Classifications

• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L15/00—Washing or rinsing machines for crockery or tableware
  • A47L15/0076—Washing or rinsing machines for crockery or tableware of non-domestic use type, e.g. commercial dishwashers for bars, hotels, restaurants, canteens or hospitals
  • A47L15/0078—Washing or rinsing machines for crockery or tableware of non-domestic use type, e.g. commercial dishwashers for bars, hotels, restaurants, canteens or hospitals with a plurality of fluid recirculation arrangements, e.g. with separated washing liquid and rinsing liquid recirculation circuits
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L15/00—Washing or rinsing machines for crockery or tableware
  • A47L15/0018—Controlling processes, i.e. processes to control the operation of the machine characterised by the purpose or target of the control
  • A47L15/0055—Metering or indication of used products, e.g. type or quantity of detergent, rinse aid or salt; for measuring or controlling the product concentration
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L15/00—Washing or rinsing machines for crockery or tableware
  • A47L15/24—Washing or rinsing machines for crockery or tableware with movement of the crockery baskets by conveyors
  • A47L15/241—Washing or rinsing machines for crockery or tableware with movement of the crockery baskets by conveyors the dishes moving in a horizontal plane
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L2401/00—Automatic detection in controlling methods of washing or rinsing machines for crockery or tableware, e.g. information provided by sensors entered into controlling devices
  • A47L2401/04—Crockery or tableware details, e.g. material, quantity, condition
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L2401/00—Automatic detection in controlling methods of washing or rinsing machines for crockery or tableware, e.g. information provided by sensors entered into controlling devices
  • A47L2401/30—Variation of electrical, magnetical or optical quantities
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
  • A47L2501/00—Output in controlling method of washing or rinsing machines for crockery or tableware, i.e. quantities or components controlled, or actions performed by the controlling device executing the controlling method
  • A47L2501/07—Consumable products, e.g. detergent, rinse aids or salt

Definitions

• the invention relates to a conveyor dishwasher according to the preamble of independent Patent Claim 1.
• the invention also relates to a method for operating a conveyor dishwasher according to the preamble of independent Patent Claim 18.
• the invention relates, in particular, to a conveyor dishwasher having at least one wash zone and at least one final rinse zone, and having a conveyor apparatus for conveying washware through the at least one wash zone and the at least one final rinse zone, with final rinse liquid, which comprises fresh water and rinse aid which is added in a metered fashion, being sprayed onto the washware in the at least one final rinse zone by means of at least one final rinse nozzle.
• the conveyor dishwasher is, in particular, a commercial conveyor dishwasher and can be in the form of a flight-type dishwasher (flight-type warewasher) or a rack-conveyor dishwasher (rack-conveyor warewasher).
• Conveyor dishwashers (conveyor warewashers) are used in the commercial sector. In contrast to domestic dishwashers, in which the washware to be cleaned remains stationary in the machine during cleaning, in conveyor dishwashers the washware is conveyed through various treatment zones of the machine.
• the washware for example dishes, pots, glasses, cutlery and other articles which are to be cleaned
• a conveyor apparatus which generally has compartments for accommodating washware is used to convey washware in a conveying direction through the conveyor dishwasher.
• the compartments can be formed by supporting fingers on a conveyor belt of the conveyor apparatus.
• dish racks in which compartments can be formed in order to accommodate the washware to be treated serve as the conveyor apparatus. It is feasible here for the dish racks to be conveyed through the rack- conveyor dishwasher by a conveying device.
• US 6,530,996 B2 describes a rack-conveyor dishwasher in which the washware to be treated is fed to the respective treatment zones in a state in which it is pre-sorted in dish racks.
• This conveyor dishwasher which is known from the prior art is provided with sensors which can be used to detect an identifying feature which is fitted on the dish rack and indicates the type of washware accommodated in the dish rack.
• a suitable washing and/or rinsing programme of the rack-conveyor dishwasher can be selected as a function of the detected identifying feature.
• DE 196 08 030 CI discloses a conveyor dishwasher in which, depending on the type and degree of soiling of the washware to be cleaned in the individual treatment zones of the conveyor dishwasher, additional spray systems are switched on or off in order to change the size of the action section in the treatment zones.
• a similar conveyor dishwasher is also known from DE 695 25 337 T2.
• a sensor is used to detect the presence of washware to be treated. If no washware is present, washing operation is interrupted until washware passes the sensor again.
