JP2004081880A - Dish washing/drying machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dish washing/drying machine which has an improved washing performance to shorten the washing period of time and to reduce the amount of detergent. <P>SOLUTION: This dish washing/drying machine has a washing tub 2 to contain a basket on which dishes are placed, a water supplying route through which cold or hot water for washing or rinsing is supplied to the washing tub 2 by the operation of a water valve, a circulating route to spray the supplied water in the washing tub to the dishes from a nozzle, and a control circuit 12 to control washing and rinsing processes. In this dish washing and drying machine, a hard water-generating tub 23 is fixed in the water supplying route and its washing process is carried out using hard water whose hardness is heightened from the water supplied from its outer water source for the water supply for the washing process. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates generally to a dishwasher and, more particularly, to a dishwasher improved so that it can be washed in a short time and the amount of detergent used can be reduced.

(3) In the conventional dishwasher / dryer shown in FIG. 3, tableware 48 installed in the tableware basket 3 is stored in the washing tank 2. In operation, after putting detergent, the door is closed and the operation is started by pressing the start button.

{Circle over (1)} First, the water supply valve 15 is opened, water is supplied from the water supply connection part 14 through the water supply pipe 16, the water is supplied from the water supply port 17 into the cleaning tank 2, and the water is accumulated to a level higher than the temperature at which the heater 4 is immersed. When the water level reaches the washable water level, when a water level sensor (not shown) detects the water level, the control circuit 12 stops the opening operation of the water supply valve 15, stops the water supply, and automatically performs a series of subsequent operations. Carry out.

と 同時 に At the same time as the water supply is stopped, the motor 8 starts rotating forward, and the impeller of the pump 7 connected to the motor shaft also starts rotating. As a result, the pump pumps water from the bottom of the washing tank 2 to the washing and discharging pipe 9 via the suction pipe 6, is further supplied from the discharging pipe 9 to the rotating nozzle 11, and is installed at the top from the nozzle opening. It is jetted vigorously to the tableware 48 and the circulation is repeated.

At this time, if necessary, power is supplied to the heater 4 to heat the water supply. As a result, dirt is separated from the tableware, dissolved and decomposed by the action of the mechanical force of the cleaning water injected from the rotary nozzle 11, the heat, and the detergent, and the tableware is washed. When the cleaning water reaches the set temperature or when the set time has elapsed, the cleaning process is completed, the motor 8 is rotated in the reverse direction, and the dirty cleaning water in the cleaning tank 2 is discharged from the pump 7 through the drainage discharge pipe 10, The water is discharged from the drain 13 to the outside of the washing tank. Next, the water supply valve 15 is opened, new tap water is supplied, and the process proceeds to the rinsing step.

In the rinsing step, the step of rotating the pump 7 forward to inject water from the nozzle 11 for rinsing, and then again rotating the pump 7 in the reverse direction to drain the water is repeated several times to remove dirt remaining in the dishes and the washing tank. Drain and rinse. At this time, in the final rinsing step, the heater is used to heat and rinse with hot water.

When the drainage of the final rinsing step is performed and the entire rinsing step is completed, the blowing fan (not shown) starts operating and the drying step starts. Air is blown into the washing tank from the outside, exhausted from an exhaust port opened near the door, and intermittently operated to the heater 4 to dry the tableware 48 and the inside of the washing tank. When the drying operation for an arbitrary time is completed, the operations of the blower fan and the heater are stopped, and all the processes are completed.
JP-A-2000-300494 JP 2001-238845 A

In recent years, awareness of environmental issues has increased, and the burden on the environment due to detergent drainage has been emphasized. However, when washing dishes with a dishwasher and dryer without adding detergent, starch, protein, oil and fat, etc., can be washed only with mechanical power and heat if sufficient temperature and time are spent. It is.

油 Also, oil stains can be separated from tableware by raising the temperature, but without detergent, they re-adhere, resulting in slimy washing and fogging of glass products. Furthermore, protein stains such as eggs, unlike other stains, are denatured and become hard when the temperature is high, and are difficult to wash without a detergent.

す ぎ Further, when rinsing is performed using tap water, hardness components such as Ca ions and Mg ions in the tap water become calcium carbonate or the like and remain white on the surface of tableware, resulting in a water spot. Especially in Europe, water spots are likely to occur due to high hardness of tap water. Therefore, in Europe, a dishwasher that softens tap water using an ion exchange resin and supplies the water is marketed.

