JPH07184822A - Dish washer and dryer - Google Patents

Abstract

PURPOSE:To feed air hotter than the outside air in a tank to increase the drying efficiency, by providing a recycled blow-through means making use of a part of the exhaust air from the tank or the whole thereof as the recycling air into the tank. CONSTITUTION:In a dish washer and dryer, washing liquid or water retained in a water storage tank 4 is sucked by a washing pump 3 and jetted from a nozzle 5 to force the water to collide with dishes in order to wash and rinse the dishes. After completion of discharge of water, the dishes are dried by an air-feeding fan 8. In this drying process, the outside air sucked from an air suction opening 9 by the fan 8 is blown from a blow-through opening 11 into the tank 2 through an air suction duct 10 and heated by a heater 6. In this case, a discharge opening for mixing air is opened at the top of the tank as a recycled blow-through means 15 and connected to the air suction duct 10 through a mixing air duct provided with a valve as a variable means of the mixing ratio. In this way, the exhaust air from the tank through the discharge opening can be reused as the recycled blow-through air and hence the drying efficiency is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dishwasher for washing and drying tableware used for home or business.

[0002]

2. Description of the Related Art A dishwasher is designed to wash and dry soiled dishes by the steps shown in FIG. 6, for example. First, the washing process is performed by spraying the heated washing liquid stored on the bottom of the tank with a washing pump from a nozzle and colliding it with dishes. Then, after removing the cleaning liquid, the water stored on the bottom of the tank is sucked by a cleaning pump and sprayed from a nozzle to collide with dishes to perform a rinsing step, and the water is further heated to about 70 ° C. to perform the same rinsing. A heat rinse step is performed. After the heating and rinsing process is completed, the water used for rinsing is drained, then the air blower fan is activated to draw in the outside air, and the air is blown into the tank to heat it. , I am trying to finish the whole process.

[0003]

By the way, the evaporation rate Wv of water on the surface of the tableware during the above-mentioned drying process is represented by the following equation.

Wv = h _d · ρ ₀ · A _w (X _d −X ₀ ) ... (1) where, h _d : mass transfer coefficient, ρ ₀ : air density, A _w : dish wet area, X _d : Saturated absolute humidity on the tableware surface, X
₀ : Absolute air humidity. Further, the heat transfer Q _0d from the air to the tableware _{Q 0d = h · A d (} T 0 -T d) ... (2) where A _d: tableware area, h: heat transfer coefficient, T _0: air temperature, _Td : Tableware temperature. When the dishwasher is dried, the tank is filled with steam at the start of drying, and the absolute humidity of exhaust gas is very high. The wet area decreases as the tableware dries. There is a difference in the evaporation rate depending on the heat capacity and shape of the tableware, and after the tableware having a high evaporation rate is dried, the tableware having a low evaporation rate needs to be dried over time. The evaporation rate decreases with time for the reason (1) (FIG. 7A). On the other hand, when the enthalpy is equal, the temperature of the exhaust gas from the tank becomes higher as the absolute humidity becomes lower. As described above, as the drying progresses, the absolute humidity of the exhaust gas from the tank decreases, so that the exhaust gas temperature rises with time (FIG. 7B). Figure 7
As shown in (a) and (b), the air discharged from the tank is hot and humid as compared with the outside air. In other words, it has two aspects of being advantageous in terms of temperature for drying and being disadvantageous in terms of humidity. However, as described above, the exhaust gas has a low absolute humidity and a high temperature as the drying time elapses, that is, changes to a state suitable for drying.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a dishwasher / dryer capable of improving the drying efficiency by utilizing high temperature tank exhaust air as the air blown into the tank.

[0006]

In order to solve the above-mentioned problems, the present invention firstly, in the drying process, sucks the outside air and blows it into the tank in which the tableware to be dried is stored and heats it.
A dishwasher / dryer that dries the dried dishes according to a route to be discharged to the outside of the tank, has a re-blowing unit that uses part or all of the air discharged from the tank as re-blowing air into the tank. And

Secondly, in the dishwasher / dryer for sucking the outside air during the drying process, blowing it into the tank in which the tableware to be dried is heated, and drying the tableware to be dried outside the tank, It is provided with mixing ratio varying means for varying the mixing ratio of the exhaust air from the tank to the external air, and having re-blowing means for using the exhaust air from the tank as re-blowing air into the tank. To do.

