Food washing machine and microbubble jet generator

Abstract

To provide a food washing machine capable of effectively washing washing-target food.SOLUTION: A food washing machine comprises: a washing water tank 1 storing washing water and washing food; a plurality of ejectors 10 jetting water including microbubbles to washing-target food; an ejection pump 20 forcibly feeding air-mixed water in which air is mixed to each ejector; and an intake adjusting valve 24A adjusting a suction amount of air from suction piping of the ejection pump. The ejector comprises: a hollow short tubular nozzle main body ejecting the jet water including microbubbles; a throttled portion ejecting water from the ejection pump formed in the nozzle main body; and an opening located between the throttled portion and an ejecting port, and taking in water in the washing water tank. In the food washing machine, the air-mixed water from each ejector is ejected through the throttled portion by the ejection pump, and consequently the air-mixed water is ejected as jet water by venturi effect by the throttled portion while the air mixed in the air-mixed water is formed as microbubbles.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a food washer used to wash away foreign matter adhering to food such as vegetables and fruit, and to a microbubble jet generator used in the food washer. [Background technology]

[0002] For example, a food washer that washes vegetables, fruit, etc. with water to clean them has traditionally been known in which the item to be cleaned is placed in a cleaning water tank that stores cleaning water, and an injection device attached to the cleaning water tank simultaneously injects air bubbles along with the cleaning water to generate a jet water flow containing bubbles (hereinafter referred to as aerated jet water) to remove foreign matter such as dirt that is attached to the food being washed.

[0003] For example, the food washer shown in Patent Document 1, which is an example of a food washer that sprays aerated jet water to wash, is equipped with a washing water tank and a filtrated water tank, and a pressurized water pipe is installed between a circulation pump installed in the filtrated water tank and a bottom chamber of the washing water tank, with an aeration bubble generator installed midway through the pressurized water pipe. This aeration bubble generator has an upstream disk with an injection nozzle attached and a downstream disk with a throttle portion attached, which are connected opposite each other and hold an air intake, and circulating water sent from the circulation pump is sprayed from the injection nozzle toward the throttle portion, and air is taken in from the air intake by the force of the water, and the aerated jet water is sprayed from the bottom of the washing water tank toward the food to be washed.

[0004] Furthermore, the aeration foam generating device in the food washer shown in Patent Document 2 consists of a high-pressure pump that pressurizes tap water (cleaning water) from a water pipe, and a high-pressure ejector connected to this high-pressure pump and attached to the lower part of the side wall of the cleaning water tank. The high-pressure ejector has a throttling section, a circulating water intake port that opens into the throttling section and the tank, and an air intake port having an air intake tube that is open to the outside air. When the high-pressure water generated by the high-pressure pump passes through the throttling section, air is taken in from the air intake port due to the Venturi effect, and water in the cleaning water tank is taken in from the circulating water intake port and sprayed onto the object to be cleaned as an aeration jet water. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-152084 A [Patent Document 2] Japanese Patent Application Publication No. 8-257432 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there are some objects that are not suitable for the type of food washer that sprays aerated jet water onto the object as disclosed in each patent document. For example, when seafood with a slimy surface is washed with a food washer that sprays aerated jet water, a large amount of bubbles is generated in the water tank, which undesirably contaminates the installation space.

[0007] Recently, microbubbles with a bubble diameter of 1 μm to 100 μm have been attracting attention as having a high cleaning and purifying effect. In addition, water containing microbubbles is said to have the effect of preserving the freshness of food and improving its taste. If a food washer that sprays a jet of water containing microbubbles could be realized, it would provide a new option for cleaning methods for objects that are not suitable for cleaning with aerated jet water, and it is expected to add value to the cleaned food in terms of freshness and taste.

[0008] However, it is not easy to realize a food washer that sprays a jet of water containing microbubbles. Simply combining an existing microbubble generator with a conventional food washer would result in problems such as the device becoming more complicated and expensive, and insufficient water flow. Furthermore, if aerated water is sprayed into a water tank containing microvalves to obtain a sufficient water flow, the microbubbles will be absorbed by the large bubbles contained in the aerated water, making it impossible to achieve cleaning with a water flow containing microbubbles.

[0009] The present invention has been made in light of the above-mentioned problems, and aims to provide a food washer and a microbubble jet generator that can effectively wash food using a jet of water containing microbubbles. [Means for solving the problem]

[0010] In order to solve the above problems, a food washer according to an embodiment of the present invention includes a washing water tank for storing washing water to wash food, a plurality of ejectors for spraying jet water containing microbubbles onto food in the washing water tank, a discharge pump for pumping aerated water containing gas (hereinafter referred to as air) into each ejector, and an intake adjustment valve for adjusting the amount of air sucked from the suction pipe of the discharge pump. The ejector includes a nozzle body in the form of a hollow short tube whose end is opened as a nozzle for spraying the jet water containing microbubbles, a throttle part formed in the nozzle body for ejecting water from the discharge pump, and an opening located between the throttle part and the nozzle for taking in water in the washing water tank. In the food washer, the discharge pump sprays aerated water from each ejector through the throttle part, and the air mixed in the aerated water is turned into microbubbles, and the aerated water is sprayed as a jet water by the Venturi effect of the throttle part. The amount of air sucked is preferably 5% or less of the discharge amount of the discharge pump.