• DE 196 08 036 C5 discloses a further conveyor dishwasher in which the quantity of final rinse liquid sprayed in the final rinse zone per unit time is changed as a function of the conveying speed and as a function of the respective rinsing programme.
• the quantity of fresh water sprayed during final rinsing and the quantity of rinse aid used for final rinsing are in each case coupled to the conveying speed and to the respective rinsing programme and are changed as a function of these.
• the invention is based on the object of developing a conveyor dishwasher of the type mentioned in the introduction in such a way that an optimum final rinse result can be achieved in spite of a reduction in the consumption of rinse aid and power for the washware to be treated.
• a further object to be achieved is that of specifying a corresponding method for operating a conveyor dishwasher of this type.
• the advantages which can be achieved by the invention include: provision is made, according to the invention, for a main line system and a secondary line system, which is separate from the said main line system, to be used to supply the final rinse liquid which is to be sprayed in the final rinse zone by means of the least one final rinse nozzle.
• a first portion of the final rinse liquid, which is to be sprayed in the final rinse zone by means of the at least one final rinse nozzle, is supplied by means of the main line system, while a second portion of the final rinse liquid which is to be sprayed is supplied by means of the secondary line system.
• the main line system and the secondary line system are combined immediately upstream of the at least one final rinse nozzle.
• the main line system and the secondary line system are combined in a region between the at least one final rinse nozzle and an apparatus, which is associated with the main line system, for heating the liquid which is supplied by means of the main line system.
• the liquid which is supplied by means of the main line system can be either pure fresh water or fresh water with rinse aid which is added in a metered fashion.
• a rinse aid metering apparatus which is associated with the secondary line system and with which rinse aid is metered into the secondary line system. Accordingly, the liquid which is supplied to the at least one final rinse nozzle by means of the secondary line system is fresh water to which rinse aid is added in a metered fashion.
• a control apparatus is also provided for automatically adapting the quantity of rinse aid which is metered into the secondary line system by the rinse aid metering apparatus per unit time.
• the secondary line system and the main line system are combined in a region between the at least one final rinse nozzle and an apparatus, which is associated with the main line system, for heating the liquid (pure fresh water or fresh water with added rinse aid) which is supplied by means of the main line system.
• an apparatus which is associated with the main line system, for heating the liquid (pure fresh water or fresh water with added rinse aid) which is supplied by means of the main line system.
• the volume of the final rinse nozzle system of the final rinse zone is usually approximately 1 L. Therefore, given a volumetric flow of final rinse liquid of approximately 3 L/min, the rinse aid concentration in the liquid which is sprayed by the final rinse nozzles can be adapted within approximately 20 seconds. If the fresh water which is supplied by means of the secondary line system and has rinse aid added was not admixed with the liquid, which is supplied by means of the main line system, immediately upstream of the at least one final rinse nozzle, the reaction time in which the rinse aid concentration in the final rinse liquid which is sprayed by means of the at least one final rinse nozzle can be adapted would be extended.
• the invention consciously proposes a secondary line system, since it would be disadvantageous to meter pure rinse aid into the liquid which is supplied by means of the main line system immediately upstream of the at least one final rinse nozzle. It should be noted here that experiments showed that metering rinse aid into unheated water leads to a significant improvement in mixing of the rinse aid with the fresh water and therefore ultimately and critically leads to a significantly better rinsing result. Since, according to the invention, the rinse aid is metered into the fresh water which is supplied by means of the secondary line system, and not into the heated fresh water which is supplied by means of the main line system, the rinse aid is metered into fresh water which is at a relatively low temperature (that is to say ⁇ 40°C). This ensures optimum mixing of fresh water and rinse aid which has been added in a metered fashion in the secondary line system. As a result, less rinse aid is required overall than when the rinse aid is metered into heated fresh water.
• the metered rinse aid can be admixed in an optimum manner with the fresh water, which is supplied by means of the secondary line system, while at the same time ensuring a rapid reaction time.
• a control apparatus is provided according to the invention, the control apparatus being designed to automatically adapt the quantity of rinse aid, which is metered into the secondary line system by the rinse aid metering apparatus, which is associated with the secondary line system, per unit time.
• the quantity of rinse aid which is metered into the secondary line system per unit time is preferably adapted as a function of the type of washware to be treated in the conveyor dishwasher. In this way, the concentration of rinse aid in the final rinse liquid which is sprayed in the at least one final rinse zone can be optimally matched to the type of washware to be treated. As a result, the consumption of rinse aid can be effectively reduced.