水道 Tap water in Japan is soft water with less hardness components than in Europe, but even if a little dirt such as oils and fats remains on the tableware surface, the hardness components are combined and clouding is likely to occur. Correspondingly, Japanese Patent Application Laid-Open No. 2000-300494 discloses a structure in which an ion exchange device is provided in a water supply path, and in either one or both of a washing step and a final rinsing step, tap water in the supply water is softened. Proposed.

Japanese Patent Application Laid-Open No. 2001-238845 proposes a structure in which a regenerating unit of a water softening device is further provided and the regenerating unit regenerates the water before the final rinsing step. In any case, tap water is softened, and washing and rinsing are performed. Also in the latter, the hardness component detached from the water softener by the regenerating agent at the time of regeneration is only drained, and the hardness component and Na ions in the salt are not used for washing.

The present invention has been made in order to solve the above-described problems, and it is an object of the present invention to provide an improved dishwasher which can be washed in a short time and can reduce the amount of detergent used. Aim.

The present invention provides a washing tank for storing a basket on which dishes are placed, a water supply path for supplying water or hot water for washing and rinsing into the washing tank by operation of a water supply valve, and water supply in the washing tank. In a method for cleaning a dishwasher having a circulation path for spraying from a nozzle to tableware and a control circuit for controlling a cleaning step and a rinsing step, a hard water generating means is disposed in the water supply path, and external water is supplied as water in the cleaning step. The cleaning step is performed using hard water whose hardness is higher than the supply water supplied from the water supply source.

According to a preferred embodiment of the present invention, it is preferable to execute the cleaning step using hard water having a hardness of more than 180 mg / L (hereinafter referred to as CaCO ₃ ) as water supply in the cleaning step.

According to a further preferred embodiment of the present invention, the rinsing step is performed using soft water having a hardness of less than 50 mg / L as water supply in the rinsing step.

According to a further preferred embodiment of the present invention, before the washing step with hard water, washing is performed using soft water having a hardness of less than 50 mg / L.

According to a further preferred embodiment of the present invention, the water supply path is made into a plurality of switchable paths, and water is passed through at least one of the paths, so that the hardness component can be dissolved in the water. A tank filled with a hard water-generating ceramic is provided, and at least water is passed through the tank when water is supplied in the washing step.

According to a further preferred embodiment of the present invention, at least one of calcium sulfate, calcium sulfite, calcium chloride, calcium lactate, magnesium chloride, magnesium sulfate and calcium glycerophosphate is used as the ceramic for dissolving the hardness component.

According to a further preferred embodiment of the present invention, when the hardness of tap water is low, the time for which the ceramic filling tank is passed during the water supply in the washing step is set long.

According to a further preferred embodiment of the present invention, when the hardness of tap water is high, the time during which the ceramic filling tank is passed during the water supply in the washing step is set short.

According to a further preferred embodiment of the present invention, a filling tank filled with an ion exchanger of ion exchange resin or ion exchange zeolite is provided in the middle of the water supply path, and when supplying soft water to the washing tank, tap water is used. When the hardness component is removed by ion exchange and water is supplied as soft water and the hard water is supplied to the washing tank, the salt water is passed through the filling tank of the ion exchanger to thereby perform the previous operation and / or the previous step. The hardness component stored in step is desorbed to generate hard water and supply the water.

According to a further preferred embodiment of the present invention, when washing with hard water obtained by passing salt water through the filling tank of the ion exchanger, the salt concentration of the feedwater accumulated in the washing tank is 0.3%. % Or more.

According to a further preferred embodiment of the present invention, when the hardness of tap water is low, the washing step, the rinsing step or the water supply / drainage step is increased one or more times, or the amount of water passed through the salt water ion exchanger is increased.

According to a further preferred embodiment of the present invention, when the hardness of tap water is high, the washing step or the rinsing step is reduced by one or more times, or the amount of brine passed through the ion exchanger is reduced.

According to a further preferred embodiment of the present invention, soft water or raw tap water is used for water supply in the preceding step, and salt water is passed through the filling tank of the ion exchanger immediately before the start of the washing step or immediately before the rinsing step after the end of the washing step. An operation mode is provided in which a regeneration step of desorbing and draining the stored hardness component by water is added, and at least soft water is used as water supply in the rinsing step.

