FR2545347A1 - METHOD FOR RECOVERING LOST HEAT IN HOUSEHOLD DISHWASHER AND MACHINE FOR IMPLEMENTING THE METHOD - Google Patents

Abstract

METHOD FOR RECOVERING LOST HEAT IN A DISHWASHER FOR HOUSEHOLD USE INCLUDING A WASHING TANK, A SOFTENING DEVICE, A DRAIN PUMP AND A HEATER FOR HEATING THE WASHING WATER. DOWNSTREAM OF A FRESH WATER INLET VALVE F1, A DUCT 8 ENDS IN A FREE-FLOW TRUNCLE 9 OF THE MANIFOLD 5 PLACED ABOVE THE SOFTENER DEVICE 3, 4 AND WHERE, on the one hand, A SUPPLY DUCT 10 LEADING INTO TANK 2 AND, ON THE OTHER HAND, A DUCT 6 GOING TO SALT BOX 3, AND TANK 2, INCLUDING A VENTILATION DUCT 27, IS CONNECTED TO THE ION EXCHANGER 4 BY A DOSING AND STOPPING DEVICE F2, F3 WITH A VIEW TO DELIVERING DETERMINED PARTIAL WATER QUANTITIES V3, V4.

Description

Method for recovering waste heat in a dishwashing machine

  household and machine for the implementation of the method.

  The invention relates to a method for recovering waste heat in a household dishwashing machine comprising a washing tub, a softening device, a drain pump and heating for heating the washing liquid which is sprayed by means of a pump on the dishes by an upper spraying device and a lower spraying device, and a tank connected to the tank thermally constructing and

  acting as a heat exchanger.

  In a process of this type known from the German patent application 27 30 489, the washing is carried out as follows: a) in the "prewash" phase of the program, by the freshwater supply line or from of the tank, water is sent to the washing tank which is circulated by means of the spraying device and then pumped out, b) in the "washing" phase of the program, by the supply of fresh water or from the tank, water is sent to the washing tank

  heated to a predetermined washing temperature and which is made

  then, after a certain period of action, the reservoir

  see and, heating being stopped, then preheat the contents of the re-

  direct thermal contact with the washing tank and a flow line through the tank to reach the upper spraying device, and after the heat exchange, the used liquid from the washing tank is pumped out. (c) at the beginning of the "intermediate rinse" phase of the program, the preheated water from the tank is introduced into the washing tank, and (d) at the end of the "final rinse" phase of the program, after removal of the flushing liquid contained in the wash tub, the water tank is refilled to cool the wash tub and condense the water vapor forming during the "drying" phase of the program, e) the water is kept finding in the tank for the phase

  "prewash or wash" of a new program.

  With this known method, thermal energy is drawn from the heated wash liquid that has been used and, with this energy, the fresh water used in the subsequent phases of the program is warmed up, so that more than one economy is saved. considerable energy, one also gets a treatment

  cleaning dishes with regard to temperature variations.

  As the tank designed for a filling volume of the washing tub corresponding to a washing process is emptied after the prewash, the amount of water in the tub available for washing is fresh water and must be heated from the water. temperature of the latter at the washing temperature The tank is also emptied for the intermediate rinsing so that the quantity of water available in the tank for the final rinsing is composed of cool or softened cold water which must then be heated to the

final washing temperature.

  By the German utility model 80 19 951, there is known a dishwasher which, instead of a balancing weight, comprises a water tank which is constituted by a blown piece of plastic material and is filled with water only at the place of assembly of the machine This water tank is arranged between the ion exchanger and the fresh water inlet of the washing curve and, therefore, being made in the area without pressure of the water inlet into the wash tank, can be made thin-walled Moreover, the water tank is kept constantly filled by means of a cooling coil installed on the envelopes of the washing tank and connected to the water tank, it is possible, during the "drying" phase of the program, to bring the water stored in the tank to the tank for

  cooling the casing of the wash tub.

  To measure more exactly and better adapt the amount of regeneration product to the local hardness of the water, German Patent No. 31 44 866 discloses a reservoir that can be filled when supplying fresh water, comprising at least two chambers and a venting valve and the contents of which may flow wholly or in part through an outlet pipe into the salt container to supply a quantity of brine suitable for

the ion exchanger.

