Cleaning device with defoaming function

Abstract

The objective is to provide a cleaning machine with defoaming capabilities that can reliably and efficiently defoam the foam generated in the cleaning tank by using a cleaning solution without the need for defoaming agents, thereby maintaining the cleaning water in the septic tank in a clean state. [Solution] The cleaning machine with defoaming function of the present invention adjusts the position and orientation of multiple jet means so that a swirling water flow is formed in one direction within the cleaning tank. It utilizes the fact that the swirling flow forms a spiral vortex at certain points, and installs the defoaming means above the point where the water flow swirls. As a result, the foam generated by the cleaning agent liquid in the cleaning tank autonomously gathers at the water surface of the vortex, i.e., near the intake port of the defoaming means, due to the swirling water flow. Therefore, the defoaming means can efficiently suck up a large amount of foam and defoam it quickly and reliably. In addition, since a discharge pipe is connected to the defoaming means to discharge the cleaning water sucked up by the defoaming means along with a large amount of foam to the outside, the cleaning water containing dirt does not return to the cleaning tank, and the cleaning water can be kept clean.

Description

Technical Field

[0001] The present invention relates to a cleaning device, and more particularly to a device for cleaning dishes such as plates used in school lunches, hospital meals, etc., or machine parts with bubbles, and particularly to a cleaning device with a function of defoaming bubbles generated by the use of a cleaning agent.

Background Art

[0002] Regarding dishwashing devices, there has conventionally been a method of washing dishes by injecting washing water toward the dishes in a state where a plurality of used dishes are arranged and stored in a dish basket. Most of them transfer the dish basket by a conveyor, perform rinsing for a set time after washing on the conveyor, and inject washing water toward the dishes from injection nozzles provided above and below the conveyor.

[0003] However, in order not to cause unwashed areas on the dishes by the injection method of the washing water in the conventional dishwashing device, it is necessary to have an appropriate margin in the interval between each dish so that the washing water can spread over the entire dish. Even if an attempt is made to separate the dishes by the injection force of the washing water, depending on the number of dishes in the dish basket, the dishes may fall forward or backward with respect to the alignment direction, and the washing water may not be sprayed over the entire dish, resulting in unwashed areas. Therefore, a dishwashing device using a bubble cleaning method has been proposed, in which fine bubbles (hereinafter also referred to as "bubbles") in which bubbles are mixed into the liquid in the immersion tank are used to separate solid dirt adhering to the dishes (see Patent Documents 1 and 2 below).

[0004] The bubble cleaning method is such that the bubbles adsorb to the oil content etc. adhering to the plate and peel off the oil content etc. from the dish, and finally when these bubbles disappear, the oil content etc. floats in the immersion water in the tank. Bubbles with a diameter less than 100 μm corresponding to the volume are defined as "Fine Bubble (registered trademark)", and an oil removal process using the utility of hydrophobic substance adsorption of bubbles or fine bubbles having a cleaning effect on hydrophobic (non-water-compatible) substances is applied to the cleaning device. The same applies to the cleaning of machine parts, where a bubble cleaning method is employed.

[0005] While the bubble cleaning method has high cleaning ability, its cleaning power is further enhanced by using an aqueous solution of a cleaning agent containing a surfactant. The use of surfactants reduces the interfacial tension between water molecules, making the object being cleaned more compatible with water and easier to remove dirt. In addition, the repulsive force created on the surface of the dirt surrounded by surfactant molecules prevents the dirt dispersed in the water from reattaching to the object being cleaned. On the other hand, because surfactants have foaming properties, a large amount of foam tends to be generated when using an aqueous solution of a cleaning agent containing a surfactant.

[0006] To address the problem of large amounts of foam generated by surfactants in the cleaning solution overflowing from the cleaning tank and contaminating the cleaning machine's installation site and surrounding area, proposals have been made to use defoaming agents or to guide the foam to an adjacent defoaming tank to break it (see Patent Document 3 below). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Special Publication No. 2017-500136 [Patent Document 2] Japanese Patent Publication No. 2022-007463 [Patent Document 3] Japanese Patent Publication No. 2005-161265 [Overview of the project] [Problems that the invention aims to solve]

[0008] While silicone-based defoamers are used for cleaning machined parts and other components, their use is difficult for cleaning dishes used in school and hospital meals. Indeed, silicone resins and emulsifiers are used as defoamers in the production of some foods, such as tofu, and there are no concerns regarding the harmful effects or risks of defoamers on the human body. However, many aspects of long-term ingestion and interactions with other food additives remain unclear, and some experts point out that it is desirable to avoid ingestion as much as possible. Therefore, approaches to defoaming without using defoamers are important for cleaning dishes. Moreover, the use of defoamers is costly.

