JPH0719744A - Gas discharging device - Google Patents

Abstract

PURPOSE:To perform condensation of water vapor contained in discharged gas and concurrently eliminate noise of a vacuum pump as well as extend the life of a deodoring device. CONSTITUTION:A condensor 2 into which discharged gas containing water vapor caused to flow from a vacuum pump 1 is provided with a plurality of expansion and shrinking chambers through which discharged gas passes while repeating expansion and shrinking by a condensing wall (a partition wall) 21. The condensor 2 is also operated as a muffler. In addition, water condensed at the condensor is dripped into a condensed water tank 3, discharged gas caused to flow from the condensor is always passed through the dripped water, thereby water-soluble odor component contained in water solution in the discharged gas is resolved and removed. In addition, a deodoring device 4 is connected to an air outlet extending from the condensed water tank and the discharged gas washed with water is further deodored.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust system, and in particular,
In a limited closed space such as spacecraft, submarines, airplanes, at homes and restaurants, an exhaust device suitable for use as a vacuum heating and drying device for drying garbage, or at the above-mentioned location, The present invention relates to an exhaust device suitable for use in a vacuum heating / drying device for drying an organic substance (including food) or an inorganic substance in a solution.

[0002]

2. Description of the Related Art As a conventional vacuum heating / drying apparatus using microwaves, for example, JP-A-61-211201, JP-A-61-211202, and JP-A-62-162.
The techniques described in Japanese Patent No. 194181 and Japanese Patent Laid-Open No. 4-80585 can be mentioned.

In the devices disclosed in these prior applications, the exhaust containing water vapor from the material to be dried heated by the magnetron in the microwave shielding container is sucked by the vacuum pump. Exhaust from this vacuum pump is released to the atmosphere as it is,
Alternatively, after deodorizing through a deodorizer, it was released into the atmosphere.

[0004]

By the way, it has been pointed out that when the vacuum pump is used as described above, an offensive exhaust noise similar to a beating sound such as "pocopoco" is emitted from the vacuum pump. However, in the above-mentioned conventional technique, no consideration has been given to noise from the vacuum pump, which is problematic in terms of noise countermeasures.

Further, in the prior art in which the exhaust gas from the vacuum pump is released into the atmosphere as it is, the problem that the odorous component of the exhaust gas attaches to the nose and the exhaust gas containing a large amount of water vapor is released into the atmosphere. There is a problem that the ambient humidity rises.

Further, in the prior art using a deodorizer, no consideration is given to the life of the deodorizer, and in order to remove the odor in the exhaust gas for a long period of time, the deodorizer must be upsized or replaced frequently. There was a problem that it was necessary to do.

Therefore, the technical problem to be solved by the present invention is to solve the above-mentioned problems of the prior art,
Its purpose is to condense and remove the water vapor in the exhaust before releasing it into the atmosphere, and to eliminate the exhaust noise emitted by the vacuum pump with an exhaust device with a simple configuration with a small number of parts. It is to be realized. Another object of the present invention is to realize an exhaust device capable of removing odorous components in exhaust gas as much as possible and extending the life of the deodorizer.

[0008]

In order to achieve the above-mentioned object, in short, the exhaust device according to the present invention is provided with a muffling function in the subsequent stage (to the exhaust port side) of exhaust blowing means such as a vacuum pump. It is equipped with a condenser (also used as a silencer). That is, a plurality of expansion / contraction chambers through which exhaust gas repeatedly expands and contracts along an exhaust passage are provided in a condenser into which exhaust gas (including water vapor) emitted from a vacuum pump is introduced. The partition wall that forms the contraction chamber is used as a condensation wall that cools and condenses the water vapor in the exhaust, and the exhaust sound is silenced by repeating expansion and contraction of the exhaust, and the condenser also doubles as a silencer. It is configured to allow.

Further, in the exhaust device according to the present invention, a condensed water tank is provided at the exhaust outlet of the condenser described above, and the water condensed in the condenser is dropped into the condensed water tank. The outlet of the exhaust pipe from the condenser (opening at the tip) is set to be always located, and the exhaust from the condenser is constantly passed through water so that the odorous components are dissolved. A deodorizer is connected to the air outlet from the space above the condensed water tank so that the exhaust gas washed with water is further deodorized.

