GB2302398A

GB2302398A - Air treatment in a condenser of an appliance

Info

Publication number: GB2302398A
Application number: GB9610437A
Authority: GB
Inventors: Gerald Hildebrand; Andreas Stolze
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-06-20
Filing date: 1996-05-17
Publication date: 1997-01-15
Anticipated expiration: 2016-05-17
Also published as: DE19522307A1; ES2143892B1; KR100395469B1; KR970001652A; RU2162906C2; GB9610437D0; GB2302398B; UA43856C2; ES2143892A1; DE19522307C2

Description

AIR TREATMENT IN A CONDENSER OF AN APPLIANCE 2302398 The present invention

relates to an appliance, such as a laundry washing machine or dishwashing machine, which is operable with water and equippped for drying and which includes a condenser, and has 5 particular reference to air treatment in the condenser.

A laundry drier with such features is disclosed in German published specification 41 04 760. It has proved to be a problem in the condenser thereof that fluff carried along in the process air during, in particular, the drying phase can be deposited on the inner wall of the condenser and dry out at the end of the drying phase. This problem is promoted by the wish to limit the throughflow of the cooling water to the smallest possible quantity in order to minimise fresh water consumption. Although distribution of the cooling water over the widest possible area is sought by suitable constructional measures within the hollow condenser body (DE 43 25 209 A1), fresh water consumption is still too high.

It would thus be desirable to so improve an appliance with condenser that the quantity of water needed for the condensation process is as small as possible in conjunction with satifactory flushing-out of the fluff or lint depositing in the condenser. Both functions should preferably be realised with only one inlet valve.

According to the present invention there is provided an appliance equipped for drying and with a condenser which comprises a hollow body, which is flowable through by moist process air substantially upwardly from below and which is flushed for cooling purposes by mains water, which in that case runs down as cooling water in part from the inward walls of the hollow body and is conducted away below by way of a lye outlet system, by way of a switchable valve in the inlet led to the upper region of the hollow body, characterised in that the hollow body in the entry region of the air has an at least nearly horizontal tear-off edge which by nearly cylindrical turbulence under the effect of the counterflowing process air is suitable for keeping the cooling water, which is running down, from running away unhindered.

In the case of such a condenser, the cooling water is retained therein during the condensation process for such a period of time that it has an opportunity several times of coming into contact with the warm, moisture-laden process air flow. It is therefore utilised appreciably more fully before it can flow away together with the condensate. The outflow occurs whenever the mass of the cooling water turbulence becomes so great that it can no longer be held back by the counterflpwing air. The turbulence roll or cylinder then collapses and the water contained therein flows in a surge to the lye outlet system. Cooling water flowing on behind slowly builds up a new roll or cylinder, but with cooler water.

The invention can be further developed in particularly advantageous manner by the edge being constructed to be annularly encircling. In that case, a greatest possible quantity of cooling water may be retained in the roll or cylinder of turbulence and the condensation of the moisture from the air intensified by the uniform distribution of the cooling water. Moreover, due to constriction of the cross-section in the region of the turublence at and above it, fluff is separated from the air to an increasing degree and entrained by the water. Fluff, together with the cooling water and the condensate, can then be conducted to the lye outlet system.

A particularly good effect can be achieved if the edge is so dimensioned that a water quantity of 7 to 150 millilitres supplied in a closed time period is kept in the hollow body for a duration of 1 to 20 seconds. A particular air flow rate produced by the blower output or performance rating and the property of the associated flow paths is linked with a certain quantity of water attaining a particularly good utilisation. Since these properties are not clearly definable and are strongly influenced by the constructional boundary conditions of the appliance, the respective optimum can be ascertained empirically within the given limits. The stated dimensioning ranges represent orders of magnitude within which particularly good utilisation of the cooling effect can be expected and fluff effectively washed out of the air at the same time.

In an advantageous embodiment, a temperature sensor is arranged at the wall in the region of the turbulence and connected to an evaluating and control circuit for a switchable valve, the circuit being so arranged that when the turbulent cooling water reaches a predetermined threshold temperature the valve is opened for supply of a replacement quantity for the water forming the water ring. It can thereby be achieved in simple manner that the intermittent supply of cooling water takes place only when the water for the condensation process has actually been utilised completely.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a schematic side elevation of a condenser in an appliance embodying the invention; and Fig. 2 is the detail II of Fig. 1 to an enlarged scale.

Referring now to the drawings there is shown a condenser in a washing machine. The condenser comprises a hollow condenser body 1 which is shaped in correspondence with a free space in the machine and is flowed through substantially upwardly from below by moist process air, which enters by way of an air inlet opening 2 arranged below and passes to a lower connection opening 3 arranged above.