[0009] Furthermore, the idea described in Patent Document 3 above involves transferring bubbles that have crossed an overflow wall higher than the liquid level of the cleaning agent solution onto a bubble transfer plate and guiding them to the defoaming tank. However, not all bubbles can cross the overflow wall, and a large amount of bubbles remain in the cleaning tank. Thus, in reality, even when a defoaming agent is added, bubbles that cannot be completely defoamed overflow from the cleaning tank, and the problem of soiling the installation site of the cleaning machine and its surroundings remains unresolved.

[0010] Therefore, in order to solve the above-mentioned problems, the present invention aims to provide a cleaning machine with defoaming capabilities that can reliably and efficiently defoam foam generated in the cleaning tank by using an aqueous solution of cleaning agent without using an antifoaming agent, thereby maintaining the cleaning water in the septic tank in a clean state. [Means for solving the problem]

[0011] To solve the above problems, the present invention provides a washing machine with defoaming function, comprising: a washing tank for washing an object to be washed; a bubble generating means for generating fine bubbles in the washing water in the washing tank; a defoaming means for sucking up and defoaming bubbles generated by a detergent solution contained in the washing water and floating on the surface of the washing water, the defoaming means having a discharge pipe for discharging the washing water droplets after defoaming to the outside; and a plurality of jet means installed in the washing tank, the position and orientation of each jet means being adjusted so that the bubbles become a water flow that gathers near the suction port of the defoaming means.

[0012] Furthermore, the defoaming means is installed above the water surface of the vortex formed by the plurality of jet means, the jet means discharge cleaning water toward the opposing tank walls of the cleaning tank, and the jet means is installed in a direction offset by a predetermined angle from the opposing tank walls of the cleaning tank. [Effects of the Invention]

[0013] The cleaning machine with defoaming function according to the present invention has multiple jet means adjusted in position and orientation so that a unidirectional swirling water flow is formed in the cleaning tank. Taking advantage of the fact that the swirling flow forms a spiral vortex at certain points, the defoaming means is installed above the point where the water flow swirls. As a result, the foam generated by the cleaning agent liquid in the cleaning tank autonomously gathers at the water surface of the vortex, i.e., near the intake port of the defoaming means, along with the swirling water flow. Therefore, the defoaming means can efficiently suck up a large amount of foam and defoam it reliably in a short time. Furthermore, since the defoaming device is connected to a discharge pipe that discharges the cleaning water sucked in along with a large amount of foam to the outside, the cleaning water containing dirt does not return to the cleaning tank, thus keeping the cleaning water clean. [Brief explanation of the drawing]

[0014] [Figure 1] This is an overall external view of a cleaning machine with defoaming capabilities, which is one embodiment of the present invention. [Figure 2] This is a schematic diagram showing the defoaming process using a defoaming method. [Figure 3]This is a front view of the washing tank. [Figure 4] This is a plan view of a cleaning tank, showing an example of a jetting mechanism and the flow of water inside the cleaning tank. [Best Mode for Carrying Out the Invention]

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Figure 1 is an overall external view of the defoaming washing machine 100 of this embodiment. The defoaming washing machine 100 has a roughly rectangular parallelepiped shape with an open top and is equipped with a washing tank 1 for washing the objects to be washed. The washing tank 1 may have a tapered shape, with its sides widening slightly towards the top. This invention applies to objects to be cleaned, such as tableware and machine parts. The following description focuses on the case of cleaning tableware, but it can also be applied to machine parts and other objects to be cleaned.

[0016] The washing tank 1 has enough space to accommodate a dish basket 4 for storing items to be washed, such as plates 3. Generally, to immerse the dish basket 4 in the washing tank 1, the dish basket 4 is lowered from above the washing tank 1 using any belt conveyor (including rollers) or lifting means, and then raised after washing. However, a description of lifting means and the like, which are not directly related to the present invention, will be omitted.

[0017] The defoaming dishwasher 100 is equipped with defoaming means 2 above the washing tub 1. Although details will be described later, the defoaming means 2 is installed in the washing tub 1 to conform to the maximum water level of the washing water in the washing tub so that the foam generated on the water surface of the washing water can be sucked. In the case of this embodiment, as shown in FIG. 1, the defoaming means 2 is positioned approximately at the center of the washing tub 1, but it is not necessarily limited to this, and the defoaming means may be installed at the corner or any other arbitrary position of the washing tub 1. Also, in this embodiment, the defoaming means ② is fixed and used in the washing tub 1, but an installation method that can be moved manually or automatically may also be used. When the defoaming means 2 is movable, during the washing of the dish 3 etc., the defoaming means 2 is moved to, for example, the corner of the washing tub so as not to interfere with the washing, and during the defoaming process after washing, the defoaming means 2 can be moved to a predetermined position. Also, the defoaming means 2 may be incorporated into a part of the lift means (not shown) for raising and lowering the dish basket 4 so that the defoaming means 2 can be positioned above the washing tub 1 as the dish basket 4 moves.

