KR101888108B1 - Exhaust Pressure Controller and Exhaust Flow Controller - Google Patents

Abstract

Provided is an exhaust pressure controller that has high controllability and is small in corrosion resistance and durability.
By using the rubber expansion valve at the driving portion of the exhaust pressure controller, the damper control can be performed with high precision. A valve having a rigid body having a through passage, an expansion member disposed in the through passage, and an airtight cavity formed with the expansion member,
A pressure / flow rate measuring means for measuring a pressure and / or a flow rate of the through-flow passage;
And an air supply / exhaust control means for expanding or contracting the expansion member to change the flow path cross-sectional area of the through-flow passage by supplying or exhausting the control gas to / from the airtight cavity.

Description

Exhaust Pressure Controller and Exhaust Flow Controller

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pressure / flow controller for controlling an exhaust pressure and an exhaust flow rate of a local exhaust system or a dryer.

Generally, in various laboratories, semiconductor manufacturing plants, and chemical plants, local exhaust systems such as draft chambers are installed to prevent the spread of harmful gases and odors.

In general, the local exhausting device sucks the noxious gas from the hood by a fan installed on the downstream side of the duct Duct. The harmful gas sucked from the hood is sent to the fan through the duct after the harmful substance removal treatment, and is discharged to the atmosphere through the exhaust duct provided on the downstream side of the fan. A damper for controlling the exhaust pressure is generally inserted into the duct of the local exhaust system.

Fig. 9 is a configuration diagram showing an example of a conventional local exhaust system. 9, reference numeral 801 denotes a hood. The hood 801 is connected to the suction side of the fan 805 through the ducts 803a and 803b. An exhaust duct 807 is connected to the exhaust side of the fan 805. A damper 900 is inserted between the duct 803a and the duct 803b. Reference numeral 901 denotes a housing constituting the damper 900, The openings are hermetically connected to one ends of the ducts 803a and 803b, respectively.

Fig. 10 is a configuration diagram showing an example of a conventional damper 900. As shown in Fig. In Fig. 10, reference numeral 901 denotes a housing shaped like a cylinder having openings at both ends. In the cylinder, a disc-shaped valve disc 903 is rotatable in accordance with the rotation of the valve shaft 904 Is installed. The valve disc 903 is rotated by the actuator 905. The angle of opening and closing of the valve changes with the rotation of the valve disc 903. Thus, the exhaust pressure and the exhaust flow rate of the duct connected to both ends of the housing 901 are adjusted. That is, when the exhaust pressure is desired to be lowered (negative pressure is desired to be increased), the valve disc 903 is rotated to widen the flow path in the duct, and when it is desired to increase the exhaust pressure We narrow the euro. When it is desired to increase the exhaust flow rate in the same manner, the valve body disk 903 is rotated to widen the flow path in the duct, and when it is desired to reduce the exhaust flow amount, the flow path in the duct is narrowed.

Patent Document 1 discloses a flow control valve constituted by using such a damper. This damper has a problem described below.

The exhaust pressure or the exhaust flow rate is adjusted by the clearance between the valve body disk and the housing, which is generated by the rotation of the valve body disk. It is not easy to obtain a control constant such as a PID at the time of feedback control in the pressure sensor or the flowmeter because the variation of the adjustment amount is large with respect to the minute clearance change. Also, depending on the conditions, the actual value varies before and after the set value with respect to the pressure value or the flow rate value set so that the rotation of the valve disc does not converge.

Further, in order to rotate the valve disc, an actuator is required outside the housing, thereby increasing the size and weight of the damper device. Durability may be insufficient because it has a sliding part. Further, when the rotation angle of the valve disc by the actuator is controlled to be finely controlled, the damper device becomes expensive.

Patent disclosure 2009-31866

An object of the present invention is to provide an exhaust pressure / flow controller which has high controllability and is small in corrosion resistance and durability as a controller for controlling the exhaust pressure and the exhaust flow rate.

The present inventor has focused on the use of a rubber expansion valve in the driving portion of the exhaust pressure / flow rate controller. This rubber expansion valve has been found to be small in the number of components, small in size, able to improve damper control accuracy, and excellent in durability and corrosion resistance because it does not have a sliding portion, thereby completing the present invention.