[0011] In the present invention, a clean water pipe for supplying clean water may be connected to a pipe extending from the cleaning water tank to the discharge pump so that the water in the cleaning water tank and clean water are supplied to the discharge pump.

[0012] In the present invention, it is preferable that low-pressure aeration jet water is jetted from each ejector at a pressure of 0.1 MPa to 1 MPa.

[0013] In the present invention, the multiple ejectors may be positioned on opposing side wall surfaces of the cleaning water tank and arranged in a staggered pattern facing each other.

[0014] In the present invention, in addition to being positioned on opposite side walls of the washing tank and arranged in a staggered pattern facing each other, it is also preferable that the ejectors are positioned on the supply side of the food to be washed, facing the discharge side.

[0015] In the present invention, the food washer is preferably a food washer for food that floats on water, in which case the ejector is preferably positioned slightly below the surface of the wash water in the wash water tank.

[0016] Alternatively, the food washer may be a food washer for food in which the food to be washed is submerged in water, in which case the ejector is arranged near the bottom within the cleaning water tank and at least a food transport conveyor is located within the cleaning water tank and provided on the discharge side of the cleaning water tank.

[0017] In the present invention, it is preferable that multiple upper and lower ejectors are arranged on the inner wall of the washing water tank, and a food transport conveyor is provided at least on the discharge side of the washing water tank, and that switching control is enabled so that a jet of water containing microbubbles is sprayed from any one of the multiple upper and lower ejectors depending on the specific gravity of the food to be washed. In this case, it is particularly preferable that the multiple upper and lower ejectors are arranged in a staggered pattern vertically.

[0018] In the present invention, it is preferable that the bottom of the cleaning water tank is provided with a convex portion having an inclined surface that becomes higher from both sides in the width direction toward the center.

[0019] In the present invention, the food washer may include a gate at the discharge end of the washing water tank, the gate being a plate body having a through opening, and a roof plate having a through opening extending from an upper end of the shutter plate toward the upstream side in the conveying direction.

[0020] Moreover, the microbubble jet generator according to the embodiment of the present invention includes one or more ejectors that spray jet water containing microbubbles into an installed water tank, and a discharge pump that pressure-feeds aerated water, which is water mixed with air and is supplied with air, to the ejector. The ejector includes a nozzle body in the form of a hollow short tube whose end is opened as a nozzle port for spraying the jet water containing microbubbles, a throttle part formed in the nozzle body for discharging water from the discharge pump, and an opening part located between the throttle part and the nozzle port for taking in water from the water tank. The discharge pump sprays the aerated water from the ejector through the throttle part, and the air mixed in the aerated water is converted into microbubbles and sprayed as a jet water by the Venturi effect of the throttle part. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram illustrating a food washing machine according to a first embodiment. [Diagram 2] FIG. 2 is a partially cutaway perspective view of the food washer. [Diagram 3] FIG. [Figure 4] FIG. 4 is a perspective view showing a second capturing means. [Diagram 5] FIG. 4 is a cross-sectional view showing a second capturing means. [Figure 6] FIG. 11 is a schematic diagram illustrating a food washing machine according to a second embodiment. [Figure 7] FIG. 13 is a schematic explanatory diagram showing a modified example of the present invention. [Figure 8] FIG. 11 is a schematic explanatory diagram showing another modified example of the present invention. [Figure 9] FIG. 11 is a schematic cross-sectional view of a cleaning water tank in still another modified example of the present invention. [Figure 10] FIG. 13 is a schematic diagram of a modified food washing machine having a gate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0023] [First embodiment] In the first embodiment, the present invention will be described as an example of a washing device for washing mainly agricultural products such as vegetables and fruits floating on water. Fig. 1 shows an outline of the food washer of the present invention, and as shown in the figure, the food washer is composed of a washing water tank 1 having a rectangular box shape with an open top for mainly storing washing water, a plurality of ejectors 10 for injecting running water containing microbubbles onto the food A to be washed, a discharge pump 20 for pressure-feeding the washing water to the ejectors 10, and a circulation pump 25 for sucking the washing water in the washing water tank 1 and circulating it back into the washing water tank 1 to generate a reflux in the washing water tank 1.

