JP2779431B2 - 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, and is provided below the drying tank. With a structure that collects and stays in the drain tank
The amount of water evaporated from the fibers was measured by measuring the amount of drain retained 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 layer 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 break 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, 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 in the drain tank 6, 13 is a water supply valve for supplying cooling water to a heat exchanger in the condenser 10, and 14 is an exhaust pipe. A vacuum pump connected to the condenser 10 via a 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, 19
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 retained and measured in a drain tank below the drying tank. In addition to the necessity, there is a problem that a large amount of cooling water is supplied to the condenser, which results in high energy costs.

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, a high-frequency vacuum drying apparatus of the present invention is an apparatus for heating and drying fiber materials in a drying tank by high-frequency dielectric heating under reduced pressure atmosphere. A vacuum pump (14) (20) for absorbing evaporated water from 2), an exhaust cooling water supply device (28) for supplying cooling water to the exhaust of the vacuum pump (14) (20),
The cooling water of the vacuum pump discharged to the exhaust pipes (25) and (26) of the vacuum pumps (14) and (20), the cooling water from the exhaust cooling water supply device (28), and the exhaust cooling water supply device (28) ), An adjusting tank (39) for receiving the evaporated water mixed and liquefied with the cooling water from the above, and for storing a certain level of water, a cooling water supply to the vacuum pump (14) and an exhaust cooling water supply device ( 28)
A constant flow rate cooling water supply device (30) for supplying a constant flow rate of cooling water supplied to the exhaust of the vacuum pump (14) from the cooling water; A constant flow drainage device (30 ') for draining water of the same flow rate from the regulating tank (39) and an overflow measuring device (52) for measuring the amount of water exceeding a certain level in the regulating tank (39).

[Action]

The water contained in the fiber material in the drying tank is subjected to high-frequency dielectric heating under a reduced pressure atmosphere by a vacuum pump and evaporates 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 discharged to the adjustment tank. You. The cooling water to the vacuum pump and the cooling water to be supplied to the exhaust of the vacuum pump from the exhaust cooling water supply device are supplied with a constant flow of water from the cooling water constant flow supply device. The water is mixed with the evaporated water from the fibrous material and released to the adjustment tank.

A constant level of water is stored in the regulating tank, and a part of the water in the regulating tank, i.e., the same flow rate of the cooling water supplied from the cooling water constant flow supply device, is fixed. The water is drained through the flow rate drainage device, and the excess, that is, the same amount of water as the water evaporated from the fibrous material overflows and is measured by the overflow metering device.

〔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 fibrous 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 breaking valve, 5 is a vacuum gauge, 14 is a vacuum pump, and the upper part of the drying tank 1 is evacuated through an exhaust valve 15 and a vacuum check valve 16.
Further, it is connected to the bottom of the drying tank 1 through a strainer 7, an exhaust valve 15 'and a vacuum check valve 16. Reference numeral 17 denotes a fine control valve, and reference numeral 18 denotes a filter.
The internal pressure is adjusted to 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. Exhaust pipes 25 and 26 communicate with the outlets of the vacuum pump 14 and the roughing vacuum pump 20, respectively, and are connected to the steam separator 27. 28 is the exhaust pipe 25 of the vacuum pump 14
An exhaust cooling water supply device that supplies cooling water to the nozzle 28a
And a pipeline 28b downstream of the nozzle 28a and connected to the exhaust pipe 25. The cooling water from the exhaust cooling water supply device 28 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 the cooling water of the vacuum pump 14, which is composed of a nozzle 29a and a pipe 29b downstream of the nozzle 29a and connected to the cooling water inlet of the vacuum pump 14. Reference numeral 30 denotes a cooling water constant flow supply device, which includes a water supply tank 30a, an overflow pipe 30b, and a water supply tank.
Water pipe 30c and water pipe 30c extended downward from the bottom of 30a
And a water supply nozzle 30d provided at the lower end of the water supply device 30a, so that the water level of the water supply device 30a is adjusted to be constant. 30
e is a filter provided at the upper end opening of the water supply pipe, 31 is a liquid level detection sensor, and 32 is a water supply valve for supplying water to the water supply tank 30a, which opens when water is supplied. Numeral 33 denotes an adjustment cock, and if the amount of water supplied to the water supply tank 30a is too large, the water is drained from the overflow pipe 30b and wasted. By opening the water supply valve 34 of the water supply tank, the amount of water supplied to cool the vacuum pump 14 from the water supply device 29 via the pipe line 35 and the amount of water supplied to the drain pipe 25 via the exhaust cooling water supply device 28. The sum of the flow rates is adjusted to a constant flow rate determined by the head H from the water surface of the water supply tank 30a to the water supply nozzle 30d and the fluid resistance of the water supply nozzle 30d.