The present invention for achieving the above object is as follows.

[1] A valve comprising: a hard body having a through-flow passage; an expansion member disposed in the through-flow passage; and a valve having an airtight cavity formed at least including the expansion member,

Pressure / flow rate measuring means for measuring a pressure and / or a flow rate in the through-flow passage;

And an air supply / exhaust control unit for expanding or contracting the expansion member to change a flow path cross-sectional area of the through-flow passage by supplying or exhausting a control gas to the airtight cavity.

[2]

A rigid body having a penetrating flow path,

A tubular rubber tube inserted into the through-flow passage in parallel with the flow direction of the through-flow passage and its axial center, and both ends thereof being hermetically connected to both ends in the through- The exhaust pressure / flow rate controller according to the above [1].

[3] The pressure / flow rate measuring device according to the above [1], wherein the pressure / flow rate measuring means uses a differential pressure sensor and includes a mechanism for purifying the differential pressure sensor, controller.

The exhaust pressure / flow controller (hereinafter referred to as "main exhaust pressure / flow controller") of the present invention can improve damper control precision and has no damping portion, and therefore is excellent in durability and corrosion resistance.

1 is an explanatory view showing an example of the configuration of the exhaust pressure / flow controller of the present invention.
2 is an explanatory view showing an example of the internal structure of the rubber expansion valve.
Figs. 3 (a) to 3 (c) are cross-sectional views showing planes orthogonal to the flow direction of the through passage of the rubber expansion valve. Fig.
FIG. 4A is a front view, FIG. 4B is a side view, and FIG. 4C is a rear view showing the structure of a driving unit of the present exhaust pressure / flow controller.
5 is a configuration diagram showing an example of a local exhaust system constructed by assembling the exhaust pressure / flow controller of the present invention.
6 is a cross-sectional view showing another example of the internal structure of the rubber expansion valve.
7 is an explanatory view showing another example of the configuration of the exhaust pressure / flow controller of the present invention.
8 is a partial cross-sectional view showing a configuration example of a differential pressure type flow meter.
9 is a configuration diagram showing an example of a conventional local exhaust system.
10 is a configuration diagram showing a configuration example of a conventional damper.

Hereinafter, the present invention will be described in detail by enumerating two embodiments.

≪ First Embodiment >

1 is an explanatory view showing an example of the configuration of an exhaust pressure / flow controller of the present invention. 1, reference numeral 100 denotes an exhaust pressure controller. The exhaust pressure controller 100 includes a driving unit 70 and an air supply / discharge controller 33 and a pressure measuring unit 38 for controlling the driving unit 70.

The driving unit 70 includes a housing 21 having a through passage 71 formed therein and duct connecting portions 17 and 31 formed at both ends of the through passage 71 in the flow direction of the housing 21, And a rubber expansion valve 50 that is installed in the cylinder block 21.

One end (the side connected to the duct) of the duct connecting portions 17 and 31 is opened (open) and the other end is connected to the opposite ends of the through-flow path 71 of the housing 21 And is hermetically connected to the housing 21, respectively.

The duct connecting portion 17 is provided with a pressure detecting hole 19 communicating with the through-passage in the duct. One end of the purge pipe (29) is connected to the pressure detecting hole (19) through a connection port (25). The other end of the purge pipe (29) is coupled to the pressure measuring part (38). The pressure measuring unit 38 is provided with a differential pressure sensor (not shown), and one end of the supply pipe 37 is connected. The other end of the supply pipe 37 is connected to a pressure source (not shown).

One end of the supply pipe 35 is connected to the air supply / discharge controller 33. The other end of the supply pipe 35 is connected to a pressure source (not shown).

An air supply and exhaust pipe connection port 23 is formed in the housing 21 and one end of an air supply and exhaust pipe 27 is connected to the air supply and exhaust pipe connection port 23. The other end of the air supply and exhaust pipe (27) is connected to the air supply and exhaust controller (33).

