Patent Application
20100018393
The present invention relates to a humidity exchanger for exchanging humidity between two air streams, which has two cavities separated by a structure permeable to water vapor.
A humidity exchanger for exchanging humidity between two air streams is known from U.S. Pat. No. 7,357,830. Such a humidity exchanger essentially comprises two cavities, which are separated by a structure permeable to water vapor. The structure permeable to water vapor separates the two air streams, but allows the exchange of humidity between the two air streams. The air stream to be dehumidified is guided through the first cavity and the air stream to be humidified is guided through the second cavity. The embodiment having two such humidity exchangers, which are connected to one another by a closed air circulation loop, is especially advantageous. The first air stream consists of outside air, which is to be supplied as processed supply air to a room, and a second air stream consists of return air, which is to be exhausted from the room and discharged to the surroundings as exhaust air, the humidity contained in the return air to be transferred to the supply air using one or two such humidity exchangers. Furthermore, cleaning such a humidity exchanger using water, the water being able to be heated using a heating element, is known from U.S. Pat. No. 7,357,830. The achievable degree of cleanness does not meet all practical demands, however.
A façade element for buildings, which contains an integrated humidity exchanger, is known from WO 9953245.
Diaphragms which are capable of separating water vapor and corresponding dehumidifying devices are known from U.S. Pat. No. 3,735,559.
Air streams which circulate in such humidity exchangers of the prior art often entrain particles, bacteria, and other undesired foreign materials. These foreign materials may accumulate in the cavities of the humidity exchangers and in the pores of the diaphragm. Such accumulations have a negative effect on the efficiency. In addition, the inflowing outside air is contaminated by the foreign materials.
The invention is based on the object of improving the cleaning of a humidity exchanger, which has two cavities separated by a structure permeable to water vapor, in such a way that a higher degree of cleanliness is achievable in the cavities. In particular, the cavities are to be able to be nearly or entirely sterilized.
This object is achieved by a humidity exchanger having a cleaning system.
A humidity exchanger for exchanging humidity between a first air stream and a second air stream contains two cavities separated by a structure permeable to water vapor, the first air stream flowing through the first cavity and the second air stream flowing through the second cavity. The humidity exchanger also contains a cleaning system, which comprises a cleaning module, at least one line system, and at least one pump. The cleaning module provides a cleaning fluid. The cleaning module is connected via the line system to the first cavity and/or the second cavity. The cleaning system comprises at least one pump to pump cleaning fluid out of the cleaning module into the first cavity and/or the second cavity and/or out of the cavities. Using the cleaning system, the first cavity and/or the second cavity and/or the structure permeable to water vapor may be efficiently cleaned in such a way that a higher degree of cleanliness is achieved.
The cleaning module may provide a gaseous or a liquid cleaning fluid. Pure water (H2O) in the liquid aggregate state is not considered a cleaning fluid. In particular, hot steam is suitable as the cleaning fluid and the cleaning module is set up to generate hot steam in a preferred exemplary embodiment.
Furthermore, the cleaning module advantageously comprises an additive device, which is used to admix at least one liquid or gaseous additive to the cleaning fluid.
The invention is explained in greater detail hereafter on the basis of exemplary embodiments and on the basis of the drawing.
The cleaning module 5 is designed in such a way that it is capable of providing a cleaning fluid. Gaseous, vaporized, or liquid materials are suitable as the cleaning fluid. The cleaning fluid is used to clean the first cavity 1, the second cavity 2, and the diaphragm 3. During the cleaning of the cavities, the walls which delimit the cavities, and also other parts connected to the cavities 1, 2, such as valves, etc., are cleaned by the cleaning fluid. Cleaning of the diaphragm 3 is understood as both cleaning the surface of the diaphragm 3 and also cleaning its pores.
Hot steam is preferably used as the cleaning fluid. In this case, the cleaning module 5 is provided with a corresponding apparatus 55, which may generate hot steam. The apparatus 55 is a steam generator, for example. Using the hot steam, the cavities 1, 2 and the diaphragm 3 may be sterilized. The temperature of the hot steam is a function of the desired degree of sterilization. It is typically in the range from 100 to 120° C. The hot steam is under a certain pressure. The cavities 1, 2 and the diaphragm 3 are correspondingly implemented as pressure resistant.
Instead of hot steam, other fluids, such as organic or inorganic solvents, may also be used. Cleaning fluids which are based on soaps or suds are also possible. In addition, zeolite additives may be admixed. The cited fluids and also other arbitrary fluids may be mixed with one another. The cleaning module 5 therefore preferably contains an additive device 56, which may admix additives to the cleaning fluid. The additives may have a gaseous or liquid aggregate state. Only a single additive or an additive mixture comprising at least two additives may be admixed.
The cleaning system is additionally preferably equipped with a flushing device, so that after the cleaning procedure, it may flush at least the first cavity 1, through which the fresh outside air streams, which reaches the room in normal operation as supply air, during a specific period of time using outside air, without this air reaching the room. In the example, the flushing device comprises an armature 66 and a pipe section 67, which connects the first cavity 1 and the second cavity 2. The armature 66 is a flap, for example, which covers the outlet opening 22 in flushing operation and the entry to the pipe section 67 in normal operation. In flushing operation, the inflowing outside air reaches the cavity 1, flows through the cavity 1, is conducted at the exit of the cavity 1 into the cavity 2, flows through the cavity 2, and reaches the outside. In this way, unpleasant odors are removed from the cavities 1 and 2, without reaching the room to be supplied with supply air.