[0024] In Figure 1, the left side of the cleaning water tank 1 is the entrance side for the food A to be cleaned, and the right side is the exit side for the food A to be cleaned. The circulation pump 25 is arranged at the exit end of the cleaning water tank 1, and an overflow tank 2 is connected to it for draining excess cleaning water. The cleaning water in the cleaning water tank 1 sucked up by the circulation pump 25 is discharged to both side edges of the cleaning water tank 1, thereby generating a water flow in the centre of the cleaning water tank 1 from the entrance side to the exit side of the cleaning water tank 1 (indicated by arrow a in Figure 2), and at the exit side of the cleaning water tank 1, a reflux (indicated by arrow b in Figure 2) is generated which branches off to the left and right from the centre of the cleaning water tank 1 and flows along both side wall surfaces 1A, 1A of the cleaning water tank 1 back towards the entrance side, and the excess cleaning water in the cleaning water tank 1 is drained from the overflow tank 2.

[0025] In addition, within the washing water tank 1, a pair of partition walls 3, 3 are formed along both side wall surfaces 1A, 1A to define a reflux flow path 4 generated by the circulation pump 25, and a water-permeable net 5 is detachably attached to the downstream side of this flow path 4 as a first capturing means for capturing foreign matter S removed from the food to be washed. Also, a dirt collecting net 5A for removing dirt and the like is attached to the overflow tank 2.

[0026] 4 and 5, a water-permeable net 6 is provided as a second trapping means for trapping floating foreign matter S carried away by the water current from the carry-in side to the carry-out side, and a frame 7 to which the net 6 is attached is provided. The frame 7 is made up of left and right mounting plates 7A, a back plate 7B, and a front plate 7C, and the bottom of the frame 7 is made up of a number of parallel rods 8, with the net 6 attached to the back plate 7B located on the downstream side. By forming the bottom of the frame 7 with a number of parallel rods 8, water flows through the gaps between the parallel rods 8 to ensure water permeability, and each parallel rod 8 has an inclined portion 9 formed thereon to guide food A to be washed floating on the water upstream of the frame 7 so that it does not get blocked by the frame 7 but sinks to the bottom of the frame 7. Furthermore, the left and right mounting plates 7A have horizontal pieces 7D bent outward, and the horizontal pieces 7D are hung between the partition walls 3, 3 to detachably attach the frame body 7 to the cleaning water tank 1. The frame body 7 thus attached to the cleaning water tank 1 is placed in the cleaning water tank 1 with the top of the frame body 7 protruding from the surface of the cleaning water and the net 6 submerged in the water, as shown in Figure 5. As a result, floating foreign matter S flowing with the water current passes through the frame body 7 and is captured by the net 6, and food A to be cleaned, which is washed with the water current, is transported downstream under the frame body 7 along the inclined parts 9 of the parallel rods 8.

[0027] The multiple ejectors 10 are disposed on opposing side wall surfaces 1A, 1A of the cleaning water tank 1, and are disposed in a staggered pattern facing each other as shown in Fig. 1, and each ejector 10 is connected to a discharge pump 20 via a water supply pipe 21. In this embodiment, the objects to be cleaned are vegetables, fruits, etc. that float on the water, and each ejector 10 (100) is disposed slightly below the surface of the cleaning water in the cleaning water tank 1.

[0028] The discharge pump 20 takes in the washing water in the washing water tank 1 from the discharge side of the washing water tank 1 and pumps it to each ejector 10. A centrifugal pump is preferably used as the discharge pump 20. Furthermore, a plurality of ejectors 100 are arranged at the center of the carry-in side (the supply side of the food to be washed) of the washing water tank 1 facing the discharge side, and the washing water taken in from the discharge side of the washing water tank 1 by the discharge pump 20 is also sprayed from the ejector 100 attached to the center of the carry-in side of the washing water tank 1. This also helps to form a water flow (indicated by arrow a in FIG. 2) from the carry-in side of the washing water tank 1 to the carry-out side.

[0029] A clean water pipe 23 for supplying clean water and an intake pipe 24 for sucking in gas (hereinafter referred to as air) are connected to the pipe 22 from the cleaning water tank 1 to the discharge pump 20. The intake pipe 24 is provided with an intake adjustment valve 24A for adjusting the amount of air to be sucked in. The intake adjustment valve 24A is preferably a valve (e.g., a needle valve) capable of finely adjusting the amount of air to be introduced. When the discharge pump 20 is operated, the discharge pump 20 sucks in a small amount of air from the intake pipe 24 according to the opening degree of the intake adjustment valve 24A, together with the water in the cleaning water tank 1 and the clean water from the clean water pipe 23. The amount of air to be sucked in is preferably 5% or less of the discharge amount of the discharge pump 20. The air to be sucked in may be the surrounding air, or may be a gas such as oxygen, ozone, carbon dioxide, nitrogen, or fluorine that is expected to have functions such as sterilization and freshness maintenance.