A rubber expansion valve (50) is mounted in the housing (21). Fig. 2 is an explanatory view showing the internal structure of the rubber expansion valve 50. Fig. 2, reference numeral 11 denotes a cylindrical valve body made of a hard material such as stainless steel and having openings at both ends thereof. Reference numeral 13 denotes a rubber-made rubber tube (expansion member) having a cylindrical shape with openings at both ends. The rubber tube 13 is inserted into the cylinder of the valve body 11 in the same direction as the opening direction of the valve body 11.

Both ends of the rubber tube 13 are hermetically connected to both end portions of the valve body 11. [ Thus, an airtight cavity 12 is formed between the inner peripheral surface of the valve body 11 and the outer peripheral surface of the rubber tube 13. The valve body (11) is provided with an air supply / exhaust port (14) for supplying / exhausting a control gas into the cavity (12). The rubber tube 13 can be expanded or contracted by supplying / discharging the control gas from the air supply / discharge port 14.

Next, the operation of the rubber expansion valve 50 will be described. 3A to 3C are cross-sectional views showing surfaces of the rubber expansion valve 50 perpendicular to the flow direction of the through-passage 15. 3A shows a state in which the control gas is not supplied into the cavity 12 of the rubber expansion valve 50. In this state, the outer periphery of the tube 13 is in close contact with the inner circumferential surface of the valve body, and therefore the cross-sectional area of the through-flow passage 15 is maximally extended (maximum flow cross-sectional area value). In this state, when the control gas is supplied into the cavity 12, the rubber tube 13 expands, thereby reducing the cross-sectional area of the flow passage 15 (Fig. 3B). When the control gas is further supplied in the cavity 12 in this state, the rubber tube 13 further expands, and the flow path cross-sectional area of the through-flow passage 15 further decreases (Fig. 3C, minimum flow cross-sectional area value). On the other hand, when the control gas in the cavity 12 is evacuated, the flow path cross-sectional area of the through passage 15 increases due to shrinkage of the rubber tube 13. The maximum flow path cross-sectional area value is at least two times the minimum flow path cross-sectional area value, and preferably at least five times.

(Not shown) is built in the air supply / discharge controller 33 (air supply / exhaust control means) so that the pressure value measured by the pressure measurement unit 38 coincides with the set pressure value And controls the driving unit 70. That is, as the control gas is supplied to and discharged from the rubber expansion valve 50, the flow path cross-sectional area of the through passage 15 formed in the rubber expansion valve 50 is freely controlled.

This exhaust pressure controller 100 is assembled and used in a local exhaust system. 5 is a configuration diagram showing an example of a local exhaust system in which the exhaust pressure controller 100 of the present invention is assembled. 5, reference numeral 501 denotes a hood. The hood 501 is connected to one end of the duct 503a and the other end of the duct 503a is connected to the duct connecting portion 17. One end of the duct 503b is connected to the duct connecting portion 31 and the other end of the duct 503b is connected to the suction side of the fan 505. [ One end of the exhaust duct 507 is connected to the exhaust side of the fan 505, and the other end of the exhaust duct 507 is opened.

The noxious gas sucked in the hood 501 moves to the fan 505 through the ducts 503a and 503b and is discharged to the atmosphere from the exhaust duct 507. [ At this time, the exhaust pressure controller 100 appropriately adjusts the exhaust pressure.

The flow path cross sectional area of the rubber expansion valve 50 is reduced when the exhaust pressure on the upstream side (on the side of the duct 501) of the exhaust pressure controller 100 is increased (negative pressure is reduced). The compressed gas (control gas) supplied from the pressure source to the air supply / discharge controller 33 via the supply pipe 35 is sent to the housing 21 through the air supply and exhaust pipe 27. The control gas sent to the housing 21 is fed into the cavity 12 of the rubber expansion valve 50 and inflates the rubber tube 13 to maintain this state. As a result, the flow path cross-sectional area of the flow path 15 becomes small,

When the exhaust pressure on the upstream side (duct 501 side) of the exhaust pressure controller 100 is lowered (when the negative pressure is increased), the flow path cross-sectional area of the rubber expansion valve 50 is increased. The control gas supplied in the cavity 12 of the rubber expansion valve 50 is discharged to the outside from the cavity 12. [ That is, the air supply / discharge controller 33 releases the pressure holding state and discharges the control gas in the cavity 12 to the outside through the air supply and exhaust pipe 27. The rubber tube is shrunk by the elastic force of the rubber when the control gas being charged and held in the cavity 12 is discharged. As a result, the flow path cross-sectional area of the flow path 15 becomes large.

