JP2860149B2 - High frequency vacuum drying equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a high-frequency vacuum drying apparatus for drying fibrous materials such as loose hair and yarn by a high-frequency dielectric heating under a reduced-pressure atmosphere and drying at a relatively low temperature. About.

[Conventional technology]

Conventionally, this type of apparatus is provided with a condenser between a drying tank and a vacuum pump, and evacuated by a vacuum pump to liquefy water evaporating from fibers in the drying tank by the condenser. With a structure that collects and accumulates in the drain tank
The amount of water evaporated from the fibers was measured by measuring the amount of drain accumulated in the drain tank.

FIG. 2 shows such a conventional high-frequency vacuum drying apparatus.

Numeral 1 denotes a drying tank, in which fibers such as cheese 2 are placed between the electrodes 1a and 1b.
Is processed. The number of the cheeses 2 is actually not a single one as shown in the figure but a large number. The electrode 1a is raised to the position indicated by reference numeral 1a 'when the cheese 2 is put into the drying tank and when it is taken out of the drying tank, and is lowered to the position indicated by reference numeral 1a during the dielectric heating. 1c is a lid of the drying tank 1. Numeral 3 denotes a high-frequency oscillator, whose output is also applied between the electrodes 1a and 1b to dielectrically heat the cheese 2. 3a is a heat exchanger for cooling provided in the high frequency oscillator 3. 4 is a vacuum release valve, 5 is a vacuum gauge, 6 is a drain tank connected to the bottom of the drying tank 1 via a strainer 7, 8 is a level sensor for detecting the liquid level in the drain tank 6, and 9 is a drain valve. , 10 is a condenser, 11 is a discharge pipe, 12 is a drain pipe for collecting the liquefied drain in the condenser 10 into the drain tank 6, 13 is a water supply valve for supplying cooling water to the heat exchanger in the condenser 10, and 14 is A vacuum pump connected to the condenser 10 via an exhaust valve 15 and a vacuum check valve 16, 17 a fine control valve, 18 a filter, 19 a steam separator, 20 a vacuum pump for roughing, 21
Is a roughing valve, 22 is a vacuum check valve, and 23 is a steam / water separation tank for a roughing pump. The cooling water was supplied to the vacuum pump 20 for use. Vacuum pump for roughing 20
Is operated for a short time at the beginning and at the end of the drying operation.

An example of the processing capacity of this type of high-frequency vacuum drying apparatus is a processing capacity of 300 kg (about 300 cheeses) and a high-frequency output of 100 kw.

[Problems to be solved by the invention]

In the above-mentioned conventional technology, a condenser is provided between a drying tank and a vacuum pump, and the evaporated water liquefied by the condenser is accumulated in a drain tank below the drying tank and measured. In addition to the above, there is a problem that a large amount of cooling water is supplied to the condenser, which increases the energy cost.

An object of the present invention is to provide a high-frequency vacuum drying apparatus that can solve such a problem.

[Means for solving the problem]

In order to achieve the above object, the high-frequency reduced-pressure drying apparatus of the present invention uses a fiber (2) in a drying tank (1) under a reduced-pressure atmosphere.
Pump for drying by heating the fiber by high-frequency dielectric heating and absorbing moisture evaporated from the fiber material (2) in the drying tank (1), a vacuum pump (20) for roughing and a vacuum pump Cooling water flow meter (3
Water supply pipes (29) and (31) for supplying cooling water via 0) and exhaust pipes (25) and (26) for vacuum pumps (14) and (20)
An exhaust cooling water supply device (28) for adding cooling water to the mixed exhaust gas discharged to the exhaust pipe, and a steam-water separation tank (27) that joins and communicates the exhaust pipes (25) and (26). Water separation tank (2
7) A drain pipe (33) having a drain pump (24) and a drain flow meter (30 ') is connected to an exhaust pipe (37).

