METHOD FOR RECOVERING HEAT ENERGY RELEASED BY LAUNDRY MACHINES

Abstract
The use of at least one central heat exchanger to extract and dry the heat energy released by laundry machines, in particular their gland steam. The energy thus recovered can be fed back to the laundry machines as hot air or hot water. This represents a significant reduction in the energy requirements of laundry machines as laundry machines discharge a great amount of unused energy into the environment, which, particularly in light of rising energy prices, represents an unnecessary operational cost for a laundry.
Description

BRIEF DESCRIPTION OF THE DRAWING

A preferred exemplary embodiment of the invention will be explained in more detail below on the basis of the drawing. The sole FIGURE of the drawing shows:


A flow chart illustrating the method according to the invention.





DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The method illustrated here is employed to recover energy discharged by laundry machines, in particular heat energy, in such a manner that at least one portion of the energy can be reutilized in the operation of preferably laundry machines. The recovery of energy can be applied to all laundry machines used in commercial laundries which discharge unspent energy.


The drawing shows schematic representations of a washing machine, namely a tunnel washing machine 10, a dryer 11, a finisher 12 and a mangle 13. In these laundry machines—to which, however, the invention is not limited—a particularly large amount of heat energy accumulates, which is normally vented outside without being utilized. The energy discharged by the laundry machines takes the form of moist air, or gland steam. The gland steam still possesses a relatively high temperature that can be greater than 100 C. The object of the invention is therefore to recover at least part of the energy still contained in the gland steam so that it does not have to be released outdoors without being utilized.


The FIGURE shows gland steam lines 14 by means of which gland steam accumulating at the tunnel washing machine 10, the dryer 11, the finisher 12 and the mangle 13 can be conducted through a compressor 15 or also a pump 19 to a first heat exchanger 16. In this heat exchanger 16 the gland steam is converted into energy. The heat exchanger 16 can be a steam dryer, for example.


The heat exchanger 16 dries the gland steam supplied to it through the gland steam pipes 14. In the process, energy is extracted from the gland steam that is employed to heat up the water in the heat exchanger 16. The heated water is cycled through a heat exchanger line 17, specifically from the heat exchanger 16 to a further, second heat exchanger 18, and from the latter back to the first heat exchanger 16. A pump 19 circulates the water in the heat exchanger line 17.


The air, in particular hot air, dried in the (first) heat exchanger 16, is returned via a hot air line 20 from a compressor 21 assigned to the latter, or from a pump in the shown exemplary embodiment, to the dryer 11, finisher 12 and the mangle 13. By means of the appropriate valves (not shown) it is possible to alter the quantity of hot air delivered per time unit to the dryer 11, the finisher 12 or the mangle 13 as needed, or to supply the dryer 11, the finisher 12 and/or the mangle 13 only with hot air from the first heat exchanger 16.


The second heat exchanger 18 is provided via a feed line 22 with preferably cold fresh water or wash water from the tunnel washing machine 10. The wash water or fresh water, warmed in second heat exchanger 18 from the heat energy of the hot water heated by the first heat exchanger 16 and circulated via the heat exchanger line 17, is fed via a second heat exchanger line 23 to a hot water storage tank 24. The hot water storage tank 24, which is provided with insulation 25, stores the energy extracted from the gland steam by the first heat exchanger 16 in the form of hot water that has been heated by the second heat exchanger 18 until it is reutilized.


Three feeder lines 26, 27, 28 lead out of the hot water storage tank 24. Heated hot water can be optionally fed through the feeder lines 26, 27, 28 to the tunnel washing machine 10 or possibly to another laundry machine as well, such as the mangle 13. A feeder line 26, 27, 28 can also supply warm water for other uses that are not necessarily associated with laundry operations, such as district heating for heating houses or apartments.


It is also conceivable to include a heat exchanger or heat transfer medium having an higher boiling point in the secondary loop of the second heat exchanger 18, namely in the second heat exchanger line 23. Such a medium can also be arranged in a heat reservoir that is substituted for the hot water storage tank 24. This heat reservoir is then assigned a further (third) heat exchanger in which the heat reservoir medium heats wash water or fresh water as needed for supplying a laundry machine, in particular the tunnel washing machine 10 and/or the mangle 13. In the case of an oil-heated mangle 13, oil can also be heated by the heat transfer medium using a third heat exchanger in order to provide heat to the trough of the mangle 13, specifically at temperatures exceeding 100° C.


The method according to the invention is executed with the previously described central heat recovery installation as follows:


Gland steam from a plurality of laundry machines, in the shown embodiment from the tunnel washing machine 10, if necessary from a hydroextractor spin-dryer (not shown), the dryer 11, the mangle 13 and, if necessary, the finisher 12, is conducted to the heat exchanger 16, which is assigned to said laundry machines, for the central recovery of energy.