  To determine the amount of water to be poured into the washing tub, there is furthermore known a level regulating device (German Utility Model 82 18 877) having a first small volume chamber which is connected to the washing tub of the machine via an overflow edge placed at the height of a specified filling level of

254534?

  this washing tank, while a second chamber, arranged upstream of the chamber relative to the overflow plate, is connected to a water supply and to the suction enclosure of the drain pump , the body forming the chamber having an opening for venting, and in the first chamber is connected a control device for stopping the supply of water to the washing tub The two chambers are connected by a siphon passing through above the overflow and in the first chamber can be provided a float and on the body a switch actuated by this float for

  close the fresh water intake valve.

  Finally, by the German patent 31 14 664, there is known an overflow valve which not only determines the safety level of the tank of

  washing, but also detects any water leaking out of the washing machine.

  The object of the invention is to develop a method of the aforementioned type which makes it possible to further reduce energy and water consumption, gives the possibility of shortening the duration of the washing programs and ensures a very accurate dosage. filling volumes of the tank

washing.

  This result is achieved according to the invention with a method characterized by the fact that during phases of the program occurring before or after the prewashing phase, a quantity of partial water is withdrawn from the tank and sent to the washing tank. through the ion exchanger to pass through the regenerated ion exchange mass, which is then pumped out and the reservoir refilled; that in the "prewash" phase of the program, part of the water stored in the tank is sent into the washing tank, circulated by means of the spraying device and pumped thereafter; that in the "wash" phase of the program, the water remaining in the tank is sent into the washing tank, heated to a predetermined washing temperature after or during the addition of an adjuvant and circulated, after rising to the washing temperature, the heating being switched off and the circulation pump started, the tank is filled with water and a manifold mounted upstream of it in the supply line of water, the contents of the tank are preheated by direct thermal contact with the washing tank and after the heat exchange, the used washing liquid is pumped from the tank; at the beginning of the "intermediate rinse" phase of the program, part of the preheated water is discharged into the washing tank, it is circulated by means of a spraying device, after which it is pumped; that in the "final rinse" phase of the program, the water remaining in the tank is sent to the washing tank, heated to the predetermined rinsing temperature, circulated after or during the addition of a product. rinse, then pump it; that in the "drying" phase of the program, the water tank is filled to cool the wash tank and condense the water vapor forming in the wash tank and the water is stored for cycles "prewash and wash "a new program; during or after the "drying" phase during one or more cycles of the program, water is sent from the collector to the salt container and the brine of the

salt container with ion exchanger.

  According to another advantageous characteristic of the invention, in the case of extended programs comprising a second pre-wash and / or several intermediate rinses and / or a washing with a larger volume of water in the washing tank, the quantities of water are withdrawn. additional partial requirements in the tank that are refilled after each withdrawal; according to another feature of the invention, the tank is filled with fresh water exclusively via the collector mounted upstream and empty

  in the wash tank via the ion exchanger.

  The method according to the invention can be used both in the case of a normal program in the case of soft economic programs or economic programs for delicate dishes, as well as in case of intensive program for particularly dirty dishes With the method, energy is withdrawn before the used washing liquid is pumped and is passed on to the following wash cycles, so that the dishes are subjected to

  gentle treatment sparing him strong temperature variations.

  The saved energy helps to significantly shorten the process of

  heating and therefore the duration of the entire program.

  Due to the large difference in temperature that occurs at the end of the "final rinse" phase of the program between the temperature of the hot dishes and the cold water flowing into the tank, the surface of the tank of

  washing that is applied to the latter constitutes a surface of

  densification, which greatly enhances and accelerates the drying of the dishes The very precise measurement of the volume of water brought to the washing tub at each washing cycle is ensured by the intercalation of the tank in which the partial quantities of water are constantly taken. desired independently of valve tolerances and pressure of the water pipes and also by the fact that the tank can always be filled to a precisely defined volume As the tank is constantly filled during the loading and unloading of the washing machine. dishes, a balancing weight

  additional to ensure the stability of the machine can be removed.

