Dishwasher

Abstract

To provide a dishwasher with reduced noise, having a heat exchanger that can be easily manufactured but excels in condensation efficiency.SOLUTION: In a dishwasher, a flexible stainless pipe whose surface is bent in a corrugated shape is used as a cooling pipe for a heat exchanger, and an acoustic insulation material is provided outside a washing tank and inside an enclosure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dishwasher that can condense steam or vapor generated during dishwashing within the device without emitting it to the outside, and that is also quiet. [Background technology]

[0002] Dishwashers spray warm or hot water from nozzles attached to the rotating propeller during washing and rinsing, causing steam and vapor to leak from the housing and generating noise. In restaurants and other establishments, dishwashers are sometimes installed under the counter where no exhaust system is installed, but the steam, steam, and noise that fills the area around the counter can be unpleasant for customers.

[0003] Conventionally, devices for condensing steam and vapor inside a dishwasher include those that introduce steam and vapor into a heat exchanger wound around a cylindrical tube through which cooling water flows, as described in JP 2015-124993 A, and those that attach fins to the cylindrical tube through which cooling water flows to increase the heat exchange area, as described in JP 2017-123924 A. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Publication No. 2015-124993 [Patent Document 2] Publication No. 2017-123924 Summary of the Invention [Problem to be solved by the invention]

[0005] Simply wrapping a cylindrical tube around the inside of the heat exchanger was problematic in that heat exchange was insufficient, allowing steam and vapor to escape from the dishwasher, and adding fins to the cylindrical tube complicated the manufacturing process.

[0006] The object of the present invention is to provide a dishwasher that has a simple manufacturing process, a heat exchanger that can condense water within the device without releasing steam or vapor to the outside, has excellent condensation efficiency, and reduces noise. [Means for solving the problem]

[0007] Because steam and vapor generated by dishwashers condense upon contact with the cooling pipes installed in the heat exchanger, the cooling efficiency increases the more densely the cooling pipes with a larger surface area per unit length (specific surface area) are installed. The researchers discovered that flexible stainless steel pipes with a wavy surface have a large specific surface area and can be easily bent, allowing them to be installed densely inside the heat exchanger without compromising workability during manufacturing. They also discovered that the noise generated by a dishwasher can be broken down into the sound of hot or warm water being pumped out of nozzles on the propeller, the sound of the hot or warm water hitting the dishes or the inside of the washing tub, the vibration of the washing tub caused by the rotation of the propeller, and the sound of the pump itself. The present invention is a dishwasher characterized in that flexible stainless steel pipes are used as cooling pipes for the heat exchanger, and soundproofing materials are installed on the outside of the washing tank and inside the housing. [Effects of the Invention]

[0008] The dishwasher of the present invention uses flexible stainless steel pipes, which have a simple manufacturing process and high cooling efficiency, as the cooling pipes of the heat exchanger, so steam and vapor are condensed within the device without being released to the outside, and soundproofing materials are installed on the outside of the washing tank and inside the housing, so noise is suppressed and the device is quiet. [Brief explanation of the drawings]

[0009] [Figure 1] Overall view of the dishwasher [Figure 2] Overall view of the dishwasher, excluding the top plate [Figure 3] Flexible stainless steel pipe with independent surface corrugations [Figure 4] Flexible stainless steel pipe with a continuous corrugated surface [Figure 5] Diagram showing the structure of a dishwasher [Figure 6] Exploded view of the cleaning tank [Figure 7] Door exploded view [Figure 8] Exploded view of the housing [Figure 9] Cleaning pump and peripheral parts DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described with reference to the drawings.

[0011] FIG. 1 is a schematic diagram showing the entire dishwasher of the present invention.

[0012] Figure 2 shows the structure of a dishwasher, excluding the top plate of the housing and the heat exchanger lid. During dishwashing, dishes are washed with warm water and then rinsed with hot water at around 80°C, generating steam and vapor in the washing tub 2. The steam and vapor are sucked in by fan 12 and introduced into heat exchanger 10. Inside heat exchanger 10, flexible stainless steel pipes 11 (surface corrugations omitted) are arranged, bent into a roughly oval shape and placed so that they are tightly fitted together, through which cooling water passes. The steam and vapor exchange heat with the cooled flexible stainless steel pipes 11 and are condensed. At the bottom of heat exchanger 10, there is a discharge pipe 14 for condensed water that connects to the washing tub, and on the side of the heat exchanger, there is an air outlet 13 that connects to the washing tub.

[0013] The corrugations on the surface of the flexible stainless steel pipe may be arranged independently and at equal intervals as shown in Figure 3, or may be continuous in a spiral shape as shown in Figure 4. Higher corrugations and narrower intervals between corrugations are desirable because they increase the specific surface area, but both types of corrugation make the pipe more difficult to bend, so the corrugation type should be selected appropriately depending on the internal volume and shape of the heat exchanger.

