JP4974879B2 - Vacuuming device - Google Patents

Description

The present invention relates to a vacuum evacuation apparatus using a water flow ejector utilized for evacuation for vacuum drying.

  Conventionally, rotary vacuum pumps, piston vacuum pumps and diaphragm vacuum pumps have been used for evacuation. Today, however, water flow ejectors that are extremely simple in structure, durable, reliable, and inexpensive are widely used. (For example, see Non-Patent Document 1). The water flow ejector described in Non-Patent Document 1 is shown in FIG. This water flow ejector injects a large amount of driving water at a low pressure supersonic flow from a nozzle 50 having a wide shape, and sucks a suction gas 53 introduced from a supply port 52 into a box 51 surrounding the nozzle 50 by this driving water injection. The driving water and the suction gas are mixed in the first half 54a that gradually narrows in the diffuser 54, and then the second half 54b having a gradually diverging shape decreases toward the discharge port while increasing the pressure by reducing the flow velocity. .

  It is necessary to operate at a low temperature of 30 to 45 ° C. for vacuum drying without impairing the quality composition of food or the like, and the degree of vacuum required in that case is 95 to 85 kPa. Ordinary water ejectors achieve this level of vacuum pressure. (For example, refer to Patent Document 1). The water flow ejector described in Patent Document 1 has the configuration shown in FIG. That is, a nozzle 60 for introducing driving water is provided in the jacket pipe 61, a suction pipe 62 for introducing suction gas is attached to the side surface of the jacket pipe 61, and suction gas and driving water from the suction pipe 62 are installed downstream of the nozzle 60 Is provided, and a diffuser 64 composed of a pipe whose inner diameter is gradually enlarged is provided on the downstream side of the main pipe throat 63.

Suikan Giken Co., Ltd. homepage http: // www5. ocn. ne. jp JP 2002-31100 A

  Optimal design of a water flow ejector to a pipe shape is complicated and difficult, and requires various trials and errors. The conventional water flow ejector shown in FIG. 3 has a structure in which the inner diameter of the pipe of the diffuser 54 is enlarged or narrowed. Since this structure is a straight or curved shape that is complicated by machining, it is not suitable for mass production with a simple and inexpensive manufacturing process.

  Moreover, when using the conventional water flow ejector shown in FIG. 3 and FIG. 4, there is a defect that noise such as a sound of running water and an explosive sound due to an air hammer action that occurs at the start of operation is generated at the output port of the ejector. When installed, it is essential to take measures to suppress noise during operation.

  Further, the conventional water flow ejector requires a sufficient ceiling height in the space to be installed when used as a vacuum drying device, and therefore has a drawback of narrowing the installation and installation conditions.

An object of the present invention, Ru near to provide a vacuum apparatus using an improved water flow ejector so as to suppress the noise in the ejector driving water discharge port.

The vacuuming device of the present invention that solves the above problems is as follows.
A cylindrical inlet piece for receiving driving water;
A main pipe throat that is provided on the downstream side of the inlet piece and mixes the driving water and the suction gas flowing from the inlet piece;
An output piece comprising a pipe having a shape in which the inner diameter is widened toward the downstream end of the main pipe throat;
A cylindrical shape, provided at the downstream end of the output piece, and a silencer for flowing a mixed gas of driving water and suction gas,
An intake pipe which is attached to the silencer and takes in air into the silencer when driving water flows out to prevent a sudden change in atmospheric pressure in the silencer ;
In addition to providing a water storage tank for storing water that can be immersed in the downstream side of the silencer in order to silence the water flow ejector and to make it non-brominated,
The circulation path including the circulation pump that sucks water from the water storage tank and discharges it from the inlet piece, the inlet piece, the main pipe throat, the output piece, and the silencer is set lower than the water level in the water storage tank. Features.

According to the present invention, the water flow ejector has the function of mitigating sudden changes in air pressure through the intake pipe attached to the silencer when the explosion sound at the start of operation and the noise when the driving water flows out. Demonstrate.

Further , a circulation path including a circulation pump that sucks water from the water storage tank and discharges it from the inlet piece, the inlet piece, the main pipe throat, the output piece, and the silencer is set lower than the water level in the water storage tank. Therefore, it is possible to provide a vacuum drying apparatus that exhibits the convenience of being able to be installed without considering the ceiling height limitation. In addition, since the circulation path is always lower than the water level of the water storage tank, when the operation is resumed, the water ejector is filled with water, and there is no generation of an injection sound into the air of a rapid high-speed water flow when the operation is resumed.

  Hereinafter, an embodiment of a water flow ejector of the present invention will be described with reference to FIG. FIG. 1 shows an outline of a water flow ejector main body and a silencer connected thereto according to the present invention, and FIG. 2 shows a mode in which a water flow ejector is installed in a lateral direction and connected to a water storage tank when the present invention is used in a vacuum drying apparatus. Indicates. In the shape of the water flow ejector shown in FIG. 1, the drive water inlet piece 1 is chamfered to reduce water flow resistance. A main pipe throat 6 having a diameter larger than that of the driving water inlet piece 1 is connected to the inlet piece 1 by welding or an adhesive method. The main throat 6 has a simple pipe shape and is not specially processed.

  A plurality of suction holes 4 penetrating the pipe tube wall are opened at the inlet of the main pipe throat 6, and the suction holes 4 are sucked gas when evacuated through the suction pipe 3 when the apparatus is operated. Is sucked into the main pipe throat 6.