[Action]

Moisture contained in the fiber material in the drying tank is heated at a high frequency under a reduced pressure atmosphere by a vacuum pump and evaporated at a relatively low temperature. The evaporated water is sucked by the vacuum pump, mixed with the cooling water of the vacuum pump, discharged to the exhaust pipe of the vacuum pump, further mixed with the cooling water from the exhaust cooling water supply device, liquefied, and released to the steam-water separation layer. Is done. The cooling water supplied to the vacuum pump and the cooling water supplied from the exhaust cooling water supply device to the exhaust of the vacuum pump are mixed with the evaporated water from the fibers as described above and discharged to the steam separator. The water collected in the steam separator is measured and discharged by a drain flow meter through a drain pump.
On the other hand, since the amount of water supplied for cooling is measured by the cooling water flow meter, the difference, that is, the above-mentioned liquefied amount (drain amount) of evaporated water can be easily measured. The drying operation is performed using the drain amount as a guide.

〔Example〕

In the embodiment shown in FIG. 1, reference numeral 1 denotes a drying tank provided with electrodes 1a and 1b for dielectric heating and a lid 1c. 2 is a cheese as a material to be dried. The reference numeral 1a 'indicates a state in which the electrode 1a is moved so as not to be in the way when the cheese 2 is taken in and out. Reference numeral 3 denotes a high-frequency oscillator for supplying high-frequency power to the electrodes 1a and 1b, and includes a heat exchanger 3a for cooling. 4 is a vacuum release valve, 5 is a vacuum gauge, 14 is a vacuum pump, which is disposed above the drying tank 1 through an exhaust valve 15 and a vacuum check valve 16, and a strainer 7, an exhaust valve 15 'and a vacuum check valve 16 are provided. Through the bottom of the drying tank 1. Reference numeral 17 denotes a fine control valve, and reference numeral 18 denotes a filter that adjusts the opening of the fine control valve 17 so that the pressure in the drying tank becomes a predetermined pressure. A vacuum pump 20 for roughing is connected to the upper part of the drying tank 1 through a roughing valve 21 and a vacuum check valve 22. twenty five
Numerals 26 and 26 denote exhaust pipes derived from the outlets of the vacuum pump 14 and the roughing vacuum pump 20, and are connected to the steam separator 27. Numeral 28 denotes a water supply device for supplying cooling water to an exhaust pipe 25 of the vacuum pump 14, a nozzle 28 a, and a pipe connecting the nozzle 28 a to the exhaust pipe 25.
28b. The cooling water from the exhaust cooling water supply device 28 further cools the exhaust of both vacuum pumps 14 and 20 to liquefy the evaporated water. Reference numeral 29 denotes a water supply device for supplying cooling water to the vacuum pump 14, which is composed of a nozzle 29a and a pipe line 29b extending from the nozzle 29a to the vacuum pump 14. 31 is a roughing vacuum pump 20
A water supply device for supplying cooling water to the nozzle 31a and the nozzle 3
It comprises a conduit 31b connected to the vacuum pump 20 from 1a. Reference numeral 24 denotes a water supply pipe which supplies cooling water to three water supply devices 28, 29, and 31 via a cooling water flow meter 30. The cooling water measured by the cooling water flow meter 30 cools both the vacuum pumps 14 and 20, and at the same time, sends the cooling water to the exhaust pipe 25 via the water supply device 28, and completely liquefies the evaporated water in the gas-water separation tank 27. Then, the water is measured and drained by the drain flow meter 30 '. The difference between the two flowmeters 30, 30 'is integrated by a computer or sequencer control, and this is a measure of the drying operation of the apparatus.