[0010]

[Operation] The water vapor in the exhaust gas introduced from the vacuum pump into the condenser contacts the partition wall (condensing wall) for forming a large number of expansion / contraction chambers provided along the exhaust flow path. The water droplets are cooled and condensed into water droplets, which are dropped along the downwardly inclined condensing wall into the condensed water tank to remove water vapor from the exhaust gas. Also, the exhaust gas introduced into the condenser is
The sound is reduced (silenced) by repeating expansion and contraction when passing through a large number of expansion / contraction chambers and expanding and hitting the partition wall (condensing wall) of the expansion / contraction chambers. Therefore, since the condenser also serves as a muffler, it is possible to achieve the removal of water vapor and the muffling with a single member at the same time, and it is possible to achieve quiet exhaust without exhaust noise and exhaust to the outside. It is possible to construct an exhaust device capable of reducing the humidity to a relatively low cost with a simple structure.

Further, the water condensed from the condenser is dropped into the condensed water tank, and the exhaust gas from the condenser is constantly passed through the water accumulated by the dropping so that the water-soluble odorous component in the exhaust gas is discharged. Since it dissolves and removes, the condensed water can be reused as exhaust cleaning water. In addition, since a deodorizer is connected to the air outlet from the condensed water tank to further deodorize the exhaust gas that has been washed with water as described above, the odorous components that could not be completely deodorized in the condensed water tank can be removed by the deodorizer, and more reliable deodorization can be achieved. It becomes possible to do. Moreover, since the deodorizer deodorizes the exhaust gas after washing with water, the burden on the deodorizer can be reduced, and the life of the deodorizer can be extended.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to each embodiment shown in FIGS. Each of the following examples is an example of application as an exhaust device of a vacuum heating and drying device.

FIG. 1 is a block diagram showing a vacuum heating / drying apparatus equipped with an exhaust device according to an embodiment of the present invention. In the figure, 1 is a vacuum pump, 2 is a condenser, 3 is a condensed water tank, 4 is a deodorizer, 5 is a water gauge, 6 is a valve, 7 is a drain port, 1
Reference numeral 0 is a magnetron, 11 is a processing container, and 12 is a material to be dried. The intake port 1a of the vacuum pump 1 is connected to the processing container 11 made of a sealed microwave shielding container, while the exhaust port 1b of the vacuum pump 1 is connected to the condenser 2 and the condenser 2 is It is connected to the condensed water tank 3 via an exhaust pipe line 9. A deodorizer 4 is connected to the air outlet above the condensed water tank 3. In addition, the processing container 1
A magnetron 10 is attached to 1 and a processing container 11
An object to be dried 12 is placed in the box. Further, a water level gauge 5 is attached to the condensed water tank 3, and a valve 6 controlled by a valve controller (not shown) is installed in a drainage conduit 13 between the condensed water tank 3 and a drainage port 7 for external discharge. Has been done. .

Here, as shown in FIG. 1, a large number of partition walls (condensing walls) 21 are provided in the condenser 2 described above.
Radiating fins 23 are provided on the outer wall of the condenser 2.
Each of the partition walls 21 is used as a condensing wall for cooling and condensing water vapor in the exhaust gas, and has a shape inclined obliquely downward toward the exhaust flow passage hole at the substantially central portion so that the attached water droplets can easily drop. Has become. Also, this partition wall (condensing wall)
21 forms a large number of expansion / contraction chambers 22 through which the exhaust gas discharged from the vacuum pump 1 repeatedly expands and contracts along the exhaust flow path. Then, the exhaust gas introduced into the condenser 2 repeats expansion and contraction when sequentially passing through a large number of expansion / contraction chambers 22, and the partition wall (condensing wall) 21
Exhaust sound (blowing sound)
Is configured to be muted.

In the above structure, the material to be dried 12 housed in the processing container 11 is heated by the magnetron 10 to mainly generate water vapor and other volatile components.
This water vapor, along with other volatile components etc.
Is sucked to the outside of the processing container 11. And
The exhaust gas discharged from the processing container 11 enters the condenser 2 via the vacuum pump 1, and while repeating expansion and contraction in the expansion / contraction chamber 22, the exhaust sound is removed and the exhaust gas passes through the exhaust pipe line 9. Then, it is sent to the condensed water tank 3. Further, at this time, the water vapor in the exhaust gas is cooled by the partition wall (condensing wall) 21 and condensed by releasing the latent heat of condensation from the heat radiation fins 23, and drops into the condensed water tank 3 via the exhaust pipe line 9. .