• the solution according to the invention makes it possible to thoroughly mix the rinse aid, which is added in a metered fashion, with the supplied fresh water in an optimum manner, the consumption of fresh water can also be reduced.
• the quantity of water to be heated is lower on account of the lower consumption of fresh water, as a result of which energy is also ultimately saved.
• Fig. 1 shows a schematic longitudinal view of a conveyor dishwasher according to a first embodiment of the invention
• Fig. 2 shows a schematic longitudinal view of a conveyor dishwasher according to a second embodiment of the invention.
• Fig. 3 shows a schematic longitudinal view of a conveyor dishwasher according to a third embodiment of the present invention.
• Fig. 1 shows a conveyor dishwasher 1 having a conveyor apparatus 2 for conveying washware (not illustrated) in a conveying direction T through the conveyor dishwasher 1.
• the conveyor dishwasher 1 has at least one wash zone, as illustrated in Fig. 1 for example, a prewash zone 10 and two main-wash zones 11.1, 11.2 which are arranged downstream of the prewash zone 10 as seen in the conveying direction T.
• a postwash zone 12 is arranged downstream of the at least one wash zone 10, 11.1, 11.2, and at least one final rinse zone, for example only a single final rinse zone 13 as illustrated, is arranged downstream of the postwash zone 12.
• the final rinse zone 13 is followed in the conveying direction T of the washware by a drying zone 14.
• the respective zones 10, 11.1, 11.2, 12, 13, 14 of the conveyor dishwasher 1 can be separated from one another by means of separating curtains 5.
• the inlet tunnel 3 of the conveyor dishwasher 1 itself is also separated from the inlet 4 by a separating curtain 5.
• the provision of the separating curtains 5 prevents wash liquid and final rinse liquid spraying between zones and prevents vapours escaping from the conveyor dishwasher 1.
• the treatment zones 10, 11.1, 11.2, 12, 13 of the conveyor dishwasher 1 have associated spray nozzles 30a, 30b, 31.1a, 31.1b, 31.2a, 31.2b, 32a, 32b, 33a, 33b, 33c.
• These spray nozzles 30a, 30b, 31.1a, 31.1b, 31.2a, 31.2b, 32a, 32b, 33a, 33b, 33c serve to spray liquid onto the washware to be treated as the washware is conveyed through the respective treatment zones 10, 11.1, 11.2, 12, 13 by the conveyor apparatus 2.
• the individual spray systems of the treatment zones 10, 11.1, 11.2, 12, 13 ensure that the washware to be treated is hosed down both from the top and from the bottom.
• the final rinse zone 13 not only has downwardly directed upper spray nozzles 33a and upwardly directed lower spray nozzles 33b, but also transversely directed lateral final rinse nozzles 33c on either side of the conveyor apparatus 2.
• the use of lateral final rinse nozzles 33c permits areas of the washware (areas of the dishes) to be sprayed with final rinse liquid in a targeted manner in shadow zones too.
• lateral final rinse nozzles 33c in the final rinse zone 13 has a significant advantage in terms of the final rinse result (effective rinsing-off of detergent residues from dish surfaces in shadow zones too) over systems in which only upper and lower final rinse nozzles 33a, 33b and no transversely directed final rinse nozzles 33c are provided in the final rinse zone 13, specifically when the conveying system is fully loaded, that is to say with plate-to-plate loading of the dish rack.
• the postwash zone or pre-rinse zone 12, main-wash zones 11.1, 11.2 and prewash zone 10 also have associated tanks (postwash tank 22, main-wash tank 21.1, 21.2, prewash tank 20) for accommodating sprayed liquid and/or for providing liquid for the spray nozzles 30a, 30b, 31.1a, 31.1b, 31.2a, 31.2b, 32a, 32b of the relevant treatment zones 10, 11.1, 11.2, 12.
• final rinse liquid which comprises fresh water with rinse aid which is added in a metered fashion
• final rinse nozzles 33a, 33b, 33c which are arranged above and below the conveyor apparatus 2 and on the side in the conveyor dishwasher 1 which is illustrated in Fig. 1.
• a portion of the sprayed final rinse liquid is conveyed from treatment zone to treatment zone via a cascade system in the opposite direction to the conveying direction T of the washware.
• the remaining portion of the final rinse liquid which is sprayed in the final rinse zone 13 is conducted directly to the prewash tank 20, which is associated with the prewash zone 10, via a valve VI and a bypass line 6.