  For the implementation of the method, the invention proposes a dishwasher

  for household use which is characterized by the fact that downstream of an inlet valve

  a fresh water mission, a pipe ends in a free flow section of the collector which is above the softening device and from which, on the one hand, a supply pipe opening into the upper part of the tank in downstream of the free flow section in the direction of flow and, on the other hand, an outlet pipe to the salt container, and that the tank comprising an aeration pipe is connected to the ion exchanger via a dosing and stopping device

  to deliver specified amounts of partial water.

  In the dishwasher according to the invention, the collector comprises at

  minus two chambers and a venting valve allowing deli-

  at will, a partial volume or all of its volume to the salt container, this manifold being filled by the leakage water falling from the free flow section and / or by the discharge water of the supply line when the tank is full and being associated with a level sensor closing the intake valve of fresh water when the tank-and the collector are filled,

  the outlet of the latter opening into the salt container can be closed.

  According to an advantageous characteristic of the invention, the level sensor consists of an overflow chamber separated from the two chambers of the collector by a partition, which can be emptied by means of a siphon and in which a float or analog which, at the final raised position, actuates a switch closing the fresh water intake valve. The ventilation duct of the dishwasher tank according to the invention is preferably connected to the collector while it is connected to the washing tub by an overflow line. It is also advantageous that the bottom of the tank a drain line to the ion exchanger and in which a controlled arrat valve is installed and that in the zone of the threshold of the levels between the partial volumes of the reservoir is arranged for the cycles "prewash and wash" or "intermediate rinse and final rinse" means a second drain line terminating at the ion exchanger via a second shut-off valve, or a drain control device responsive by means of a magnetic float and flow switches; blade, light barrier or the like, on the valve

stopping the drain line.

  According to another advantageous feature of the invention, in the outlet duct between the collector and the salt container is installed a regeneration valve controlled by program and the bladder admission valve is associated with an overflow valve. which is controlled by a safety level sensor The safety level sensor may preferably be constituted by an air retaining chamber and an overflow chamber which can be emptied by a siphon and controlling the safety valve. overflow, as well as the fresh water intake valve when a safety level is reached, are integrated in the manifold or installed on the ion exchanger and connected by a pressure pipe to a valve chamber

acting on a membrane.

  The dishwasher according to the invention is further characterized in that in the event of a rise in the level of water in the tank up to the height of the mouth of the supply line, the tank is filled and the water flowing back into this pipe momentarily fills the collector until its level sensor responds and closes the intake valve of fresh water An instantaneous water heater can also be advantageously installed in the path water from the washing tub to the spraying device. Since the volume of the reservoir makes it possible to fill the washing tank with a quantity of liquid corresponding to two washing phases, with the water stored in the reservoir during the preceding program, it is possible, for example, to carry out a prewash and a wash to which case, during the washing, it suffices to heat the bath from the storage temperature to the desired washing temperature. The tank being empty during the heating phases, no thermal energy is taken from the washing tank The volume of water the tank heated by the heat dissipated by the washing liquid before its pumping is also sufficient for the intermediate rinse and the final rinse, so that during the "final rinse" phase, the tank being emptied, it suffices to heat the final rinse liquid from the storage temperature to the rinsing temperature In case of program variations, for example several intermediate rinses or a washing with more large volume of water in the tank, it is possible to refill the tank after

  each sample to provide the partial quantities of water

  In the same way, before prewashing, the amount of partial water required for

  pass through the regenerated ion exchanger and then fill it

  again before withdrawing from the tank the amount of partial

necessary for prewash.

  The course of the process according to the invention is easy to control.

  Since the filling volumes of the wash tank are independent of the valves, exact volumes are obtained for the bath, which guarantee a perfect result. The heating is less stressed and because of the cooling of the washing tank during drying, it is possible to avoid additional air heating The particularly efficient condensing surface on the washing tub generates an air flow which favors the drying of the dishes, so that additional blowing can be suppressed. at the same time the removal of any safety device against heating overheating, which can for example be reduced to an instantaneous water heater installed so that no heating system does not appear in the wash tub and that there is no longer any drilling, or support for the heating bars, nor

  seal for it and the thermostat.