[0030] The cleaning water used in the cleaning water tank 1 is usually purified in a septic tank before being discharged outside, but as one of the items in the water quality test for the septic tank, it is considered desirable to have a certain level of dissolved oxygen (DO) (for example, 0.3 mg / L for a single-treatment septic tank) or more. If the air to be sucked in is oxygen, the amount of dissolved oxygen in the cleaning water can be increased, making it easier to maintain the water quality in the septic tank within an appropriate range.

[0031] The discharge pump 20 agitates the sucked water and air and sends them out toward the ejector 10, 100. In this way, the discharge pump 20 pressure-feeds the aerated water containing a small amount of air to the ejector 10, 100 via the water supply pipe 21. At this time, the discharge pump 20 preferably pressure-feeds the aerated mixed water so that the water pressure in the water supply pipe 21 is about 0.3 MPa to 0.5 MPa.

[0032] FIG. 3 shows a cross-sectional view of the ejector 10. Since the ejector 10 has the same configuration as the ejector 100 arranged on the loading side of the cleaning water tank 1, the specific configuration of the ejector 10 will be described as a representative, and the ejector 100 will be omitted. As shown in the figure, the ejector 10 has a nozzle body 12 in the form of a hollow short tube whose end is opened as an injection port 11. A throttle portion 13 is formed inside the nozzle body 12, and an opening portion 14 is formed between the throttle portion 13 and the injection port 11 to take in water from the cleaning water tank 1. In the ejector 10, the inner diameter of the injection port 11 is preferably about φ15 to 25 mm, and the inner diameters of the front and rear throttle portions 13 of the throttle portion 13 are preferably about φ3.0 mm to 5.0 mm. As a result, when the discharge pump 20 is operated, aerated water is sprayed from the ejector 10 (100), and the water in the cleaning water tank 1 is sucked in from the opening 14 by the Venturi effect of the throttle section 13 of each ejector 10 (100), and is sprayed as a jet of water toward the food A to be washed. At this time, the air mixed in the mixed water becomes microbubbles with a bubble diameter of 1 μm to 100 μm in the jet of water. Therefore, the ejector sprays jet of water containing microbubbles toward the food A to be washed in the cleaning water tank 1.

[0033] To confirm the generation of microbubbles, the cleaning water containing microbubbles generated in the cleaning water tank 1 by the food washer of this embodiment was analyzed by a laser diffraction particle size distribution analyzer SALD-7500X10 manufactured by Shimadzu Corporation. The discharge volume of the discharge pump 20 when generating the microbubbles was 400 L / min, and the amount of air suction was 12 to 20 L / min (i.e., in the range of 3 to 5% of the discharge volume). As a result, the average diameter was 35.8 μm to 38.9 μm, and it was confirmed that the microbubbles were generated. That is, the discharge pump 20 and the ejector 10 (100) installed in the cleaning water tank 1 constitute a microbubble jet generator.

[0034] The jet pressure of the jet water is preferably 0.1 MPa to 1 MPa. That is, if the jet pressure of the ejector 10 (100) exceeds 1 MPa, the leaves of leafy vegetables and the like will be significantly crushed or crushed, and the commercial value of the washed food A will be significantly reduced. In addition, if the jet pressure is less than 0.1 MPa, the washing water and fine air bubbles will have difficulty penetrating between the leaves of leafy vegetables and the like, resulting in poor washing efficiency, which is not preferable. Therefore, a jet pressure of the jet water in the range of 0.1 MPa to 1 MPa is preferable because it allows efficient washing without damaging the food A to be washed.

[0035] By using the above-mentioned method, it is possible to supply a large amount of jet water containing microbubbles from the ejector 10 (100) into the cleaning water tank 1 with sufficient jet pressure.

