JP2002078661A - Dishwasher - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save energy by effectively employing the heat of the drain of washing water heated in the washing step of a dishwasher. SOLUTION: In the dishwasher, water in a washing tank 2 is heated by a heater 5 and the heated water is supplied to a washing nozzle 3 by a circulating passage 14 provided with a washing pump 11 to wash or rinse dishes 20. A water storage tank 15 is provided in a machine body 1 and the water storage tank 15 is connected to the circulating passage 14 through a water supply selector valve 12. A heat exchanger 17 is disposed in the water storage tank 15. The heat exchanger 17 performs a heat exchange between the drain of the washing tank 2 and water in the water storage tank 15 to employ the water of the water storage tank 15 for heating and rinsing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dishwasher used in ordinary households, and more particularly to a water supply structure thereof.

[0002]

2. Description of the Related Art In a dishwasher used in ordinary households, washing water is heated to a certain temperature (for example, about 57 ° C.) by a heater provided in a washing tank in order to improve the washing effect. That is being done.

[0003] The washing water heated as described above is drained to the outside after one washing step is completed. Also, in the heating rinsing step performed after the water rinsing step is completed, the washing water is similarly heated,
Also in this case, when the heating and rinsing step is completed, the water is drained to the outside.

As described above, conventionally, water having a certain amount of heat is discharged to the outside as it is, so that the heat becomes waste heat and is not effectively used.

Therefore, an object of the present invention is to effectively utilize the waste heat for washing dishes.

[0006]

In order to solve the above-mentioned problems, the present invention heats water in a washing tank by a heater and supplies the water to a washing nozzle through a circulation passage provided with a washing pump. In a dishwasher configured to wash or rinse dishes, a water storage tank is provided inside or outside the body, the water storage tank is connected to the circulation passage via a water supply switching valve, and a heat exchanger is provided in the water storage tank. Install,
The heat exchanger exchanges heat between the wastewater from the washing tank and the water in the water storage tank.

According to the above configuration, the water in the water storage tank is heated by the heat of the wastewater used in the cleaning process,
By using the water in a post-heating rinsing step or the like, it is possible to save heating power and shorten the heating time.

The capacity of the water storage tank is a size corresponding to the amount of water required for heating and rinsing, and water for washing and water rinsing can be supplied from outside to the washing tank. According to this configuration, there is an advantage that the capacity of the water storage tank is reduced.

A drainage switching valve is provided in the middle of a drainage passage from the drainage port of the washing tank to the heat exchanger. One of the switched drainage passages is connected to the heat exchanger, and the other drainage passage is connected to the outside. And in the case of rinsing with water, the drainage switching valve can be switched to a drainage passage on the outside open side. According to this configuration, since the waste water in the water rinsing step does not pass through the heat exchanger, it is possible to prevent the heat in the water storage tank heated in the previous step from being removed.

[0010] It is possible to adopt a configuration in which the capacity of the water storage tank is large enough to accommodate a sufficient amount of water for performing all steps of dishwashing. In the case of this configuration, in each step of washing, water rinsing, and heating rinsing, the water in the water storage tank is transferred to the washing tank. By performing the heating by the heater in each of the washing steps and the heating and rinsing steps, a decrease in the temperature of the water in the water storage tank is prevented.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the dishwasher according to the first embodiment shown in FIG. 1, a washing tank 2 is provided inside a body 1;
A cleaning nozzle 3 is provided in the cleaning tank 2. In addition, tableware 4 is installed above the washing nozzle 3 so that the tableware 4 can be freely taken in and out. A heater 5 is provided at the bottom of the cleaning tank 2. A water supply port 6 is provided on a wall surface of the washing tank 2, and a distal end of a water supply hose 9 connected to an external water supply system 7 via a solenoid valve 8 is connected to the water supply port 6.

A washing pump 11 is provided below the washing tank 2, and a water supply switching valve 12 composed of a three-way valve is provided at an inlet of the washing pump 11. One inlet of the feed water switching valve 12 is connected to the bottom of the washing tank 2. The above-described cleaning tank 2, three-way valve 12, cleaning pump 11, and cleaning nozzle 3 form a circulation passage 14 (see a dashed line).

Further, a water storage tank 15 is installed inside the above-mentioned body 1. The water storage tank 15 has a capacity for storing an amount of water (about 3 liters) necessary for one heating rinse. The inlet of the water storage tank 15 is connected to the water supply hose 9 by a switching valve 16.
Is connected to another inlet of the feed water switching valve 12. That is, the outlet of the water storage tank 15 is
Is connected to the circulation passage 14 through the opening.

