SEPARATION DEVICE FOR SEPARATING GRANULES FROM DISHWATER

Abstract: The invention relates to a separation device for separating granules from dishwater especially in a dishwasher for washing large articles comprising a valve means which in one position releases granules and dishwater directly into the pump conduit and in a second position forces the liquid with granules against a separation means (48) such as straining cloth cooperating with the valve means (51) movable between a lower and an upper position.

Description: The present invention relates to a separation device for separating granules from dishwater in a dishwasher, especially in a dishwasher for large articles as claimed according to EP-A-0126 760 and WO-A-8402068, disclosed in US-A-4 374 443. Separation devices of the kind indicated in the preamble of the accompanying Claim 1 for separating particles of dirt from dishwater are disclosed in CH-A-413 259 and US-A-2621 505. When washing and cleaning large and heavy articles in a dishwasher it is suitable and known to use dishwater mixed with an additive of granulate to increase the washing effect. This granulate, for instance made of plastic helps to remove burned-on food from the articles. This granulate follows with the dishwater when washing and performs the above mentioned effect. At the end of the washing programme the granules are separated from the dishwater, so that only dishwater without granules rinses off the articles. The invention proposes a new separation device as revealed in the claims. In the final phase of washing, it is desirable to spray liquid without granules to rinse the articles free of granules, and for this the separation device is set for separating out granules. The new separation device according to the invention eliminates the risk of granules clogging the separation means such as a straining cloth or a perforated or slotted plate by virtue of the fact that the liquid with granules is drawn up against the underside of the straining cloth or perforated or slotted plate and granules with a larger specific weight than the liquid will, due to their own weight, tend to sink down against the effect of the flow forces. These and other advantages of the invention will be explained in more detail with reference to an embodiment shown in the accompanying drawings of a dishwasher with a separation device according to the invention with the various new features. Fig. 1 is a schematic section through a bottom drain with a separating device for separating out granules from the dishwasher with the device set to separate out the granules. Fig. 2 shows a device set to allow the granules to pass out together with the liquid in a conduit to the dishwasher pump. Fig. 3 is a detailed view of the mounting of the separating means. If washing is to be done with the aid of granules, it is advisable to use a bottom valve of the construction shown in Figs. 1-3. This bottom valve forms a separation device which when in the position shown in Fig. 1 causes the granules to be stopped by their own weight when moving against the underside of a separating means in the form of an annular straining cloth 48 stretched between an outer ring 49 and an inner ring 50. The granules then fall down to a bottom tank about a vertically movable pipe or valve ring 51, which is in Fig. 1 in its lower end position closing a gap 52 at the lower end of the valve ring 51. At the upper end of the ring 51, liquid passes through the straining cloth 48 and down through the ring to the pump conduit. A roof 53 is arranged on top of the valve ring 51 and has a downwardly directed edge 54. The outer ring 49 is fixed on the inside of said edge 54 in a groove, while the inner ring 50 is fixed in a groove at the upper end of the valve ring 51. This mounting of the straining cloth 48 prevents granules from lodging in a gap between these parts which are movable relative to each other, thus reducing the need for maintenance and assuring reliability of operation. When the valve ring 51 is lifted with the aid of a servo control lifting device 55 to its upper position, the flow through the straining cloth 48 is completely or partially cut off and the liquid with granules flows freely out through the lower gap 52 directly into the pump conduit as shown in Fig. 2. The ring 51 is loaded by tensions springs 56 which keep the ring 51 in contact with the bottom of the tank in the position shown in Fig. 1. An electric motor 57 turns an arm 58 in either direction. From the position shown in Fig. 1, the ring 51 is rotated so that the pin 59 on the ring rides up on a cam 60 thus lifting the ring 51 to the position shown in Fig. 2. Rotating the ring 51 in the opposite direction causes the ring 51 to be lowered to the position shown in Fig. 1. If the separating means 48 is a perforated plate or the like, its inner edge 50 will be slidably disposed about the valve ring 51 so that the ring can slide up and down relative to the annular separating means 48. The outer edge of this annular separating means is fixed to the roof 53.

Claims: Separation device for separating granules from dishwater in a dishwasher, especially in a dishwasher for large articles, in which granules can be mixed in the dishwater and separated therefrom, in which separation device a separation means (48) cooperates with a valve means (51) which in one position releases granules and dishwater directly into the pump conduit and in a second position forces the liquid with granules against the separation means (48) so that the granules are separated out and the liquid passes without the granules on to the pump conduit, characterized in that a valve ring (51) or a piece of pipe with a vertical central axis and preferably of circular cross section, is movable into a lower position, in which the lower end of the ring (51) closes off a discharge gap (52) for liquid and granules at the bottom of the tank, at the same time as a gap is opened between the upper end of the ring (51) and a roof (53) above the ring (51) so that liquid flows from below against the underside of the annular separation means (48) such as a straining cloth between the ring (51) and the outer edge portion (54) of the roof (53) to separate out granules which then sink to the tank bottom which is inclined down towards the ring (51) to collect granules about the ring, the liquid freed of granules being drawn to the suction conduit of the pump. Device according to Claim 1, characterized in that the straining cloth (48) is stretched between an inner ring (50) and an outer ring (49), the inner ring (50) being detachably fixed to the outside of the valve ring (51) and the outer ring (49) being detachably fixed to the inside of the roof edge portion (54). Device according to claim 1 or 2, characterized in that the vertically movable valve ring (51) is cylindrical and is rotatable back and forth between two end positions with the aid of driving means (57,55,58) and that cooperating means (59,60) will upon rotation raise or lower the valve ring (51) between its upper and lower end positions. Device according to any of the preceding claims, characterized in that the valve ring (51) is biased towards its lower end position by spring means (56).

Inventors: ALVEMARKER, ARNE
Applicants: ALVEMARKER, ARNE
Application year: 1983
Main classification: A47L15
IPC codes: A47L15