[0036] The washing method of the present invention configured as above will be described. When the circulating pump 25 is operated with washing water stored in the washing water tank 1 to a predetermined level, a water flow from the carry-in side to the carry-out side of the washing water tank 1 is generated in the center of the washing water tank 1, and the food A to be washed supplied from the carry-in side is transported by this flow. In addition, the discharge pump 20 causes each ejector 10 (100) to spray a jet of water containing microbubbles toward the food A to be washed. At this time, the jet of water from each ejector 10 is sprayed toward the food A to be washed, which is transported by the water flow from the carry-in side to the carry-out side. The spray angle of each ejector 10 is adjustable, and although not particularly limited, in this embodiment, the jet water sprayed from the ejector 10 onto the food A is sprayed in a direction crossing the water flow from the carry-in side to the carry-out side, and each ejector 10 is arranged in a staggered pattern on both opposing side walls 1A, 1A of the washing water tank 1, so that the food A, which is carried downstream by the water flow, moves in a meandering manner due to the jet water sprayed from each ejector 10. Therefore, the food A is washed for a longer period of time, and the action of the jet water containing microbubbles allows fine air bubbles to penetrate deep between the leaves of, for example, leafy vegetables, and foreign matter such as insects and soil present between the leaves can be effectively removed. In addition, for example, in seafood with a slimy surface, slime and other dirt can be effectively removed while suppressing the generation of bubbles. Furthermore, a large amount of jet water containing microbubbles can be sprayed from the ejector 10 (100) into the washing water tank 1, and the washing water is agitated by the jet water, which generates agitation and turbulence in the washing water, greatly agitating the food A to be washed, enabling it to be massaged by the water flow and improving the washing effect. At the same time, the jet pressure of the water flow containing fine bubbles that collides with the food A to be washed is low, so there is no damage to leafy vegetables and other foods that are particularly susceptible to damage. Washing with jet water containing microbubbles is also expected to have the effect of maintaining the freshness of the food A to be washed and to improve its taste.

[0037] In addition, the ejector 10,100 that sprays a jet of water onto the food A to be washed is connected to a clean water piping line 23 that supplies clean water to a pipe 22 leading from the ejector 10,100 to the discharge pump 20, and clean water is supplied to the cleaning water tank 1 at a constant rate from the ejector 10,100. This makes it possible to prevent the cleaning water from becoming contaminated compared to when cleaning is done only with circulating water in the cleaning water tank 1, and also reduces running costs compared to when cleaning is done always with clean water, making it more rational.

[0038] The excess cleaning water in the cleaning water tank 1 is drained from the overflow tank 2, and foreign matter contained in the drainage is removed by a dirt catcher net 5A provided in the overflow tank 2 before being drained.

[0039] Next, the removal of foreign matter mixed into the washing water circulating in the washing water tank 1 will be described. In this embodiment, a water flow from the carry-in side to the carry-out side of the washing water tank 1 and a return flow from the carry-out side to the carry-in side of the washing water tank 1 are generated by a circulation pump 25 arranged on the carry-out side of the washing water tank 1, and the return flow flows through a flow path 4 partitioned by partition walls 3, 3, and a discharge pump 20 sprays jet water from ejectors 10, 100 onto the food A to be washed, washing the foreign matter S attached to the food A. At that time, depending on the type of food A to be washed, fine debris is peeled off, and this also tends to be mixed into the washing water tank 1 as the foreign matter S. In particular, the demand for cut vegetables has increased in recent years, and when the cut vegetables are washed, fine debris is easily generated from the cut vegetables as the foreign matter S. The foreign matter S generated by washing with the jet water of the ejector 10, 100 can be efficiently captured by the net 6 arranged as the second capturing means so as to block the water flow from the carry-in side to the carry-out side of the washing water tank 1. That is, the frame 7 equipped with the net 6 constituting the second capturing means is arranged so that only the upper part partially protrudes above the water surface. On the other hand, foreign matter S such as vegetable scraps peeled off from cut vegetables and fine dust floats on the water surface and flows, so it is efficiently and reliably captured by the net 6 arranged facing the water surface. Furthermore, when the frame 7 is arranged so as to face the water surface and block the water flow, the food A to be washed is blocked by the frame 7, but the food A to be washed riding on the water flow abuts against the inclined portion 9 formed on the parallel rod 8 of the frame 7 and is transported downstream along the inclined portion 9 under the frame 7, so there is no risk of impeding the washing of the food A to be washed. Furthermore, since the frame 7 can be detachably attached to the washing water tank 1, when washing food A that is easy to peel, such as cut vegetables, it is possible to arrange a plurality of nets 6 side by side.

[0040] In this way, after the floating foreign matter S is removed by the net 6, the foreign matter S that cannot be completely removed by the net 6 can be captured by the net 5, which is the first capturing means provided in the return flow path 4 partitioned and formed by the partition walls 3, 3. That is, the washing water path through which the washing water flows in the washing process with washing water and the return flow path 4 after washing are completely partitioned by the partition walls 3, 3, and the foreign matter S cannot be removed by the net 6 provided in the washing water path, and even if the foreign matter S flows into the return flow path 4 after washing, the foreign matter S will not be mixed into the washing water path from the flow path partitioned and formed by the partition walls 3, 3. Therefore, in a food washer that washes by circulating washing water as in this embodiment, by partitioning the washing water path and the return flow path 4 by the partition walls 3, 3, even if the foreign matter S cannot be completely removed by the net 6 provided in the washing water path, there is no risk of the remaining foreign matter S circulating back to the washing water path and adhering to the food A to be washed, thereby reducing the commercial value.