A heat exchanger 17 is housed inside the water storage tank 15. An inlet of the heat exchanger 17 is connected to a drain switching valve 18 provided at a drain of the washing tank 2 through a drain passage 25, and a drain hose 19 is connected to an outlet of the heat exchanger 17. Another outlet of the drainage switching valve 18 is connected to a drainage hose 19 via a drainage passage 21. The drain switching valve 18 may be provided at the drain of the washing tank 2 as described above, or may be provided in the drain passage 25 between the drain and the inlet of the heat exchanger 17.

The dishwasher of the first embodiment is as described above, and includes a control device 22 including a microcomputer provided therein.
Is operated as follows to automatically wash dishes.

(Water Supply Process) When the user stores the tableware 20 in the tableware basket 4 in the washing tank 2 and gives an operation command to the control device 22 by operating a button or the like, the control device 22 enters a water supply process and the electromagnetic valve 8 And the tap water is supplied from the water supply port 6 into the washing tank 2. The water level is detected by a water level sensor 23 provided at the bottom of the washing tank 2, and when a predetermined water amount is reached, the switching valve 1
6 is operated to supply water to the water storage tank 15. A water level sensor 24 is also provided in the water storage tank 15 to detect a predetermined water level. Based on the detection, the solenoid valve 8 is operated to stop the water supply.

(Cleaning Step) Next, when the cleaning pump 11 is driven, water in the cleaning tank 2 is continuously jetted from the cleaning nozzle 3 to the tableware 20 through the circulation passage 14 to perform cleaning. Immediately after the start of the cleaning, the heater 5 is energized to increase the temperature of the cleaning water to about 57 ° C. while performing the cleaning.

When the washing is completed, the water in the washing tank 2 is drained by operating the drainage switching valve 18 by the control device 22.
Then, the water is passed through a heat exchanger 17 and further drained from a drain hose 19 to the outside (a sink of a sink, etc.). At this time, heat exchange is performed between waste heat in the drainage and water in the water storage tank 15, and the water in the water storage tank 15 is heated. Water storage tank 1
5 with 3 liters of water and initial water temperature of 20 ° C, about 3
Heat to 9 ° C.

(Water rinsing step) Next, the electromagnetic valve 8 is opened by the control device 22 and the switching valve 16 is operated to supply water into the washing tank 2 from the water supply port 6, and a predetermined water level is detected by the water level sensor 23. Then, the solenoid valve 8 is closed. Cleaning pump 1
1 is driven to rinse the tableware 20 with water. When one water rinse is completed, the drainage switching valve 18 is switched to the drainage passage 21 side, and the water is drained from the drainage hose 19 without passing through the heat exchanger 17. This water rinse is repeated four times.

(Heating Rinse Step) Next, the water supply switching valve 12 is driven by the control device 22 to switch to the water storage tank 15 side, and then the cleaning pump 11 is driven to drive the water storage tank 1
The water in 5 is transferred to the washing tank 2. The heater 5 is energized to heat the water in the cleaning tank 2 to 63 ° C (80 ° C in some cases). At this time, the water in the water storage tank 15 is heated to a certain degree (Δt ° C. = (38.
5-20) ° C.), the time required to raise the temperature to the above is reduced. As energy, electric power for heating the water in the water storage tank 15 by Δt ° C. is saved. When the completion of the transfer of the water in the water storage tank 15 into the washing tank 2 is detected by the water level sensor 23, the water supply switching valve 12 is switched to the circulation passage 14 side, and the washing pump 11 is driven to perform heating and rinsing.

In the dishwasher of the first embodiment described above, the water storage tank 15 is fixed inside the body 1, but this water storage tank 15 may be installed outside the body 1. . In the above case, the drainage is allowed to pass through the heat exchanger 17 by natural fall. However, if the pressure is insufficient, a drainage pump 27 (see a two-dot chain line in FIG. 1) is provided in the drainage passage 25. May be installed.

Next, the second embodiment shown in FIGS. 2 and 3 differs in the capacity of the water storage tank 15 'and the water supply structure. That is, the water storage tank 15 'has a capacity corresponding to the total amount of water required from the start to the completion of the washing, and the water supply port 26 with a lid is provided. As shown in FIG. 3, the water storage tank 15 'can be inserted and removed from the front in the form of a cartridge. The drain switching valve 18 'is a two-way valve.
Other configurations are the same as those in the first embodiment. The operation is as follows.

(Water supply step) The user stores the tableware 20 in the tableware basket 4 in the washing tank 2 and also stores the tableware 20 '.
Then, a required amount of water is supplied from a water tap or the like, stored in the body 1, and an operation command is given to the control device 22 by button operation or the like. The control device 22 enters the water supply step, switches the water supply switching valve 12 to the water storage tank 15 ′, and drives the cleaning pump 11 to supply the amount of water required for cleaning into the cleaning tank 2. Cleaning tank 2
The water level is detected by the water level sensor 23 provided at the bottom of the
The cleaning pump 11 is stopped.