• the final rinse liquid which is sprayed by the final rinse nozzles 33a, 33b, 33c flows from the final rinse zone 13 into the postwash tank 22 which is associated with the postwash zone 12 due to the force of gravity.
• the final rinse liquid which is sprayed in the final rinse zone 13 and collected by the postwash tank 22 is then delivered to the spray nozzles of the postwash zone 12 (upper and lower postwash nozzles 32a, 32b) of the postwash zone 16 with the aid of a postwash pump 36.
• Wash liquid is rinsed off from the washware in the postwash zone 12.
• the liquid (postwash liquid) which is produced in the process flows into the main-wash tank 21.1, which is associated with the first main-wash zone 11.1, due to the force of gravity.
• a discharge element 7, for example a discharge base or a baffle plate, which conducts the postwash liquid which is sprayed by the postwash nozzles 32a, 32b into the main-wash tank 21.1 is preferably provided for this purpose.
• the outlet element 7 can be dispensed with if the main-wash tank 21.1 extends as far as beneath the postwash nozzles 32a, 32b of the postwash zone 12.
• the liquid accommodated by the main-wash tank 21.1 of the main-wash zone 11.1 is usually provided with a detergent and sprayed onto the washware by means of the spray nozzles of the main-wash zone 11.1 (upper and lower main-wash nozzles 31.1a, 31.1b) with the aid of a first main-wash pump 35.1.
• the wash liquid which is sprayed by the main-wash nozzles 31.1a, 31.1b then flows back into the main-wash tank 21.1 due to the force of gravity.
• the main-wash tank 21.1 is fluidically connected to the main-wash tank 21.2 which is associated with the second main-wash zone 11.2 via an overflow line 9.1.
• the wash liquid which is sprayed in the first main-wash zone 11.1 enters the main-wash tank 21.2 of the second main-wash zone 11.2 via this overflow line 9.1 when there is a sufficient quantity of wash liquid in the main-wash tank 21.1 of the first main-wash zone 11.1.
• the liquid which is accommodated in the main-wash tank 21.2 of the second main-wash zone 11.2 is sprayed onto the washware by means of the spray nozzles of the second main-wash zone 11.2 (upper and lower main-wash nozzles 31.2a, 31.2b) with the aid of a second main-wash pump 35.2.
• the wash liquid which is sprayed by the main-wash nozzles 31.2a, 31.2b then flows back into the main-wash tank 21.2 of the second main-wash zone 11.2 due to the force of gravity.
• the main-wash tank 21.2 of the second main-wash zone 11.2 is fluidically connected to the prewash tank 20 which is associated with the prewash zone 10 via an overflow line 9.2.
• the wash liquid which is sprayed in the second main-wash zone 11.2 enters the prewash tank 20 via this overflow line 9.2 when there is a sufficient quantity of wash liquid in the main-wash tank 21.2 of the second main-wash zone 11.2.
• the liquid which is accommodated in the prewash tank 20 of the prewash zone 10 is then sprayed onto the washware by means of the spray nozzles of the prewash zone 10 (upper and lower prewash nozzles 30a, 30b) with the aid of a prewash pump 34, in order to remove coarse particles of dirt from the washware.
• the wash liquid which is sprayed by the prewash nozzles 30a, 30b then flows back into the prewash tank 20 due to the force of gravity.
• the prewash tank 20 is provided with an overflow line 8 which is used to feed the excess quantity of liquid to a waste water system if a specific liquid level in the prewash tank 20 is exceeded.
• the liquid which is sprayed in the main-wash zones 11.1, 11.2 and in the prewash zone 10 preferably contains detergent which is added in a metered fashion with the aid of a detergent metering apparatus (not shown in the drawings), for example, to the liquid accommodated in the main-wash tank 21.1 of the first main-wash zone 11.1.
• the final rinse zone 13 is followed by the drying zone 14 in the conveying direction T.
• the washware is dried using dry and heated air in order to blow off and/or dry up the moisture on the washware.
• the warm and moisture-laden air in the drying zone 14 is then drawn-off from the drying zone 14 via a further opening, for example with the aid of a fan 15. It is advantageous here if the exhaust-air stream from the drying zone 14 passes a heat recovery device 16 in which, for example, a condenser can be provided.
• the heat recovery device 16 serves to recover at least some of the thermal energy contained in the exhaust air. This recovered thermal energy can be used, for example, to heat the liquid which is to be sprayed in the final rinse zone 13.