Thirdly, in the dishwasher / dryer for sucking the outside air during the drying process to blow it into the tank in which the tableware to be dried is heated, and to dry the tableware to be dried outside the tank, 1 of the air discharged from the tank
The gist of the present invention is to have control means for using part or all of the air as re-blowing air into the tank.

[0009] Fourth, in the dishwasher / dryer for sucking the outside air during the drying process, blowing it into the tank in which the tableware to be dried is heated, and drying the tableware to be dried outside the tank, First temperature / humidity detecting means for detecting the temperature / humidity of the air discharged from the tank, second temperature / humidity detecting means for detecting the temperature / humidity of the air from the outside, and the first and second Control means for varying the mixing ratio of the air discharged from the tank to the external air based on the detection value of the temperature / humidity detecting means and using the air discharged from the tank as the re-blown air into the tank. The point is to have and.

[0010]

In the above structure, first, the air discharged from the tank becomes low in humidity for a high temperature as the drying time elapses.
Therefore, by using part or all of the air discharged from the tank as the blowing air, it is possible to blow the air having a temperature higher than that of the outside air into the tank, and it is possible to improve the drying efficiency.

Secondly, for example, the temperature and humidity of the air discharged from the tank and the outside air are detected, and the tank is exposed to the outside air so that the evaporation rate of water from the tableware surface becomes higher based on the detected values. It is possible to further improve the drying efficiency by changing the mixing ratio of the exhaust air from the.

Thirdly, the use of the exhaust air from the tank as re-injection air into a part or all of the tank is controlled by the control means so that the temperature and humidity of the tank exhaust air can be quickly changed. Therefore, it is possible to reliably improve the drying efficiency.

Fourthly, specifically, the temperature and humidity of the exhaust air from the tank and the outside air are detected, and the control means increases the evaporation rate of water from the surface of the tableware based on these detected values. As described above, it is possible to further improve the drying efficiency by variably controlling the mixing ratio of the air discharged from the tank to the outside air and using the air discharged from the tank as the air blown back into the tank. .

[0014]

Embodiments of the present invention will be described below with reference to FIGS. In FIG. 1, 1 is a dishwasher / dryer main body, and 2 is a tank for storing, washing, rinsing and drying dishes. Washing and rinsing are performed by sucking up the cleaning liquid or water accumulated in the water reservoir 4 at the bottom of the tank by the cleaning pump 3, spraying it from the nozzle 5 and colliding it with the dishes. At this time, it is necessary to raise the temperature of the cleaning liquid or water to obtain the predetermined performance of washing and rinsing, and the heater 6 provided in the tank 2 heats the cleaning liquid or water. After the rinsing process is completed, the water used for rinsing is drained by the drainage pump 7. After the drainage is completed, the blower fan 8 operates to start the drying process. In the drying process, the outside air (intake air) sucked from the intake port 9 by the blower fan 8 passes through the intake duct 10 and is blown into the tank 2 from the blowing port 11. The blown air (blown air) is heated by the heater 6 and reaches a high temperature. With the hot air, the temperature of the tableware is increased to increase the water vapor pressure on the surface of the tableware, and moisture is moved by the pressure difference from the water vapor pressure of the air in the tank 2 to dry the tableware. The air that has absorbed water from the tableware is discharged from the tank discharge port 12 (tank discharge air), passes through the exhaust duct 13 shown in FIG.

Here, referring to FIG. 3, the re-blowing means 1
The mixing section of the tank exhaust air and the intake air, which is No. 5, will be described. The mixing outlet 16 is opened in the tank top plate, and the mixing outlet 16
Are connected to the intake duct 10 by a mixing duct 17. With this configuration, the tank discharge air from the mixing tank discharge port 16 is guided to the intake duct 10 through the mixing duct 17 and mixed with the intake air to be used as re-blown air. In addition, a valve 18 serving as a mixing ratio varying means is installed in the mixing duct 17. The valve 18 is rotated by a drive motor 19 so that the opening area is variable as shown in FIGS. 3 (b) and 3 (c). By providing the re-blowing means 15, the drying after completion of the heating and rinsing proceeds as follows. That is, the valve 18 is closed during the time when the air discharged from the tank at the start of drying is high in humidity. In this case, it is the same as the conventional exhaust-type dishwasher, and all high-humidity exhaust is discharged to the outside of the machine. After a predetermined time determined by checking the correlation between the drying time and the change in the humidity of the air discharged from the tank, the drive motor 19 is rotated to open the valve 18 to mix the air discharged from the tank with the intake air. The mixed air is blown into the tank through the intake duct 10. Although not shown in the drawing, a microcomputer as a control means for controlling the drive motor 19 and the like is mounted in the dryer main body 1. As shown in FIG. 4, a temperature / humidity sensor 20 as a temperature / humidity detecting means is installed in the exhaust duct 13 in order to measure the humidity of the air discharged from the tank. The temperature / humidity sensor 20 is installed near the center of the flow path away from the wall surface of the duct in order to prevent dew condensation. The temperature / humidity sensor 20 measures the humidity of the air discharged from the tank, and when the humidity becomes lower than the set humidity, the valve 1
Open 8 and mix tank exhaust air with intake air. Also, FIG.
As shown therein, a temperature / humidity sensor 21 for measuring the temperature / humidity of the intake air is also installed in the intake duct 10.

