JPH07269741A - Bedewing preventing type valve - Google Patents

Abstract

PURPOSE:To prevent dew condensation from occurring in every member by forestalling a flow of cold being transmitted from a duct line via a valve stem from being transmitted to all the member being connected to this valve stem. CONSTITUTION:In this valve with a bonnet 6 othogonally attached to the outside of a tubular valve case 2, and a valve stem 7 being inserted into this bonnet 6 free of rotation and driving a valve element 8, an electric heater 41 is installed in this bonnet 6. A flow of cold out of a fluid flowing a passage in the valve case 2 is heated in a part of this bonnet 6, so that various apparatuses and members being attached to the circumference of a top flange on the bonnet 6 will in no case be dewed at all.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensation prevention type valve for preventing condensation.

[0002]

2. Description of the Related Art For example, a ball valve used for water pipes,
In an on-off valve such as a butterfly valve, cold heat from a fluid flowing in a pipe is transmitted to various attached devices via a valve rod. In the case of a motorized valve, the drive system connected to it,
It is transmitted to the power supply operation system and control system, and the surface of each part condenses due to contact with the ambient air, which causes insulation deterioration,
Failures may occur in various electrical devices. The situation is the same for a manual valve as well, and the cold heat that has passed through the valve rod is transmitted to each member, causing dew condensation on the surface of the member that comes into contact with the outside air. In such cases,
When the surface of the pipe is heat-insulated by a heat insulating material, condensed water accumulates, which causes deterioration of heat insulating performance and dripping of condensed water.

In view of such circumstances, the applicant previously disclosed in Japanese Utility Model Laid-Open No. 5-67886, as a countermeasure against a manual valve, shortens the valve rod and stores it in a heat insulating layer to form a heat insulating structure. The structure of the valve that shuts off the outside air by a cap having the same high airtightness is disclosed.

[0004]

According to the above-mentioned prior art, since the valve rod to which the cold heat from the pipe is transmitted does not come into contact with the ambient outside air, dew condensation does not occur. However, in the case where, for example, a motor-operated valve, the valve rod cannot be shortened because of its structure, and the bonnet that rotatably accommodates and supports the valve rod protrudes from the heat insulating material that surrounds the pipe material, The protruding part comes into contact with the ambient air,
Condensation is expected. Even if the valve rod can be shortened, it is impossible to completely cover the drive system, power supply operation system, and control system devices mentioned above with a cap, and condensation will still occur. If this occurs, these devices may be affected by dew condensation water.

The present invention has been made in view of the above points, and solves the above-mentioned problem by preventing the cold heat transmitted from the pipe line through the valve rod from being transmitted to various members connected to the valve rod. It is a thing.

[0006]

In order to achieve the above-mentioned object, according to claim 1, a bonnet mounted orthogonally to the outside of a tubular valve case and rotatable about the axis of this bonnet. In a valve having a valve rod mounted in the bonnet and a valve body fixed to the valve rod and capable of blocking the flow path in the valve case by rotation of the valve rod, a heating heater is provided in the bonnet. An anti-condensation type valve is provided.

According to a second aspect of the present invention, a bonnet mounted orthogonally to the outside of the tubular valve case, a valve rod mounted in the bonnet so as to be rotatable around the axis of the bonnet, and A valve fixed to the valve stem, having a valve body capable of blocking the flow passage in the valve case by rotation of the valve stem, and having a configuration in which the outer periphery of the valve case is covered with a heat insulating material, the outside of the heat insulating material, That is, a dew condensation preventing valve is provided, which is characterized in that a heater is provided in a bonnet portion projecting to the outside air side.

Further, as described in claim 3, it is preferable that the heater in each of the dew condensation preventing valves is constructed so that the valve rod and its vicinity can be heated up to 40 ° C to 45 ° C.

Furthermore, it is more preferable that the heating element of the heater is constructed by blending crystalline thermoplastic resin with carbon black as described in claim 4. In such a case, as described in claim 5, the heating element is laminated with the thermosetting resin plate to form the entire heater into a flexible and substantially flat plate shape, or as described in claim 6. Alternatively, it may be formed into a substantially ring shape.