[0018] By supplying water from a water supply port for washing water (not shown), the washing tub 1 is preliminarily stored with washing water which is a liquid of water (or hot water), and it is made to maintain a certain amount. For example, a water level detection means such as a float switch may be provided to control the water level. Also, in the case of this embodiment, one bubble generation means 5 connected to the bubble pump 6 is installed in the washing tub 1, but in other embodiments, a plurality of bubble generation means 5 may be installed at arbitrary positions. The bubble pump 6 circulates the water or hot water in the washing tub 1, and a nozzle which is the tip port of the bubble generation means is attached to the discharge side thereof (hereinafter, the nozzle may be regarded as equivalent to the bubble generation means and may be referred to as "nozzle 5"). During the washing process, the bubble pump 6 is operated, and during that time, the bubble generation means 5 mixes fine bubbles into the washing water. Furthermore, a detergent tank (not shown) is connected to the washing tub 1, and the liquid detergent in this detergent tank is automatically supplied to the washing tub 1 through the detergent inlet. The detergent is not limited to liquid, and may be solid or powder, or the detergent may be manually input.

[0019] The mechanism of cleaning using bubbles is explained using ultrafine bubbles as an example. Because ultrafine bubbles are gaseous, they have a property that makes them easily adsorbed by oil droplets and other substances that do not mix with water in water. In particular, ultrafine bubbles, which are extremely small bubbles with a diameter of less than 1 μm, can remain suspended in water for long periods of time. For this reason, oil droplets and iron oxide particles dispersed in the water or hot water in the cleaning tank are also adsorbed by ultrafine bubbles.

[0020] Furthermore, because ultrafine bubbles have a lower surface tension compared to simple water droplets, they can easily penetrate the tiny gaps between the object being cleaned, such as a dish, and the attached dirt. The collision with the dirt increases the dissolved gas concentration, generating microbubbles, which are a more stable gas phase. In other words, the ultrafine bubbles gradually grow larger as they repeatedly collide, forming microbubbles that detach the dirt attached to the dish. Moreover, if fluidity is imparted to the microbubbles in the water using ultrasound or other means, the impact on the attached dirt increases, and the detaching force is enhanced.

[0021] Therefore, when used dishes 3 are immersed in the washing tank 1, the water or hot water in the washing tank 1 will contain iron oxide particles. Due to their electrical properties, ultrafine bubbles can attract positively charged iron oxide particles. In this way, they have high cleaning power even against stubborn dirt.

[0022] The bubble generation means 5 of this embodiment has a structure that combines a Venturi type, which rapidly changes the pressure in the gas-liquid flow path using a bubble pump 6 to crush bubbles and mix fine bubbles into the washing water, and a swirling flow type, which crushes bubbles in the washing water with a high-speed swirling flow and mixes fine bubbles into the washing water. However, it may be a Venturi type only or a swirling flow type only. Alternatively, a pressurized dissolution ejection type, in which gas is saturated in the liquid under pressure and then the pressure is rapidly reduced to precipitate fine bubbles, or a micropore type, in which fine bubbles are mixed into the washing water through fine gas dispersion holes, may be applied. In this embodiment, as described above, water is supplied to the washing tank 1 from the washing water inlet. However, it is also possible to generate bubble water by mixing and finely dispersing fine bubbles and water (hot water) within the bubble generating means 5 and then supplying it from the bubble generating means 5.

[0023] Figure 2 is a schematic diagram showing the defoaming means 2 of this embodiment and the defoaming process. The defoaming means 2 of this embodiment includes a rotary drive unit comprising a rotor 22 that breaks bubbles by mechanical force through rotational motion, and a drive motor 21 that rotates the rotor around the axis of the rotation shaft 23. The upper right of Figure 2 shows a schematic cross-sectional view of the rotary drive unit. The multiple rotors 22 are provided substantially perpendicular to the rotation shaft 23 and are inclined upward radially outward from the rotation shaft 23. The rotors 22 can be provided in an appropriate shape, number, axial length, radial width, and pitch, and the inclination angle does not have to be provided.