The flow is indicated by the large arrows P shown in outline. The air inlet opening 2 is connected to a lye container (not shown) of the washing machine and serves at the same time as an outflow opening for rinsing or cooling water supplied from above and used as such in the hollow body. The water is pumped out of the container in usual manner by a pump in the lye outlet system.

The inlet 4 contains an electromagnetic valve 13 and opens out onto a baffle plate 5, which distributes inflowing water in bell shape into the interior of the condenser hollow body 1. The water flows down the inner wall surface of the body 1 towards the air inlet and water outlet opening 2 and in that case takes up moisture from the counterflowing process air. In addition, fluff entrained in the air separates out and is flushed away by the water. The overhanging inner wall 7 is still so steep that a film K of the cooling water (illustrated in dashed lines) does not detach. On the other hand, the sloping inner wall surfaces 8 and 9 are so strongly inclined that the cooling water film flows away swiftly.

At the vertical inner walls 10, the cooling water flows rapidly - 1:

towards the entry region 11 of the process air, but passes an annular detaching or tear-off edge 12 on this path. There the water film K impinges on the air P flowing accelerated at the region constricted by the edge 12. In that case, parts of the water are torn off upwardly and become turbulent above the edge 12 to form a kind of annular roll or cylinder W, which collects an increasing quantity of water until it finally collapses due to its gravitational force overcoming the air friction. The water released downwardly then flows in the manner of a surge towards the air inlet opening 2 and the lye outlet system.

For the condensing of the process air moisture, the cooling water is fed intermittently by way of the water inlet 4. For this purpose, the valve 13 is switched on and off at time intervals by a control circuit 14. These time intervals can be fixed and, for example for a throughflow speed of the valve of 600 millilitres per minute, amount to a switch-on duration of 0.7 seconds to 15 seconds and a closing pause of 1 second to 20 seconds. In that case, 7 to 150 millilitres, preferably about 50 millilitres, of cooling water flow to the water ring W, which water is kept in the ring for up to 20 seconds. During a period of the accumulation of the cooling water, the water ring also still takes up condensate in a quantity of up to about 30 millilitres.

The water ring W now increases in mass due either to the additional condensate accumulation until the collapse or to renewed opening of the valve 13. Thereafter, the "consumed" cooling water is replaced by fresh water.

The time intervals between the switch-on or open phase can, however, be controlled automatically by the temperature level cf the water ring. For this purpose, a temperature sensor in the form of a capillary tube 15 (Fig. 1) or an elastic or step spring transmitter or measuring resistance transmitter 16 (Fig. 2) is mounted at the wall in the immediate proximity of the water ring. As soon as a fixed 'threshold temperature is measured in the water ring W, the temperature sensor passes a signal to the evaluating and control circuit 14, which in turn delivers a switching-on pulse of a length, which is fixed or determined in dependence on the sensor signals to the valve 13.

Advantageously, an intensive contact of the process air with the cooling water is also made possible in the cycle pauses in the case of intermittent water feed. In this manner, the condensation process is maintained in the cycle pauses.

The roll, cylinder or toroid shaped water ring W has, apart from its good cooling effect, proved itself to be a very good fluff trap. The intensive contact of the air P with the cooling water K in the water ring W washes almost all the fluff out of the air.

Such a condenser requires only one inlet valve and one hose to the condenser inlet 4. No further components are necessary for a possible second valve, since the control of the water throughflow quantities can be managed by different durations of or cyclical switching-on of the valve.

1:

Claims

1. An appliance which is operable with water and equipped for drying and which includes a condenser comprising a hollow body with an air inlet for moist air to flow substantially upwardly through the body and a valvecontrolled water inlet for cooling water to flow substantially downwardly through the body at least partly along the inner wall surface thereof, the body being provided in the region of the air inlet with a substantially horizontal water film detaching edge arranged to produce a zone of generally roll-like turbulence of inflowing air for checking direct outflow of the water through the air inlet.

2. An appliance as claimed in claim 1, wherein the edge extends annularly around the inner wall surface.

3. An appliance as claimed in claim 1 or claim 2, wherein the edge is so dimensioned as to cause a quantity of water in the range of 7 to 150 millilitres supplied through the water inlet in a given time period to be retained in the hollow body for substantially 1 to 20 seconds.

4. An appliance as claimed in any one of the preceding claims, comprising temperature detecting means arranged to detect the temperature in said zone and to issue a signal when the temperature reaches a predetermined value and circuit means responsive to the signal to open valve means of the water inlet.

5. An appliance as claimed in claim 4, the temperature detecting means comprising a sensor arranged at the wall of the body.

6. An appliance including a condesner substantially as hereinbefore described with reference to the accompanying drawings.

7. An appliance as claimed in any one of the preceding claims, the appliance being a laundry washing machine or a dishwashing machine.