(Cleaning Step) Next, when the cleaning pump 11 is driven, water in the cleaning tank 2 is continuously jetted from the nozzle 3 to the tableware 20 through the circulation passage 14 to perform cleaning.
At this time, the heater 5 is energized immediately after the start of the cleaning, and the temperature of the cleaning water is raised to about 57 ° C. while performing the cleaning. When the washing is completed, the drainage switching valve 18 ′ is operated by the control device 22 to drain the water in the washing tank 2 from the drainage hose 19 to the outside (a sink of a sink, etc.) through the heat exchanger 17. At this time, heat exchange is performed between the waste heat in the drainage and the water in the water storage tank 15 ', and the water in the water storage tank 15' is heated.

(Water rinsing step) Next, as in the case of the above-mentioned water supply step, the water supply switching valve 12 is switched to the water storage tank 15 ', and the cleaning pump 11 is driven to determine the amount of water required for water rinsing. Transfer to within. When the required amount of water has been transferred, the water supply switching valve 12 is switched to the circulation passage 14 side, and the washing pump 11 performs water rinsing. The water rinsing is repeatedly performed four times, and each time, the drainage switching valve 18 'is operated to drain the water in the washing tank 2 from the drainage hose 19 through the heat exchanger 17 to the outside. The water in the water storage tank 15 'is gradually heated.

(Heating rinse step) Next, as described above,
After the water supply switching valve 12 is driven to switch to the water storage tank 15 ′, the cleaning pump 11 is driven and the water storage tank 1 ′ is driven.
The water in 5 'is transferred to the washing tank 2. The heater 5 is energized to heat the water in the cleaning tank 2 to 63 ° C (80 ° C in some cases). At this time, since the water in the water storage tank 15 'has been heated to some extent ([Delta] t [deg.] C.) by heat exchange in the previous washing step and water rinsing step, the time required to raise the temperature to the above is reduced. As energy, electric power for heating the water in the water storage tank 15 ′ by Δt ° C. is saved. When the completion of the transfer of the water in the water storage tank 15 ′ into the cleaning tank 2 is detected by the water level sensor 23, the water supply switching valve 12 is switched to the circulation passage 14, and the cleaning pump 11 is driven to perform heating and rinsing.

In the above-described dishwasher according to the second embodiment, the water storage tank 15 'is housed in the body 1 so as to be freely taken in and out, but may be installed outside the body 1. Further, as in the case of the above-described first embodiment, a drain pump 27 may be installed in the drain passage 25 in some cases.

[0028]

As described above, according to the present invention, the waste heat of the washing water heated in the washing step and the like is exchanged with the water used in the subsequent steps such as heating and rinsing to thereby reduce the waste heat. It can be used effectively. As a result, energy can be saved, and the heating time to the specified temperature can be shortened.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a first embodiment.

FIG. 2 is a schematic diagram of a second embodiment.

FIG. 3 is a perspective view of a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Airframe 2 Cleaning tank 3 Cleaning nozzle 4 Tableware basket 5 Heater 6 Water supply port 7 Water supply equipment 8 Solenoid valve 9 Water supply hose 11 Cleaning pump 12 Water supply switching valve 14 Circulation passage 15, 15 'Water storage tank 16 Switching valve 17 Heat exchanger 18 Drainage Switching valve 19 Drain hose 20 Tableware 21 Drain passage 22 Control device 23 Water level sensor 24 Water level sensor 25 Drain passage 26 Water supply port 27 Drain pump

Claims (4)

[Claims] 1. The water in a washing tank is heated by a heater,
In a dishwasher in which the water is supplied to a washing nozzle through a circulation passage intervening a washing pump to wash or rinse dishes, a water storage tank is provided inside or outside the body, and the water storage tank is provided with a water supply switching valve. Dishwashing, wherein a heat exchanger is installed in the water storage tank, and heat exchange between heat of drainage of the washing tank and water in the water storage tank is performed by the heat exchanger. Machine. 2. The capacity of the water storage tank is of a size corresponding to the amount of water required for heating and rinsing, and water for washing and rinsing is supplied from outside to the washing tank. The dishwasher according to claim 1. 3. A drainage switching valve is provided in the middle of a drainage passage from the drainage port of the washing tank to the heat exchanger, and one of the drainage passages that is switched is connected to the heat exchanger, and the other one of the drainage passages. The dishwasher according to claim 1 or 2, wherein the dishwasher is opened to the outside, and in a case of water rinsing, the drainage switching valve is switched to a drainage passage on the outside opening side. 4. The dishwasher according to claim 1, wherein the capacity of the water storage tank is large enough to accommodate a sufficient amount of water for performing all steps of dishwashing.