The device of the above-described embodiment is operated by a control device (not shown). To start the apparatus, the base valve 13 and the water supply valve 31c of the water supply pipe 24 are opened, and the water is supplied to the two water supply apparatuses 29 and 31, and at the same time, the vacuum pump 14 and the roughing vacuum pump 20 are operated. . At this point, the water supply valve 28c of the exhaust cooling water supply device 28 is closed and the evaporating action is not active until the degree of vacuum reaches a predetermined value.
c opens. Cooling water passes through exhaust pipes 25 and 26 and is separated into steam and water.
When a certain amount of water accumulates at 27, the drain pump 34 is activated and the drain valve is operated.
Drain through 35,36. When the inside of the drying tank 1 starts to be vacuumed, the high-frequency oscillator 3 is started and the fibrous material (the cheese 2) between the electrodes 1a and 1b is dielectrically heated, and the water evaporates at a relatively low boiling point. At this point, the exhaust cooling water supply device
The 28 water supply valve 28c is opened. Water supply flow meter 30 and waste water flow meter 3
Since the difference between 0 'and 0' is supposed to be displayed by the computer or the sequencer control, 0 (zero) is displayed as long as no evaporated water is generated, but the drain amount is displayed as the drying operation proceeds. You. When the degree of vacuum reaches a predetermined value, the roughing vacuum pump 20 stops, and both the water supply valve 28c and the drain valve 36 are closed. The vacuum pump 14 is operated continuously during the drying operation, during which the exhaust valves 15 and 15 ′ are alternately opened and closed, and a portion of the drain is drained from the bottom of the drying tank 1 and the evaporated water is contained from the top of the drying tank 1. Aspirate air. The roughing vacuum pump 20 has a larger capacity than the vacuum pump 14, but operates only for 5 to 6 minutes at the beginning of the drying operation and 2 to 3 minutes at the final finishing drying. Exhaust pipe 25 of vacuum pump 14 and vacuum pump for roughing
The 20 exhaust pipes 26 join together and are connected to the water / water separation tank 27 to condense and liquefy the evaporating moisture sucked, and the remaining air is discharged from the exhaust port 37 to the atmosphere. When the drying operation is completed, the high-frequency oscillator
3. The vacuum pumps 14 and 20 are stopped, the vacuum break valve 4 is opened, the inside of the drying tank 1 is returned to the atmospheric pressure, and then the lid 1c is opened to take out the object 2 to be dried.

After centrifugal dehydration of 300 kg of cheese, drying operation was performed with the device of the embodiment of high-frequency output of 100 kw. As a result, the processing time was 130 minutes, and the consumption of cooling water was 15% compared to the conventional technology.
1.0ton / Hr was saved.

〔The invention's effect〕

Since the high-frequency reduced-pressure drying apparatus of the present invention is configured as described above, it does not require a condenser provided in a reduced-pressure portion between the drying tank and the vacuum pump as in the related art, and further measures the drain amount. In addition, since only the combination of the flowmeters for water supply and drainage is used, the entire apparatus is simplified and the effect of cost reduction is great.

[Brief description of the drawings]

FIG. 1 is an overall view of an embodiment of the present invention, and FIG. 2 is an overall view of a prior art. 1 ... Drying tank, 2 ... Fiber material, 14 ... Vacuum pump, 20 ...
… Vacuum pump for roughing, 24… water supply pipe, 25,26 …… exhaust pipe, 27… water-water separation tank, 28 …… water supply device for exhaust cooling, 30
…… Cooling water flow meter, 30 ′ …… Drainage flow meter, 33 …… Drain pipe, 37 …… Exhaust pipe

Claims (2)

(57) [Claims] An apparatus for drying a fibrous material (2) in a drying tank (1) by high-frequency dielectric heating under a reduced pressure atmosphere to dry the fibrous material (2) in the drying tank (1). Vacuum pump (14) for absorbing water, vacuum pump for roughing (2
0) and water supply pipes (29), (3) for supplying cooling water to these vacuum pumps (14), (20) via a cooling water flow meter (30).
1) and the exhaust pipes (25) of the vacuum pumps (14) and (20)
An exhaust cooling water supply device (28) for adding cooling water to the mixed exhaust gas discharged to (26) and a steam-water separation tank (27) that joins and communicates the exhaust pipes (25) and (26) are provided. A high frequency vacuum drying apparatus characterized in that a drainage pipe (33) having a drainage pump (24) and a drainage flowmeter (30 ') and an exhaust pipe (37) are connected to the steam separator (27). 2. A cooling water flow meter (30) and a drain flow meter (30 ').
And a display which is interlocked by a computer or a sequencer control and constantly displays the difference between the two.
The high-frequency vacuum drying apparatus according to claim 1.