[0010]

In the first aspect of the invention, since the bonnet portion is provided with the heater, the bonnet, its periphery and the valve rod inside the bonnet are also heated. Therefore, by heating these above the dew condensation temperature, even if the cold heat of the pipe is transmitted through the valve rod, the temperature is raised and the cold heat is directly transmitted to the various members connected to the valve rod at the temperature. Can be prevented. Therefore, even if various members connected to the valve rod come into contact with the ambient outside air, dew condensation does not occur. Of course, condensation can be prevented regardless of the length of the valve rod.

In the second aspect, since the heater is provided in the bonnet portion protruding outward from the heat insulating material,
It is possible to prevent cold heat from being transmitted to various members connected to the valve rod in the bonnet as well as the bonnet portion, as in the first aspect. Therefore, even if these various members come into contact with the ambient outside air, dew condensation does not occur, and naturally, dew condensation water does not accumulate on the heat insulating material.

According to the third aspect of the present invention, since the valve rod and the vicinity thereof are heated to 40 ° C. to 45 ° C., the occurrence of dew condensation is prevented, and at the same time, various equipment, heat insulating materials, etc. in the vicinity are heated. There is no risk of trouble.

According to the fourth aspect of the present invention, the heating element of the heating heater has a structure in which carbon black is mixed with crystalline thermoplastic resin and crosslinked, so that the conductivity decreases as the temperature rises, The amount of heat generated is self-controlled. Therefore, overheat can be prevented without providing a temperature sensor or an appropriate control device.

As described in claim 5, the heating element is laminated with the thermosetting resin plate to form the entire heater into a flexible and substantially flat plate shape, or claim 6.
As described in, when molded into a substantially ring shape,
It is easy to install around the bonnet, etc., and does not interfere with the functions of various members and equipment connected to the valve stem.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross section of a dew condensation preventing butterfly valve 1 according to this embodiment, which is used in this butterfly valve 1. The valve case 2 is constructed by cutting a pipe material such as a commercially available steel pipe or scrap pipe into necessary lengths, and has a flange portion 3 having a trumpet-like opening at one end thereof and an outer end at the other end thereof. A ball seat 5 having an annular recess 4 is formed. The flange portion 3 can be easily formed by subjecting one end portion of the valve case 2 to pipe expansion processing using, for example, a Belling processing method.

At the center of the valve case 2, a bonnet 6 made of a tubular body made of a commercially available steel pipe, scrap pipe, or the like is attached so as to be orthogonal to the valve case 2. In the illustrated example, the bonnet 6 is attached by fixing the lower end of the bonnet 6 to the outer periphery of the valve case 2 by welding. In fixing the bonnet 6 in this case, first, a circular flat portion 2a is formed at a predetermined position of the valve case 2, a through hole for a valve rod 7 described later is formed in this flat portion, and then the lower end surface of the bonnet 6 is fixed. As long as the bonnet 6 is fixed to the flat portion 2a, the lower end surface of the bonnet 6 does not have to be formed into a so-called "saddle shape" in accordance with the outer shape of the valve case 2.

A bearing 10 is inserted into the inside of the bonnet 6 via an O-ring 9 above the bonnet 6, and as shown by X in FIG. 10 is fixed in the hood 6. Further, a top flange 11 for an opening degree holding mechanism (not shown) for holding the opening degree of the valve body 8 is provided at the upper end portion of the bonnet 6, and the valve rod 7
The upper end portion of the is protruding upward from the top flange 11. The lower end of the valve rod 7 is inserted into the bonnet 6 and rotatably penetrates through the insertion hole to project into the valve case 2.
A disk-shaped valve body 8 having a perfect outer shape is fixed.

