A DISH-WASHER OF CABINET TYPE

Abstract: In a dish-washer cabinet sudden escape of steam and of hot, expanded air through fissures around the door/hood when starting the machine is eliminated by preheating of the dish-washing cabinet and dish-ware with hot water for a short, initial spraying period and a subsequent pause.

Description: A dish-washer of cabinet type * The present invention relates to an improvement of a dish-washer of cabinet type, i.e. it has a closed dish-washing cabinet and a tight door or hood which is sealed with packings against a frame or the like. In a dish-washer for large-scale catering the washing up has been carried 5 out, up to now, in a way so that dish-water is kept in a tank between every dish-washing period and is changed successively during several periods. When a dish-washing period is completed the door is opened and the hot air and the steam in the dish-washing cabinet streams out into the room at the same time as cold air streams into the machine. A dish-basket with cold dish-ware is put into the 10 machine, the door is closed and the washing pump is started. The hot tank water is pumped through the nozzles of the circulation system at a high speed into the dish-washing cabinet. The cold air which filled the dish-washing room when the door was kept open is then rapidly heated which results in a rise of the pressure in the dish-washing cabinet. The gaskets around the door are then pressed out and 15 hot water and air are pressed out through the fissures around the door. Such leakage of hot dish-water can cause personal injuries and is unhygienic. The phenomenon has since long been observed, and solutions to stop the leakage have been presented. The best known arrangements which have come of use are vent holes, valves, labyrinth seals and air gaps at the door or around it. However, all 20 the solutions have great disadvantages like steam exhaust, moisture and condensa¬ tion in the surrounding room, high volume of sound and repeated leakage. A solution is presented by the present invention by an attack on the reason for the sudden expansion in the dish-washing cabinet when the circulation starts. By a short hot water spraying in the beginning of the dish-washing cycle the air 25 has time for expansion before the circulation starts and the moderate over¬ pressure which then arises can be evacuated through a labyrinth seal around the door. Features according to the invention which contribute to the solving of the problem are defined in the characterizing part of claim 1. An embodiment of the invention is described in the following with reference 30 to the attached drawing which shows in Fig. 1 a simple time-pressure diagram of a first sequence in a dish-washing cycle and in Fig. 2 a schematically illustrated dish-washer in a vertical cross-section. A dish-washing program is formed by a range of intervals when different components of the machine are working. A circulation pump (not shown) pumps OMPI washing-liquid in a main spraying system 10 at a high volume speed, the liquid being heated and kept in a tank 11 at the bottom of the dish-washing cabinet 12 between the dish-washing cycles. Through a spillway 13 liquid runs off from the tank to a sewer pump. The machine shown also contains a final spraying system 14 which is connected to a main water supply via a through-passing heater 15. The end spraying system has rotating arms with nozzles which distribute and diffuse hot water in the dish-washing cabinet. The dish-washing program is shown in Fig. 1 where each shaded area shows the spraying or pumping during an interval to be read on the time axis. The first interval 16 is short, about 1-2 seconds and is made through the spraying system 14, i.e. hot water in a volume of some decilitres. As an alternative a separate, firm nozzle can be used for injection of this volume. After this first spraying there is a pause 17 for about two seconds during which the air of the cabinet is heated to a temperature close to that of the dish-washing liquid and a quiet expansion of the air takes place whereby the overpressure arisen is evacuated through fissures around the door 18. Only after this pause the spraying starts through the main spraying system 10 and goes on for a couple of minutes whereupon there is a further pause (not shown) when there is an outflow drip of liquid from the dish-ware. The overpressure in the dish-washing cabinet 12 is shown in the curve 19 at the bottom of Fig. 1. The last interval of the dish-washing cycle is the final rinsing through the system 14. The ware is during this rinsing further heated and dries therefore rapidly by evaporation when it is taken out of the machine. The dish-washing program is controlled by a program controller which starts when the door is closed. In such a program controller it is easy to add or delete intervals - in the present case said first interval 16 and subsequent pause 17 have been introduced. The length of these intervals must of course be determined according to actual type of. machine. The values here mentioned are only examples. In other respects the machine described is only to be considered an example of a machine-type in which the invention can be realized. OMPI

Claims: Claims 1. A dish-washer with a closed dish-washing cabinet having a door or a hood sealed with gaskets against a frame and containing at least one spraying system for washing-liquid and a program controller for control of a dish-washing program divided up into dish-washing period, pauses and rinsing period, character- i z e d in that control circuits and spraying systems (14) for hot water are arranged to preheat the dish-washing cabinet for a spraying period of ten seconds at the most before said dish-washing period. 2. A dish-washer according to Claim 1, characterized in that one and the same spraying system (14) is adapted to spray during said spraying period before the dish-washing period as well as during the subsequent rinsing period. 3. A dish-washer according to Claim 1, characterized in that the volume of hot water during said spraying period is one litre at the most. 4. A dish-washer according to Claim 1, characterized in that the door (hood) (18) has a pervious sealing against the frame so that occurring over- pressure in the dish-washing cabinet during said spraying period is evacuated through this sealing.

Inventors: BOREUS CLAES GOERAN
Applicants: BOREUS CLAES GOERAN, ELECTROLUX AB
Application year: 1981
Main classification: A47L15
IPC codes: A47L15