The exhaust pressure is measured by the pressure / flow rate measuring means.

The differential pressure sensor portion (not shown) in the pressure measuring portion 38 communicates with the in-duct flow path by the pressure detecting hole 19. [ Therefore, depending on the kind of the gas or the like flowing in the flow passage, dust or mist may adhere to the differential pressure sensor portion or may be exposed to corrosive gas. In order to prevent this, it is preferable that the purge gas is sent at a constant flow rate through the purge pipe 29 in the pressure detecting hole 19. Accordingly, it is possible to prevent dust, steam , and corrosive gas from entering from the pressure detecting hole 19, and to improve the durability and corrosion resistance of the differential pressure sensor portion.

≪ Second Embodiment >

Fig. 7 is an explanatory view showing a configuration example of the exhaust pressure / flow controller according to the second embodiment of the present invention. Fig. 7, reference numeral 300 denotes an exhaust flow rate controller. The exhaust flow controller (300) is composed of a driving unit, an air supply / exhaust control unit for controlling the air supply unit, and a flow rate measuring unit.

In FIG. 7, reference numeral 321 denotes a cylindrical housing, and a rubber expansion valve 350 is installed in the interior of the housing in the same direction as the penetration direction of the shaft 321 in the housing 321. One end of the differential pressure type flow meter 340 (pressure / flow rate measurement means) is hermetically connected to one end of the housing 321. A duct connecting portion 317 is hermetically connected to the other end of the housing 321. A duct connecting portion 331 is hermetically connected to the other end side of the differential pressure type flow meter 340.

7, reference numeral 333 denotes an air supply / discharge controller. The air supply and discharge controller 333 is provided with a supply pipe connection port 335 for the control gas supplied from the outside (not shown). One end of an air supply and exhaust pipe 327 is connected to the air supply and exhaust controller 333 and the other end of the air supply and exhaust pipe 327 is connected to an air supply and exhaust pipe connection port 323 provided in the housing 321. The control gas supplied from the outside to the air supply and exhaust controller 333 is supplied to the rubber expansion valve 350 provided in the interior through the air supply and discharge pipe connection port 323 provided in the housing 321 through the air supply and exhaust pipe 327.

The purge gas supplied from the outside (not shown) is introduced into the differential pressure type flow meter 340 from the connection port 337.

The structure and operation of the rubber expansion valve 350 and the air supply / discharge controller 333 are the same as those of the first embodiment.

Next, the differential pressure type flow meter 340 will be described.

8 is a partial cross-sectional view showing an example of the differential pressure type flow meter 340. As shown in Fig. In Fig. 8, reference numeral 401 denotes a tubular flow path tube, in which a through-flow passage 403 is formed. The end of the flow pipe 401 is hermetically connected to the housing 321 and the duct connection port 331, respectively. In Fig. 8, the direction in which the process gas such as noxious gas flows flows in the direction of the arrow in the drawing. A static pressure detecting hole 411 and a pit tube inserting hole 412 are formed in the tube wall portion of the flow pipe 401. A pressure detecting pipe 405 is hermetically connected to a portion of the flow pipe 401 where the static pressure detecting hole 411 and the pit tube inserting hole 412 are formed.

In the pressure detecting pipe 405, a static pressure detecting path 415 and a backflow pressure detecting path 417 are formed. The static pressure detecting hole 411 formed in the flow pipe 401 is in communication with the static pressure detecting path 415 formed in the pressure detecting pipe 405. In the pressure detecting pipe 405, the static pressure detecting path 415 is branched into two, one connected to the differential pressure sensor 407 and the other connected to the purge pipe connecting portion 424.