Here, the water level 8 of the water accumulated in the condensed water tank 3
Is detected by the water level gauge 5, and a valve controller (not shown) controls the opening / closing of the valve 6 based on the detection information from the water level gauge 5, so that the water accumulated in the condensed water tank 3 is selectively drained through the drainage pipe 13. It is designed to be discharged from 7. That is, when the water exceeds a predetermined water level before the water overflows from the condensed water tank 3, the valve controller opens the valve for draining, and the outlet portion (tip opening portion) 9a of the exhaust pipe line 9 is in front of the water surface. When the water level reaches a predetermined level, the valve controller closes the valve to stop the drainage, and thereby controls the outlet portion 9a of the exhaust pipe line 9 so that it is always located in the condensed water that has accumulated. By doing so, the water condensed in the condenser 2 is surely prevented from overflowing the condensed water tank 3 and flowing into the deodorizer 4. Further, since the outlet portion 9a of the exhaust pipe line 9 is always located in the accumulated condensed water, the odorous components generated from the material to be dried 12 together with the steam are constantly washed by the water accumulated in the condensed water tank 3. (The water-soluble odor component in the exhaust gas will be dissolved in water). Furthermore, the steam that could not be completely condensed in the condenser 2 can also be condensed at this time.

Exhaust gas (exhaust gas after washing with water) discharged from the outlet portion 9a of the exhaust pipe 9 through the condensed water tank 3 enters the deodorizer 4 from the upper part of the condensed water tank 3 and cannot be completely removed by washing with water. Odor components are further deodorized and removed.

As described above, in this embodiment, since the condenser 2 also functions as a silencer, the removal of water vapor and the silencing are
It is possible to achieve it with one member at the same time, and it is possible to achieve an exhaust device that is quiet without exhaust noise and that allows exhaust gas emitted to the outside to have a humidity as low as possible with a simple structure and at a relatively low cost. It is possible to build. Also, condensed water tank 3
The water condensed in the condenser 2 is dropped into the inside of the condenser, and the exhaust gas from the condenser 2 is constantly passed through the dropped water, so that the water-soluble odorous components in the exhaust are dissolved and removed. The condensed water can be reused as exhaust cleaning water. Moreover, since the deodorizer 4 is connected to the air outlet from the condensed water tank 3 to further deodorize the exhaust gas washed with water as described above, the deodorizer 4 can also remove odorous components that could not be completely deodorized in the condensed water tank 3. It is possible to surely deodorize. Moreover, since the deodorizer 4 deodorizes the exhaust gas after washing with water, the burden on the deodorizer 4 can be reduced, and the life of the deodorizer 4 can be extended. Further, by providing a space on the exhaust port 1b side of the vacuum pump 1 by a condenser 2 or the like (by providing a structure in which the exhaust port 1b of the vacuum pump 1 is not closed), the vacuum pump There is also an effect that the overload at the time of start of 1 can be reduced.

In the present embodiment, the deodorizer 4 was connected to the exhaust outlet of the condensed water tank 3. However, if all the components in the exhaust are water-soluble and all components fall below the standard value by washing with water, The deodorizer 4 can be omitted. Further, the valve 6 may be any valve as long as it opens and closes by an external signal such as a solenoid valve, a pneumatic valve, a hydraulic valve or the like.

Next, some concrete examples of the structure of the condenser 2 will be described with reference to FIGS. FIG. 2 is a diagram showing a first specific example of the condenser 2. In the condenser 2 of this example,
A large number of expansion / contraction chambers 22 are formed between the exhaust inlet 24 and the exhaust outlet 25 by a large number of partition walls (condensing walls) 21 in which central exhaust passage holes are alternately formed as small diameter holes and large diameter holes. The outer wall of the condenser 2 is provided with a plurality of heat radiation fins 23 in the vertical direction along the flow path. In addition, each partition wall (condensing wall) 21 is set to have a thicker wall thickness so as to reduce thermal resistance between the partition wall and the radiation fins 23.

