Condensation dryer

Abstract

A condensation dryer, in particular a tumble dryer, having a heat exchanger (2). In the heat exchanger (2) moisture, which has been absorbed in a drying chamber (1), is separated from an air circuit (3). The condensation dryer includes a sorption unit (5). The sorption unit (5) is connectable to a liquid reservoir (7). Between the liquid reservoir (7) and the sorption unit (5) a cooling fluid flow (4) can be generated. The cooling fluid flow (4) passes through the heat exchanger (2).

Claims

1. A condensation dryer, comprising: a heat exchanger (2) for the condensation of moisture from an air circuit (3), which has been absorbed in a drying chamber (1), and a sorption unit (5), connected to a liquid reservoir (7), generates a cooling fluid flow (4) from the liquid reservoir (7) to the sorption unit (5) that passes through the heat exchanger (2), wherein the air circuit (3) and the cooling fluid flow (4) are formed as two spatially separate systems, and the sorption unit (5) and the liquid reservoir (7) with at least one passage (8) connected therebetween form a closed system.

2. The condensation dryer according to claim 1, wherein the sorption unit (5) and the liquid reservoir (7) are connected via the at least one passage which comprises a hermetically sealed passage (8), which leads through the heat exchanger (2).

3. The condensation dryer according to claim 2, wherein the sorption unit (5) and the liquid reservoir (7) are connected with a further hermetically sealed passage (16), which does not pass through the heat exchanger (2).

4. The condensation dryer according to claim 1, wherein the condensation dryer comprises a passage (19) for a fresh air flow (18) in which the liquid reservoir (7) is embedded at least partly.

5. The condensation dryer according to claim 1, further comprising a passage (9) for a fresh air flow (10), in which the sorption unit (5) is embedded at least partly.

6. The condensation dryer according to claim 1, wherein the sorption unit (5) is embedded at least partly in the air circuit (3).

7. The condensation dryer according to claim 1, further comprising at least one component (12, 20) for transferring heat from at least a fresh air flow (10, 18) to the air circuit (3).

8. The condensation dryer of claim 1, wherein the condensation dryer is a tumble dryer.

9. A method of operating a condensation dryer according to claim 1, comprising the following steps: in a first phase, opening a first connection (8) between the sorption unit (5) and the liquid reservoir (7), which leads through the heat exchanger (2) generating a cooling fluid flow (4) from the liquid reservoir (7) to the sorption unit (5), which flows through the heat exchanger (2), in the heat exchanger (2), condensing moisture from an air circuit (3), which has been absorbed in a drying chamber (1), adsorption of fluid in the sorption unit (5), closing the first connection (8), and in a second phase opening a second connection (16) between the sorption unit (5) and the liquid reservoir (7), which does not pass through the heat exchanger (2), desorption of the fluid from the sorption unit (5), condensing the fluid in the liquid reservoir (7), and closing the second connection (16).

10. The method according to claim 9, wherein at least one of during or after the second phase, a flow of fresh air (18) passes the liquid reservoir (7) and is thereby heated, and transfers heat to the air circuit (3) afterwards.

11. The method according to claim 10, wherein at least one of during or after the first phase, a flow of fresh air (10) flows through the sorption (5) unit and is thereby heated, and transfers heat to the air circuit (3) afterwards.

12. The method according to claim 9, wherein after the second phase a flow of fresh air (10) passes the sorption (5) unit and is thereby heated, and transfers heat to the air circuit (3) afterwards.

13. The method according to claim 9, wherein during at least one of the first phase, the second phase, or after the second phase, the process air of the air circuit (3) passes through the sorption unit (5) and heat of the sorption unit (5) is transferred to the air circuit (3).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features and advantages of the invention will become apparent from the description of embodiments with reference to drawings and from the drawings themselves.

(2) In the drawings:

(3) FIG. 1 shows a variant in which the sorption unit is arranged in a fresh-air passage.

(4) FIG. 2 shows a variant in which the sorption unit is arranged in the air circuit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) FIG. 1 shows a condenser clothes dryer with a drying chamber 1. In this embodiment the drying chamber 1 is a rotatable drum. The drum rotates around a horizontal axis. Carriers are attached within the drum for moving the laundry during tumbling.

(6) The warm dry process air flows through the damp laundry and becomes laden with moisture. The moist process air stream flows through heat exchanger 2. The process air flows in a closed air circuit 3.

(7) In the heat exchanger 2 is a cross flow heat exchanger. It may be a conventional heat exchanger used in a conventional condenser dryer. But it proves to be particularly advantageous when a heat exchanger is used, which has a larger surface for the condensation of moisture from the air circuit 3, compared to conventional heat exchangers.