  The invention will be better understood with the help of the description of a mode of

  embodiment taken as an example, but not limited to, and illustrated by the accompanying drawing, in which: Figure 1 is a block diagram of a dishwashing machine for household use according to the invention; Figure 2 shows schematically the structure of the dishwasher according to Figure 1; Fig. 3 is a diagram showing the flow of the dishwasher program according to Figs. 1 and 2;

  FIG. 4 represents a household dishwashing machine according to the invention.

  in which the security level sensor is integrated in the collector; FIG. 5 represents a variant of the household dishwashing machine according to the invention comprising a safety level sensor installed on the ion exchanger and an evacuation device associated with the tank. The household dishwashing machine comprises a washing tub 1 made of thin sheet metal, the rear wall of which in the example shown is made double O 10 to form a tank 2 Above the softening device constituted by a salt container 3 and a ion exchanger 4, there is a collector 5 of preference installed on a side wall of the washing tank and from the bottom of which an outlet pipe 6 leading to the salt container The machine is connected to a supply line water 7 via a fresh water intake valve flo Starting from the fresh water intake valve fl, a pipe 8 leads to the collector 5 and ends with a nozzle-shaped end in a free flow section 9 formed therein. A feed line 10 commencing downstream of the free flow section in the direction of flow arrives in the

upper part of the tank 2.

  On the side of its bottom, the tank can be filled up to the height of the mouth of the supply line 10 is connected by a drain line 11 and a controlled shutoff valve f 2 to the exchanger d 4 and, according to the embodiments of Figures 1 to 4, in the zone of the threshold of the levels 13 between its upper partial volume V 3 for the prewash or the intermediate rinse and its lower partial volume V 4 for the washing or the final rinse is connected by a second drain line 12 and another shut-off valve f 3 also to the exchanger

  of ions that can be emptied into the wash tub 1.

  The salt container 3 also connected to the ion exchanger for the regeneration of the ion exchange mass for the addition of salt to a filling pipe 14 which can be closed and protruding into the washing tub, and a regeneration valve f 4 is further provided in the outlet line 6 to better match the amount of brine which, depending on the local hardness of the water, is each time necessary to regenerate the spent ion exchange mass, the collector 5 comprises two chambers Vi, V 2 and a venting valve 15 The two chambers VI and V 2, placed next to each other, of the collector 5, are separated by a partition 16 which is capped by a siphon 17 whose two branches descend to near the bottom of the two chambers The bend of the siphon 17 is located below the level 19 formed by an overflow pipe 18, opening into the washing tub, collector 5 At the siphon bend 17 is connected a

  ventilation duct 20 which carries the vent valve 15 to its ex-

  While fresh water is brought to the tank by

  8,10, the water falling from the free flow section 9 is collected in the chambers VI, V 2 of the collector 5 When the tank 2 is full enough so that its water level reaches the mouth of the pipe d 10, the collector under the effect of the reflux occurring in the pipe 10 is quickly sufficiently filled to reach the level 21 at which the water arrives through a partition 22 in an overflow chamber 23 and raises to the inside thereof a float 24 actuating a switch which closes the fresh water intake valve fl and interrupts the supply of water to the machine Excess water being between the filling level 19 of the chambers VI, V 2 and the level 21 of the collector can flow into the washing tank via the overflow line 18, another

  siphon 26 for emptying the overflow chamber 23.

  In dishwashers that operate in areas of low water hardness, a small amount of brine is sufficient to regenerate the mass contained in the ion exchanger In case of extreme hardness of the water, it is however necessary to introduce a larger quantity of brine into the ion exchanger To initiate the regeneration process during which no additional water is supplied to the collector 5, the regeneration valve 4 releases the outlet of the stored water which The chamber Vi empties firstly and the volume of water lying above the wall 16 and reaching the level 19 also flows in the regions of low hardness. the water, the aeration pipe 20 and its valve are open so that the siphon 17 is vented and is therefore defused The water contained in the chamber V 2 remains in the collector 5 Water flowing through the outlet pipe 6 exp ulse salt tray brine that reaches the exchanger

  of ions and processes the regeneration of the ion exchange mass.