The present invention provides a washing tank for storing a basket on which dishes are placed, a water supply path for supplying water or hot water for washing and rinsing into the washing tank by the operation of a water supply valve, and water supply in the washing tank from a nozzle. In a dishwasher / dryer having a circulation path for injecting into tableware and a control circuit for controlling a washing step and a rinsing step, a saltwater generating means is provided in the water supply path, and a salt concentration of 0.3% is supplied as water in the washing step. It is characterized by being a dishwasher and dryer using salt water of at least%.

According to a further preferred embodiment of the present invention, no detergent is used in the washing step.

As described above, according to the present invention, hard water obtained by arranging a ceramic filling tank for dissolving the hardness component in the water supply path and passing water through the water supply path or distributing the cation exchanger to the water supply path is used. During rinsing, the hardness component in tap water is stored by ion exchange to soften it, and during washing, the hard component obtained by desorbing the hardness component stored in the cation exchanger by passing it through a regenerant such as salt water is used. By using, water is used for cleaning using water having a high hardness component and a high Na ion concentration.

As a result, the protein stain is rapidly dissolved in the washing water by the salt dissolving effect, and even for a small amount of oil stain, the oil and fat are surrounded to suppress reattachment, thereby increasing the washing efficiency and washing without detergent. It is possible.

Even in the case of washing with hard water together with the detergent, the dishwasher's special detergent often uses a nonionic surfactant, so it combines with the hardness component to produce metal soap, and the effect of the detergent is reduced. Since the protein dissolution performance does not increase and the protein dissolution performance increases, the cleaning performance is improved, and conversely, the cleaning can be performed in a short time or the amount of the detergent used can be reduced. Further, when the cation exchanger is used, the generation of water spots is suppressed by using soft water at the time of rinsing.

As described above, according to the first to fourth aspects of the present invention, by using hard water whose hardness is higher than that of water supplied from an external water supply source as water used for cleaning, egg-based water or the like can be obtained by a salt dissolution effect. Is easily dissolved, and can be washed without a detergent. Further, by washing with soft water before washing with hard water, even if the hardness when washing with hard water is too high, dirt of milk and legume food does not solidify on the tableware surface, and the washing performance is improved. Furthermore, by using soft water in the rinsing step, even if the hardness component and the binding component of the hardness component and the stain used in the cleaning step remain in the tableware and the washing tank until the rinsing step, they can be easily dissolved and cleaned neatly. In addition, generation of a water spot can be suppressed. When used in the cleaning step together with a detergent containing a nonionic surfactant as a main component, the cleaning performance is further improved by the synergistic effect of the detergent and the hardness component.

According to the fifth to eighth aspects of the present invention, hard water can be generated by a simple structure that only allows water to flow through the hard water generating ceramic, and the structure is simplified. Further, the hardness of the hard water can be easily changed only by changing the amount of water passing through the hard water-generating ceramic, that is, the water supply time, and can cope with the variation of the tap water hardness depending on the region.

According to the ninth to thirteenth aspects of the present invention, hard water and soft water can be obtained by using an ion exchanger, and Na ions in salt water can be used when hard water is generated. Can be dissolved, and the cleaning performance is improved. Further, a substance which is difficult to obtain in ordinary households such as hard water-generating ceramic is not used, and only household salt is used. This improves the convenience of the product. Further, the hardness can be adjusted only by changing the amount of saline solution passing through the ion exchanger, or by changing the amount of water softened in the washing step or the rinsing step, and can cope with variations in tap water hardness depending on regions. In addition, by adding an operation mode in which cleaning and rinsing is performed using only soft water, the cleaning performance is not impaired even when cleaning is performed using a detergent that easily binds to the hardness component.

According to the fourteenth aspect, the use of salt water having a salt concentration of 0.3% or more can dissolve the yolk stain.

According to the invention, the running cost can be reduced by washing without using a detergent. Further, since the detergent is not discharged, the load on the environment can be reduced, and a user can be provided with an earth-friendly dishwasher and dryer.

洗浄 A method for cleaning a dishwasher according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
With reference to FIG. 1, the dishwasher includes a cabinet 1 and a washing tank 2. In the washing tub 2, a tableware basket 3 for storing tableware 48 is slidably fitted forward. A pump 7 connected to a shaft of a motor 8 is provided at the bottom of the washing tank 2. The pump 7 uses, for example, a forward / reverse rotation type motor. The pump casing has one suction port and two discharge ports, and the discharge ports are connected to the cleaning discharge pipe 9 and the drain discharge pipe 10, respectively. I have. Switching valves are disposed at both discharge ports, and one of the discharge ports is opened. In the case of forward rotation, the water sucked from the suction pipe 6 is switched by the dynamic pressure of the flow in the casing due to the rotation of the pump impeller. Has a structure in which the drain discharge port is closed and the cleaning discharge pipe 9 is pressure-fed, and in the case of reverse rotation, the switching valve closes the cleaning discharge port and pressure-fed to the drain discharge pipe 10.