Next, the temperature / humidity of the tank and the temperature / humidity of the intake air detected by the temperature / humidity sensors 20 and 21 are respectively inputted to the microcomputer by previously inputting the relationship between the temperature / humidity of the air and the water vapor pressure. The control for calculating the optimum mixing ratio of the tank exhaust air and the intake air at that moment from the value and the formulas (1) and (2), and controlling the opening area of the valve 18 so as to obtain the mixing ratio. The aspect will be described with reference to the flowchart of FIG. Initially, the mixture ratio α is reset to zero (step 25). Exhaust each temperature and humidity sensors 20 and 21, outside air temperature and humidity T, detects the X, calculated enthalpy i corresponding thereto (step 26, 27), such an exhaust (X _out, i _out, T _out ), outside air (X ₀ , i
₀ , T ₀ ) at a mixing ratio of α: (1-α) (step 28), the state of the air blown into the tank (X _in , i
_in , T _in ) is as follows (step 29).

I _in = α · i _out + (1−α) i ₀ X _in = α · X _out + (1−α) X ₀ T _in = g (i _in , X _in ) Then, the mixed blowing Increase in air temperature due to air, increase in heat transfer to tableware, increase in tableware temperature, increase in saturated absolute humidity on tableware surface, increase in enthalpy of blown air are calculated as follows (steps 30 to 3).
4).

(A) Increase _in air temperature ΔT _in = T _in −T ₀ (b) Increase in heat transfer to tableware ΔQ _0d = h · A _d · ΔT _in (c) Temperature rise of tableware ΔT _d = ΔQ _0d / m _d · c _d (m: mass, c: specific heat) increase ΔX saturated absolute humidity (d) dish surface _{d = f (T d + ΔT} d) -f (T d) (f (T): at T ° C. Saturated absolute humidity) Since it is difficult to measure the temperature of tableware and the temperature range during drying of tableware is limited, the temperature rise of tableware and the saturated absolute humidity are expressed as ΔX _d = h (ΔT _d ). An approximate expression for the increase in humidity may be given.

(E) Increase amount of enthalpy of blown air ΔX _in = α (X _out −X ₀ ) From the above, the amount of evaporated water in this embodiment is obtained by the following equation (step 35).

[0020]

[Number 1] _{Wv = h d · ρ 0 ·} A w ((X d + ΔX d) -
(X ₀ + ΔX _in )) Since the mixture ratio of intake and exhaust is α, the amount of α is mixed with outside air and blown into the tank again, so the amount of exhaust water in this embodiment is

[Expression 2] Wv ₁ = (1-α) h _d · ρ ₀ · A _d ((X <sub>d
+ ΔX d) - (X 0</sub> + ΔX 0)) because the conventional exhaust water is _{Wv 2 = h d · ρ 0} · A d (X d -X 0), Wv 1> Wv valve 18 so as to satisfy the _second condition If the opening ratio is controlled to mix the intake air and the outside air, the drying efficiency is improved (steps 36-40). Incidentally, the expression of the heat transfer coefficient h of supra, specific heat c _d, mass m _d, dishware area A _d is preliminarily given as a set value. Further, the relationship between the mixing ratio and the opening ratio of the valve 18 is also checked in advance and stored in the microcomputer.