On the other hand, a cylindrical bottom case 21 is also attached to the outside of the valve case 2 on the side facing the bonnet 6 by welding as in the case of the bonnet 6, and the O-ring is placed in the bottom case 21. The lower valve stem 23 is inserted through the valve 22, and the upper end of the lower valve stem 23 is inserted into the valve case 2.
Is inserted so as to be rotatable about its axis through the pipe wall of the lower valve rod 23, and the lower portion of the valve body 8 is supported by the upper end portion of the lower valve rod 23.
It is fixed. Finally, a cap-shaped bottom cover 24 is screwed to the bottom case 21.

Even when the bottom case 21 is fixed, a circular flat portion 2b is first formed at a predetermined position of the valve case 2 as in the case of mounting the bonnet 6 and the lower valve rod 23 is formed on the flat portion 2b. If a hole for insertion is formed and then the upper end of the bottom case 21 is fixed to the flat portion 2b, the upper end surface of the bottom case 21 is adjusted to the outer shape of the valve case 2, so-called "saddle". It does not have to be formed into a “shape” shape, and it is easy to manufacture and can achieve strong fixation.

In the state shown in FIG. 1, the valve body 8 is located at a position where it blocks the flow path of the valve case 2, and when the valve rod 6 is rotated 90 ° from this state, the valve body 8 is closed.
The inner flow path is opened to the maximum. When the valve body 8 is in the shut-off position as described above, it is necessary to completely seal the outer peripheral edge of the valve body 8 and the inner peripheral surface of the valve case 2. Therefore, in the present embodiment, a rubber is used as the sealing material. Using a seat ring 31 made of
The configuration is such that the tubular seat ring retainers 32 and 33 are fixed to the inner surface of the valve case 2. When fixing the seat ring retainers 32 and 33 to the inner surface of the valve case 2, the seat ring retainers 32 and 33 are fitted to the annular grooves 34 and 35 formed on the inner surface of the valve case 2.
Is made by bulging by bulging.

Thus, in this embodiment, the heater 41 is provided on the outer periphery of the bonnet 6 having the above-mentioned structure. As shown in FIG. 2, the heater 41 in the present embodiment has a conductor portion 42 and a conductor portion 43, which are arranged in parallel at a distance from each other, integrated by a heating element 44 as shown in FIG. It has a structure in which it is covered with a resinous jacket 45 from the outside, and has flexibility as a whole.

The heating element 44 is a crystalline thermoplastic resin compound to which conductivity is imparted by blending carbon black, for example, and a crosslinked one is used. With this configuration, when the conductors 42 and 43 are energized, the heating element 44 generates heat by so-called resistance heating, but when it reaches a certain temperature, that is, near the crystal melting point of the material of the heating element, the conductivity sharply decreases. The amount of heat generated is self-controlled and excessive heat is prevented.

The butterfly valve 1 according to the present embodiment has the above-mentioned structure, and when the conductor portions 42 and 43 of the heater 41 are energized by an AC power supply (not shown) provided separately,
The heating element 44 generates heat to heat the bonnet 6. Therefore, the cold heat of the low temperature fluid flowing through the flow path in the valve case 2 is going to be transmitted to the valve opening holding mechanism or the electronic circuit device attached to the top flange 11 via the valve body 8 and the valve rod 7. However, since the bonnet 6 is heated as described above, even if the bonnet 6 comes into contact with ambient air, the surface will not be condensed. Therefore, the valve opening holding mechanism and the electronic circuit device are not contaminated by the dew condensation water, and the desired function can be permanently exhibited.

The heating element 44 of the heater 41 is
Since the calorific value is self-suppressed, by setting the suppression set temperature appropriately, for example, the maximum temperature due to heating is set to 40
It is also easy to suppress the valve opening degree holding mechanism and the electronic circuit device by suppressing the temperature to about 45 ° C. Further, the heating heater 41 can be attached to the bonnet 6 simply by winding it around the outer periphery of the bonnet 6, which allows extremely simple and quick construction.

As described above, since the butterfly valve 1 according to the embodiment has the valve case 2 formed with the flange 3 and the ball seat 5 at both ends, as shown in FIG. Flexible joint connections are possible with the other tubes 51, 52 shown in phantom. That is, at the connection end of the other tubular body 51,
For example, a collar portion 53 of the valve case 2 is formed in a tapered shape similar to that of the collar portion 3, and an O-ring 54 is attached to the recess portion 4 of the ball seat portion 5, and a collar portion of another tubular body 51. 5
3 and the ball seat portion 5 are opposed to each other, and a cover housing 55 formed of, for example, two half-split halves is covered from the outside of the flange portion 53 and the ball seat portion 5.
The joint connection is completed simply by tightening and fixing.

The watertightness of the joint portion thus constructed is ensured by the O-ring 54 which is interposed between the collar portion 53 and the ball seat portion 5 and pressed by both, and further the collar portion. The joint portion has flexibility until the edge portion of 3 abuts on the inner peripheral wall of the housing 55. Therefore, it is possible to perform joint connection that is extremely practical in addition to having good workability on site. Further, such a joint connection can be performed without any trouble even when the pipe diameter is different from that of the valve case 2 as in the pipe body 52 shown by the two-dot chain line in FIG.

Next, the second embodiment will be described. FIG. 3 shows an axial front view of an electric butterfly valve 61 according to the second embodiment, and a valve capable of blocking a flow passage in a valve case 62. The valve rod for rotating the body 63 is a bonnet 64 fixed to the outside of the valve case 62, as in the above-described embodiment.
It is rotatably housed inside. A motor for rotating the valve rod, gears, and an electronic circuit for control are housed in a box 65 provided at the upper end of the hood 64. A heating cable 66 is wound around the bonnet 64 around the box 65 as a heater. The heating cable 66 has an outer periphery coated with an insulating material and is configured to generate heat when energized. The energization is performed by a power supply lead 67 led out from the box 65.
It is supposed to be done through.

According to the second embodiment, the cold heat of the low temperature fluid flowing in the valve case 62 is directly transmitted to the various devices, members and circuits in the box 65 via the valve rod in the bonnet 64. However, since it is heated by the heating cable 66 on the way, no condensation occurs on the outside or inside of the box 65. Therefore, even if the ambient air is exposed, various devices, members and circuits housed in the box 65 will not be damaged by dew condensation water.

In each of the above-mentioned embodiments, the heater is substantially belt-shaped or cable-shaped, but the heaters may be formed as shown in FIGS. 4 and 5, for example. Figure 4
Shows a plane of a heater 73 having a structure in which a heating element 71 is laminated with a plate 72 made of a substantially rectangular thermosetting resin, and has a flexible and substantially film structure as a whole. The heating element 71 may be of the type used in the above-described embodiment and of which the amount of heat generation is suppressed by itself.

The heater 81 shown in FIG. 5 also has basically the same structure as the heater 73,
The heating element 82 is laminated with a plate 83 made of a thermosetting resin. A circular hole 84 is formed in the center of the plate 83, and the heating element 82 also has this hole 84.
It has become a pattern to avoid. 8 in the figure
Reference numeral 5 is a terminal portion, and 86 is a lead wire for supplying power to the heating element 82 through the terminal portion 85. These heaters 73, which are shaped like a flexible plate,
If you use 81, you can attach the valve to the bonnet part,
It can be performed more simply and quickly than in each of the above embodiments.

For example, in the example shown in FIG. 6, the valve case 9
1 shows a state in which the heater 73 is attached to the outer periphery of the bonnet 92 provided on the outer side of 1 and below the top flange 93 with, for example, an adhesive material or an adhesive tape. Further, reference numeral 94 is a heat insulating layer made of a heat insulating material. According to this example, the outer periphery of the valve case 91 is not condensed by the heat insulation layer 94, and the periphery of the bonnet 92 is also heated by the heater so that it is not condensed. Since the valve rod inserted in the bonnet 92 is also heated, the cold heat of the fluid flowing through the flow path in the valve case 91 rises at the valve rod portion, so various devices provided on the top flange 93. , There is no condensation on the parts. Moreover, since the heater 73 need only be attached around the hood 92 in this manner, it can be attached very easily and quickly.

In the example shown in FIG. 7, the outer periphery of the side surface of the operating member 98 connected to the valve rod is provided on the top flange 97 on the upper portion of the bonnet 96 provided outside the valve case 95. In the figure, a state is shown in which the heater 73 is attached with an adhesive material or an adhesive tape. Reference numeral 99 is a heat insulating layer made of a heat insulating material. Also in this example, even if various devices and members mounted around the operation member 98 come into contact with the ambient atmosphere, no condensation occurs,
Further, there is no possibility that condensed water will accumulate in the heat retaining layer 99. Of course, like the example of FIG. 6, attachment of the heater 73 is extremely easy.

[0033]

According to the first aspect of the present invention, regardless of the length of the valve rod, even if various members connected to the valve rod come into contact with the ambient air, dew condensation does not occur.

According to the second aspect, even in the valve provided with the heat insulating material, dew does not occur even when various members connected to the valve rod in the bonnet come into contact with the ambient outside air,
In addition, dew condensation water does not accumulate on the heat insulating material.

According to claim 3, the valve rod and its vicinity are 4
Since it is heated to 0 ° C to 45 ° C, the occurrence of dew condensation is prevented, and there is no possibility of causing troubles in the vicinity of various devices, heat insulating materials, etc. due to the temperature rise.

According to the fourth aspect, even if a temperature sensor or an appropriate control device is not provided, the amount of heat generated is automatically suppressed when the temperature rises, and overheating can be prevented.

According to the fifth and sixth aspects, it is easy to mount around the bonnet and the like, and the handling is easy, and the functions of various members and devices connected to the valve stem are not hindered.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a butterfly valve according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a heater used in the butterfly valve of FIG.

FIG. 3 is an axial front view of an electric butterfly valve according to another embodiment of the present invention.

FIG. 4 is a plan view showing another example of the heater.

FIG. 5 is a plan view showing another example of the heater.

FIG. 6 is a side view of essential parts showing a state in which the heater shown in FIG. 4 is mounted around a bonnet.

FIG. 7 is a side view showing the manner in which the heater of FIG. 4 is mounted around the operation member on the top flange.

[Explanation of symbols]

 1 Butterfly Valve 2 Valve Case 6 Bonnet 7 Valve Rod 8 Valve Body 11 Top Flange 41 Heater 42, 43 Conductor 44 Heater

Claims (6)

[Claims] 1. A bonnet mounted orthogonally to the outside of a tubular valve case, a valve rod mounted in the bonnet so as to be rotatable about the axis of the bonnet, and fixed to the valve rod, A valve having a valve body capable of blocking a flow path in a valve case by rotation of a valve rod, wherein a heating heater is provided in the bonnet, wherein a dew condensation preventing valve is provided. 2. A bonnet mounted orthogonally to the outside of a tubular valve case, a valve rod mounted in the bonnet so as to be rotatable about the axis of the bonnet, and fixed to the valve rod, A valve having a valve body capable of blocking a flow path in the valve case by rotation of a valve rod, and having a configuration in which an outer circumference of the valve case is covered with a heat insulating material, in a bonnet portion protruding outward from the heat insulating material. A dew condensation prevention valve, characterized by having a heater. 3. The heater comprises a valve rod and a portion near the valve rod.
The anti-condensation type valve according to claim 1 or 2, wherein the valve is configured to be heated to ° C to 45 ° C. 4. The anti-condensation valve according to claim 1, 2 or 3, wherein the heating element of the heater comprises a crystalline thermoplastic resin mixed with carbon black. 5. The dew condensation preventing valve according to claim 4, wherein the heating element is laminated with a thermosetting resin plate, and the entire heater is formed into a flexible and substantially flat plate shape. 6. The dew condensation preventing valve according to claim 4, wherein the heating element is laminated with a thermosetting resin plate, and the entire heater is formed into a substantially ring shape.