In the heat exchanger 16, the gland steam from in particular the tunnel washing machine 10, the dryer 11, the mangle 13 and, if applicable, the finisher 12 is dried, that is to say, moisture is extracted from the humid hot air of the gland steam. This is preferably carried out by employing the principle of a steam dryer, for example by conducting the gland steam through a water bath or other such liquid such that after the gland steam has been dried, dry hot air accumulates at the heat exchanger 16 and can be fed back to the tunnel washing machine 10, the dryer 11, the mangle 13 and, if applicable, the finisher 12 as needed. If necessary, the hot air line 20 leading to the laundry machines can be assigned a device for sterilizing and/or filtering the hot air, in particular for removing lint from the hot air. This step eliminates impurities from the dry hot air that were not removed in the heat exchanger 16 before the hot air is fed back to the laundry machines.


Provision is also made to utilize the energy recovered during the drying of the gland steam for heating water or some other liquid in the bath of the first heat exchanger 16. This heated liquid is employed via the second heat exchanger 18 for the indirect application of heat to fresh water, wash water or another heat transfer medium having a higher boiling point. This measure keeps the fresh water, the washing water or the heat transfer medium from any possible contact with the liquid of the first heat exchanger 16 that may have been contaminated by the gland steam. There is thus no carry-over of gland steam impurities into the fresh water or washing water heated by the waste heat of the gland steam. Above all, the second heat exchanger 18 can also be employed to use the energy recovered from the gland steam to heat a medium other than water to a relatively high temperature, such as oil or another heat transfer medium having a boiling point higher than that of water.


Provision is further made for the temporary storage of the fresh water, wash water or other heat transfer medium heated by the second heat exchanger 18. By virtue of this intermediate storage it is possible to utilize the recovered energy as needed, which means that the recovered energy does not have to be fed immediately to the laundry machines. The storage tank is expediently insulated in order to maintain the high temperature of the liquid or other heat transfer medium for an extended period of time without any appreciable loss of temperature. This allows the recovered energy to be utilized on the following working day without incurring any significant energy losses beforehand.


LIST OF DESIGNATIONS




  • 10 tunnel washing machine


  • 11 dryer


  • 12 finisher


  • 13 mangle


  • 14 gland steam line


  • 15 compressor


  • 16 heat exchanger


  • 17 heat exchanger line


  • 18 second heat exchanger


  • 19 pump


  • 20 hot air line


  • 21 compressor


  • 22 feed line


  • 23 second heat exchanger line


  • 24 hot water storage tank


  • 25 insulation


  • 26 feeder line


  • 27 feeder line


  • 28 feeder line


Claims
  • 1. A method for recovering heat energy released by laundry machines, characterized in that the heat energy released by a plurality of laundry machines is conducted to at least one common heat exchanger (16, 18).
  • 2. The method according to claim 1, characterized in that the heat energy conducted to the at least one heat exchanger (16, 18) is converted into hot water and/or hot air.
  • 3. The method according to claim 1, characterized in that moist hot air accumulating at the laundry machines is conducted to the at least one heat exchanger (16).
  • 4. The method according to claim 3, characterized in that the at least one heat exchanger (16) dehumidifies moist hot air discharged from the laundry machines as gland steam.
  • 5. The method according to claim 4, characterized in that a second heat exchanger (18) is arranged downstream of the heat exchanger (16) that is supplied with gland steam.
  • 6. The method according to claim 1, characterized in that the at least one heat exchanger (16) is supplied with gland steam from the group consisting of washing machines, tunnel washing machines (10), hydroextractor spin-dryers, dryers (11), mangles (13), and finishers (12).
  • 7. A method for recovering heat energy released by laundry machines, characterized in that the heat energy released by at least one laundry machine is fed to a first heat exchanger (16), water is heated by the heat energy in the first heat exchanger (16), and this heated water is cycled in a loop through at least a further heat exchanger (18), which heats a medium.
  • 8. The method according to claim 7, characterized in that the medium heated by the at least one further heat exchanger (18) is fed to a laundry machine.
  • 9. The method according to claim 7, characterized in that water is heated by the at least one further heat exchanger (18) and fed to the laundry machine.
  • 10. The method according to claim 1, characterized in that the gland steam is dehumidified by the first heat exchanger (16) and the dehumidified hot air, after being heated up if necessary, is fed at least to the laundry machine.
  • 11. A method for recovering heat energy released by laundry machines, characterized in that moist hot air discharged by at least one laundry machine is dried in at least one heat exchanger (16).
  • 12. The method according to claim 11, characterized in that the dried air is fed to at least one laundry machine.
  • 13. The method according to claim 11, characterized in that the dried air is sterilized before it is fed to at least one laundry machine.
  • 14. A method for recovering heat energy released by laundry machines, characterized in that heat transfer medium heated during the recovery of energy is stored at least in part.
  • 15. The method according to claim 14, characterized in that the at least one heat exchanger (16, 18) charges at least one energy store.
  • 16. The method according to claim 14, characterized in that the heated heat transfer medium is temporarily stored in at least one insulated storage tank (24).
  • 17. The method according to claim 15, characterized in that water heated by at least one second heat exchanger (18) is temporarily stored in at least one insulated storage tank (24).
  • 18. The method according to claim 16, characterized in that the energy store has a heat transfer medium, which stores heat at a temperature greater than 100° C.
  • 19. The method according to claim 15, characterized in that a medium employed in the operation of a laundry machine is heated with the energy stored in the storage tank (24).
Priority Claims (1)
Number Date Country Kind
102006020003.9 Apr 2006 DE national