KR102362417B1 - sample pressure reducing valve - Google Patents

Abstract

The present invention relates to a sample pressure reducing valve (SPRV) for smoothly regulating the flow of a sample fluid and its associated pressure drop. The SPRV includes an elongate shell, at least one tube disposed within the elongate shell, a needle holder subassembly disposed above the at least one tube within the elongate shell, and at least one rod coupled with the needle holder subassembly within the tube. The rod is configured to reciprocate within the tube by a narrow annular gap disposed within the tube. The SPRV also includes a screw that engages the upper end of the needle holder subassembly and a handle for rotating the screw. The screw includes at least one slot disposed within the screw for trapping impurities in the sample within the thread between the screw and the needle holder subassembly, and at least one guide means for engaging the needle holder subassembly to prevent rotation. do.

Description

sample pressure reducing valve

FIELD OF THE INVENTION The present invention relates to a valve for fluids, and more particularly to a sample pressure reducing valve for a steam and moisture analysis system, which is used to condition a sample in a diagnostic monitoring system for a power boiler.

In steam power plants, it is necessary to monitor the quality of the working fluid, such as water or steam, for parameters such as pH, conductivity, silica content, etc. to improve the life of plant key components such as boilers, turbines, piping, etc. The work is done with the help of a Steam Water Analysis System (SWAS).

A sample pressure reducing valve (SPRV) is a device used for the purpose of smooth pressure reduction and flow modulation, thereby configured to supply a conditioned (conditioned) sample to the analyzer.

In general, SPRV is a rod-in-tube type decompression device in which decompression is achieved by passing a flow through a narrow annular region between a rod and a tube. These narrow passages are configured to control the flow while providing frictional resistance to the fluid flow causing the required pressure drop. The flow rate and associated pressure drop depend on the effective length the rod is inserted into the tube.

Specifically, US Patent RE37,153 discloses a variable decompression device for reducing high pressure in steam and hot water samples, wherein the device passes liquid through an annular passageway between a pair of rods disposed within a pair of complementary tubes. is configured to apply a force to The flow rate through the rod-in-tube device, or the pressure drop through the device, is adjustable by means of a rotatable guide screw for adjusting the position of the rods within the tube. The rods are configured to be tapered so that liquid flows smoothly through the device. The seal around the guide screw is self-energized by a sealing jacket between the valve gland and the stem of the guide screw so that the biasing force of a spring disposed on the sealing jacket is removed from the liquid flowing through the device. It is configured to be replenished by pressure. The guide screw is centered on the valve gland to keep the guide screw properly aligned, and is configured to maintain proper alignment, particularly when the device is used with a motor to rotate the guide screw to adjust the position of the rods.

In general, conventional valves with two rods are more susceptible to jamming problems during operation. This is caused by a relatively rigid structure, which may cause a jamming phenomenon due to misalignment between the rod and the tube.

The disclosed conventional valve does not have any safety device to protect the valve as well as the operator. In addition, the rod used in the prior art sample pressure reducing valve does not self-align with the tube, so there is a risk of jamming/deformation during operation.

Accordingly, there is a need to provide a pressure reducing valve that overcomes the above-mentioned drawbacks of the prior art.

It is an object of the present invention to provide a sample pressure reducing valve capable of smoothly regulating the flow of a fluid and the associated pressure drop.

Another object of the present invention is to provide a sample pressure reducing valve that reduces deformation or jamming in rods and tubes during operation by means of a self-aligning mechanism.

Another object of the present invention is to provide a sample pressure reducing valve that can be cleaned in situ without disconnecting lines.

Accordingly, the present invention provides a sample pressure reducing valve (SPRV) comprising an elongate shell having a top cap secured on a first end thereof. The top cap is configured to have an outlet for the outflow of the sample.