The cleaning water stored in the cleaning tank by the forward rotation of the pump passes through the residue filter 5, is sent from the suction pipe 6 to the rotary nozzle 11 through the cleaning discharge pipe 9, and is stored just above the rotary nozzle. The tableware 48 is sprayed.

(4) When the pump rotates in the reverse direction, the water accumulated in the washing tank 2 is discharged from the suction pipe 6 to the outside through the drain port 13 through the drain pipe 10.

However, the pump configuration is not limited to this, and a single motor shaft has two casings, and a suction port and a discharge port are formed in each chamber, and impellers for cleaning and drainage are arranged. A pump that switches between cleaning and drainage by forward / reverse rotation may be used, or a cleaning pump and a motor and a drainage pump and a motor may be independently provided.

In a state where water is accumulated in the washing water level near the bottom of the washing tank 2, a heater for heating the washing water at the time of washing and rinsing, or heating and drying the air in the washing tank at the time of washing and rinsing at a position immersed in water. 4 are provided. A control circuit 12 for executing and controlling a series of sequences from washing to rinsing to drying using various sensors is disposed near the bottom of the cabinet.

The connecting portion 14 supplies tap water from the tap to the system via a hose, and thereafter branches in two directions, one of which is directly connected to the tap water supply valve 18 via the tap water supply pipe 20. , Water is supplied to the washing tank. On the other hand, water is supplied from a hard water supply valve 19 to a hard water generation tank 23 via a hard water generation tank water supply pipe 22.

In the hard water generation tank 23, a ceramic storage basket 24 configured to allow water to enter the interior from any surface is installed freely through a ceramic storage basket input port 28. A hard water generating ceramic 25 such as calcium sulfate, calcium sulfite, calcium chloride, calcium lactate, magnesium chloride, magnesium sulfate, calcium glycerophosphate, etc., in the form of a block, a foam, a honeycomb, etc. is housed. A hard water supply pipe 26 connected to a hard water supply port 27 for supplying hard water into the washing tank is connected to a bottom surface of the hard water generation tank 23.

In the dishwasher / dryer having the above-described configuration, first, the tableware is housed in the tank and the door is closed without introducing the detergent. After the start of washing, the hard water supply valve 19 is opened, and tap water is supplied to the hard water generation tank 23. And water. When tap water gradually accumulates at the bottom of the hard water generation tank, water permeates into the basket from around and from the bottom of the ceramic housing cage 24, and flows while immersing the bottom of the hard water generation ceramic 25 by a certain amount.

At this time, the hard water-forming ceramic gradually dissolves and generates a Ca ion or Mg ion hardness component in tap water to form hard water having a certain hardness. After the hard water thus generated is supplied with an arbitrary amount from the hard water supply port 27 to the washing tank, the hard water supply valve 19 is closed, the tap water supply valve 20 is opened, and tap water is supplied to a washable water level. Is started.

The operation method of the washing step is basically the same as that of the conventional example, and thus will be omitted. However, unlike the conventional example, proteins such as eggs can be easily formed by washing with hard water containing a large amount of Ca ions and Mg ions, thereby achieving a salt dissolution effect. And good cleaning performance can be obtained without detergent. The magnitude of the salt dissolution effect by the ions is as follows. The ions on the left side have a stronger salt dissolving effect and dissolve the dirt easily, and the ions on the right side tend to cause a salting out effect and contaminate the dirt easily.

^{Ca 2+> Mg 2+> Na +} > K +> CnO 4-> I -> NO 3 -> Cl -> CH 3 COO -> SO 4 2-
At the start of the rinsing step after the completion of the washing step, the tap water supply valve 18 is opened, and tap water is directly supplied from the tap water supply port 21 to the washing tank without dissolving the hardness component. Start. Here, when the rinsing step includes a plurality of steps, the tap water is supplied by the tap water supply valve opening operation in all the rinsing steps. The amount of the hard water generating ceramic gradually decreases as the operation is repeated. When the amount of the hard water generating ceramic decreases, the ceramic housing basket 24 is opened to take out the ceramic housing cage 24, and the hard water generating ceramic is replenished.