[0024] As described above, liquid detergent from the detergent tank is poured into the washing tank 1. There are no particular restrictions on the type of liquid detergent, which is a surfactant, but if the items to be washed are dishes, etc., a detergent that conforms to the ingredient standards for detergents based on the Food Sanitation Law or the quality standards for detergents based on the Japanese Industrial Standards (JIS) is used. During the washing process, fine bubbles are mixed into the washing water by the bubble generating means 5, which agitates the washing water, and as a result, bubbles 30 from the liquid detergent are generated.

[0025] As the foam 30 floats to the surface of the liquid in the washing tank 1, this foam 30 is sucked in by the rotation of the rotor blade 22 of the defoaming means 2. The air inside the defoaming means 2 is pushed out by the rotation of the rotor blade 22, creating negative pressure on the intake side and drawing in the foam. Alternatively, an air pump (not shown) may be connected to the defoaming means 2 to reduce the pressure inside the rotor blade housing 24 and suck in the foam. The foam 30 is moved to the outer circumference of the rotor blade 22 by centrifugal force and can be broken by collision with the rotor blade or the side wall of the rotor blade housing 24 on its outer circumference, or by shearing due to rotation after adhering to the rotor blade 22.

[0026] When the foam is defoamed or burst, it becomes a droplet, but since these droplets 31 contain dirt such as oil, if they return to the washing tank 1, the cleanliness of the washing water cannot be maintained. Therefore, the defoaming means 2 of this embodiment has a discharge pipe 25 for discharging the sucked washing water to the outside. The defoamed or burst droplets 31 discharged from the discharge opening of the rotor blade housing 24 flow out into the discharge pipe 25 and are collected in a discharge tank (not shown) outside the washing tank. Therefore, the dirt contained in the foam 30 does not return to the washing tank 1. By providing the defoaming means 2 in the washing tank 1, the foam 30 generated in the washing tank can be reliably captured and defoamed, and the clean state of the washing water in the septic tank can be maintained.

[0027] Next, we will describe the jet means 10 that enables the defoaming means 2 to efficiently suck up the foam 30. Figure 3 is a front view of the washing tank equipped with the jet mechanism 10, and Figure 4(A) is a top view of the washing tank 1 equipped with the jet mechanism 10. Before the washing process, the dish basket 4, on which the dishes to be washed are arranged, is immersed in the washing tank 1, but this is omitted in the figures.

[0028] In this embodiment, as shown in the figure, four jet nozzles 10 are installed on each of the long-side walls and one on each of the short-side walls of the cleaning tank 1. The nozzle 5, which is the tip of the bubble generating means described above, is also installed near the jet nozzles 10, and in this embodiment, it is installed on the short-side wall. The number of jet nozzles 10 is arbitrary and is not limited to the number shown in this embodiment. In addition, the bubble generating means 5 is not limited to being sprayed from the short-side of the cleaning tank 1, but may also be installed on the long-side wall, or there may be two or more of them.

[0029] The jet nozzles 10, which agitate the water or hot water in the washing tank 1, receive pressurized water or hot water from the bubble pump 6 into the connecting pipe 11, and the water is discharged from the bubble generating means 5 and each jet nozzle 10 connected to the connecting pipe 11. This continuous discharge forms a constant water flow. The bubble pump 6 also circulates the water or hot water as needed to maintain the bubble water.

[0030] Figure 4(B) shows the water flow in the cleaning tank as a result of the jet nozzle 10 shown in Figures 3 and 4(A). The bubble water discharged from the bubble generating means 5, as indicated by the arrow in Figure 4(B), forms a unidirectional (clockwise) swirling flow in the cleaning tank, and the applicant's experiments have proven that it forms a spiral vortex near the center of the cleaning tank 1. Liquid detergent is added to the cleaning tank 1 and bubbles are generated, so these bubbles, due to the swirling flow, gather at the vortex near the center of the cleaning tank 1 in this embodiment. Therefore, a defoaming means 2 is installed near the center of the cleaning tank 1, and the defoaming means 2 sucks up the bubbles 30 and performs defoaming treatment. However, in the case of the jet nozzle orientation shown in Figure 4(B), the water discharged from jet nozzles 10-1 and 10-6 promotes the formation of this swirling flow, while the water discharged from jet nozzles 10-3 and 10-4, etc., obstructs the clockwise flow, making it difficult to form. As a result, the swirling flow is weaker compared to Figure 4(C), which will be described later, and the bubbles concentrate in one place in the washing tank 1 relatively slowly.