In the above-mentioned structure, the exhaust containing the water vapor entered from the exhaust inlet 24 (exhaust mainly consisting of water vapor)
Enters the expansion / contraction chambers 22 in sequence and repeats expansion and contraction as described above, whereby the exhaust sound of the vacuum pump 1 is eliminated. Further, at this time, the condensation wall (partition wall) 21 cooled by the radiation fins 23 can have a temperature sufficiently lower than the temperature of the steam, so that the steam contained in the exhaust gas is not included in the surface of the condensation wall 21. Condense with. The condensed water drops from the inclined condensing wall 21 and flows out from the exhaust outlet 25 together with the exhaust gas in which the water vapor is reduced.

The condenser 2 of this embodiment has the effect of improving the thermal efficiency by thickening the expansion / contraction chamber wall 21. In the present example, the exhaust passage hole at the center of the condensing wall (partition wall) 21 has two types of sizes, but it is also possible that they all have the same size or different sizes.

FIG. 3 is a diagram showing a second specific example of the condenser 2. This example differs from the first specific example in FIG. 2 in the position of the exhaust flow passage hole of the condensation wall (partition wall) 21, and in this example, the exhaust flow passage of the adjacent condensation wall (partition wall) 21. The holes are formed as staggered ones. The operation in this example is the same as that in FIG. 2 except for the passage of the exhaust gas.

According to this example, since the exhaust gas cannot pass in a straight line, there is an effect that the silencing efficiency is increased. In this example, the positions of the exhaust flow path holes are two, but the positions of all the exhaust flow path holes can be changed.

FIG. 4 is a diagram showing a third specific example of the condenser 2. This example is different from the first specific example of FIG. 2 in the shape and installation location of the radiation fins 23, and in this example, the outer peripheral position of the condenser 2 corresponding to each condensation wall (partition wall) 21. , And ring-shaped heat radiation fins 23 are respectively installed. The operation in this example is the same as that in FIG.

According to this example, since the correspondence between the water condensing section and the heat radiating section is thermally close to each other, the thermal efficiency is improved.

FIG. 5 is a diagram showing a fourth specific example of the condenser 2. This example is different from the first specific example of FIG. 2 in that instead of the radiation fins 23, the cooling water circulation flow path 26 is provided on the lower surface of the condensation wall (partition wall) 21 and each condensation wall (partition wall) 21.
It is a point installed at the outer peripheral position of the condenser 2 corresponding to. The operation in this example is the same as that in FIG.

According to this embodiment, the cooling water circulation passage is used in place of the heat radiation fin, so that there is an effect that the device can be downsized. In this example, the cooling water circulation flow path 26 is provided both on the outer periphery of the condenser 2 and on the back surface of the condensation wall (partition wall) 21, but either one may be omitted depending on the thermal efficiency of the material used. Is.

In each of the concrete examples of the condenser 2 shown in FIGS. 2 to 5, the exhaust passage hole formed in each condensation wall (partition wall) 21 has a circular hole at a typical position for convenience of drawing. Although it is configured to be opened, the exhaust inlet 24 and the exhaust outlet 25 are actually used.
The position and the shape can be arbitrary as long as they penetrate between and.

Next, a concrete example of the condensed water tank 3 will be described with reference to FIG. As shown in the figure, the condensed water tank 3 is provided with a condensed water inlet 31, a condensed water outlet 32, and an exhaust outlet 33, and further includes a float 51, an upper water level limit switch 52, and a lower water level limit switch 53. A water level gauge 5 with is attached. The condensed water inlet 31 corresponds to a position directly above the condensed water tank 3 in the exhaust pipe 9 from the condenser 2 described above, and the condensed water outlet 32 corresponds to the valve 6 described above.
Is connected to the drain pipe line 13 provided with. Further, the outlet portion 9a of the exhaust pipe line 9 is positioned at a position near the bottom portion in the condensed water tank 3 so as to be constantly immersed in the water in the condensed water tank 3 as described above. Furthermore, the deodorizer 4 is connected to the exhaust outlet 33 provided at the top of the condensed water tank 3.

