JPH04224726A - Dish washer - Google Patents

Abstract

PURPOSE:To suppress propagation of bacteria efficiently by the thorough irradiation with an ultraviolet lamp for sterilization which is provided in a washing tank of a dish washer. CONSTITUTION:In a washing tank 1, a washing pump 3 which washes dishes by splashing water and a drainage pump 4 which drains water after the washing are equipped, and in addition, dishes are sterilized by the radiation with an ultraviolet lamp 5. A rack 6 on which dishes are arranged in parallel with the direction of the ultraviolet ray irradiation is provided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dishwasher mainly used in households.

0002

2. Description of the Related Art FIG. 5 shows an example of a dishwasher conventionally used in general households. Reference numeral 7 denotes a washing tank for storing and washing dishes, and 8 is a water supply mechanism connected to the washing tank 7 to supply water into the washing tank 7. A washing mechanism 9 sprays water into the washing tank 7 to wash the dishes. Reference numeral 10 denotes a drainage mechanism for discharging the water in the cleaning tank 7 to the outside of the machine. Reference numeral 11 denotes a rack on which tableware is arranged in a line in the washing tank. 7 to 11 constitute a dishwasher.

In this configuration, first, as shown in FIGS. 6 and 7, dishes to be washed are placed in the washing tank 7 using a rack 11. When the dishwasher starts operating, water is supplied from the water supply mechanism 8 to the washing tank 7 and accumulates at the bottom of the washing tank 7. Next, the washing mechanism 9 sprinkles the water accumulated at the bottom of the washing tank 7 into the washing tank 7 to wash the dishes. After the cleaning is completed, the drainage mechanism 10 operates to perform a drainage process in which water in the cleaning tank 7 is discharged to the outside of the machine.

0004

However, in the conventional dishwasher as described above, a small amount of bacteria remains on the dishes after washing them. In addition, bacteria grow on the food residue remaining in the cleaning tank after cleaning, causing the residue to rot and produce a putrid odor, which is a sanitary problem.

The purpose of the present invention is to solve the above-mentioned conventional problems, to sterilize tableware after cleaning by irradiating ultraviolet rays, to suppress the proliferation of bacteria on food residue, and furthermore, to The purpose of the present invention is to provide a dishwasher that can uniformly sterilize dishes placed therein by irradiation.

[0006]

[Means for Solving the Problems] In order to achieve the above objects, the present invention provides a washing tank for storing and washing tableware, a water supply mechanism connected to the washing tank and sending water into the washing tank, and a water supply mechanism for supplying water into the washing tank. It has a washing mechanism that sprays water in the tank to wash the dishes, and a drainage mechanism that discharges the water in the washing tank to the outside of the machine, and the washing tank is equipped with an ultraviolet lamp that irradiates the inside of the washing tank. The dishwasher was equipped with a rack for placing dishes parallel to the direction of ultraviolet irradiation.

[0007]

[Function] By irradiating the inside of the washing tank with ultraviolet rays, bacteria remaining on the dishes after washing can be sterilized, and the proliferation of bacteria in the residue inside the washing tank can be suppressed. In addition, by providing a rack for arranging dishes parallel to the direction of ultraviolet light irradiation from the ultraviolet lamp, the dishes are evenly irradiated with ultraviolet rays, so that the sterilizing effect of ultraviolet rays can be fully demonstrated.

[0008]

[Embodiment] An embodiment will be described below with reference to FIG. Figure 1 shows a washing tank that accommodates tableware and washes it, and 2
A water supply mechanism is a water supply pump that supplies water into the cleaning tank 1. 3 is a washing mechanism, which is a washing pump that sprays water into the washing tank 1 to wash the dishes. Reference numeral 4 denotes a drainage mechanism, which is a drainage pump that sucks water from the bottom of the cleaning tank 1 and drains it to the outside of the machine. 5 is an ultraviolet lamp which irradiates the inside of the cleaning tank 1 with ultraviolet rays. Reference numeral 6 denotes a rack for arranging tableware in the washing tank 1.

The operation will be explained with reference to FIGS. 1, 2, and 3. First, dishes are placed in the washing tank 1 using the rack 6. When the dishwasher starts operating, water is supplied from the water supply mechanism 2 to the washing tank 1 and accumulates at the bottom of the washing tank 1. next,
The cleaning mechanism 3 drains the water accumulated at the bottom of the cleaning tank 1 into the cleaning tank 1.
Sprinkle water inside and wash dishes. After the cleaning process is completed, the drainage mechanism 4 operates to discharge the water in the cleaning tank 1 to the outside of the machine. When the operation is finished, ultraviolet rays are irradiated from the ultraviolet lamp 5 installed in the washing tank 1 onto the dishes arranged parallel to the direction of ultraviolet irradiation by the rack 6 and on the food residue in the washing tank, sterilizing the dishes and removing the food residue. curb corruption.