• the tanks prewash tank 20, main- wash tank 21.1, 21.2, postwash tank 22 which are associated with the treatment zones 10, 11.1, 11.2, 12 are empty or insufficiently filled, the tanks first have to be filled with fresh water via a fresh-water line 18 and/or by spraying final rinse liquid in the final rinse zone 13.
• the fresh-water line 18 can be connected to a fresh-water supply system via an actuable valve V3.
• the quantity of wash liquid available in the main-wash zones 11.1, 11.2 and in the prewash zone 10 can in each case be monitored and signalled to a control apparatus 40 with the aid of a level sensor which is provided in the main-wash tank 21.1, 21.2 of the first and/or of the second main-wash zone 11.1, 11.2 and with the aid of a level sensor which is provided in the prewash tank 20.
• the final rinse zone 13 can - as illustrated in Fig. 1 - have an associated fresh-water container 23 for temporarily storing at least a portion of the fresh water which is provided for final rising purposes.
• the fresh-water container 23 is firstly provided with a fresh-water connection which can be connected to a fresh-water supply system via an actuable freshwater feed valve V2. Secondly, the fresh-water container 23 is connected to the intake end of a first final rinse pump 37a and to the intake end of a second final rinse pump 37b.
• the delivery end of the first final rinse pump 37a is connected to the upstream end region 47 of a main line system 44, by means of which main line system fresh water is delivered from the fresh-water container 23 to the final rinse nozzles 33a, 33b, 33c when the first final rinse pump 37a is operated.
• the main line system 44 connects the delivery end of the first final rinse pump 37a to a water heater 17 (boiler).
• the main line system 44 is designed in such a way that the liquid which is supplied from the first final rinse pump 37a to the final rinse nozzles 33a, 33b, 33c of the final rinse zone 18 first passes the heat recovery device 16 before reaching the water heater 17. In this way, it is possible to use at least some of the thermal energy from the discharged exhaust air to heat the liquid which is supplied to the spray nozzles 33a, 33b, 33c by means of the main line system 44.
• a further final rinse pump 37b of which the intake end is likewise connected to the fresh-water container 23, is provided in the exemplary embodiment of the conveyor dishwasher 1 according to the invention, this exemplary embodiment being illustrated in Fig. 1, in addition to the first final rinse pump 37a which is associated with the main line system.
• a secondary line system 45 which is designed separately from the main line system, is also provided in the embodiment of the conveyor dishwasher 1 which is illustrated in Fig. 1. In this case, the upstream end region 48 of the secondary line system 45 is connected to the delivery end of the second final rinse pump 37b.
• the downstream end region of the secondary line system 45 is combined with the main line system 44 in a region 46.
• the combination region 46 is provided between the at least one final rinse nozzle 33a, 33b, 33c and the water heater 17, which is associated with the main line system 44 on the one hand and the heat recovery device 16, which is associated with the main line system 44, on the other hand.
• the secondary line system 45 and the main line system 44 are preferably combined immediately upstream of the final rinse nozzles 33a, 33b, 33c.
• fresh water reaches the final rinse nozzles 33a, 33b, 33c from the fresh-water container 23 by means of two different line systems, specifically the main line system 44 on the one hand and the secondary line system 45 on the other hand.
• the fresh water which is supplied by means of the main line system 44 passes the heat recovery device 16 and the water heater 17 on its way from the fresh-water container 23 to the final rinse nozzles 33a, 33b, 33c, and consequently the fresh water which is supplied by means of the main line system 44 is correspondingly heated.
• the secondary line system 45 does not have an associated apparatus which serves to heat the liquid which is supplied by means of the secondary line system 45.
• the secondary line system 45 is in the form of a bypass line which supplies fresh water from the fresh-water container 23 to the final rinse nozzles 33a, 33b, 33c, such that it bypasses the heating assemblies (water heater 17, heat recovery device 16) which are associated with the main line system 44, when the second final rinse pump 37b is operated. Accordingly, the fresh water which is supplied by means of the secondary line system 45 is at a temperature of less than 40°C, and in particular less than 30°C.
• rinse aid is added in a metered fashion and as required to the fresh water, which is supplied from the fresh-water container 23 by means of the secondary line system 45, with the aid of a rinse aid metering apparatus 42 which is associated with the secondary line system 45.
• the rinse aid is consciously metered into the secondary line system 45 upstream of the combination region 46, so that the rinse aid is added to unheated fresh water, that is to say to fresh water which is at a temperature of less than 40°C and in particular less than 30° C.