In the pit tube insertion hole 412 of the flow pipe 401, a backflow pit 409 is inserted toward the inside of the flow pipe. The backflow pit tube 409 is provided with a reverse flow pressure detecting hole 413 at a position opposite to the flow direction of the process gas flowing through the flow pipe 401. The reverse flow pressure detection hole 413 formed in the pressure detection pipe 405, (Not shown). In the pressure detecting pipe 405, the backflow pressure detecting path 417 is branched into two, one connected to the differential pressure sensor 407 and the other connected to the purge pipe connecting portion 423.

The differential pressure sensor 407 is provided with differential pressure sensor ports 419 and 421. The differential pressure sensor 417 is connected to the high side of the pressure 419 and the low side of the pressure 421. [ 8, the process gas such as noxious gas flowing in the direction of the arrow is measured by the differential pressure sensor 407 to measure the static pressure and the backflow pressure, respectively, and the exhaust flow rate is calculated.

In the purge pipe connecting portions 423 and 424, And one end of the purge pipe 329 is connected to the other end of the purge pipe 329 is connected to the connection port 337 (Fig. 7). Thus, the purge gas is supplied to the positive pressure detection path 415 and the reverse flow pressure detection path 417, respectively. The purge gas supplied to the reverse pressure detector 417 and the reverse pressure detector 415 is discharged into the flow pipe 401 through the constant pressure detecting hole 411 and the reverse flow pressure detecting hole 413. The supply amount of the purge gas is adjusted by the flow rate adjusting units 425 and 426, respectively.

Depending on the type of the gas flowing through the through passage 403, dust or vapor may adhere to the differential pressure sensor 407 and may be exposed to the corrosive gas. In order to prevent this, the purge gas is always discharged from the positive pressure detection hole 411 and the backflow pressure detection hole 413. This prevents dust, steam, corrosive gas, and the like from entering the positive pressure detection hole 411 and the reverse flow pressure detection hole 413 to the positive pressure detection path 415 and the reverse flow pressure detection path 417. As a result, the durability and corrosion resistance of the differential pressure sensor 407 can be improved.

<Rubber expansion valve>

The valve body 11 of the rubber expansion valve 50 is required to have such a strength that the shape of the valve body 11 is not changed by the pressure of the control gas. For example, it can be made of a material such as stainless steel, iron, and hard plastic.

The rubber tube 13 of the rubber expansion valve 50 needs to be made of a material that can be expanded by the pressure of the control gas. For example, it can be composed of a material of silicone rubber or chloroprene rubber.

Such a rubber expansion valve 50 may be a commercially available product. For example, an air pressure holder (manufactured by Bridgestone Corporation, Air Gripper Part Number G050GCA or the like) for firmly fixing a component or the like by air pressure can be used.

In addition to the configuration of the rubber expansion valve 50, the following configuration may be considered as the rubber expansion valve. 6 is a cross-sectional view showing another example of the internal structure of the rubber expansion valve.

Both ends of the rubber tube 113 are hermetically connected to both ends of the valve body 111. Hence, an airtight cavity 112 is formed between the peripheral surface of the valve body 111 and the outer peripheral surface of the rubber tube 113. The flow path cross-sectional area of the flow path 115 can be freely changed by supplying / exhausting the control gas to / from the cavity 112 in the air supply / exhaust port 114.

&Lt; Means for measuring pressure and flow rate >

In the second embodiment, a differential pressure type flow meter is used as the pressure / flow rate measurement means. However, the present invention is not limited to this, and known pressure / flow rate measurement means such as a hot line type flow meter and a Kalman flow type flow meter can be used. Particularly preferred is a differential pressure type flow meter, and a differential pressure type flow meter of the type such as PIT, ANNEVA, orifice, or Venturi is employed. The differential pressure type flow meter preferably includes a purge mechanism for protecting the differential pressure sensor from the process gas as described above.

As the purge mechanism, it is preferable to send a purge gas to the differential pressure sensor unit and discharge it from the pressure detection hole. The flow rate of the purge gas is 10 to 1000 mL / min, preferably 100 to 500 mL / min, and particularly preferably 200 to 400 mL / min.