In addition, the shape of the hard water generation tank is, in addition, a unit in which a hard water generating ceramic is filled in a column-shaped container having an inlet at one end and an outlet at the other end, and the entire amount of the ceramic is passed to obtain hard water. A water-permeable structure may be used. After that, the basic operation method from the rinsing step to the end of the operation through the drying step is the same as the conventional method, and the description is omitted.

By the way, tap water hardness varies depending on the area, but in areas where tap water hardness is low, hard water generation is performed by setting the open time of the hard water supply valve longer at the start of the washing process by operating the key at the start. The amount of water passing through the ceramic can be increased to increase the dissolution of the hardness component. Further, in the case of a region where tap water hardness is high, the above operation is reversed, and by setting the opening time of the hard water supply valve short at the start of the washing process, the amount of water passing through the hard water generating ceramic is reduced. In addition, the amount of dissolution of the hardness component can be reduced.

Table 1 shows the results when calcium sulfate was used as the hard water generating ceramic and egg yolk and milk, which are protein stains, were dissolved at various hardnesses.

(4) In the case of egg yolk, stains were applied to a tea bowl with a brush, dried for 1 hour, left in water of any hardness for 4 minutes, stirred for 1 minute, and compared with the area of the remaining egg yolk stain. From this, if the hardness is 180 (mg / L) or more, dissolution of the yolk stain due to the salt dissolution effect is observed.

In the case of milk stains, pour the milk into a transparent glass cup, discard it, form a milk film on the inner surface, leave it for 1 hour, add water of any hardness, leave it for 4 minutes, and then stir for 1 minute The comparison was made based on the remaining cloudy area. As a result, the lower the hardness of milk stain, that is, the softer the water, the less clouding is likely to occur. Further, as the hardness increases, fogging is likely to occur due to the salting out effect. However, fogging is reduced by rinsing with soft water having a hardness of 100 mg / L or less.

Table 2 compares cleaning performance according to the JEMA voluntary standard test method in the first embodiment.

This is a case where calcium sulfate is used as the hard water generating ceramic and the hardness at the time of washing is 500 (mg / L). Under these conditions, there are two kinds of measurement, one without detergent and one with detergent (using a nonionic surfactant). did. As a result, in the present embodiment, the cleaning performance is better than that of the conventional method with the detergent without the detergent, and the cleaning performance is further improved by the synergistic effect when the detergent is used in combination. In particular, in the conventional example, the egg stains remaining on the tableware after washing can be washed cleanly in the present example described in Table 2. That is, in the present embodiment, an example without a detergent is shown. However, when a detergent mainly containing a nonionic surfactant is used in a dishwasher-specific detergent, a synergistic effect of the detergent and hard water is used. Thereby, the cleaning performance is improved as compared with the cleaning using only the detergent.

(Embodiment 2)
In FIG. 2, components different from those of the first embodiment shown in FIG. 1 will be described.

構成 A configuration different from the first embodiment is only a water supply path. The connection unit 14 supplies tap water into the system from a water tap via a hose.

後 で Thereafter, branching is performed in two directions, one of which is supplied to the overflow tank 37 from the overflow tank water supply pipe 36 via the hard water supply valve 30. One is connected to an ion exchange tank 31 via a soft water supply valve 29. The overflow tank 37 is provided with two weirs, and one of the weirs flows out to the return water tank 39 and the other to the salt tank 43.

戻 し A return water supply pipe 40 is connected to the bottom of the return water tank 39 and communicates with a return water supply port 41 formed in a part of the cleaning tank 2. In the salt tank 43, a salt cage 44 for accommodating salt 45 is stored, and the salt cage is configured so that water can enter the inside from any surface. Further, the salt basket 44 is configured so that a salt basket inlet 46 formed in a part of the washing tank 2 is opened to take out the salt basket from the salt tank, and salt can be replenished to the salt basket. An opening is provided at the bottom of the salt tank 43, and the salt tank 43 communicates with an upper portion of the ion exchange tank 31 disposed below the salt tank by a salt water supply pipe 47.

Inside the ion exchange tank 31, a cation exchange resin such as Diaion SK1B (R) or Amberlite IR120B (R) of Mitsubishi Chemical Corporation or an ion exchanger 32 such as a cation exchange zeolite is used. The space is filled up and down. The salt water supply pipe 47 opens at the front of the upper space, and the side surface of the upper space communicates with a soft water supply port 33 formed in the washing tank 2.