  In regions of high water hardness, vent line 20 and vent valve 15 are closed so that trap 17 can act during emptying of manifold 5 When priming the process regeneration, there is therefore a dump of both the chamber V 1 of the chamber V 2 of the collector 5 The water stored in the two chambers VI and V 2

  now expels a large amount of brine from the salt container.

  The execution of a washing program comprising the following successive phases: pre-washing, washing, intermediate rinsing, final rinsing, drying and regeneration, is carried out in the following manner in accordance with FIG.

  for the passage D of the water through the ion exchange mass re-

  generated at the end of the preceding washing program, at the beginning of a new washing program, the stop valve f 2 is opened for a predetermined duration by the value of a step length of the measuring apparatus and, from the tank 2, a partial amount of water is sent to the washing tank 1 by passing through the ion exchanger 4, and then evacuated by starting the pump P In the next phase of the program by opening the fresh water inlet valve f1, the tank 2 is refilled until the associated level sensor 22-25 responds when the filling level is reached and closes the water supply valve. El admission For ventilation

  of the reservoir, a pipe 27 disposed above the feed pipe

  10 connects the tank to the manifold 5.

  The actual washing program now begins with a filling phase during which, with the shut-off valve f 3 open, the upper partial volume V 3 intended for the prewash can flow from the tank to the wash tank through the ion exchanger The water stored in the reservoir during the preceding washing program has for example a temperature of 20 ° C corresponding to the ambient temperature After the supply of the partial volume V 3 exactly measured, the valve of stopping f 3 is closed and, during the prewashing phase, by means of the pump U the water contained in the washing tank is circulated in order to clean the dishes using the spraying device of the machine and then, at the means of the drain pump,

it is pumped into the pipeline.

  After completion of the "prewash" phase of the program, during another filling phase and the shutoff valve f 2 being opened, from the tank, it is sent to the washing tank via the drain line II and 1 l the ion exchanger the lower partial volume V 4 exactly defined After that, the tank is completely emptied, because the lower partial volume V 4 brought to the washing tank from the tank corresponds to the filling volume of the tank necessary for washing The tank being empty, the liquid is heated to the washing temperature of for example 680 C and is

  circulates with the addition of a detergent When the temperature

  washing is reached and the heating is stopped, by the valve of

  open fresh water mission f 1, the pipe 8, the free flow section 9 and the feed pipe 10, the tank is filled until the level sensor 22-25 closes the intake valve f 1 As the stern continues to operate, there is a heat exchange between the washing liquid and the water in the tank O The heat is then taken from the washing liquid and the water from the tank is heated to example 40 QC Like the washing bath to be evacuated in line a

  also cooled at this temperature, the evacuation tubes and the

  environment are not affected by the hot wash bath, and uneamenée

  extra cold water for cooling the bath can be

  winning. At the beginning of the intermediate rinse, the upper partial volume V 3 of the preheated water is again taken from the tank and, the stop valve f 3 being open, is sent by the second drain line 12 and the heat exchanger. to the wash tank Since the temperature transition from wash to intermediate rinse is relatively low due to

  the exchange of heat, we obtain a very gentle treatment of the dishes.

  During the intermediate rinsing phase, the water contained in the

  in the wash tank and then pumped out.

  After completion of the intermediate rinsing, through the drain line 11 and the open stop valve f 2, the tank is completely emptied into the wash tank, the lower partial volume V 4 brought in the form of fresh water to the tank of washing corresponding here also to the amount of water required for the final rinse By adding a rinsing product and the tank being empty, the already hot water is heated to 400 C to bring it to the temperature of

  final rinse of eg 680 C and circulated by means of

  Positive spraying Pumping the final rinse liquid takes over

drying.