[0041] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 6. In the first embodiment, the objects to be washed were vegetables and fruits that float on water, but in this embodiment, the objects to be washed are vegetables and fruits that sink in water, and the ejector 10 attached to the washing water tank 1 is attached near the bottom of the washing water tank 1, and the food transport conveyor 30 is provided at the bottom of the washing water tank 1 and on the discharge side of the washing water tank 1. Other than this, the configuration is substantially the same as the first embodiment, and the same parts as in the first embodiment are given the same reference numerals, and explanations of the overlapping parts are omitted, and only the different parts are explained.

[0042] Food transport conveyor 30 in this embodiment is composed of horizontal section 30A that fits along the bottom of cleaning water tank 1, inclined section 30B that is inclined so as to be exposed above the water surface on the downstream side of cleaning water tank 1, and horizontal section 30C that is connected to inclined section 30B and faces the discharge side of cleaning water tank 1. Ejector 10 is attached so as to be located slightly above horizontal section 30A.

[0043] In the present embodiment configured as described above, even if a submerged food is washed, as in the first embodiment, a water flow from the carry-in side to the carry-out side of the washing water tank 1 is generated by the circulation pump 25, and the food is transported on that flow, and jets of water containing microbubbles are sprayed from each ejector 10 toward the food, so that even if the food is submerged in water, it can be washed reliably and efficiently without damaging the food, and the food submerged in the washing water is reliably transported to the carry-out side of the washing water tank 1 by the food transport conveyor 30. Also, washing with jets of water containing microbubbles can be expected to have the effect of maintaining the freshness of the food and improving its taste.

[0044] [Modifications of the embodiment] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist of the present invention.

[0045] For example, in the first embodiment, an example is shown in which the ejector 10 is arranged slightly below the surface of the cleaning water in the cleaning water tank 1 for food that floats on the water, and in the second embodiment, an example is shown in which the ejector 10 is arranged near the bottom of the cleaning water tank 1 for food that sinks in the water, but it is also possible to combine the first and second embodiments as shown in Fig. 7. That is, in the configuration of the second embodiment in which the food transport conveyor 30 is provided at the bottom of the cleaning water tank 1 and on the discharge side of the cleaning water tank 1, the ejector 10 can be provided slightly below the surface of the cleaning water in the cleaning water tank 1 shown in the first embodiment, and the ejectors 10 can be arranged in multiple levels above and below. In this case, it is also possible to switch and control so that the jet water is sprayed from any of the upper and lower ejectors 10 depending on the specific gravity of the food to be washed. With this configuration, food floating on the water can be sprayed with jets of water only from the upper ejector 10, and food submerged in the water can be sprayed with jets of water only from the lower ejector 10, making it possible to use the device as a food washing device for various foods regardless of whether the food floats or sinks in water. When such ejectors 10 are arranged in multiple vertical stages, more complex turbulence can be generated by arranging the ejectors 10 in a staggered pattern both above and below as shown in Fig. 7, thereby enabling more efficient washing. Although Fig. 7 shows an example in which the ejectors 10 are arranged in two stages, one above the other, the ejectors 10 may be arranged in more than two stages.

[0046] In addition, the ejectors 10 and 100 of the above embodiments may be configured to have an outside air intake opening formed opposite the opening 14, so that outside air can be sucked in through the outside air intake opening and the aerated jet water can be sprayed from the ejector. When spraying jet water containing microbubbles, it is recommended to close the outside air intake opening. In other words, the ejector may be configured to be able to switch between a configuration for spraying jet water containing microbubbles and a configuration for spraying aerated jet water depending on the application.

[0047] In addition, in each of the above embodiments, a food washer has been described as an example in which food is washed while being transported by a water flow or conveyor from the loading side to the unloading side. However, the scope of the present invention also includes a food washer of a simple configuration in which a microbubble jet generator such as a discharge pump and ejector similar to that of the first embodiment is attached to a washing water tank (so-called sink type) that does not involve loading or unloading.

[0048] Furthermore, in the food washer in which ejectors 10 are arranged in two upper and lower stages as shown in Fig. 7, the bottom of washing water tank 111 may be formed into shallow bottom section 111A and deep bottom section 111B, and two upper and lower stages of ejectors 10 may be arranged in shallow bottom section 111A as a washing area, and food conveyor 30 may be arranged in deep bottom section 111B as a discharge area, as shown in Fig. 8. With this configuration, the bottom conveyor can be omitted in the washing area, the structure can be simplified, and the water tank capacity can be reduced as much as possible to save water. Also, even if ejectors 10 are provided in two upper and lower stages, it is possible to use only one stage on the water surface side when they are not needed, and it can be designed according to the ingredients to be washed.