[0031] In Figure 4(B), each of the jet nozzles 10 was mounted perpendicular to the longitudinal side wall and directly opposite the opposing jet nozzle. However, Figure 4(C) shows an example of jet nozzles 12 that are mounted diagonally opposite the longitudinal side wall, rather than perpendicular to it. There is one nozzle 5, which is the tip of the bubble generating means. In the case of the orientation of the jet nozzles 12 shown in Figure 4(C), the water or hot water being agitated in the cleaning tank also creates a swirling flow in one direction (clockwise) within the cleaning tank 1, similar to Figure 4(B), forming a vortex near the center of the cleaning tank 1, and the generated bubbles 30 gather near this vortex. Unlike Figure 4(B), the tilted jet nozzles 12-1 to 12-10 promote the movement of the bubble water discharged from the bubble generating means 5 in the longitudinal direction, accelerating the flow and promoting the formation of a swirling flow, thus generating a strong vortex. Therefore, compared to Figure 4(B), bubbles carried by a fast swirling flow move to the central area, which is the vortex, in a short amount of time.

[0032] Although not shown in the diagram, the strength of the swirling flow can be further increased by arranging the jet nozzles 12-1 and 12-6 in the same orientation as the jet nozzles 10-1 and 10-6, or by arranging the jet nozzles 12-5 and 12-10 in the same orientation as the jet nozzles 10-5 and 10-10. The degree of the tilt angle of the jet nozzles 12 can be determined according to the discharge amount and strength of the bubble water from the bubble generating means 5 and the size of the washing tank 1, thereby adjusting the strength of the vortex flow.

[0033] The formation of swirling flows and vortices by the installation of multiple jet nozzles 10 and 12 as shown in Figures 4(B) and (C) causes the foam 30 to autonomously gather and move near the area directly below the defoaming means 2, thereby enabling efficient suction by the defoaming means 2. In other words, if there is no swirling flow, the foam 30 will disperse and float across the entire surface of the water in the washing tank 1, and the defoaming means 2 will take a lot of time to suck up all of the foam 30, so it is necessary to install multiple defoaming means 2. In contrast, in the present invention, even when using a large washing tank, by installing the defoaming means 2 in one place where the foam 30 autonomously accumulates, it is possible to suck up almost all of the foam 30 in the tank, minimizing the cost required for the defoaming means 2 and enabling efficient defoaming in a short time.

[0034] Furthermore, in the example of multiple jet nozzles 10, 12 shown in Figure 4, since vortices are generated near the center of the cleaning tank 1, the defoaming means 2 is installed near the center of the cleaning tank 1. However, depending on the number and installation position of the bubble generating means 5, and other installation methods for the jet nozzles, vortices may be generated in locations other than near the center of the cleaning tank 1. The installation position of the defoaming means 2 should be adjusted according to the number and orientation of the bubble generating means 5 and jet nozzles, and the location of the resulting vortices.

[0035] According to the defoaming cleaning machine of this embodiment, defoaming can be achieved without using an antifoaming agent, thus eliminating various concerns associated with antifoaming agents, ensuring safety, and reducing antifoaming agent costs. Furthermore, the use of multiple series of jet nozzles 10, 12 creates a unidirectional swirling flow in the cleaning water, allowing the foam 30 generated in the cleaning tank by the use of a cleaning agent solution to autonomously concentrate at the location of the vortex within the cleaning tank. Therefore, the defoaming means 2, installed above this vortex, can very efficiently suck up and defoam a large amount of foam 30 in the cleaning tank. [Explanation of Symbols]

[0036] 1 Washing tank 2 Defoaming means 4 Dish basket 5. Bubble generation means 6. Pump for bubbles 10 Jet nozzles 12 Jet Nozzles 30 bubbles 100 Washing machines with defoaming function

Claims

1. A washing tank for washing the objects to be washed, A bubble generating means for generating fine bubbles in the cleaning water in the cleaning tank, A defoaming means for suctioning and eliminating foam generated by the detergent solution contained in the washing water and floating on the surface of the washing water, the defoaming means having a discharge pipe for discharging the washing water droplets after defoaming to the outside, A plurality of jet means installed in the washing tank, wherein the position and orientation of each jet means are adjusted so that the foam becomes a water flow that collects near the suction port of the defoaming means, A cleaning device equipped with a defoaming function.

2. The defoaming means is installed above the water surface of the vortex formed by the plurality of jet means, as described in claim 1.

3. The defoaming cleaning apparatus according to claim 1 or 2, wherein the jet means discharges cleaning water toward the opposing tank walls of the cleaning tank.

4. The defoaming cleaning apparatus according to claim 1 or 2, wherein the jet means is installed in a direction offset by a predetermined angle from the opposing tank walls of the cleaning tank.

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