36 and 37 are drain pipes, 38 is an exhaust port, 39 is a regulating tank, 40 is a water supply valve, 41 is a drain valve, 42 is a water supply valve, 43 is a nozzle, and 44 is a filter. 45 is a pocket provided near the water surface of the adjustment tank 39, and a nozzle 30d 'is provided at the bottom of the pocket 45, that is, at the lower end of a drain pipe 30c' whose upper end is opened slightly below the water surface of the adjustment tank 39. A filter 30e 'is provided at the upper end opening of the tube 30c'. The drain pipe 30c ', nozzle 30d' and filter 30e 'constitute a constant flow drain device 30'. 46 is a drain valve. And
The water head H from the water surface of the regulating tank 39 to the nozzle 30d 'and the nozzle 3
With the fluid resistance of 0d ', the flow rate of the water drained through the drain valve 46 is adjusted to a constant flow rate, and the value is set to the same flow rate as the constant flow rate of the cooling water supplied from the cooling water constant flow rate supply device 30. Determined. 47 is an overflow pipe through which water overflows when the water level of the adjusting tank 39 exceeds a certain level, 48 is an overflow valve inserted into the overflow pipe, 49 is a measuring tank connected downstream thereof, 50 is a measuring tank 49 A drain valve 51 connected to the outlet of the sensor is a liquid level detection sensor. The overflow valve 48, the measuring tank 49, the drain valve 50 and the liquid level detection sensor 51 constitute an overflow measuring device 52. Reference numeral 53 denotes a liquid level detection sensor provided in the adjustment tank.

The device of the above embodiment is operated by a control device (not shown).

In order to start the apparatus, first, the water supply valve 40 is temporarily opened so that water of a certain level is kept in the adjustment tank 39, and water is supplied. At this time, the drain valve 41 is closed.

The water in the measuring tank 49 is emptied, the overflow valve 48 is opened, and the drain valve 50 is closed. The drain valve 46 is closed. The water supply valve 42 is kept open.

The water supply valve 32 is opened to supply water to the water supply tank 30a, and when a predetermined liquid level is reached, the water supply valve 34 is opened to supply cooling water at a constant flow rate, and the vacuum pump 14 and the roughing pump 20 are started. . At this time, the drain valve 46 is also opened to start draining at a constant flow rate. 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 water is evaporated at a relatively low boiling point. The amount of water to the water supply tank 30a is manually adjusted to an appropriate amount by the adjusting cock 33 as described above. Cooling water having a constant flow rate supplied from the water supply nozzle 30d is divided into approximately half by the nozzles 28a and 29a, and supplied to the drain pipe 25 and the cooling water inlet of the vacuum pump 14. The vacuum pump 14 is operated continuously during the drying operation, during which the exhaust valves 15 and 15 ′ are alternately opened and closed to open the drying tank 1.
, And air containing evaporated water is sucked in from the bottom of the drying tank 1. Although the roughing vacuum pump 20 has a larger capacity than the vacuum pump 14, the roughing
Run for a few minutes and the last 3 minutes of finish drying.

An exhaust pipe 25 of the vacuum pump 14 and an exhaust pipe 26 of the roughing vacuum pump 20 are connected to a steam separation tank 27, and the moisture evaporated from the cable 2 in these exhaust pipes is condensed and liquefied by cooling water from a pipe 28b. Most of the air is discharged into the atmosphere from the exhaust port 38. The drainage with a little air mixed in from the water pipe 37
Other wastewater is discharged from the drain pipe 36 to the regulating tank 39. Thus, the flow rate discharged to the adjustment tank 39, that is, the adjustment tank 39
Is the sum of the cooling water of the vacuum pumps 14 and 20 and the water obtained by liquefying the evaporated water from the cheese 2, of which the cooling water of the roughing vacuum pump 20 is at the bottom of the regulating tank 39. The water supplied through the water supply valve 42 only circulates back to the regulating tank, and is supplied from the cooling water constant flow supply device 30 by being divided into the vacuum pump 14 and the pipe 28b. Since the same amount of cooling water is drained from the regulating tank 39 through the constant flow drainage device 30 ', the same amount of water as the amount of water evaporated from the dried matter is eventually liquefied in the overflow pipe 47.
And enters the measuring tank 49. The water entering the measuring tank 49 is not limited to the liquefied evaporated water itself, but merely the same amount of water corresponding to the amount of the liquefied evaporated water. When the liquid level in the measuring tank reaches a certain level, the liquid level detecting sensor 51 detects this, closes the overflow valve 48, opens the drain valve 50, and drains the water in the measuring tank 49 in a short time. After a short period of time sufficient to drain the water in the measuring tank, the control device closes the drain valve 50 and the overflow valve.
Open 48. Such an operation is repeated, and the amount of water corresponding to the evaporated water is integrated by counting the number of repetitions. The capacity of the measuring tank 49 is 1, and the total drain amount is displayed by automatically integrating the number of times of drainage. The water discharged from the water / water separation tank 27 to the adjustment tank 39 is heated to about 50 ° C., stored in the upper part of the adjustment tank 39, drained through the drain pipe 30c ′, or flows out to the measuring tank 49. .