[0014] It is desirable to install the flexible stainless steel pipe bent into a roughly oval shape so that its longitudinal direction follows the line connecting the fan 12 and the air outlet 13 provided on the heat exchanger, as this will facilitate the flow of air containing steam and vapor, but this is not a limitation. The flexible stainless steel pipe may also be in a shape other than an oval, such as a spiral or triangular shape, or different shapes may be used in combination.

[0015] Figure 5 shows the structure of a dishwasher. Washing tub 2 has washing propeller 21 and rinsing propeller 23, which are installed above and below the washing tub so that a washing basket (not shown) containing dishes is sandwiched between them. Washing water pumped by washing pump 31 is sprayed from nozzle 22 attached to washing propeller 21, and rinsing water pumped by rinsing pump 32 is sprayed from nozzle 24 attached to rinsing propeller 23. In addition to the spraying sound and the collision sound of the sprayed warm or hot water hitting the dishes or the washing tub, the vibration sound of the washing tub caused by the rotation of the propellers and the driving sound of the pump all leak out of the dishwasher and become noise during the washing and rinsing processes.

[0016] Figure 6 is an exploded view of the cleaning tank excluding the door. Elastic members 51-56, cut to fit each of the following three components, are attached to the cleaning tank top plate 41, which houses the heat exchanger; the cleaning tank side plate 42, which has recesses for added strength; and the cleaning tank bottom plate 43, which has drainage holes. Elastic members 51-56 are installed on each of these plates. Elastic members quickly convert expansion and compression caused by vibration into frictional heat, quickly reducing vibration in the cleaning tank and preventing noise. Examples of elastic members include natural rubber, butyl rubber, ethylene propylene rubber, silicone rubber, and asphalt. Elastic members are also effective in reducing the impact noise caused by hot or warm water hitting the cleaning tank.

[0017] Figure 7 is an exploded view of the door, with metal-containing rubber 63 sandwiched inside the door. Since materials with a high specific gravity do not transmit sound vibrations that travel through the air as easily, rubber containing metals with a high specific gravity is suitable as a soundproofing material. Metal-containing rubber is also effective in preventing noise caused by collisions and vibrations.

[0018] FIG. 8 is an exploded view of the housing, showing that synthetic resins 57-61 with fine voids are installed on the inner surface of the housing. The synthetic resins with fine voids trap and attenuate sound vibrations resonating inside the housing, preventing noise. Examples of synthetic resins with fine voids include ethylene vinyl acetate foam with a three-dimensional mesh structure and porous synthetic resins such as polyurethane foam and polystyrene foam. Fiber aggregates such as glass wool and felt can also be used.

[0019] Figure 9 shows the washing pump 31 and its surrounding components, with 62 being a sheet made of a synthetic polymer compound containing an inorganic substance with a high specific gravity and ethylene vinyl acetate foam bonded together, which is placed over the pump to reduce driving noise. The rinsing pump 32 can be similarly constructed.

[0020] The frequency and volume of sound vary depending on the source, but the optimal soundproofing material can be found through experiments and simulations. It is not enough to stick or sandwich one type of soundproofing material on one noise source; it is also possible to combine two or more types of soundproofing materials with different effects, and the order in which they are used can be freely selected. [Explanation of symbols]

[0021] 1 dishwasher 2 Cleaning tank 10 Heat exchanger 11 Flexible stainless steel pipe 12 Fans 13 Air exhaust port 14 Discharge pipe 21 Cleaning propeller 22 nozzles 23 Rinse Propeller 24 nozzles 31 Cleaning pump 32 Rinse pump 41 Cleaning tank top plate 42 Cleaning tank side panel 43 Cleaning tank bottom plate 51-56 Elastic material (soundproofing material) 57-61 Synthetic resin with fine voids inside (soundproofing material) 62 A sheet made by bonding together a synthetic polymer compound containing inorganic substances with a high specific gravity and ethylene vinyl acetate foam (soundproofing material) 63 Rubber containing metal (soundproofing material)

Claims

1. This dishwasher is characterized in that stainless steel pipes with corrugated surfaces are used as cooling pipes for the heat exchanger, and soundproofing materials are installed on the outside of the washing tank and inside the housing.

2. 2. The dishwasher according to claim 1, wherein the soundproofing material is one or more selected from the group consisting of elastic material, synthetic resin having fine voids, fiber aggregate, and metal-containing rubber.

3. 2. The dishwasher according to claim 1, wherein the synthetic resin having a three-dimensional network structure forms a part of the soundproofing material.

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