[0049] In addition, in each of the above embodiments, agricultural products such as vegetables and fruits are described as examples of foods to be washed, but the present invention is not limited thereto and can be applied to various foods such as seafood and meat. The size and shape of the washing water tank 1, or the number and arrangement of the ejectors 10, are not particularly limited. Furthermore, the number of the net 6 and its frame body 7 as the second catching means may be one, two sets, or more than one frame body 7 may be arranged in parallel, and the number may be appropriately selected according to the amount of washing. Furthermore, a configuration in which a shower for spraying clean water for finishing is provided on the food transport conveyor 30 arranged on the discharge side, or a configuration in which a blower is provided at the bottom of the washing water tank 1 and bubbles are generated by the blower to improve the washing efficiency may be used, and the basic structure of the food washer can be modified in various ways within the scope of the present invention.

[0050] In each of the above-mentioned embodiments, as shown in FIG. 9, a convex portion 17 having an inclined surface that becomes higher from both sides in the width direction toward the center may be provided at the bottom of the washing water tank (1, 111). In FIG. 9, the direction perpendicular to the paper surface corresponds to the conveying direction from the carry-in side to the carry-out side of the washing water tank (1, 111). The convex portion 17 may be provided in the conveying direction over the range in which the ejector 10 is provided. The jet of water sprayed from the ejector 10 is directed upward by the inclined surface of the convex portion 17. As a result, a flow of circulating washing water is generated in the cross section of the width direction of the washing water tank 111 as shown by the arrows in FIG. 9. In combination with the water flow from the carry-in side to the discharge side of the washing water tank 1 by the ejector 100, the washing water has a spiral flow from the carry-in side to the discharge side of the washing water tank 1. This flow of washing water allows the washing object (food to be washed) to be washed more thoroughly than when a jet of water is simply sprayed. The mechanism for generating a flow of circulating cleaning water using the convex portion 17 is particularly effective when the jet water from the ejector 10 is jet water containing microbubbles, but is also effective when the jet water from the ejector 10 is normal aerated jet water.

[0051] In each of the above-mentioned embodiments, the object to be washed (food to be washed) is transported from the carry-in side to the carry-out side of the washing water tank (1, 111) by the water flow or conveyor, but depending on the condition and characteristics of the object to be washed (e.g., weight, size, shape, degree of dirt, etc.), there may not be enough time for the object to be washed from when it is carried in until it is carried out. Therefore, as shown in FIG. 10(a), the food washer may be provided with a gate 18 having an openable and closable shutter plate 18A at the carry-out end of the washing water tank. The shutter plate 18A is a plate body having a through opening, which allows the water flow from upstream to downstream to pass through while preventing the object to be washed from being carried downstream by the water flow. The shutter plate 18A may be formed, for example, in a mesh, lattice, punch, fence, etc. shape.

[0052] The gate 18 is controlled to open and close by a control means (not shown). In the open state, the shutter plate 18A is located at the top of the discharge end of the cleaning tank, allowing the object to be cleaned to be freely transported downstream by the water flow or conveyor. On the other hand, in the closed state, the shutter plate 18A descends to a position at the discharge end of the cleaning tank where it prevents the object to be cleaned from being transported downstream (for example, a position that covers from the bottom of the cleaning tank at the discharge end to the water surface), keeping the object to be cleaned in the cleaning tank and ensuring a sufficient cleaning time. Since the shutter plate 18A is a plate with an opening, it prevents the object to be cleaned from being transported downstream, but does not impede the water flow.

[0053] As shown in FIG. 10(b), the gate 18 may further include a roof plate 18B, which is a plate having a through opening. The roof plate 18B may be formed, for example, in a mesh, lattice, punch, or fence shape. The roof plate 18B extends from the upper end of the shutter plate 18A toward the upstream side in the conveying direction. The roof plate 18B may extend, for example, to the vicinity of the input end of the cleaning water tank. The roof plate 18B is located near the surface of the cleaning water when the gate 18 is closed and the shutter plate 18A descends. This allows the cleaning object to float on water, so that the cleaning object can be reliably washed by the jet water while the shutter plate 18A keeps the cleaning object in the cleaning water tank and the roof plate 18B immerses the cleaning object below the surface of the cleaning water while the gate 18 is closed.