  At the beginning of the drying phase, the shutoff valves f 2, f 3 being closed and the bladder admission valve blown open, the tank 2 is filled.

  of fresh cold water, the level sensor 22-25 here also causing the

  Inlet of the intake valve Due to the cool cold water, the partition between the wash tub and the tank is an effective cundensation surface on which the moist air present in the wash tank condenses without the intervention. of an additional drying heater, this has the effect of accelerating the drying process, the air flow forming in the washing tub having in addition a beneficial action.

  possible to optimally isolate the wash tub and the outer surface of the

  the tank, without limiting the function of the condensing surface or significantly affecting the drying process. In addition to effective thermal insulation, it is possible to obtain

  same time good soundproofing -

  During the drying phase, the spent ion exchange mass can be regenerated. Since the chambers VI and V 2 of the collector 5 have also been filled during the filling of the tank 2, the valves fl, f 2, f 3 being closed, it is possible to open the regeneration valve f 4 so that, depending on the setting of the air valve 15 in the atmosphere 15, the water of the chamber V1 or both chambers V 1 and V 2 flows into the salt container 3 by the

  outlet pipe 6 A corresponding quantity of brine is then expelled

  In the course of the program according to FIG. 3, the expulsion of the brine in the ioa exchanger is divided into two phases separated in time at the completion of the last phase T

  "drying" of the program, the motor is stopped.

  The dishwasher is furthermore equipped with an overflow valve 28 which reacts to the safety level not to be exceeded in the washing tub as well as to any leaks occurring in the machine. this effect a torque capsule which is connected to a level sensor 29 by a pressure line 30 The safety level sensor comprising an overflow chamber 31, a spill partition 32, a ventilation chamber 33 and a siphon 34, can be installed on the ion exchanger 4 or integrated in the collector 5 For the detection of leaks, on the bottom 35 of the dishwasher is provided a float 36 acting

  on the load cell of the overflow valve 28.

  In the embodiment according to FIG. 5, the tank 2 can be emptied into the washing tank 1 only via an arresting valve f 2, a discharge line 11 and the heat exchanger. 4 to measure exactly the partial volumes V 3, V 4 of the tank, in a tube 37 communicating with the reservoir is installed a float 38 provided with a permanent magnet and at the level of the threshold of the levels 13 between the partial volumes

  V 3, V 4, as well as near the bottom of the tank are arranged cnm-

  blade mutators 39 which respond to the magnetic attraction and cooperate with the float magnet 38 When the float reaches the threshold of the levels 13 or the level of the bottom of the tank, via the blade cosmetics, it provokes at each time closing the valve

stop f 2.

  If you want to widen the washing program by adding a second prewash phase, a washing process with a larger amount of

  washing liquid or a second or third cycle of

  However, the quantities of additional water are also taken from the tank, which can, however, be refilled after each additional water withdrawal by means of the fresh water intake valve that is controlled by fl.

Claims (10)

