TWI761563B - Valve with built-in heater - Google Patents

Abstract

Compared with the conventional valve with built-in heater, a valve with built-in heater can be provided, which can reduce the liquefaction and evaporation of gas passing through the valve.

A valve 1 with a built-in heater, comprising: a valve body 10 having an inlet flow path 11 for gas, an outlet flow path 12 and a valve seat 13 formed between the flow paths; a valve stem 20 at a lower end portion The valve body 21 abuts and separates from the valve seat 13; the cover member 31 is airtightly fixed to the upper part of the valve body 10 and penetrated by the valve stem 20; the bellows 39 is welded and fixed to the valve stem 20 and the cover The member 31 ; the cover member 31 has at least one heater insertion hole 34 , and at least one rod-shaped heater 36 is inserted into the heater insertion hole 34 .

Description

Valve with built-in heater

The present invention relates to a valve with a built-in heater.

Valves installed in the middle of the flow path connecting the vacuum chamber and the vacuum pump in the semiconductor manufacturing process have built-in heaters and are used under high temperature conditions exceeding 200°C.

The bellows valve for high temperature of the valve system described in Patent Document 1 is heated externally and a heater is provided in the valve body.

prior art literature Patent Literature

Patent Document 1 Japanese Patent No. 4923105

When the valve is used under high temperature conditions, the temperature varies depending on the gas flowing through the valve, resulting in liquefaction and vapor deposition of the gas inside the valve. A valve system with a built-in heater is used to solve such a problem. However, as shown in Patent Document 1, even in a valve with a heater built in the valve body, due to the non-uniformity of the internal temperature of the valve, there may be some problems. The liquefaction and vapor deposition of the gas occurs due to the conditions. At this time, since liquefaction and vapor deposition are mainly generated in the upper part of the bellows, it is desirable to prevent heat radiation from above the valve and to uniformly heat the entire inside of the valve.

The present invention (1) relates to a valve with a built-in heater, comprising: a valve body having an inlet flow path for gas, an outlet flow path, and a valve seat formed between the flow paths; and a valve stem having a lower end portion having a valve body that is in contact with and separated from the valve seat; a cover member, which is airtightly fixed to the upper part of the valve body and through which the valve stem passes; and a bellows that is welded and fixed to the valve stem and the cover member; The upper cover member has at least one heater insertion hole, and at least one rod-shaped heater is inserted into the heater insertion hole.

According to the present invention (1), by having this configuration, the temperature non-uniformity inside the valve can be corrected, and the liquefaction or vapor deposition of the gas passing through the valve in the upper part of the bellows can be prevented. Furthermore, the cover member is provided with a heater insertion hole, and since it is only necessary to insert the rod-shaped heater into the heater insertion hole, replacement of the heater is facilitated.

The present invention (2) is a valve provided with a heater as in the present invention (1), further comprising a heater arranged inside the valve stem.

In the present invention (2), in addition to the rod-shaped heater provided inside the cover member of the present invention (1), a heater is also provided inside the valve stem, so the temperature inside the heater is more uniform than that in the present invention (1). , which can improve the temperature non-uniformity inside the valve, and can further prevent the liquefaction or evaporation of the gas passing through the valve.

The present invention (3) is a valve with a built-in heater according to the present invention (1) or (2), wherein the heater insertion hole is provided on the side surface of the cover member.

According to the present invention (3), since the heater insertion hole is provided on the side surface of the cover member, when the heater must be pulled out and reinserted when replacing the heater or repairing the heater, etc., the valve does not need to be disassembled, and the operation is changed. easy.

The present invention (4) is a valve provided with a heater as in the present invention (3), wherein the heater insertion hole is a through hole.

According to the present invention (4), since the heater insertion hole is open at both ends, the heater can be inserted and withdrawn from either side of the opening, and it is possible to reduce the difficulty of entering and exiting the heater due to the installation environment of the valve. .

The present invention (5) is a valve provided with a heater according to the present invention (3), wherein the heater insertion holes are at least two holes arranged in parallel to sandwich the valve stem.

According to the present invention (5), since there are two or more heater insertion holes sandwiching the valve stem, if a predetermined number of heater insertion holes are drilled in advance, liquefaction and vapor deposition are more efficient than other types of gas. When a high gas flow is required in the valve, a heater can be easily added by inserting a heater into an unused heater insertion hole.

Compared with the conventional valve with built-in heater, according to the valve with built-in heater of the heater with heating bellows of the present invention, the liquefaction and vapor deposition of gas passing through the valve can be reduced, and the heater can be easily performed. exchange etc.

1‧‧‧Valve with built-in heater

10‧‧‧Valve body

11‧‧‧Inlet flow path

12‧‧‧Outlet flow path

13‧‧‧Valve seat

20‧‧‧Stem

21‧‧‧Valve body

31‧‧‧Cover member

34‧‧‧Heater insertion through hole

35‧‧‧1st Cartridge Heater

36‧‧‧2nd Cartridge Heater

39‧‧‧Bellows

FIG. 1 shows Embodiment 1 of the valve with built-in heater according to the present invention.

FIG. 2 is a plan view showing the cover member of the valve provided with the heater in Embodiment 1 when viewed from above.

3 is a perspective view showing the valve body and the periphery of the cover member of the valve with built-in heater in Example 2. FIG.

Hereinafter, preferred embodiments of the present invention will be exemplarily described in detail with reference to the accompanying drawings. However, as long as the relative arrangement of the components described in this embodiment is not specifically described, it is not intended to limit the scope of the present invention, but is merely an illustrative example. In addition, for the sake of convenience, the directions of members and the like are referred to as up, down, left and right according to the directions in the drawings, but these do not limit the scope of the present invention.