In the dishwasher having the construction of this embodiment, when the drying process is started without heating and rinsing (when the dishwasher is used only as a dish dryer after hand washing, etc.), the temperature in the tank at the start of operation is the outside air. It is necessary to heat the dishes and the tank wall to a temperature that is equivalent and suitable for drying. In this case, the valve 18 is opened until the temperature of each part in the tank reaches a temperature suitable for drying, and the tank exhaust air whose temperature has risen due to the heating of the heater 6 is used as blowing air.

[0022]

As described above, according to the present invention,
First, since the re-blowing means for using part or all of the air discharged from the tank as the re-blowing air into the tank is provided, it is possible to blow air having a temperature higher than that of the outside air into the tank. The drying efficiency can be improved.

Secondly, since there is provided a re-blowing means which has a mixing ratio varying means for varying the mixing ratio of the tank exhaust air to the outside air and uses the tank exhaust air as the re-blowing air into the tank, for example, It is possible to change the mixing ratio of the tank exhaust air to the outside air so that the evaporation rate of water from the tableware surface becomes higher based on the temperature and humidity of the tank exhaust air and the outside air. Can be improved.

Third, since the control means for using part or all of the air discharged from the tank as re-blowing air into the tank is provided, it is possible to quickly respond to changes in temperature and humidity of the air discharged from the tank. The drying efficiency can be surely improved.

Fourthly, specifically, first temperature / humidity detecting means for detecting the temperature / humidity of the tank exhaust air, second temperature / humidity detecting means for detecting the temperature / humidity of the outside air, and The first and second temperature / humidity detecting means are provided with the control means for varying the mixing ratio of the tank discharge air to the outside air while using the tank discharge air as the re-blowing air into the tank.
The mixing ratio of the air discharged from the tank to the outside air can be variably and quickly controlled by the control means based on the temperature and humidity of the air discharged from the tank and the outside air so that the evaporation rate of water from the surface of the tableware becomes higher. Therefore, the drying efficiency can be further improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an internal configuration of an embodiment of a dishwasher / dryer according to the present invention.

FIG. 2 is a plan view showing an arrangement of an intake duct, an exhaust duct and the like in the above embodiment.

FIG. 3 is an enlarged view showing a mixing portion of the tank exhaust air and intake air in the above embodiment.

FIG. 4 is a diagram showing an example of installation of a temperature / humidity sensor inside an exhaust duct in the above embodiment.

FIG. 5 shows the temperature of the air discharged from the tank and the outside air
6 is a flowchart for explaining a variable control action of a mixing ratio of the tank exhaust air to the outside air based on humidity.

FIG. 6 is a process diagram of a conventional dishwasher / dryer.

FIG. 7 is a diagram showing changes in temperature and humidity of the air discharged from the tank and the outside air over time.

[Explanation of symbols]

2 tank 6 heater 9 intake port 10 intake duct 15 re-blowing means 16 mixing outlet 17 mixing duct 18 valve (mixing ratio varying means) 20, 21 first and second temperature / humidity sensor (temperature / humidity detecting means) )

Claims (4)

[Claims] 1. A dishwasher for drying the tableware to be dried by a route in which outside air is sucked into the tank containing the tableware to be dried and heated during the drying process to be discharged outside the tank. 1. A dishwasher / dryer having a re-blowing means for using a part or all of the exhausted air as described above as re-blowing air into the tank. 2. A dishwasher for drying the tableware to be dried according to a route in which outside air is sucked into the tank in which the tableware to be dried is heated during the drying process to be heated and then discharged to the outside of the tank. A dishwasher having a mixing ratio varying means for varying a mixing ratio of air discharged from the tank to air, and having re-blowing means for using the air discharged from the tank as re-blowing air into the tank. Dryer. 3. A dish washer / dryer that dries the tableware to be dried by a route in which outside air is sucked into the tank in which the tableware to be dried is stored and heated during the drying process to be discharged outside the tank. 2. A dishwashing / drying machine having a control means for using a part or all of the exhaust air of (1) as re-blowing air into the tank. 4. A dishwasher for drying the tableware to be dried according to a route in which outside air is sucked into the tank in which the tableware to be dried is stored and heated during the drying process to be discharged outside the tank. First temperature / humidity detecting means for detecting the temperature / humidity of the exhaust air, and second temperature / humidity detecting means for detecting the temperature / humidity of the air from the outside,
Based on the detection values of the first and second temperature / humidity detecting means, while varying the mixing ratio of the air discharged from the tank to the external air, the air discharged from the tank is re-injected into the tank. A dishwasher / dryer, comprising: a control means used as air.