• experiments have shown that the rinse aid and fresh water mix significantly better and more uniformly when the rinse aid is added in a metered fashion to unheated fresh water.
• rinse aid should be added in a metered manner to fresh water which is at a temperature of less than 40°C, and preferably less than 30°C.
• the rinse aid metering apparatus 42 which is associated with the secondary line system 45 preferably has a controllable rinse aid metering pump which can be actuated by means of a control apparatus 40 which is schematically illustrated in Fig. 1.
• the control apparatus 40 is designed to preferably automatically adjust or, as a function of the type of washware to be treated, adapt the quantity of rinse aid which is metered into the secondary line system 45 by the rinse aid metering apparatus 42 per unit time.
• the control apparatus 40 is designed to, preferably automatically, change the quantity of rinse aid, which is metered into the secondary line system 45 with the aid of the rinse aid metering apparatus 42 per unit time, as a function of the type of washware conveyed through the at least one final rinse zone 13.
• the conveyor dishwasher 1 illustrated in Fig. 1 has a washware detector apparatus 41.
• the term "washware detector apparatus” used here is to be understood as any detection apparatus which is designed to detect and/or to determine the type of washware to be treated in the conveyor dishwasher 1. It is feasible for the washware detector apparatus 41 to have at least one detector device which can detect the size and/or the shape and/or the material of the washware to be treated in the conveyor dishwasher 1. In one possible embodiment of the washware detector apparatus 41, it comprises at least one preferably optically, inductively or capacitively operating detector device, so that the size, the shape and/or the material of the washware can be detected for the purpose of identifying the type of washware.
• other types of detector for example inductively operating proximity sensors, light sensors, light curtains, laser scanners, 3D lasers, cameras, rotary transducers, etc., can be used as the detector device.
• the washware detector apparatus 41 is preferably arranged at the inlet 4 to the conveyor dishwasher 1, so that it is possible to detect the type of washware to be supplied to the individual treatment zones 10, 11.1, 11.2, 12, 13, 14 of the conveyor dishwasher 1.
• the washware detector apparatus 41 is arranged at least upstream of the inlet into the final rinse zone 13. The distance between the washware detector apparatus 41 and the inlet into the final rinse zone 13 depends on the reaction time with which the concentration of rinse aid in the final rinse liquid which is sprayed by means of the final rinse nozzles 33a, 33b, 33c can be changed.
• This reaction time depends substantially on the volume of the final rinse system which comprises the upper, lower and lateral rinsing arms, on the volume of the line system between the region in which rinse aid is metered into the secondary line system 45 with the aid of the rinse aid metering apparatus 42 and the region in which the secondary line system 45, which is combined with the main line system 44, merges with the final rinse system, and also on the conveying speed at which the washware is conveyed through the individual treatment zones 10, 11.1, 11.2, 12, 13, 14 of the conveyor dishwasher 1 in the conveying direction T.
• the reaction time with which the concentration of rinse aid in the final rinse liquid, which is sprayed by the final rinse nozzles 33a, 33b, 33c, can be adjusted as a function of the type of washware to be treated can only be increased at a constant conveying speed by the volume of the line system between the region in which the rinse aid is metered into the secondary line system 45 and the region in which the secondary line system 45, which is combined with the main line system 44, merges with the final rinse system being reduced as far as possible. Therefore, in order to ensure as rapid a reaction time as possible, it is advantageous if the rinse aid is metered into the secondary line system 45 with the aid of the rinse aid metering apparatus 42 immediately upstream of the combination region 46.
• the combination region 46 that is to say the region in which the secondary line system 45 is combined with the main line system 44, is as close as possible to the final rinse nozzles 33a, 33b, 33c or to the region in which the secondary line system 45, which is combined with the main line system 44, merges with the final rinse system.
• the concentration of rinse aid in the final rinse liquid which is sprayed can be adapted to the type of washware to be treated within
• the washware detector apparatus 41 would have to be arranged approximately 0.5 m upstream of the inlet into the final rinse zone 13, so that the quantity of rinse aid which is metered into the secondary line system 45 by means of the rinse aid metering apparatus 42 per unit time can be matched to the type of washware, which is detected with the aid of the washware detector apparatus 41, in good time with the aid of the control apparatus 40.
• the control apparatus 40 is connected to the washware detector apparatus 41 in particular via a suitable communication connection, in order for the type of washware which is to be supplied to the final rinse zone 13 and is detected by the washware detector apparatus 41 to be checked continuously or at predetermined times and/or as predetermined events occur.