In the above structure, the condensed water that has entered from the condensed water inlet 31 is assimilated with the water accumulated in the condensed water tank 3.
Further, the exhaust gas that has entered the condensed water tank 3 from the outlet portion 9a of the exhaust pipe line 9 passes through the water, exits to the upper space of the condensed water tank 3 due to the difference in specific gravity, and is guided to the deodorizer 4 from the exhaust outlet 33. At this time, the remaining water vapor contained in the exhaust gas is condensed with the accumulated water, and the water-soluble odor component contained in the exhaust gas is dissolved in the water stored in the condensed water tank 3. The water thus flows into the condensed water tank 3 so that the water level in the condensed water tank 3 rises. Along with this rise in the water level, the float 51 attached to the water level gauge 5 rises, and when the float reaches a predetermined water level, the float 51 actuates the upper water level limit switch 52 to generate a signal. A signal from the upper water level limit switch 52 is sent to a valve controller (not shown), and the valve controller causes the valve 6 described above to operate.
To drive the valve 6 to open, and drain the water accumulated in the condensed water tank 3 to the outside from the condensed water outlet 32 via the drainage pipe 13. When the drainage operation from the condensed water tank 3 progresses, the water level in the condensed water tank 3 lowers, and the float 51 also lowers accordingly. Then, when the water level in the condensed water tank 3 is lowered to a predetermined water level set in advance, the float 51 actuates the lower water level limit switch 53 to generate a signal. The signal from this lower water level limit switch 53 is
It is sent to a valve controller (not shown), and the valve controller sends a drive signal to the valve 6 to close the valve 6 and stop the drainage operation. As a result, the drop of the water level in the condensed water tank 3 is stopped, and the water level starts rising again due to the inflowing condensed water as described above.

By adopting such a constitution, the drainage operation can be surely performed before the water accumulated in the condensed water tank 3 overflows and flows into the deodorizer 4. Further, since the outlet portion 9a of the exhaust pipe line 9 can be always located in the condensed water that has accumulated, the odorous components in the exhaust gas generated from the material to be dried 12 together with the water vapor are collected in the condensed water tank 3. Will always be washed with water (the water-soluble odorous components in the exhaust will be dissolved). Furthermore, since the water vapor in the exhaust gas is condensed and used for washing the exhaust gas, there is no need to separately supply water for washing, which also contributes to downsizing of the apparatus.

In the example shown in FIG. 6, the exhaust gas flowing into the condensed water from the outlet portion 9a of the exhaust pipe line 9 rises in the water as bubbles or the like, and further a wave is generated on the water surface. Let Therefore, in order to make the float 51 less susceptible to this influence, it is desirable to separate the water level gauge 5 and the outlet 9a of the exhaust pipe line 9 as far as possible.

In the example shown in FIG. 6, the water level gauge 5 has two limit switches and a float 51. However, two types of water level gauges having only one of the limit switches are used. It is also possible to In addition to the float system, it is also possible to employ, as the water level gauge 5, a device that generates an arbitrary water level detection signal such as a magnetic detection system.

Next, a vacuum heating / drying apparatus having an exhaust device according to another embodiment of the present invention will be described with reference to FIG.
In FIG. 7, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted to avoid duplication.

This embodiment differs from the embodiment of FIG. 1 in that
The water level gauge 5 and the valve 6 are removed from the configuration of FIG. 1, and instead, a condensed water outlet pipe 60 extending obliquely upward from the side surface of the condensed water tank 3.
Is located in the drainage pipe line 13, and the tip end opening of the condensed water outlet pipe 60 is placed at a predetermined water level position. That is, the tip end opening of the condensed water outlet pipe 60 can surely prevent the water accumulated in the condensed water tank 3 from flowing into the deodorizer 4, and the outlet 9a of the exhaust pipe line 9 is always accumulated. It is located in a set position that ensures it is located in the condensed water.

In the present embodiment having such a configuration, the condensed water having a predetermined water level or higher accumulated in the condensed water tank 3 always overflows and is drained from the condensed water outlet pipe 60 to the drainage pipe 13, and the condensed water tank 3 The condensed water level 8 is always equal to the tip opening of the condensed water outlet pipe 60. Therefore, as compared with the configuration of FIG. 1, the water level gauge 5, the valve 6 and the like are not required, so that it is possible to reduce the number of parts and contribute to downsizing of the device.