The SPRV further includes at least one tube disposed within the elongate shell along the second end. The elongate shell and tube are coupled to the inlet cap at the second end. The SPRV also includes a needle holder subassembly disposed within the elongate shell, which is positioned above at least one tube and at least one rod, the rod being connected with the needle holder subassembly at the lower end within the tube. is composed The rod is configured to be reciprocable within the tube by a narrow annular gap disposed within the tube.

The SPRV also includes a screw that engages the upper end of the needle holder subassembly. The screw is configured to trap impurities in the sample within a thread between the screw and the needle holder subassembly by including at least one slot disposed therein. In particular, the screw is fixed in place of the top cap and is hermetically shielded on the inner diameter.

The SPRV also comprises at least one guiding means arranged in the shell in the upper half. At least one guiding means engages the needle holder subassembly to prevent rotation. The SPRV also includes a handle disposed on the screw for rotating the screw.

Upon rotation of the handle, the needle holder subassembly reciprocates in the elongate shell, thereby causing the rod to reciprocate within the tube, causing a frictional pressure drop by the narrow annular gap between the rod and the tube, while the flow of the sample is configured to control

The present invention provides a sample pressure reducing valve capable of smoothly regulating the flow of a fluid and the associated pressure drop. Also provided is a sample pressure reducing valve that reduces deformation or jamming in rods and tubes during operation by means of a self-aligning mechanism. In addition, there is provided a sample pressure reducing valve that can be cleaned in situ without disconnecting the lines.

1 shows a sample pressure reducing valve according to the present invention.
FIG. 2 shows a screw for adjusting the sample pressure reducing valve of FIG. 1 .
3 illustrates an automated sample decompression system 200 in accordance with an aspect of the present invention.
4 shows a sample pressure reducing valve according to another aspect of the present invention.

The object of the present invention and the problems and disadvantages associated with the prior art are overcome by a sample pressure-reducing valve according to the present invention, which is described below in a preferred embodiment.

Accordingly, the present invention provides a sample pressure reducing valve (SPRV). The SPRV is configured to seamlessly coordinate the flow and associated pressure drop of the sample fluid. In addition, SPRVs can reduce deformation or jamming in rods and tubes during operation. In addition, the SPRV is configured to enable on-site cleaning of the sample pressure reducing valve in its original position without disconnecting the line.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is described with reference to the accompanying drawings in which reference numerals are assigned to denote like parts in the various drawings. These reference numbers are indicated in parentheses in the description below.

Referring now to FIG. 1 , there is shown a sample pressure reducing valve 100 (hereinafter 'SPRV 100') according to the present invention. The SPRV 100 functions as a smooth pressure reduction and flow modulation, and thus is configured to supply a conditioned sample to an analyzer for a fluid.

The SPRV 100 includes a shell 10 , at least one tube 20 , a needle holder subassembly 30 , at least one rod 40 , a screw 50 , at least one guide means 60 , and a handle. (70).

The shell 10 is composed of an elongate shell 10 and includes an upper cap 12 fixed to the first end 10a. The top cap 12 is configured to have an outlet 14 for the sample. In one embodiment, the upper cap 12 is connected to the shell 10 by a screw joint. The elongate shell 10 includes at least one tube 20 disposed therein.

Specifically, the tube 20 is disposed within the elongate shell 10 along the second end 10b. For easy understanding of the present invention, as shown in FIG. 1 , the second end 10b is also referred to as a lower end.

The tube 20 is disposed in the lower half of the shell 10 . The shell 10 and the tube 20 are coupled with the inlet cap 22 at the second end 10b. In one embodiment, the elongate shell 10 and the tube 20 are joined to the inlet cap 22 by welding. The elongate shell 10 also includes a needle holder subassembly 30 disposed therein while disposed above the at least one tube 20 .