• control apparatus 40 is preferably designed not only to automatically adjust the quantity of rinse aid metered into the secondary line system 45 per unit time, but is also designed to actuate the various actuable components of the conveyor dishwasher 1, for example the respective pumps (prewash pump 34, main-wash pump 35, postwash pump 36, final rinse pumps 37a, 37b), valves (VI, V2, V3) and the water heater 17, in order to thus be able to adjust the process parameters in the individual treatment zones 10, 11.1, 11.2, 12, 13 of the conveyor dishwasher 1, and in particular the process parameters in the final rinse zone 13.
• control apparatus 40 it is feasible, for example, for the control apparatus 40 to be designed to actuate firstly the final rinse pump 37a, which is associated with the main line system 44, and secondly the final rinse pump 37b, which is associated with the secondary line system 45, in such a way that the quantity of liquid which is supplied from the fresh-water container 23 by means of the secondary line system 45 per unit time corresponds to less than 10%, and preferably less than 5%, of the quantity of liquid which is supplied by means of the main line system 44 per unit time.
• a volumetric flow of liquid of less than 20 L/h is supplied by means of the secondary line system 45, it being particularly preferred if the volumetric flow of liquid which is supplied by means of the secondary line system 45 is in a range of from 5 L/h to 3 L/h. This ensures that only a comparatively small portion of liquid is supplied by means of the secondary line system 45 compared to the total quantity of liquid which is supplied to the final rinse nozzles 33a, 33b, 33c per unit time.
• the majority of the liquid which is supplied to the final rinse nozzles 33a, 33b, 33c is delivered by the main line system 44 and consequently passes firstly the heat recovery device 16, which is associated with the main line system 44, and secondly the water heater 17, which is likewise associated with the main line system 44, so that the majority of the liquid which is supplied to the final rinse nozzles 33a, 33b, 33c is correspondingly heated.
• control arrangement 40 is designed to automatically identify the washware to be treated on the basis of the type of washware which is detected by the washware detector apparatus 41.
• the control apparatus 40 can preferably automatically identify at least the following washware: plates which are produced from porcelain or a porcelain-like material; cups which are produced from porcelain or a porcelain-like material, glass or a glass-like material;
• trays, or tray-like articles which are produced from a plastics material
• drinking glasses which are produced from glass or a glass-like material.
• control apparatus 40 does not identify the washware on the basis of the type of washware which is detected by the washware detector apparatus 41, the relevant washware is identified as "other washware”.
• the solution according to the invention is distinguished not just by the automatic identification of the washware to be treated in the at least one drying zone 13, but also by the additional functionality of the control apparatus 40, according to which this control apparatus is designed to automatically select a predefined or predefinable value for the quantity of rinse aid which is to be metered into the secondary line system 45 with the aid of the rinse aid metering apparatus 42 per unit time as a function of the detected type of washware, and to accordingly actuate the rinse aid metering apparatus 42.
• the rinse aid metering apparatus 42 which is associated with the secondary line system 45, to have a controllable rinse aid metering pump.
• control apparatus 40 it is preferred for the control apparatus 40 to be designed to correspondingly actuate the rinse aid metering pump in order to adjust the quantity of rinse aid, which is to be metered into the secondary line system 45 per unit time, as a function of the detected type of washware.
• control apparatus 40 it is feasible for the control apparatus 40 to have, for example, a memory device (not illustrated in Fig. 1) which can be accessed by the control apparatus 40 and in which optimally adapted quantities of rinse aid, which are to be metered into the secondary line system 45 per unit time, are or can be stored for the individual types of washware in question.
• the task of the rinse aid in the final rinse liquid which is to be sprayed in the final rinse zone 13 is that of reducing the surface tension of the final rinse liquid which is sprayed in the final rinse zone 13 and therefore to prevent drop formation, this assisting the drying result or, in certain circumstances, making it possible to achieve the drying result.
• the extent to which the rinse aid influences the drying result depends on the drying properties of the material from which the washware which is to be treated in the final rinse zone 13 is produced.
• washware which is produced from porcelain or a porcelain-like material and from glass or a glass-like material has relatively good drying properties compared to trays or tray-like items which are produced from a plastics material. Accordingly, when trays or tray-like items which are produced from a plastics material are treated in the final rinse zone 13, the amount of rinse aid metered has to be increased in order to achieve a good drying result.