[0038]

As described above, according to the present invention, since the condenser also serves as the silencer, it is possible to achieve the removal of water vapor and the silence at the same time with one member, and there is no exhaust noise. It is possible to construct an exhaust device that is quiet and that allows exhaust gas discharged to the outside to have a humidity as low as possible with a simple configuration and at a relatively low cost. In addition, the water condensed in the condenser is dropped into the condensate tank, and the exhaust gas from the condenser is constantly passed through the dropped water to dissolve and remove the water-soluble odorous components in the exhaust gas. The condensed water can be reused as exhaust cleaning water. In addition, since a deodorizer is connected to the air outlet from the condensed water tank to further deodorize the exhaust gas that has been washed with water as described above, the odorous components that could not be completely deodorized in the condensed water tank can be removed by the deodorizer, and more reliable deodorization can be achieved. It becomes possible to do. Moreover, since the deodorizer deodorizes the exhaust gas after washing with water, the burden on the deodorizer can be reduced, and the life of the deodorizer can be extended. In general, it is possible to construct an exhaust system that is noise-free and has no steam or odor in the exhaust discharged to the outside as an efficient system, and its value is enormous.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the configuration of a vacuum heating / drying apparatus equipped with an exhaust device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a first specific example of a condenser used in an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a second specific example of the condenser used in the embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a third specific example of the condenser used in the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a fourth specific example of the condenser used in the embodiment of the present invention.

FIG. 6 is an explanatory view showing one specific example of the condensed water tank used in the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a configuration of a vacuum heating / drying device including an exhaust device according to another embodiment of the present invention.

[Explanation of Codes] 1 Vacuum pump 2 Condenser 3 Condensed water tank 4 Deodorizer 5 Water level meter 6 Valve 7 Drain port 8 Water level 9 Exhaust pipe 9a Outlet 10 Magnetron 11 Treatment container 12 Dried matter 13 Drain pipe 21 Partition Wall (condensing wall) 22 Expansion / contraction chamber 23 Radiating fin 24 Exhaust inlet 25 Exhaust outlet 26 Cooling water circulation flow channel 31 Condensate inlet 32 Condensate outlet 33 Exhaust outlet 51 Float 52 Upper water level limit switch 53 Lower water level limit switch 60 Condensate outlet tube

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location F26B 3/347 9140-3L 5/04 9140-3L 9/06 Q 9140-3L G10K 11/16

Claims (7)

[Claims] 1. A plurality of expansion and contraction chambers through which exhaust gas repeatedly repeats expansion and contraction are provided in a condenser into which exhaust gas containing water vapor is introduced, and the expansion and contraction chambers are formed. The partition wall is used as a condensing wall for cooling and condensing water vapor in the exhaust gas, and the exhaust sound is silenced by repeating expansion and contraction of the exhaust gas so that the condenser also functions as a silencer. Exhaust device characterized by that. 2. The exhaust system according to claim 1, wherein an exhaust blowing means such as a vacuum pump is connected to an exhaust inlet side of the condenser. 3. The condensed water tank according to claim 1, wherein a condensed water tank is provided on the exhaust outlet side of the condenser, and water condensed in the condenser is dropped into the condensed water tank. The outlet part of the exhaust pipe from the condenser is located in the condenser, and the exhaust gas from the condenser is passed through water to dissolve the odorous components, and the condensed water tank is provided with an exhaust water washing function. An exhaust device characterized by the above. 4. The water level detection device according to claim 3, wherein the condensed water tank is provided with a water level detecting means, and a valve is provided in a drainage path for discharging water from the condensed water tank to the outside so that the condensed water tank has a predetermined water level. When the value exceeds the value, the valve is opened to perform drainage, and when the water level in the condensed water tank falls below a predetermined value, the valve is controlled to be closed, and the outlet of the exhaust pipe from the condenser is controlled. An exhaust system characterized by being positioned in water at all times. 5. The condensate according to claim 3, wherein the water in the condensed water tank overflows to a drainage path for external discharge by an amount that exceeds a predetermined value. An exhaust device characterized in that the outlet of the exhaust pipe from the vessel is always positioned in water. 6. The exhaust device according to claim 3, wherein a deodorizer is connected to the air outlet of the condensed water tank to further deodorize the exhaust gas washed with water. 7. A microwave shielding container, a vacuum pump, and at least an exhaust pipe of the vacuum pump of a vacuum heating / drying device having a microwave heater as a basic structure according to any one of claims 3 to 6. An exhaust device, wherein the condenser and the condensed water tank are sequentially connected.