A water supply path from the soft water supply valve 29 communicates with the lower space of the ion exchange tank 31, and a hard water supply pipe 34 that communicates with the vicinity of the bottom of the washing tank 2 is connected to the bottom of the ion exchange tank 31.

(4) In the dishwasher with the above-described configuration, first, the dishes are stored in the tank and the door is closed without introducing the detergent. Then, when the washing is started, the hard water supply valve 29 is opened, and tap water is supplied to overflow. The tap water supplied to the overflow tank 37 is distributed and supplied to the return water tank 39 and the salt tank 43 at an arbitrary ratio by overflow here. The water supplied to the return water tank 39 is returned to the washing tank as it is and supplied as tap water from the water supply port 41, and the water supplied to the other salt tank 43 enters the salt basket 44. Then, the salt 45 stored therein is dissolved to form a high concentration salt water having a salt concentration of about 5 to 10%, and supplied to the ion exchange tank 31 from the salt water supply pipe 47 at the bottom.

塩 The salt water supplied to the upper space of the ion exchange tank 31 permeates downward from the upper part of the ion exchanger 32 by its own weight, and drops into the lower space. At this time, in the ion exchanger, the hardness components of Ca ions and Mg ions contained in the tap water are ion-exchanged with Na ions by ion exchange action by the softening in the rinsing step in the previous operation, and the ion exchanger is held in a large amount. I have.

Therefore, the hardness components such as Ca ions and Mg ions retained in the ion exchanger while the salt water passes through the ion exchanger are replaced by high-concentration Na ions of the salt and released, resulting in salt water having high hardness, It is dropped into the lower space of the exchange tank. The hard water thus generated flows through the hard water supply pipe 34, flows into the washing tank 2 from the hard water supply port 35, and accumulates.

(4) When the predetermined salt water has passed through the ion exchange tank, the hard water supply valve 30 is closed, the soft water supply valve 29 is opened to supply tap water to the ion exchange tank, and water is supplied to the washing tank while washing away remaining salt. When the water level in the cleaning tank reaches the cleaning start water level, the hard water supply valve 30 closes, the pump starts rotating forward, and the cleaning process using high hardness cleaning water starts. The operation method of the washing step is basically the same as that of the conventional example, and thus will be omitted. However, unlike the conventional example, by washing with a salt water having high hardness, the salt dissolution effect by Ca ions, Mg ions, and Na ions can be achieved. Eggs and other proteins dissolve easily, and good cleaning performance can be obtained without a detergent.

Since Na ions are present, it is possible to dissolve dirt with a hardness lower than the hardness shown in the first embodiment. At the start of the rinsing step after the washing step, the soft water supply valve 29 is opened, and tap water is supplied to the lower space of the ion exchange tank 31. A small part of this water supply flows into the washing tank 2 through the hard water supply pipe 34, but most of the water supply passes through the ion exchanger 32, passes through the upper space of the ion exchange tank 31, and becomes soft water supply water. Water is supplied from the port 33 into the washing tank.

At this time, at the start of the pre-washing step, the ion exchanger 32 desorbs Ca ions and Mg ions with salt water, and the ion exchange capacity (softening power) of the ion exchanger is sufficiently restored. Therefore, tap water is softened by ion exchange of the hardness component while passing through the ion exchanger. In this way, the water becomes soft water, and water is supplied from the soft water supply port 33 into the washing tank 2, and a rinsing process similar to the conventional control is started.

Here, in the case where the rinsing step includes a plurality of steps, in all the rinsing steps, soft water is supplied to the cleaning tank by opening the soft water supply valve. The minimum required volume of the ion exchanger need only deal with the amount of water used to perform one cycle of the multiple rinsing step. Since the rinsing step is always performed with soft water, even if milk stains and the like remain in the washing step, the stains are easily removed, and the generation of water spots is suppressed even if drying is performed after rinsing.

In addition, as a pre-process for performing the washing process using hard water and salt water as described above, the soft water supply valve 29 is opened, soft water is supplied into the washing tank, and the first washing process is performed. Dirt such as food is easily dissolved and easily falls off tableware, and when the second washing step using hard water and brine is performed, even if the cation concentration is too high, dirt such as milk and legume foods is salted out. The egg protein is easily dissolved by the salt dissolution effect without coagulation on the tableware surface due to the effect, so that the overall washing efficiency is improved.