  In the vicinity of the terminal end of the main pipe throat 6, a pipe-shaped exit piece 7 having a diameter larger than that of the main pipe throat is connected by welding or an adhesive method. The outlet piece 7 has an internal shape that widens toward the outlet. An outer tube 8 covering the driving water inlet piece 1, the main pipe throat 6 and the outlet piece 7 is welded or adhesively connected to the outside in a cylindrical shape. The water ejector main body E is comprised by the member shown by these 1-8.

  Reference numeral 12 denotes a silencer. As shown, the silencer 12 has a pipe shape whose inner diameter is thicker than the inner diameter of the outlet of the output piece 7 of the water flow ejector body E.

  A discharge pipe 15 from the circulation pump 16 shown in FIG. 2 is connected to the water flow ejector inlet piece 1 shown in FIG. A hollow circular partition plate 5 is provided so that the evacuation function is performed only through the suction tube 3. The inner part of the partition plate 5 is fixed to the outer part of the main pipe throat 6, and the outer peripheral part of the partition plate 5 is fixed to the outer tube 8 so that sufficient airtightness is maintained.

  As shown in FIG. 2, the evacuation apparatus of the present embodiment includes a water storage tank 13 in which water is stored so that the silencer 12 can be immersed in order to achieve quietness and no bromination of the water ejector. The used drive water is once stored in the water storage tank 13. The water flow ejector body E is fixed from the outside of the water storage tank 13 by using the output side flange 9 at the end thereof. The silencer 12 is fixed at the same position as the output side flange 9 from the inside of the water storage tank 13 by the flange 10. Thereby, in the water storage tank 13, the water flow ejector main body E and the silencer 12 are connected inside the water storage tank 13, and the silencer 12 has a horizontal part 12a and a vertical part 12b bent downward at a right angle at the tip thereof. From the terminal end 12c, the driving water mixed with the suction gas flows into the water in the water storage tank 13. Further, the drive water is circulated and reused through a return pipe 14 connected to a circulation pump 16 that creates a water flow. A circulation path including the return pipe 14, the circulation pump 16, the discharge pipe 15, the water flow ejector body E, and the silencer 12 is set lower than the water level 17 in the water storage tank 13.

  An intake pipe 11 for taking in air is provided near the connection part of the water flow ejector body E in the silencer 12, and the intake port of the intake pipe 11 is located above the water tank level 17 so that the intake port is immersed below the water surface. No structure. An overflow vent 18 for setting the water level 17 is installed in the water storage tank 13.

  As shown in FIG. 1, the water flow ejector of the present embodiment is provided with the suction hole 4 in the main pipe throat 6, so that the conventional ejector for sucking gas from the gap between the pipes as shown in FIG. 3 and FIG. Compared to this, it is simple and requires only a small amount of machining technology and requires only a short machining process. Therefore, it has the economic effect of low machining cost and short machining time.

  Further, the water flow ejector body E and the silencer 12 connected to the water flow ejector body E of the present invention has a water circulation path lower than the water level 17 of the water storage tank 13 as shown in FIG. It has the effect of demonstrating convenience that can be installed without considering the ceiling height limitation.

  Further, the present water flow ejector exhibits the effect of suppressing the noise during operation because the explosion sound at the start of operation and the noise at the time of driving water outflow have a function of mitigating sudden changes in air pressure through the silencer intake pipe 11. In addition, since the water circulation path is set lower than the water level 17 of the water storage tank 13, the generation of an abrupt high-speed water flow in the air when the operation is paused and then resumed is eliminated.

  A water flow ejector E and a silencer 12 were made of a chemically resistant stainless material. The drive water inlet piece 1 has a diameter of 40 (mm), a water flow rate of about 10 m / s, a length of the main pipe throat 6 of 16 (cm), and the length from the inlet piece 1 to the end of the silencer 12 is about 100 (cm). ). The number of intake holes 4 is four. As a result of measuring the noise by installing the water flow ejector body E and the silencer 12 of the embodiment as described above in a vacuum dryer, as compared with the conventional vacuum dryer, it is from 80 to 85 (dB) to 56 to 58 (dB). ) And a significantly reduced noise effect. In addition, when the operator's driving operability is improved, integration with vacuum equipment can be realized, the installation area is reduced, and the ceiling height limit for indoor installation is released.

  The simple water flow ejector having a silent effect according to the present invention is manufactured at a low price due to the simplicity of the structure, and can be installed regardless of the operating place due to the excellent quietness, and the industrial field related to the vacuum drying apparatus and the vacuum utilization equipment. Use in is expected.

Partial sectional view of a combination of a water flow ejector and a silencer according to the present invention Usage diagram related to the use of the present invention General ejector configuration diagram General water flow ejector cross section

1: Drive water inlet piece 3: Suction pipe 4: Suction hole 6: Main pipe throat 7: Output piece 8: Outer pipe 11: Intake pipe 12 Muffler 13: Water tank 17: Water level E: Water flow ejector body

Claims (1)

A cylindrical inlet piece for receiving driving water;
A main pipe throat that is provided on the downstream side of the inlet piece and mixes the driving water and the suction gas flowing from the inlet piece;
An output piece comprising a pipe having a shape in which the inner diameter is widened toward the downstream end of the main pipe throat;
A cylindrical shape, provided at the downstream end of the output piece, and a silencer for flowing a mixed gas of driving water and suction gas,
An intake pipe which is attached to the silencer and takes in air into the silencer when driving water flows out to prevent a sudden change in atmospheric pressure in the silencer ;
In addition to providing a water storage tank for storing water that can be immersed in the downstream side of the silencer in order to silence the water flow ejector and to make it non-brominated,
The circulation path including the circulation pump that sucks water from the water storage tank and discharges it from the inlet piece, the inlet piece, the main pipe throat, the output piece, and the silencer is set lower than the water level in the water storage tank. A vacuuming device characterized .

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