Also, at least one rod 40 is disposed within the tube 20 , while connected with the lower end of the needle holder subassembly 30 . At least one rod 40 is configured to reciprocate within the tube by a narrow annular gap disposed within the tube 20 . In a preferred embodiment, the rod 30 is connected with the needle holder subassembly 40 by a floating-but-constrained type arrangement. In one embodiment, the needle holder subassembly 40 may be secured if proper alignment is possible by machining.

In a preferred embodiment, the needle holder subassembly 40 is collinear with both the rod 30 and the tube 20 , thereby within the tube 20 , with a floating-constrained arrangement of the rod 30 . It is configured to reduce the risk of deformation of the rod 30 during reciprocating motion. The needle holder subassembly 30 is fixed to the screw 50 .

In one embodiment, the elongate shell 10, the second end 10b, the needle holder subassembly 40, and the inlet cap 22 are not divided into individual components but are manufactured as a single unit and then welded to each other. can be assembled together.

Specifically, the screw 50 engages the upper end of the needle holder subassembly 30 . In one embodiment, the upper end of the needle holder subassembly 40 has a female threaded arrangement that engages one end of the screw 50 . The screw 50 consists of an adjustable screw having at least one slot 50a disposed therein, thereby trapping impurities in the sample in the thread between the screw 50 and the needle holder subassembly 30 . configured to do so. In one embodiment, the screw 50 is held in position in the upper cap 12 , while its inner diameter is received in the seal 16 . The handle 70 is configured to rotate the screw 50 by being mounted to the screw 50 .

In one embodiment, when a sample liquid filter (not shown) is provided upstream and in the supply line of the SPRV 100 for capturing impurities in the sample, the screw 50 may not include a slot, and thus the screw ( 50) and the needle holder subassembly 40 is configured to avoid trapping impurities in the threads.

In addition, at least one guiding means 60 is arranged in the upper half in the elongate shell 10 along the first end 10a. At least one guiding means 60 engages the needle holder subassembly 30 to prevent rotation. In one embodiment, the guiding means 60 are spot welded to the elongate shell 10 .

As mentioned above, the top cap 12 is configured to have an outlet 14 through which the sample exits. In one embodiment, two outlets (not shown) are provided in the elongate shell 10 . As shown in Figure 1, one of the two outlets 14 is provided for the sample, while the other outlet (not shown) is provided for mounting a safety valve. An additional safety measure is provided by the installation of a safety valve. In one embodiment, the top cap 12 and outlet are provided as a single unit. The top cap 12 also includes a seal 16 received therein. The seal 86 is surrounded by a locking screw 50 .

In one embodiment, the inlet 22 and outlet 14 include female threads for connecting mating connectors for tubing of the inlet and outlet.

As shown in Fig. 2, the adjusting screw 50 is provided with a slot 50a. If the sample transported to the SPRV 100 contains particulate impurities, particularly during flushing lines or starters of the power plant system, particulate impurities may be introduced between the adjustment screw 50 and the needle holder subassembly 30. trapped in a screw thread. The slot 50a allows any such impurities to be separated from the thread in less than one turn and discharged through the slot without damaging the thread or causing a jamming problem in the screw 50, thereby reducing wear and thereby prolonging the life of the thread. while increasing product reliability.

During operation of SPRV 100 , rotation of handle 90 causes needle holder subassembly 30 to reciprocate in elongate shell 10 , resulting in rod 40 reciprocating within tube 20 . configured to exercise. The guiding means 60 serves to ensure that the needle holder subassembly 30 only performs a reciprocating motion and does not rotate with the rotation of the adjusting screw 50 . The narrow annular gap between the rod 40 and the tube 20 is configured to cause a frictional pressure drop and thus control the flow. The insertion of the rod 40 having an effective length into the tube 20 can be adjusted manually by turning the handle 70, which is configured to change the flow as needed.

Retracting rod 40 completely out of tube 20 extracts impurities floating in the flow. By this extraction procedure, there is no need to separate the lines of the SPRV 100 so that the in-situ cleaning is performed.

In one embodiment, the components of SPRV 100 are made of metal products. However, it will be apparent to one skilled in the art to use any other robust material capable of withstanding high pressure.

In another aspect, the present invention provides an automated sample decompression system 200 for ensuring a stable upstream sample pressure regardless of fluctuating inlet pressure or flow. Specifically, FIG. 3 shows an automated sample decompression system 200 . The system 200 includes a sample pressure reducing valve (SPRV) 100 , at least one controller 110 , at least one servo motor/actuator 120 having a limit switch and sensing the pressure upstream of the SPRV 100 . and a pressure transmitter 130 for

During operation, the pressure transmitter 130 senses the upstream pressure and compares it to the set pressure of the controller 110 . Also, the pressure transmitter 110 operates in two ways via a built-in proportional-integral (P-I-D) block (not shown).

For example, when the sample inlet pressure increases so that the sample outlet pressure exceeds the set pressure of the controller 110 , the controller 110 transmits a command in the form of a current to the servo motor 120 to close the SPRV 100 . . By doing so, the sample outlet pressure can be kept equal to the set pressure.

When the sample inlet pressure drops and the sample outlet pressure drops based on the set pressure of the controller 110 accordingly, the controller 110 issues a command in the form of a current to the servo motor 120 to control the SPRV 100 . open up By doing so, the sample outlet pressure can be kept equal to the set pressure.

The set pressure of the controller 110 may be changed as needed. Also, the response of the controller 110 may be adjusted by changing the PID value set in the controller 110 .
In another aspect, the present invention provides an automated sample decompression system 200 for ensuring a stable upstream sample pressure as shown in FIG. 3 . The automated sample pressure reduction system 200 includes a sample pressure reduction valve 100 , at least one controller 110 having a preset pressure limit, at least one servo motor/actuator 120 and a pressure transmitter 130 , , the at least one servo motor/actuator 120 has a limit switch for sensing the upstream pressure and comparing it to a preset predetermined pressure limit stored in the controller 110 , the pressure transmitter 130 includes the controller 110 It has a built-in Proportional-Integral-Derivative (PID) block for changing the pressure values in the controller 110 when the sample inlet and outlet pressures exceed or decrease based on the pressure limits set in the controller 110 110) is configured to open or close the sample pressure reducing valve by issuing a command in the form of a current to the servo motor 120.

In another aspect, the present invention provides a sample pressure reducing valve (SPRV [300]) as shown in FIG. 4 . SPRV 300 includes a single rod 40x identical to rod 30 of SPRV 100 and a corresponding hole/tube 20x as shown disposed within shell 10x. The SPRV 300 further includes an adjustment screw 50x capable of changing the effective insertion length of the rod 40 in the hole/tube 20x by moving the needle holder 40x up and down.

An upper cap 12x is attached to the upper portion of the elongated shell 10x, thereby configured to receive a seal 16x between the upper cap 12x body and the adjusting screw 50x. An inlet 22x is provided at the bottom of the SPRV 300 , while an outlet 14x is provided at the side of the SPRV 300 .

The SPRV 100 according to the present invention has the following advantages.

1. Flow rate and associated pressure drop can be manually and smoothly adjusted.

2. By having an actuating mechanism for the reciprocating motion of the single rod 30 in the tube 20, both the rod 30 and the tube 20 are on the same line, thereby preventing deformation or jamming during operation. can be avoided.

3. The rod 30 in the floating-constrained arrangement automatically aligns with the tube while keeping the rod in a constant position, thus reducing the possibility of deformation or jamming during operation.

4. Can be cleaned on-site as-is without line disconnection.

5. Including an additional outlet for monitoring of the pressure relief valve enhances protection for the valve and operator.