In the present embodiment, an example in which no detergent is used is shown. However, as in the case of the first embodiment, the detergent using a nonionic surfactant as a main component of the dishwasher-specific detergent is used. In the case of washing as in the embodiment, due to the synergistic effect of the detergent, Ca ions and Mg ions in hard water, and Na ions in salt water, the washing performance is improved as compared with the washing using only the detergent using tap water.

By the way, the hardness of tap water varies depending on the area, but in areas where tap water hardness is low, ion exchange is performed by setting the opening time of the hard water feed valve to be long at the start of the washing process by operating the key at the start. By increasing the amount of salt water passing through the body, the amount of desorption of the hardness component can be increased, and the amount of Na ions due to the increase in the amount of salt water can be increased. Alternatively, the washing step and / or the rinsing step may be increased one or more times, or the amount of the hardness component stored in the ion exchanger may be increased by performing water supply and drainage without performing the washing and rinsing, so that the salt water flow at the start of the washing step is increased. Many hardness components can be eliminated by water.

In addition, in the case of a high tap water hardness area, the operation is the reverse of the above operation.At the start of the washing process, the opening time of the hard water supply valve is set to be short to reduce the amount of salt water passing through the ion exchanger. Thus, the amount of desorption of the hardness component can be reduced, and the amount of Na ions due to the decrease in the amount of salt water can be reduced.

Alternatively, by reducing the amount of the hardness component stored in the ion exchanger by reducing the washing step and / or the rinsing step one or more times, it is possible to reduce the desorption amount of the hardness component due to the passage of salt water at the start of the washing step. it can.

In the present embodiment, the case where the detergent is not used is exemplified.However, in the case where the detergent as the main component of the anionic surfactant is used and the case where the operation is performed as in the present embodiment using the soap such as sodium fatty acid, etc. In such a case, the hardness component may combine with the detergent component to form a metal soap, and the cleaning ability may be reduced.

In this case, an operation mode may be provided in which the user performs a key operation to wash with tap water or soft water without using water containing a large amount of hardness components and Na ions, and perform rinsing with soft water. In this case, the water supply in all of the washing and rinsing steps is performed by opening the soft water supply valve 29 to supply water. Before the start of the washing step or immediately before the rinsing step immediately after the end of the washing step, the hard water supply valve 30 is used. Then, salt water is dropped on the ion exchanger 31 to desorb the hardness component stored in the ion exchanger to refresh the ion exchange capacity, and the desorbed hardness component is sent from the hard water supply pipe 34 to the washing tank 2 and thereafter. This is an operation mode in which a regenerating step of draining water having a high hardness component in the cleaning tank to the outside of the tank by rotating the pump 7 in the reverse direction is added.

Table 3 shows the results when egg yolk, which is a protein stain, was dissolved in water having various salt concentrations obtained by dissolving salt in soft water.

(4) The egg yolk stain was applied to the tea bowl with a brush, dried for 1 hour, left in water having an arbitrary salt concentration for 4 minutes, stirred for 1 minute, and compared with the area of the remaining yolk stain. From this, if the salt concentration is 0.3% or more, the dissolution of the yolk stain due to the salt dissolution effect is recognized.

Table 2 compares the cleaning performance according to the JEMA voluntary standard test method in the second embodiment. At this time, the hardness of the washing water is 250 (mg / L), the salt concentration is 0.3%, there is no detergent, and the hardness of the rinsing water is 20 (mg / L).

Especially, the effect on egg soil is good as in the first embodiment, and the cleaning performance of the transparent glass cup is good.

From this, it is understood that according to the present embodiment, the cleaning performance of the present embodiment without detergent is equal to or higher than that of the case of cleaning with ordinary tap water using a detergent.

In addition, when a cleaning test is performed under the same conditions as above using a dishwasher-specific detergent mainly containing a nonionic surfactant, the cleaning performance is further improved by a synergistic effect of the detergent and the hardness component. I do.

That is, in the present embodiment, an example without a detergent is shown. However, when a detergent mainly containing a nonionic surfactant is used in a dishwasher-specific detergent, a synergistic effect of the detergent and hard water is used. Accordingly, the cleaning performance is improved as compared with the cleaning using only the detergent.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing of the dishwasher which concerns on Embodiment 1. FIG. It is sectional drawing of the dishwasher which concerns on Embodiment 2. FIG. It is sectional drawing of the conventional dishwasher.