As described above, according to this embodiment, by providing an ultraviolet lamp in the washing tank and a rack for arranging the dishes in parallel to the direction of ultraviolet irradiation, bacteria on the residue on the dishes are exposed to ultraviolet rays. It is evenly sterilized by
It is possible to provide a sanitary dishwasher that suppresses decay of residue in the washing tank. Below, in order to examine the sterilization effect of installing an ultraviolet lamp in the washing tank of a dishwasher, 1. Sterilization of tableware in the washing tank using ultraviolet light 2. We conducted an experimental study on two methods of inhibiting decay by irradiating the residue with ultraviolet rays.

First of all, 1. This article describes an experimental method for sterilizing tableware in a washing tank using ultraviolet light. A certain amount of a turbid solution of Escherichia coli and Bacillus subtilis in 200 ml of 0.1% Tween 80 solution containing one slant each is applied onto the tableware and placed in the washing tank of the dishwasher as shown in Figure 4. We will irradiate the dish with a 6W ultraviolet lamp for 24 hours, measure the number of bacteria afterward, and examine the sterilization effect of the ultraviolet rays on tableware in the washing tank. Note that Escherichia coli and Bacillus subtilis were selected because the bacteria remaining on dishes after washing are mainly Gram-negative bacteria and spore-forming bacteria. The dishwasher used was NP-5600 manufactured by Matsushita Electric Industrial Co., Ltd.

Next, 2. We describe an experimental method for inhibiting decay by irradiating residue with ultraviolet rays. Put the food residue after washing in the dishwasher into the dishwasher residue basket, set it in the dishwasher cleaning tank in the standard operating condition, irradiate it with a 6W ultraviolet lamp for 3 hours, and leave it for 17 hours. After leaving it for a while, measure the number of bacteria on the residue.
Compare with control. The control was one in which food residue was similarly placed in a dishwasher residue basket, the residue basket was placed in a dishwasher after standard use under standard usage conditions, and left at room temperature for 24 hours. The food residues used were cooked meat pieces (1.8 g each), and the dishwasher used was NP-720 manufactured by Matsushita Electric Industrial Co., Ltd.

Next, the experimental results of Experiments 1 and 2 will be described. The table below shows the results of each bacterial count measurement. 1. In the case of E. coli sterilized by ultraviolet rays on tableware in the washing tank [Table 1].

[0014]

[Table 1] In the case of Bacillus subtilis [Table 2].

[0015]

[Table 2] 2. Suppressing decay by irradiating residue with ultraviolet rays

[0016]

[Table 3] The number of bacteria remaining on the dishes after washing is 101 to below the detection limit for Gram-negative bacteria, and about 101 for spore-forming bacteria. (Cleaned in standard dishwasher cycle, using High Wash Blue.) According to the results in Table 1 above, ultraviolet irradiation can kill Escherichia coli by 10 5 and Bacillus subtilis by 10 1 to 10 2 . Also, according to [Table 1] above, bacterial growth in the control was 1.
08, while the number of proliferating bacteria after UV irradiation is 1.
It is held down to 06. From the above, it can be said that ultraviolet irradiation in the washing tank of a dishwasher is sufficiently effective in sterilizing bacteria remaining on dishes, and is also effective in suppressing the proliferation of bacteria on food residue.

[0017]

[Effects of the Invention] As is clear from the above description, according to the means of the present invention, ultraviolet rays can be irradiated into the washing tank by installing an ultraviolet lamp, and a rack for arranging dishes parallel to the direction of ultraviolet rays from the ultraviolet lamp can be installed. As a result, it is possible to provide a sanitary dishwasher that evenly sterilizes bacteria remaining on dishes after washing and suppresses the proliferation of bacteria in the residue in the washing tank.

[Brief explanation of the drawing]

FIG. 1 A longitudinal cross-sectional view of a dishwasher showing an embodiment of the present invention.

[Figure 2] Plan view of the main parts

[Figure 3] Front view of the same main parts

[Figure 4] Experimental layout diagram for sterilizing tableware with ultraviolet rays

[Figure 5] Longitudinal cross-sectional view of a conventional dishwasher

[Figure 6]
Main part plan view of conventional example

[Figure 7] Front view of main parts of conventional example

[Explanation of symbols]

Claims (1)

[Claims] 1. A washing tank for storing and washing dishes, a water supply mechanism connected to the washing tank and sending water into the washing tank, a washing mechanism for sprinkling water on the washing tank to wash the dishes, and the washing tank. The washing tank has a drainage mechanism for discharging the water inside the machine to the outside, the washing tank is equipped with an ultraviolet lamp that irradiates the inside of the washing tank, and a rack is provided in which tableware is arranged parallel to the direction of ultraviolet rays irradiated by the ultraviolet lamp. A dishwasher featuring: