JP6830818B2 - Branch pipe - Google Patents

Description

The technique disclosed herein relates to a branch pipe.

Conventionally, a branch pipe has been used in various devices for circulating a fluid. Patent Document 1 discloses a steam heating device. For example, also in this steam heating device, a branch pipe is used between the circulation pump and the ejector. Specifically, in the branch pipe, the second flow path from the circulation pump to the nozzle of the ejector is branched from the second flow path to the condenser.

Japanese Unexamined Patent Publication No. 2013-204877

By the way, in such a branch pipe, a vortex may be generated at the branch portion branching from the first flow path to the second flow path. As a result, flow turbulence may occur in the portion of the first flow path on the downstream side of the branch portion. When the generated vortex is large, the flow turbulence is also large, which may adversely affect the equipment on the downstream side of the first flow path.

The technique disclosed herein was made in view of this point, and the purpose thereof is to reduce the generation of a large vortex at the branch portion of the branch pipe, which has an adverse effect on the downstream side. is there.

The technique disclosed herein is a first flow path extending along a predetermined axis, a second flow path branching from the first flow path, and branching from the first flow path to the second flow path. The target is a branch pipe provided with a branch portion. This branch pipe has a plurality of inflow openings through which the fluid flows from the first flow path to the second flow path.

According to the branch pipe, it is possible to reduce the generation of a large vortex at the branch portion that adversely affects the downstream side.

FIG. 1 is a piping system diagram showing a schematic configuration of a steam heating system. FIG. 2 is a cross-sectional view of the branch pipe in line II-II of FIG. FIG. 3 is a cross-sectional view of the branch pipe in line III-III of FIG. FIG. 4 is a perspective view in which the branch pipe is partially cut. FIG. 5 is a cross-sectional view corresponding to FIG. 3 of the branch pipe 205 according to the modified example.

Hereinafter, exemplary embodiments will be described in detail with reference to the drawings. FIG. 1 is a piping system diagram showing a schematic configuration of the steam heating system 100.

The steam heating system 100 includes a reaction vessel 1 to which steam is supplied and a vacuum generator 2 for sucking drain from the reaction vessel 1. The steam heating system 100 heats an object inside the reaction vessel 1 with steam.

The reaction tank 1 has a tank main body 11 in which an object is housed, and a jacket portion 12 formed over substantially the entire circumference of the tank main body 11. A steam supply tube 13 is connected to the jacket portion 12. The steam supply pipe 13 is provided with a supply valve 14 which is an on-off valve. The steam generated by the steam generating section (not shown) is supplied to the jacket section 12 via the steam supply pipe 13. In the reaction tank 1, the steam supplied to the jacket portion 12 indirectly exchanges heat with the object inside the tank body 11 to condense (liquefy) the object, and the object is heated. That is, the object is heated by the latent heat of condensation of steam.

The vacuum generator 2 includes a drain tank 21 for storing drain, a pump 22 for pumping drain in the drain tank 21, an ejector 3 for sucking drain, and a pipe 4 for connecting the drain tank 21, the pump 22, and the ejector 3. And have. The jacket portion 12 of the reaction tank 1 and the ejector 3 are connected by a discharge pipe 15. The vacuum generator 2 generates a suction force in the ejector 3 by circulating the drain stored in the drain tank 21 via the pump 22 and the ejector 3, and sucks the drain from the reaction tank 1. A drain supply tube 23 for supplying drain to the drain tank 21 is connected to the drain tank 21. The drain supply tube 23 is provided with a supply valve 24 which is an on-off valve.

The ejector 3 has a nozzle 31 that ejects the first fluid, a suction chamber 32 that sucks the second fluid by the negative pressure generated by the ejection of the first fluid from the nozzle 31, and a first fluid ejected from the nozzle 31 and suction. It has a diffuser 33 that discharges the second fluid sucked into the chamber 32 while boosting the pressure.

At least the spout of the nozzle 31 is housed in the suction chamber 32. The suction chamber 32 also accommodates at least the upstream end of the diffuser 33. The flow path cross-sectional area of the diffuser 33 expands from upstream to downstream. Therefore, the fluid passing through the diffuser 33 decelerates and boosts as it flows through the diffuser 33 from upstream to downstream. Further, the downstream end of the discharge pipe 15 is connected to the suction chamber 32.

In the suction chamber 32, the second fluid is sucked from the discharge pipe 15 by the negative pressure (pressure drop) generated by ejecting the first fluid from the nozzle 31. That is, in the suction chamber 32, a suction force for sucking the second fluid is generated by the negative pressure generated by the jet pump effect of the first fluid. The drain generated in the jacket portion 12 of the reaction tank 1 is thus sucked into the ejector 3 and collected in the drain tank 21.

The pipe 4 includes a branch pipe 5 that branches a part of the drain supplied from the pump 22 to the ejector 3. The branch pipe 5 is connected to the pump 22 via the first pipe 41, and is connected to the nozzle 31 of the ejector 3 via the second pipe 42. Further, a drain branch pipe 16 is connected to the branch pipe 5. The drain branch pipe 16 is connected to a steam supply pipe 13 (specifically, a portion on the downstream side of the supply valve 14). The drain branch pipe 16 is provided with a control valve 17 for adjusting the flow rate of the drain supplied to the steam supply pipe 13. The drain supplied from the drain branch pipe 16 to the steam supply pipe 13 functions as deheated water. That is, the superheated steam flowing through the steam supply pipe 13 is cooled by the drain supplied from the drain branch pipe 16 to become saturated steam. At this time, the drain flow rate supplied from the drain branch pipe 16 to the steam supply pipe 13 is adjusted by the adjusting valve 17 so that the superheated steam becomes saturated steam, preferably saturated dry steam.

Further, a discharge pipe 18 for discharging excess drain is connected to the drain branch pipe 16. The discharge pipe 18 is provided with a control valve 19 for adjusting the flow rate of the drain discharged from the discharge pipe 18. When there is a large amount of drain stored in the drain tank 21, excess drain is discharged from the discharge pipe 18.

In this way, the branch pipe 5 branches a part of the drain supplied from the pump 22 to the drain branch pipe 16, while the remaining drain is circulated to the ejector 3.

Hereinafter, the branch pipe 5 will be described in more detail. FIG. 2 is a cross-sectional view of the branch pipe 5 on the line II-II of FIG. FIG. 3 is a cross-sectional view of the branch pipe 5 in line III-III of FIG. FIG. 4 is a perspective view in which the branch pipe 5 is partially cut.

The branch pipe 5 includes a first flow path 51a extending along a linear axis X and a second flow path 52a branching from the first flow path 51a. That is, the branch pipe 5 is a T-shaped pipe having a first pipe 51 extending linearly and a second pipe 52 branching from the first pipe 51. The first pipe 51 is formed in a substantially cylindrical shape. Flange 51b and 51c are provided at the upstream end and the downstream end of the first pipe 51, respectively. The first pipe 41 is connected to the flange 51b on the upstream side. The second pipe 42 is connected to the flange 51c on the downstream side. A first flow path 51a is formed inside the first pipe 51. A second flow path 52a is formed inside the second pipe 52. The second flow path 52a extends vertically from the first flow path 51a along the linear axis Y. The branch portion 53 that branches from the first flow path 51a to the second flow path 52a (that is, the portion of the second flow path 52a that faces the first flow path 51a) 53 is formed by three inflow openings 53a.

Specifically, the second pipe 52 has a fixed pipe 54 connected to the first pipe 51, an attachment 55 inserted into the fixed pipe 54, and a connecting portion 56 connected to the fixed pipe 54 by a nut 57. ing.

The fixed pipe 54 is fixed to the first pipe 51 by welding or the like. The fixed pipe 54 is open to the first flow path 51a. That is, the internal space of the fixed pipe 54 communicates with the first flow path 51a. The inner diameter of the downstream end of the fixed pipe 54 has been increased, and a step 54a is formed at the downstream end of the fixed pipe 54. A male screw 54b is formed on the outer peripheral surface of the fixed pipe 54. A nut 57 is fastened to the male screw 54b.

The attachment 55 is formed in a columnar shape and is loosely fitted into the fixed pipe 54. A flange 55a is provided at the downstream end of the attachment 55. The flange 55a of the attachment 55 loosely fitted to the fixed pipe 54 is locked to the step 54a. The upstream end surface of the attachment 55 is curved so as to be flush with the inner peripheral surface of the first pipe 51. The attachment 55 is formed through three inflow openings 53a extending along the axis Y.

The connecting portion 56 is formed in a cylindrical shape. A flange 56a is provided at the upstream end of the connecting portion 56. A male screw 56b is formed on the outer peripheral surface of the connecting portion 56. The connecting portion 56 is attached to the fixed pipe 54 by the nut 57. At this time, the flange 56a is pressed toward the fixed pipe 54 by the nut 57. Since the upstream end of the connecting portion 56 is in contact with the flange 55a of the attachment 55, the flange 55a is pressed against the step 54a of the fixed pipe 54 by the pressing force of the nut 57. The discharge pipe 15 is connected to the connecting portion 56 via the male screw 56b.

In the branch pipe 5 configured in this way, since the upstream end surface of the attachment 55 is formed flush with the flow path wall of the first flow path 51a, it is substantially the flow path of the first flow path 51a. Three inflow openings 53a are opened in the wall. When an opening is formed in the flow path wall of the first flow path 51a, a vortex is generated at the opening. The larger the opening, the larger the vortex. When a vortex is generated at the branch portion 53 to the second flow path 52a, the flow is disturbed on the downstream side of the branch portion 53 in the first flow path 51a. As a result, the performance of the device on the downstream side of the first flow path 51a may be adversely affected. For example, in the steam heating system 100, the nozzle 31 of the ejector 3 is connected to the downstream end of the first flow path 51a via the second pipe 42. When a large vortex is generated in the first flow path 51a, the flow of drain flowing into the nozzle 31 is disturbed, and the nozzle 31 cannot exhibit the desired performance. Therefore, it is necessary to take measures such as lengthening the second pipe 42, which increases restrictions on the system design.

On the other hand, in the branch pipe 5, the opening of the second flow path 52a in the flow path wall of the first flow path 51a is formed by a plurality of inflow openings 53a. The cross-sectional area of the opening of the second flow path 52a is determined by the required flow rate of the drain flowing into the drain branch pipe 16. By forming the openings of the second flow path 52a with a plurality of inflow openings 53a, the cross-sectional area required for each inflow opening 53a can be reduced in order to realize the required flow rate of the drain. The adverse effect on the flow on the downstream side of the first flow path 51a is smaller when a plurality of small openings are formed than when one large opening is formed on the flow path wall of the first flow path 51a. That is, the place where the vortex is generated increases as the number of openings increases, but the vortex is small because the cross-sectional area of the openings is small. The smaller the generated vortex, the smaller the adverse effect on the flow on the downstream side of the first flow path 51a. In this way, by reducing the generation of large eddies in the branch portion 53, it is possible to reduce the adverse effect on the equipment on the downstream side of the first flow path 51a. Further, since it is not necessary to take measures such as lengthening the second pipe 42, restrictions on the system design can be reduced.

Further, as shown in FIGS. 3 and 4, the plurality of inflow openings 53a are arranged so as to be offset from each other in the direction of the axis X of the first flow path 51a. That is, the plurality of inflow openings 53a are not arranged in a straight line in the direction of the axis X. As a result, the places where vortices are generated can be dispersed, so that the generation of large vortices at the branch portion 53 can be further reduced.

Further, the plurality of inflow openings 53a are arranged so as to be line-symmetric with respect to a straight line extending parallel to the axis X. As a result, the places where the vortices are generated can be dispersed in the circumferential direction of the axis X in a well-balanced manner.

As described above, the branch pipe 5 includes a first flow path 51a extending along a predetermined axis X and a second flow path 52a branching from the first flow path 51a, and the first flow path 51a to the first flow path 52a. The branch portion 53 that branches into the two flow paths 52a is formed by a plurality of inflow openings 53a through which the fluid flows from the first flow path 51a into the second flow path 52a.

According to this configuration, the branch portion 53 from the first flow path 51a to the second flow path 52a is formed by the plurality of inflow openings 53a, so that the branch portion 53 can secure the flow rate of the second flow path 52a. It is possible to reduce the generation of large vortices. As a result, it is possible to reduce the adverse effect on the equipment on the downstream side of the first flow path 51a.

Further, the plurality of inflow openings 53a are arranged so as to be offset from each other in the direction of the axis X.

According to this configuration, the generation of large vortices at the branch portion 53 can be further reduced by dispersing the locations where vortices are generated.

Further, the plurality of inflow openings 53a are arranged so as to be line-symmetric with respect to a straight line extending parallel to the axis X.

According to this configuration, the locations where vortices are generated can be symmetrically dispersed, and the generation of large vortices at the branch portion 53 can be stably reduced.

Further, the first flow path 51a is connected to the nozzle 31 of the ejector 3.

According to this configuration, it is possible to reduce the deterioration of the performance of the nozzle 31 due to the generation of the vortex at the branch portion 53.

<< Other Embodiments >>
As described above, the above-described embodiment has been described as an example of the technology disclosed in the present application. However, the technique in the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, etc. are made as appropriate. It is also possible to combine the components described in the above-described embodiment into a new embodiment. In addition, among the components described in the attached drawings and the detailed description, not only the components essential for solving the problem but also the components not essential for solving the problem in order to illustrate the above-mentioned technology. Can also be included. Therefore, the fact that these non-essential components are described in the accompanying drawings or detailed description should not immediately determine that those non-essential components are essential.

The embodiment may have the following configuration.

For example, the branch pipe 5 can be applied not only to the steam heating system 1 but also to other systems and devices.

Further, the ejector 3 to which the branch pipe 5 is connected circulates water, but is not limited to the liquid ejector. That is, the ejector 3 may circulate a gas such as steam.

Further, the branch pipe 5 may be connected to the upstream side of the device other than the ejector 3. For example, the branch pipe 5 may be connected to the upstream side of the flow meter. When it is necessary to branch the flow path on the upstream side of the flow meter, the adverse effect on the flow meter can be reduced while ensuring the flow rate to the branch side by applying the branch pipe 5. In particular, when the flow path is branched on the upstream side of the vortex flowmeter, it is required to secure a sufficient distance from the branch to the vortex flowmeter in order to reduce the adverse effect of the vortex generated at the branch. On the other hand, by adopting the branch pipe 5, the generation of a large vortex at the branch portion 53 is reduced, so that the restriction on the distance from the branch portion 53 to the vortex type flowmeter can be relaxed or eliminated.

The configuration of the branch pipe 5 is not limited to the above-mentioned configuration. The number of inflow openings 53a is not limited to three. The number of inflow openings 53a may be two or four or more. Further, the arrangement of the inflow opening 53a is not limited to the above-mentioned arrangement. A plurality of inflow openings 53a may be arranged in the direction of the axis X.

Further, the inflow opening 53a does not have to be circular. The inflow opening 53a may have a flat shape in which the dimension in the direction of the axis X is shorter than the dimension in the direction orthogonal to the axis. That is, the cross-sectional shape of the inflow opening 53a may be a horizontally long flat shape when the direction of the axis X is the vertical direction. For example, FIG. 5 is a cross-sectional view of the branch pipe 205 according to the modified example, which corresponds to FIG. The cross-sectional shape of the inflow opening 253a (that is, the shape of the inflow opening 253a when viewed in the direction of the axis Y of the second flow path 52a) has a substantially elliptical shape in which the minor axis extends in the direction of the axis X. ing. That is, the dimension of the inflow opening 53a in the fluid flow direction of the first flow path 51a is shortened. The shorter the dimension in the flow direction, the smaller the size of the generated vortex can be reduced.

Further, the second pipe 42 of the branch pipe 5 is formed of a fixed pipe 54, an attachment 55, a connecting portion 56 and a nut 57 from the viewpoint of ease of making, but is not limited thereto. As long as a plurality of inflow openings 53a can be formed at the upstream end of the second pipe 42, the second pipe 42 can have an arbitrary configuration. Further, the first flow path 51a does not have to extend linearly. That is, the axis X may extend while being curved instead of being linear.

As described above, the techniques disclosed herein are useful for branch pipes.

100 Steam heating system 3 Ejector 31 Nozzle 5 Branch pipe 51a First flow path 52a Second flow path 53 Branch part 53a Inflow opening X Axis center

Claims (2)

A first flow path extending along a predetermined axis and
The second flow path branching from the first flow path and
A branch pipe provided with a branch portion that branches from the first flow path to the second flow path.
The branch portion has a plurality of inflow openings through which the fluid flows from the first flow path to the second flow path .
Water flows through the first flow path and the second flow path,
The first flow path is connected to the nozzle of the ejector on the downstream side of the branch portion, and is connected to the nozzle of the ejector.
The second flow path is a branch pipe characterized in that it is connected to a steam pipe through which steam flows . In the branch pipe according to claim 1,
The inflow opening is a branch pipe having a flat shape whose dimension in the direction of the axis is shorter than the dimension in the direction orthogonal to the axis.

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