Explanation of reference numerals

1 cabinet, 2 washing tank, 3 tableware basket, 4 heater, 7 pump, 11 rotary nozzle, 12 control circuit, 15 water supply valve, 23 hard water generating tank, 25 hard water generating ceramic, 32 ion exchanger, 37 overflow tank, 43 salt Tank, 45 salt.

Claims (15)

A washing tank for storing a basket on which dishes are placed, a water supply path for supplying water or hot water for washing and rinsing into the washing tank by the operation of a water supply valve, and water supply in the washing tank from the nozzle to the dishes. In a dishwasher having a circulation path for spraying and a control circuit for controlling a washing step and a rinsing step,
Dishwashing and drying, wherein a hard water generating means is provided in the water supply path, and the washing step is performed using hard water having a hardness higher than the supply water supplied from an external water supply source as water in the washing step. Machine. Examples feedwater in the washing step, hardness 180 mg / L (hereinafter, CaCO ₃ conversion) and executes a cleaning process with a higher hard water than, Dishwasher according to claim 1. 3. The dishwasher / dryer according to claim 1, wherein the rinsing step is performed using soft water having a hardness of less than 50 mg / L as water supply in the rinsing step. (4) The dishwasher / dryer according to any one of (1) to (3), wherein the washing is performed using soft water having a hardness of less than 50 mg / L before the washing step with hard water. A plurality of switchable water supply paths are provided, and a tank filled with a granular, massive, foam, or honeycomb hard water-generating ceramic that allows the hardness component to dissolve in the water by passing water through at least one of the paths is arranged. The dishwasher / dryer according to claim 1 or 2, wherein at least when the water is supplied in the washing step, the ceramic filling tank is passed through. The dishwashing and drying method according to claim 5, wherein at least one of calcium sulfate, calcium sulfite, calcium chloride, calcium lactate, magnesium chloride, magnesium sulfate, and calcium glycerophosphate is used as the ceramic that dissolves the hardness component. Machine. 6. The dishwasher / dryer according to claim 5, wherein when the hardness of tap water is low, the time for allowing the ceramic filling tank to pass through the water at the time of supplying water in the washing step is set to be long. 6. The dishwasher / dryer according to claim 5, wherein when the tap water has a high hardness, the time required to pass the ceramic filling tank during supply of water in the washing step is set short. A filling tank filled with ion-exchange resin or ion-exchange zeolite ion exchanger is provided in the middle of the water supply path, and when soft water is supplied to the washing tank, the hardness component in tap water is removed by ion exchange as soft water. When water is supplied and hard water is supplied to the washing tank, salt water is passed through the filling tank of the ion exchanger to remove the hardness component stored in the previous operation and / or the previous step to remove hard water. The dishwasher according to any one of claims 1 to 4, wherein the dishwasher is generated and supplied with water. When washing with hard water obtained by passing salt water through a filling tank of an ion exchanger, the salt concentration of feedwater accumulated in the washing tank is 0.3% or more, characterized in that: Item 10. A dishwasher / dryer according to item 9. 11. When the hardness of tap water is low, the washing step, the rinsing step or the water supply / draining step is increased one or more times, or the amount of salt water passed through the ion exchanger is increased. Dishwasher and dryer as described. The dishwashing / drying method according to claim 9 or 10, wherein when the hardness of tap water is high, the washing step or the rinsing step is reduced by one or more times, or the amount of salt water passing through the ion exchanger is reduced. Machine. Using soft water or raw tap water for water supply in the previous process, before the start of the washing process or immediately before the rinsing process after the end of the washing process, pass the salt water through the filling tank of the ion exchanger to desorb the stored hardness components. The dishwasher / dryer according to claim 9, further comprising an operation mode in which a regeneration step of draining water is added, and at least a soft water is used as water supply in the rinsing step. A washing tank for storing a basket on which dishes are placed, a water supply path for supplying water or hot water for washing and rinsing into the washing tank by the operation of a water supply valve, and water supply in the washing tank from the nozzle to the dishes. In a dishwasher having a circulation path for spraying and a control circuit for controlling a washing step and a rinsing step,
A dishwasher / drier, wherein a saltwater generator is provided in the water supply path, and saltwater having a salt concentration of 0.3% or more is used as water in the washing step. (15) The dishwasher / dryer according to any one of (1) to (14), wherein no detergent is used in the washing step.

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