[0054] The gate 18 may be provided not only at the discharge end of the cleaning water tank, but also midway through the cleaning water tank. By providing a plurality of gates 18 in this way and dividing the cleaning water tank from the inlet end to the outlet end into a plurality of sections, it is possible to prevent the cleaning target from accumulating at the outlet end when the gate 18 is closed, and cleaning can be performed by efficiently using the jet water in the upstream part of the cleaning water tank (the area close to the inlet end). The configuration including the gate 18 is particularly effective when the jet water from the ejector 10 is jet water containing microbubbles, but is also effective when the jet water from the ejector 10 is normal aerated jet water. [Explanation of symbols]

[0055] 1,111 Cleaning tank 1A Both side walls 2 Overflow tank 3. Partition Wall 5. Net (first capture means) 6 Net (second capture means) 7 Frame (second capture means) 9 Slope 10,100 Ejector 11 Nozzle 12 Nozzle body 13. Squeezing section 14 Openings 16 Outside air intake pipe 17 Convex 18 Gates 18A Shutter plate 18B Roof plate 20 Discharge pump 21 Water supply piping 22 Conduit 23 Clean water piping 24 Intake piping 24A Intake adjustment valve 25 Circulation Pump 30 Food transport conveyor

Claims

1. A washing water tank for storing washing water to wash food; A plurality of ejectors for ejecting jets of water containing microbubbles onto the food in the washing water tank; a discharge pump for pumping aerated water to each of the ejectors; an intake regulating valve for regulating an amount of air drawn from a suction pipe of the discharge pump; A food washing machine comprising: The ejector is a nozzle body having a hollow short tube shape, the end of which is opened as a jet port for jetting water containing microbubbles; a throttle portion formed in the nozzle body for discharging water from the discharge pump; an opening located between the throttle portion and the jet nozzle for taking in water from within a cleaning water tank; It is equipped with This food washing machine is characterized in that the aerated water is sprayed from each ejector through the throttling section by the discharge pump, thereby converting the air mixed in the aerated water into microbubbles while being sprayed as a jet of water by the Venturi effect of the throttling section.

2. 2. The food washer according to claim 1, wherein the amount of air suction is 5% or less of the amount of air discharged by the discharge pump.

3. 3. A food washer as claimed in claim 1 or 2, characterized in that a clean water piping line for supplying clean water is connected to a pipe leading from the cleaning water tank to the discharge pump so that the water in the cleaning water tank and clean water are supplied to the discharge pump.

4. 3. The food washer according to claim 1, wherein each of the ejectors ejects low-pressure aerated jets of water at a pressure of 0.1 MPa to 1 MPa.

5. 3. The food washer according to claim 1, wherein the ejectors are disposed on opposite side walls of the washing water tank and are arranged in a staggered pattern facing each other.

6. The food washing machine according to claim 1 or 2, characterized in that the multiple ejectors are positioned on opposing side walls of the cleaning water tank, facing each other in a staggered pattern, and are also positioned on the supply side of the food to be cleaned, facing the discharge side.

7. 3. The food washer according to claim 1, wherein the food to be washed is a floating food, and the ejector is disposed slightly below the surface of the washing water in the washing water tank.

8. The food washer according to claim 1 or 2, characterized in that the food to be washed is submerged in water, the ejector is arranged near the bottom of the washing water tank, and a food transport conveyor is located at least within the washing water tank on the discharge side of the washing water tank.

9. 3. A food washer as described in claim 1 or 2, in which multiple upper and lower stages of ejectors are arranged on the inner wall of the cleaning water tank, and at least a food transport conveyor is provided on the discharge side of the cleaning water tank, and switching control is possible to spray a jet of water containing microbubbles from one of the multiple upper and lower stages of ejectors depending on the specific gravity of the food to be washed.

10. 10. The food washer according to claim 9, wherein the upper and lower multi-stage ejectors are vertically arranged in a staggered pattern.

11. 3. The food washer according to claim 1, wherein the bottom of the washing water tank is provided with a convex portion having an inclined surface that becomes higher from both sides in the width direction toward the center.

12. 3. The food washer according to claim 1, further comprising a gate, which is configured to be opened and closed, and which is a shutter plate having a through opening at the discharge end of the washing water tank.

13. 13. The food washer according to claim 12, wherein the gate further comprises a roof plate which is a plate body having a through opening extending from an upper end of the shutter plate toward the upstream side in the conveying direction.

14. One or more ejectors that inject a jet of water containing microbubbles into an installed water tank; a discharge pump that is supplied with air together with water and pressure-feeds aerated water, which is water mixed with air, to the ejector; an intake regulating valve for regulating an amount of air drawn from a suction pipe of the discharge pump; Equipped with The ejector is a nozzle body having a hollow short tube shape, the end of which is opened as a jet port for jetting water containing microbubbles; a throttle portion formed in the nozzle body for discharging water from the discharge pump; an opening located between the throttle portion and the jet nozzle for taking in water from within the water tank; Equipped with The microbubble jet generator is characterized in that the aerated water is sprayed from the ejector through the throttle section by the discharge pump, whereby the air mixed in the aerated water is converted into microbubbles while being sprayed as a jet of water by the Venturi effect of the throttle section.

15. 15. The microbubble jet generator according to claim 14, wherein the amount of air sucked in is 5% or less of the amount of air discharged by the discharge pump.

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