The cleaning may be mechanically supported with shockwaves, soundwaves, and/or ultrasound waves. An element 30 is provided for this purpose, which is capable of emitting energy, in particular longitudinally propagating waves. The element 30 is, for example, an ultrasonic generator, if the cleaning is to be supported using ultrasound. The element 30 is preferably situated on the floor of the cavity 1 and/or 2, whether inside or outside the cavity, so that the energy may be efficiently transmitted to the cleaning fluid even in the event of a low level of the cleaning fluid.
Pumps 9 for the circulation of the cleaning fluid may be situated both in the supply lines 61, 71 and also the drain lines 62, 72. In the present exemplary embodiment, one pump 9 is situated in each of the supply lines 61, 71 and of the drain lines 62, 72. The pumps 9 convey the cleaning fluid through the line system 6 and/or 7 and through the cavities 1, 2. If a shared supply line and a shared drain line are used, only one pump 9 needs to be situated in each of them.
If the pump 9 may convey the cleaning fluid in two directions, it is possible to remove contaminated cleaning fluid from the cavities 1, 2 again using the pump 9. The cleaning fluid is then supplied via the supply lines 61, 71 to the first cavity 1 and/or the second cavity 2 and also drained via the supply lines 61, 71. The drain lines 62, 72 are omitted in this case.
The humidity exchanger having the integrated cleaning system comprises a control unit which controls the operation. Various operating modes are possible for the cleaning of the cavities 1, 2, which may be applied both individually and also in combination. Five operating modes are explained hereafter.
The cleaning fluid is conveyed into the first cavity 1 and/or the second cavity 2. After passage of a certain application time, which may last from a few minutes to several hours, the contaminated cleaning fluid is conveyed back out of the first cavity 1 and/or the second cavity 2. If hot steam is used as the cleaning fluid, the application time is typically 10 to 25 minutes, but it may also be shorter or longer. In this operating mode, it is additionally possible to build up a pressure in the first cavity 1 and/or in the second cavity 2. The two cavities 1, 2 must be implemented as pressure-resistant in this case. This type of operation is particularly suitable for sterilization of the cavities 1, 2.
In the exemplary embodiment according to
In this operating mode, the cleaning fluid is continuously conveyed during a predetermined period of time through the first cavity 1 and/or the second cavity 2.
In this operating mode, the cleaning fluid is conveyed in brief pressure surges through the first cavity 1 and/or the second cavity 2.
This operating mode is only possible if hot steam is used as the cleaning fluid, because it is based on the permeability of the diaphragm 3 to water vapor. The hot steam is supplied via the supply line 61 to the first cavity 1, for example. The hot steam penetrates through the diaphragm 3, which is permeable to water vapor, and into the second cavity 2. This is illustrated in
Alternatively, it is possible to have the hot steam flow in the reverse direction from the second cavity 2 through the diaphragm 3, which is permeable to water vapor, into the first cavity 1, as illustrated in
This operating mode is based on the operating mode 4. The hot steam is only permitted to flow into the cavity 1 in a first phase and the hot steam which has penetrated through the diaphragm 3 is removed from the cavity 2. In a second phase, fresh hot steam is only permitted to flow into the cavity 2, and the hot steam which has penetrated through the diaphragm 3 is removed from the cavity 1. In this operating mode, the pores of the diaphragm 3 are cleaned especially well.
For all operating modes, the possibility exists of supporting the cleaning with shockwaves, sound waves, or ultrasound.
The following is cited as an example of a possible combination of these operating modes. The cleaning is performed in a first phase according to the operating mode 1, in which the cleaning fluid is conveyed into the first cavity 1 and/or the second cavity 2 and is drained back out of the cavities after the application time. In a second phase, the cleaning is performed according to the operating mode 3, in which the cleaning fluid is conveyed through the cavities 1, 2 in one or more brief pressure surges.
The contaminated cleaning fluid is either disposed of by hand or discharged directly to the environment or recycled by the cleaning module 5. The cleaning module 5 is equipped with appropriate means for this purpose.
Each humidity exchanger 42, 43 contains the two cavities 1 and 2. The cavity 2 of the first humidity exchanger 42 is connected via a closed air circulation loop to the cavity 1 of the second humidity exchanger 43. The closed air circulation loop comprises the air streams 81, 82, 83, and 84. Pumps or ventilators 40, 41 cause the air to circulate in the closed air circulation loop.
The two humidity exchangers 42, 43 preferably have a single, shared cleaning module 5. The line system is adapted accordingly.
A flushing device may also be provided in this exemplary embodiment to flush the cavities 1, 2 of the two humidity exchangers 42, 43 with outside air after the cleaning procedure.
The cleaning fluid may also be supplied to the corresponding cavities and/or the diaphragm via the existing air channels necessary for the operation of the humidity exchanger. This is possible, for example, if alcohol is used as the cleaning fluid.
The cited exemplary embodiments show that manifold guiding of the cleaning fluid is possible and that further variants and combinations are possible.
| Number | Date | Country | Kind |
|---|---|---|---|
| 01068/06 | Jul 2006 | CH | national |
The present application is related to and claims priority of the PCT patent application number PCT/EP2007/056615 entitled Humidity exchanger with a cleaning system, filed on Jul. 1, 2007, the disclosure of which is herein incorporated by reference, which in turn claims priority of the Swiss patent application number 1068/06 filed Jul. 3, 2006.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2007/056615 | 7/1/2007 | WO | 00 | 7/1/2009 |