FIG. 1 shows Embodiment 1 of the valve with built-in heater according to the present invention, and this valve 1 is also called as vacuum switch valve with built-in heater.

The valve body 10 has an inlet flow path 11 and an outlet flow path 12 inside, and a valve seat 13 is formed therebetween. The fluid enters from the left and flows downward when the valve is open.

The opening and closing state of the valve is controlled by the movement of the valve body 21 which is in contact with the valve seat 13. When the valve seat 13 is closely connected with the valve body 21, the fluid flow system is cut off; when it is separated, the fluid system flows in from the left. valve, and will flow out below the valve.

The valve body 21 is formed at the lower end portion of the valve stem 20, and a heater housing space 22 is formed inside the valve stem 20, and a first cartridge heater 35 is inserted therein. In addition, any heater may be used as long as it can heat the inside of the valve stem, and a sheath heater or the like may also be used.

A cover member 31 through which the valve stem 20 penetrates is provided on the upper portion of the valve body 10 . The cover member 31 is welded to one end of a bellows 39, and the other end of the bellows 39 is welded to a bellows flange 30 provided on the valve stem, thereby preventing leakage of fluid to the outside.

The cover member 31 is provided with heater insertion through holes 34C and 34D into which the rod-shaped second cartridge heaters 36C and 36D are inserted. The heater insertion through hole 34 is the heater insertion through hole 34A, 34B perforated at two places on the left and right in the horizontal direction from the front to the back, and in the horizontal direction from the left to the right (shown by chain lines) The heater is inserted into the through hole 34C and 34D hidden behind the through hole 34C (the rear side in the drawing in FIG. 1 ). That is, the heater insertion through hole 34 is opened on the side surface of the cover member 31, and the cover member 31 is inserted in the horizontal direction.

1 shows a state where the second cartridge heater 36C is inserted into the front heater insertion through hole 34C from the right, and the second cartridge heater 36D is inserted into the rear heater insertion through hole 34D from the left, Also, a state in which the second cartridge heater 36 is not inserted into the heater insertion through hole 34A on the left and the heater insertion through hole 34B on the right is shown. In addition, a power cord 40a is connected to the inserted second cartridge heater 36 . In addition, the heater system inserted in the heater insertion through-hole 34 is not limited to a cartridge heater, and may be a rod-shaped one.

The actuator (symbol omitted) is supported by the cover 14 through a stay 51 , and the intervening rod 50 makes the valve stem 20 move in the up-down direction by electric force or electromagnetic force.

On the outer periphery of the valve body 10, a band heater 43a for an inlet flow path, a band heater 43b for an outlet flow path, and a band heater 43c for a valve body are wound. The inside of the valve main body 10 may also be heated from the outside of the valve main body 10 through these strip heaters.

Furthermore, depending on the type of the flowing gas, a heater may be added to prevent liquefaction and vapor deposition of the flowing gas. In the invention of the first embodiment, since the additional heater insertion through holes 34A and 34B are provided in the cover member 31 , design changes or rework for providing new heater insertion holes are not required.

Figure 2 is an arrow diagram viewed from line A-A. The cover member 31 is provided with four heater insertion through holes 34 (34A, 34B, 34C, 34D), two 34A, 34B in the longitudinal direction of the drawing, and two 34C, 34D in the horizontal direction. ; Two 34A, 34B perforated longitudinally, two 34C, 34D perforated in the transverse direction are located at different heights in the up and down direction of the valve 1 with the heater inside as shown in FIG. 1 . The cover member 31 is fixed to the valve body 10 by bolts 44 . In Example 1, since the second cartridge heaters 36A and 36B are not inserted, they are described by two-dot chain lines in FIG. 2 .

The cover 14 is mounted on the cover member 31 , the cover member 31 and the cover 14 are fixed by the bolts 42 , and the lower end of the support rod 51 is fixed on the upper surface of the cover 14 .

A thermocouple 45 is inserted into the right side surface of the cover member 31 to monitor the temperature in the vicinity of the second cartridge heater 36 .

FIG. 3 is a perspective view of the valve body 10 and the vicinity of the cover member 31, and shows a partial cross section. 1 and 2 are omitted.

1‧‧‧Valve with built-in heater

10‧‧‧Valve body

11‧‧‧Inlet flow path

12‧‧‧Outlet flow path

13‧‧‧Valve seat

14‧‧‧Cap

20‧‧‧Stem

21‧‧‧Valve body

22‧‧‧Heater storage space

30‧‧‧Bellows flange

31‧‧‧Cover member

34, 34A, 34B, 34C‧‧‧Heater insertion through hole

35‧‧‧1st Cartridge Heater

36C, 36D‧‧‧2nd Cartridge Heater

39‧‧‧Bellows

40a‧‧‧Power line

42, 44‧‧‧Bolts

43a, 43b, 43c‧‧‧Strip heater

50‧‧‧Rods

51‧‧‧Struts

Claims (4)

A valve with a built-in heater, comprising: a valve body having an inlet flow path for gas, an outlet flow path, and a valve seat formed between the flow paths; and a valve stem having a lower end portion abutting against the valve seat , a separate valve body; a cover member, which is airtightly fixed to the upper part of the valve body, and through which the valve stem passes; and a bellows, which is welded and fixed to the valve stem and the cover member; the cover member has at least One heater insertion hole, which is fastened to the side surface of the cover member and opened above the upper end of the bellows, the cover member is inserted in the horizontal direction, and at least one rod heater is inserted and arranged into the heater insertion hole. The valve with a heater according to claim 1, wherein a heater is provided inside the valve stem. A valve with a heater built-in according to claim 1 or 2, wherein the heater insertion hole is a through hole. A valve with heaters as claimed in claim 1 or 2, wherein the heater insertion holes are at least two holes arranged in parallel with the valve stem.

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