  A method for recovering heat lost in a household dishwashing machine, comprising a wash tub, a softening device, a drain pump and a heater for heating the wash liquid which is sprayed by means of a pump onto the dishwashing apparatus and a lower spraying device, and a tank thermally conductive connected to the tank and acting as a heat exchanger, characterized in that during phases of the program before or after the pre-wash phase, a quantity of partial water is withdrawn from the tank (2) and sent to the washing tank (1) via the ion exchanger to pass through the ion exchange mass. regenerated, then pumped out and refilled; in the prewash phase of the program, part of the water stored in the tank is sent to the washing tank, circulated by means of the spraying device and pumped thereafter; "washing" of the program, the water remaining in the tank is sent to the washing tank and heated to a predetermined washing temperature after or during the addition of an adjuvant and circulated, after rising to the washing temperature, the heating being switched off and the circulation pump started, the tank is filled with water and a collector (5) mounted upstream of it in the supply line of water, the contents of the tank are preheated by direct thermal contact with the washing tank and after the exchange, the   used washing liquid from the tank; at the beginning of the "flushing   In the program, one part of the preheated water is discharged into the tank, circulated by means of the spraying device, after which it is pumped, and in the "final rinse" phase of the In the program, the water remaining in the tank is sent into the washing tank, heated to the predetermined rinsing temperature, circulated after or during a rinsing product, and then pumped. In the "drying" phase of the program, the water tank is filled to cool the wash tub and condense the water vapor forming in the wash tub and the water is stored for the "prewash and wash" cycles. a new program, that during or after the "drying" phase, during a   several cycles of the program, water is sent from the collector (5) to the   salt (3) and brine from the salt container to the ion exchanger (4).   2545 t 47 2 Process according to Claim 1, characterized in that, in the case of extended programs comprising a second prewash and / or several intermediate rinses and / or a washing with a larger volume of water in the wash tank, withdraws the additional partial quantities of water needed in the tank which is refilled after each sampling.   3 Process according to claims 1 and 2, characterized in that   the tank (2) is filled with fresh water exclusively via the collector (5) mounted upstream and emptied into the washing tub (1)   via the ion exchanger (4).   4 Dishwashers for household use for the implementation of the process   according to any one of claims 1 to 3, characterized in that   downstream of a fresh water intake valve (f 1), a pipe (8) ends in a free-flow section (9) of the collector (5) which is above it of the softening device (3,4) and from which, on the one hand, a supply pipe (10) opening into the upper part of the   tank (2) downstream of the free flow section in the direction of flow.   and, on the other hand, an outlet pipe (6) to the salt container (3), and that the tank having an air line (27) is connected to   the ion exchanger (4) via a metering device and   (f 2, f 3, 38, 39) in order to deliver partial quantities of water completed (V 3, V 4).   Dishwasher for household use according to claim 4, characterized in that the collector (5) comprises at least two chambers (V1, V2) and a venting valve (15) for delivering-at will a   part or all of its volume in the salt container (3), that the collection   is filled by the leakage water falling from the free flow section (9) and / or by the discharge water of the supply line (10) when the reservoir (2) is full, that at the collector is associated a level sensor (22-26) closing the fresh water admission valve (fl) when the tank and the collector are filled and that the outlet of the collector opening in the salt container can be closed.   6 Dishwasher for household use according to claim 5, characterized in that the level sensor is constituted by an overflow chamber (23) separated from the two chambers (V 1, V 2) of the collector (5) by a partition (22), which can be emptied by means of a siphon (26) and in which is disposed a float (24) or the like which, in the final raised position, actuates a switch (25) closing the intake valve; fresh water (fi).   Dishwasher for household purposes according to claims 4 and 5,   characterized by the fact that the aeration pipe (27) of the tank (2) is connected to the collector (5) and that the latter is connected to the washing tub   (1) by an overflow line (18).   Dishwasher for household purposes according to claims 4 and 5,   characterized in that from the bottom of the tank (2) there is a drain line (11) to the ion exchanger (4) and in which a controlled shut-off valve (f 2) is installed and in which zone of the level threshold (13) between the partial volumes (V 3, V 4) of the reservoir is arranged for the cycles "prewash and wash" or "intermediate rinse and final rinse" or a second drain line (12) leading to the ion exchanger via a second shut-off valve (f 3), a drain controller responsive by means of a magnetic float (38) and slide switches (39), a light barrier or the like on the shut-off valve (f 2) the drain line (11).   Dishwasher for household use according to any one of the   4 to 8, characterized in that in the outlet pipe (6)   between the collector (5) and the salt container (3) is installed a regulating valve   (a) is controlled by program and a fresh water intake valve (fi) is associated with an overflow valve (28) which is controlled by a safety level sensor (29) or 10 Dishwasher for household use according to claim 9, characterized in that the safety level sensor (29) is constituted by a chamber (33) retaining the air and an overflow chamber (31) which, that can be emptied by a siphon (34) and controlling the overflow valve (28) and the fresh water admission valve (fl) when a safety level is reached are integrated in the collector (5). ) or installed on the ion exchanger (4) and connected by a pressure line (30) to   a valve chamber acting on a membrane.   Dishwasher for household purposes according to claims 4 and 5,   characterized by the fact that in the event of a rise in the water level in the   the reservoir (2) to the height of the mouth of the supply pipe (10), the reservoir is filled and the water flowing back into this pipe (10) momentarily fills the collector (5) until that its sensor   level (22-25) responds and closes the fresh water inlet valve (fl).   12 Dishwashers for household use according to any one of the   4 to 11, characterized in that an instantaneous water heater is installed in the water path from the washing tub to the spraying device.