After the drying work is completed, high-frequency oscillator 3, vacuum pump 1
4 and 20 are stopped, the vacuum breaking valve 4 is opened, and 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 apparatus of the embodiment with high-frequency output of 100 kw. As a result, the processing time was about 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, a condenser provided in a reduced-pressure portion between a drying tank and a vacuum pump unlike the related art is not required. Therefore, the cooling efficiency for liquefying the evaporated water is better than that of the conventional condenser, the consumption of the cooling water can be reduced, and the processing cost can be reduced accordingly. Further, since an expensive condenser is not required, the cost of the apparatus itself can be reduced. Furthermore, since the drain amount is measured under the atmospheric pressure, the measurment operation can be easily checked and the merit can be visually confirmed.

[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, 25,26 ... Exhaust pipe, 27 ... Gas-water separation tank, 28 ... Exhaust cooling water supply device, 28b ... Water supply pipe, 3
0… Cooling water constant flow supply device, 30a …… Water tank, 30c ……
Drain pipe, 30d… Water supply nozzle, 30 ′… Constant flow drainage device, 30c ′… Drain pipe, 30d ′… Nozzle, 49… Measuring tank, 52… Overflow measuring device

Claims (6)

(57) [Claims] An apparatus for drying a fibrous material in a drying tank by high-frequency dielectric heating under a reduced-pressure atmosphere to dry the fibrous material in a drying tank (1). 14) (20), an exhaust cooling water supply device (28) for supplying cooling water to the exhaust of the vacuum pumps (14) and (20),
The cooling water of the vacuum pump discharged to the exhaust pipes (25) and (26) of the vacuum pumps (14) and (20), the cooling water from the exhaust cooling water supply device (28), and the exhaust cooling water supply device (28) ), An adjusting tank (39) for receiving the evaporated water mixed and liquefied with the cooling water from the above, and for storing a certain level of water, a cooling water supply to the vacuum pump (14) and an exhaust cooling water supply device ( 28)
A constant flow rate cooling water supply device (30) for supplying a constant flow rate of cooling water supplied to the exhaust of the vacuum pump (14), and a flow rate of the cooling water supplied from the constant flow rate cooling water supply device (30). A high-frequency device comprising a constant flow drainage device (30 ') for draining water of the same flow rate from the regulating tank (39) and an overflow measuring device (52) for measuring the amount of water exceeding a certain level in the regulating tank (39). Vacuum drying equipment. 2. A vacuum pump comprising: a vacuum pump (14) which is continuously operated during the drying operation; and a roughing vacuum pump (20) which is operated only for a short time during the drying operation. The high-frequency vacuum drying apparatus according to claim 1, wherein the cooling water of the vacuum pump (20) is supplied not from the cooling water quantitative supply device (30) but from the bottom of the regulating tank (39). 3. An exhaust pipe (25) of a vacuum pump (14) (20).
(26) and a gas-water separation tank that separates gas and water from the water supply pipe (28b) of the exhaust cooling water supply device (28) into gas and water and discharges the separated water to the adjustment tank (39). The high-frequency reduced-pressure drying apparatus according to claim 1, further comprising (27). 4. A constant flow drainage device (30 ') includes a drain pipe (30c') having an upper end opening slightly below the predetermined level of the water level of the regulating tank (39), and a drain pipe (30c '). 4. The high frequency vacuum drying apparatus according to claim 1, further comprising a nozzle (30d ') provided at a lower end. 5. The cooling water constant flow supply device (30) is provided with a water tank (30).
a), a water supply pipe (30c) having an upper end connected to the water supply tank, and a nozzle (30d) provided at the lower end of the water supply pipe so that the water level of the water supply tank (30a) is adjusted to be constant. The high-frequency reduced-pressure drying device according to claim 1 or 4, which is configured. 6. The high-frequency pressure reducing device according to claim 1, wherein the overflow metering device has a metering tank for measuring the amount of water exceeding a certain level in the adjusting tank in small increments. Drying equipment.