• the amount of rinse aid metered should be correspondingly reduced when treating washware which is produced from porcelain or a porcelain-like material, glass or a glass-like material since - as already indicated - these types of washware have improved inherent drying properties compared to a tray which is produced from a plastics material.
• metering an increased amount of rinse aid, which is necessary to achieve a good drying result when treating trays or tray-like items which are produced from a plastics material would have an immediate negative effect, in the form of streaks and other residues, on the final rinse result of washware which is produced from porcelain or a porcelain-like material, glass or a glass-like material.
• control apparatus 40 should preferably be formed in such a way that it:
• the fourth predefined or predefinable value being smaller than the third predefined or predefinable value; and/or the third predefined or predefinable value being smaller than the second predefined or predefinable value; and/or the second predefined or predefinable value being smaller than the first predefined or predefinable value.
• the rinse aid metering apparatus 42 should preferably be actuated in such a way that the quantity of rinse aid which is metered into the secondary line system 45 per unit time reaches its highest value, and therefore the final rinse liquid which is sprayed in the final rinse zone 13 has a concentration of rinse aid of preferably greater than 0.5 ml per litre of final rinse liquid.
• the rinse aid metering apparatus 42 should be automatically actuated in such a way that the quantity of rinse aid which is metered into the secondary line system 45 per unit time assumes a correspondingly low level, so that the final rinse liquid which is sprayed in the final rinse zone 13 has a concentration of rinse aid of preferably less than 0.3 ml per litre of final rinse liquid.
• the quantity of metered rinse aid should automatically be adapted to an average level, so that the concentration of rinse aid in the final rinse liquid which is sprayed in the final rinse zone 13 assumes a value of preferably less than 0.5 ml per litre of final rinse liquid.
• the washware detector apparatus 41 is further designed to
• control apparatus 40 should automatically adjust the quantity of rinse aid which is metered into the secondary line system 45 per unit time to the lowest possible value.
• Fig. 2 shows a schematic side view of a further embodiment of the conveyor dishwasher 1 according to the invention.
• the conveyor dishwasher 1 corresponds substantially to the conveyor dishwasher described above with reference to the illustration in Fig. 1, and therefore the structure and the manner of operation of identical or identically acting components have not been described.
• the embodiment which is illustrated in Fig. 2 differs from the conveyor dishwasher described above with reference to Fig. 1 in that, in the conveyor dishwasher 1 according to Fig. 2, a rinse aid metering apparatus 43, which is associated with the main line system 44, is provided in addition to the rinse aid metering apparatus 42 which is associated with the secondary line system 45.
• the rinse aid metering apparatus 43 which is associated with the main line system 44 is arranged in relation to the main line system 44 in such a way that the rinse aid is metered into the main line system 44 in a region upstream of the heat recovery device 16 and upstream of the water heater 17 with the aid of the rinse aid metering apparatus 43. Accordingly, in the embodiment which is illustrated in Fig. 2, the rinse aid is metered with the aid of the rinse aid metering apparatus
• the rinse aid metering apparatus 43 which is associated with the main line system 44 is preferably formed in such a way that a constant quantity of rinse aid is metered into the main line system 44 per unit time.
• the rinse aid metering apparatus 42 which is associated with the secondary line system 45 is - as already mentioned with reference to the embodiment of the conveyor dishwasher 1 which is illustrated in Fig. 1 - accordingly designed such that the quantity of rinse aid which is metered into the secondary line system 45 by this rinse aid metering apparatus 42 per unit time can be automatically adapted with the aid of the control apparatus 40.
• Fig. 3 illustrates a schematic side view of a further embodiment of the conveyor dishwasher 1 according to the invention. This embodiment corresponds
• the secondary line system 45 does not issue into the fresh water container 23 - as illustrated in Fig. 1 and Fig. 2 - but is connected directly to a fresh-water connection by means of a valve V4 which can preferably be actuated with the aid of the control apparatus 40.
• this embodiment ensures that fresh water is supplied by means of the secondary line system 45, the fresh water - in contrast to the fresh water which is supplied by means of the main line system 44 - not being heated, this ensuring optimum admixing of the rinse aid which is metered into the secondary line system 45 with the aid of the rinse aid metering apparatus 42.

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• 2010
  • 2010-01-23 DE DE201010005533 patent/DE102010005533B4/de not_active Expired - Fee Related
• 2011
  • 2011-01-04 WO PCT/US2011/020068 patent/WO2011090810A2/en active Application Filing
  • 2011-01-04 EP EP11734975.3A patent/EP2525700B1/de active Active

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