(8) Upstream of the heat exchanger 2 a fluff filter is arranged. The moist process air of the air circuit 3 flows through the heat exchanger 2 and moisture is condensed from the process air. According to the invention the heat exchanger 2 is passed through by a cooling fluid flow 4. In the embodiment said cooling fluid flow 4 is of cold water vapor. In the heat exchanger 2 the cooling fluid flow is separated from the process air flow.

(9) The cooling fluid flow 4 is generated with a sorption unit 5. In the embodiment the sorption unit 5 comprises a bed of solid adsorbent material. As adsorbent material a zeolite adsorbent is used. At the beginning of a first phase of operation a shutoff device 6 is opened. In the embodiment the shutoff device 6 is a valve.

(10) In a liquid container 7 there is water. The liquid container 7 is connected to the sorption unit 5 via a hermetically sealed passage 8.

(11) In the heat exchanger 2 the passage 8 divides into a plurality of channels. The channels for the fluid flow are perpendicular to the channels where the process air of the air circuit 3 flows through.

(12) After flowing through the heat exchanger 2 the cooling fluid enters the sorption unit 5 where it is adsorbed at the zeolite bed. By the adsorption of water vapor at the zeolite solid material the sorption unit 5 heats up.

(13) The sorption unit 5 is embedded in a passage 9 and is being passed by a fresh air flow 10. In the embodiment the passage 9 is an air duct. The fresh air flow 10 is generated by a fan 11.

(14) When flowing around the sorption unit 5 the flow of fresh air 10 receives the heat liberated in the adsorption process and transfers the heat by means of a heat exchanger 12 to the process air of the air circuit 3.

(15) Because of the cold water vapor, the heat exchanger 2 is cooled significantly more than in a conventional air-to-air operation. The condensation efficiency of the heat exchanger 2 is increased.

(16) Downstream to the heat exchanger 2 the process air first flows through the heat exchanger 12 and then through a multistage electric heater 13. For energetic reasons the heater 13 should be constructed with multi-stages so only the lack of energy can be added to the process air stream before the process air stream flows back into the drying chamber 1.

(17) The multi-stage heater 13 heats the process air flow, before it reenters the drying chamber 1. Because of the higher condensation level in the heat exchanger 2 the process air flow of the inventive device has a lower relative humidity. Therefore it can absorb more moisture when it passes through the laundry in the drying chamber 1. Therefore the drying time is reduced compared to conventional condensation dryers.

(18) The process air flow in the air circuit 3 is maintained by means of a fan 14.

(19) During a second phase of operation the shutoff device 6 is closed and the fan 11 is off. At the beginning of the second operating phase a further shutoff device 15 is opened. In the embodiment the shutoff device 15 is a valve.

(20) The sorption unit 5 and the liquid container 7 are connected with another hermetically sealed passage 16, which does not pass through the heat exchanger 2. After opening of the further passage 16 a heater 17 is activated, which is part of the sorption unit 5. The heater 17 heats the zeolite material and fluid is desorbed. The desorbed water vapor flows through the passage 16 into the liquid container 7 and there it condenses. The condensation releases condensation heat.

(21) Through the use of a fan 18 a further fresh air flow 18 is generated, which passes around the liquid container 7 and receives the liberated heat of condensation. The liquid container 7 is embedded into a further passage 19. In the embodiment the passage 19 is an air duct. The heated fresh air flow 18 flows through the heat exchanger 12. It transfers the heat to the process air of the air circuit 3. The fresh air flow 18 leaves the condensation dryer after the transfer of heat to the process air flow.

(22) After the desorption phase the shutoff device 15 is closed and a fresh air flow 10 passes the sorption unit 5. A cooling phase can follow, during which the sorption unit 5 and/or the liquid container 7 can be cooled by fresh air flows 10 and/or 18. The heated fresh air flows 10, 18 transfer heat via the member 12, which is configured as a heat exchanger in the embodiment, to the process air of the air circuit 3 and afterwards they leave the condensation dryer.

(23) FIG. 2 shows a variant, in which the sorption unit 5 is embedded in the air circuit 3 of the process air flow. During the first operating phase, the adsorption phase, and during the second operating phase, the desorption phase, the sorption unit 5 transfers heat to the process air flow, which flows around the sorption unit 5 and is conveyed by the fan 14.

(24) The fresh air stream 18, which receives the heat of condensation from the container 7 during the second phase of operation, transmits its heat by means of a heat transfer device 20 to the process air flow.

(25) One operation cycle comprises a first and a second phase. During the drying process several cycles are carried out.

(26) In a not illustrated embodiment of the invention the cooling process of the heat exchanger 2 is continuously operated with several sorption units 5. While one sorption unit 5 is in the adsorption mode, the second sorption unit 5 operates in desorption mode. Afterwards the modes change.