<Supply and exhaust controller>

As the air supply and exhaust controller, any one may be used as long as an arbitrary amount of the control gas can be supplied and held in the cavity 12. The pressure source or differential pressure detecting means may be integrated with the supply / discharge controller.

<Control gas, purge gas>

Any gas or purge gas for control may be used, but air or nitrogen gas is preferable from the viewpoint of economical efficiency.

100: exhaust pressure controller 70:
71: Through-flow passage 50: Rubber expansion valve
11, 111: valve body 12, 112: cavity
13, 113: rubber tube 14, 114:
15, 115: through-flow passage 21: housing
17, 31: duct connecting portion 19: pressure detecting hole
23: exhaust pipe connection port 25: purge pipe connection port
27: exhaust pipe 29: purge pipe
33: an air supply / discharge controller 35, 37: a supply pipe
300: Exhaust pressure / flow controller
317, 331: duct connection port 321: housing
323: supply / exhaust pipe connection port 327: supply / exhaust pipe
329: Purge pipe 333: Supply and exhaust controller
335, 337: supply pipe connection port 338: pressure measuring section
340: Pressure / flow measuring means (differential pressure type flow meter)
401: flow pipe 403:
405: pressure detecting pipe 407: differential pressure sensor
409: counterflow pit 411: positive pressure detection hole
412: Pit tube insertion hole 413: Reverse flow pressure detection hole
415: constant pressure detection path 417: reverse flow pressure detection path
419: Differential pressure sensor port (pressure high side)
421: Differential pressure sensor port (pressure low side)
423, 424: purge pipe connection part
425, 426: Flow regulator 500: Local exhaust
501: hood 503a, 503b: duct
505: fan 507: exhaust duct
800: Local exhaust system 801: Hood
803a, 803b: duct 805: fan
807: exhaust duct 900: damper
901: Housing 903: Valve body disk
904: valve shaft 905: actuator

Claims (4)

A housing having a through-flow passage and formed with a supply and exhaust pipe connection port;
A cylindrical body having both ends thereof opened so as to be fitted to the housing in such a manner that the through-passage and the shaft center are coincident with each other, the cylindrical body having a flow path coaxial with the through- ;
A cylindrical rubber tube arranged so that the opening direction of the flow path is the same as the opening direction of the body and the outer peripheral surfaces of the both ends of the tube are in contact with the cylindrical outer peripheral wall of the body and at least the rubber tube A valve having an airtight cavity to be closed;
Pressure measuring means for measuring a pressure of the through-flow passage;
Air supply and exhaust control means for expanding or contracting the rubber tube by supplying or exhausting the control gas through the air supply and exhaust pipe connection port and the air supply and exhaust port to the airtight cavity to change the flow path cross sectional area of the through flow path; And an exhaust pressure controller for controlling the exhaust pressure. The method according to claim 1,
Wherein the pressure measuring means uses a differential pressure sensor and is a pressure measuring means including a mechanism for purging the differential pressure sensor. A housing having a through-flow passage and formed with a supply and exhaust pipe connection port;
A cylindrical body having both ends thereof opened so as to be fitted to the housing in such a manner that the through-passage and the shaft center are coincident with each other, the cylindrical body having a flow path coaxial with the through- ;
A cylindrical rubber tube arranged so that the opening direction of the flow path is the same as the opening direction of the body and the outer peripheral surfaces of the both ends of the tube are in contact with the cylindrical outer peripheral wall of the body and at least the rubber tube A valve having an airtight cavity therein;
Flow rate measuring means for measuring a flow rate of the through-flow passage;
Air supply and exhaust control means for expanding or contracting the rubber tube by supplying or exhausting the control gas through the air supply and exhaust pipe connection port and the air supply and exhaust port to the airtight cavity to change the flow path cross sectional area of the through flow path; And the exhaust flow rate controller. The method of claim 3,
Wherein the flow rate measuring means uses a differential pressure sensor and is a flow rate measuring means having a mechanism for purging the differential pressure sensor.

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