaporator and/or absorber tube construction substantially as hereinbefore described with reference to Figures 7 and 8 of the accompanying drawings.