The foregoing description of specific embodiments of the invention has been presented for purposes of illustration and description. They are to be understood in a generic sense, and are not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teachings. The above embodiments were chosen and described in order to best explain the principles of the invention and its practical application, so as to enable those skilled in the art to best utilize the various embodiments with the invention and various modifications as are suitable for the particular use for which it is intended. let there be Depending on the circumstances, various omissions and substitutions of equivalents that may be presented as appropriate may be contemplated, but are intended to cover their application or implementation without departing from the spirit or scope of the invention.

Claims (12)

an elongate shell (10), at least one tube (20), a needle holder subassembly (30), at least one rod (40), a screw (50), at least one guide means (60) and a handle (70). In the sample pressure reducing valve 100 comprising:
The elongate shell (10) includes a top cap (12) secured on a first end of the shell, the top cap (12) being arranged to have an outlet (14).
at least one tube (20) is disposed along a second end in the elongate shell (10), the elongate shell (10) and the tube engage the inlet cap (22) at the second end;
The needle holder subassembly (30) is disposed above the at least one tube (20) within the elongate shell (10),
At least one rod 40 is connected with a needle holder subassembly 30 at a lower end within the tube 20, the rod 40 being configured to reciprocate within the tube by a narrow annular gap disposed within the tube and ,
The screw engages the upper end of the needle holder subassembly 30, the screw 50 remains in position in the upper cap 12, while its inner diameter is received in the seal 16;
at least one guiding means (60) is disposed on the upper half within the shell (10), the at least one guiding means (60) engages the needle holder subassembly (30) to prevent rotation;
The handle 70 is disposed on the screw 50 to rotate the screw 50 , and upon rotation of the handle 70 , the needle holder subassembly 30 reciprocates in the elongate shell 10 , thereby allowing the load (40) is caused to reciprocate within the tube (20) and is configured to cause a frictional pressure drop by the narrow annular gap between the rod (40) and the tube (20) and to control the flow of the sample,
characterized in that two outlets are provided: an outlet for the sample and an outlet for the mounting of a safety valve.
Sample pressure relief valve. According to claim 1,
characterized in that the shell (10) and the tube (20) are joined to the inlet cap (22) by welding.
Sample pressure relief valve. According to claim 1,
wherein the screw comprises at least one slot (50a) disposed inside the screw so as to be able to trap impurities in the sample in the thread between the screw (50) and the needle holder subassembly (30).
Sample pressure relief valve. According to claim 1,
The upper cap (12) is characterized in that it is connected to the shell (10) by a threaded joint (threaded joint).
Sample pressure relief valve. According to claim 1,
The guiding means (60) is characterized in that it is spot welded to the shell (10).
Sample pressure relief valve. delete According to claim 1,
characterized in that only one outlet is provided for the sample and the safety valve and is manufactured integrally with the upper cap (12).
Sample pressure relief valve. According to claim 1,
characterized in that the rod (40) is connected with the needle holder subassembly (30) by a floating-but-constrained arrangement.
Sample pressure relief valve. According to claim 1,
The needle holder subassembly (30) is characterized in that it is collinear with both the rod (40) and the tube (20).
Sample pressure relief valve. According to claim 1,
The insertion of a rod (40) having an effective length into the tube (20) is configured to change the flow of the sample by manually adjusting the handle (90) by turning the handle (90).
Sample pressure relief valve. According to claim 1,
The screw 50 is not provided with a slot, and a sample liquid filter is provided in the supply line and upstream of the SPRV 100 for trapping impurities in the sample, thereby trapping impurities in the threads between the screws 50 . characterized in that it is configured to avoid doing
Sample pressure relief valve. An automated sample decompression system (200) for ensuring a stable upstream sample pressure, comprising:
The automated sample pressure reduction system 200 includes a sample pressure reduction valve 100 , at least one controller 110 having a preset pressure limit, at least one servo motor/actuator 120 and a pressure transmitter 130 , ,
At least one servo motor/actuator 120 has a limit switch for sensing the upstream pressure and comparing it to a preset predetermined pressure limit stored in the controller 110;
The pressure transmitter 130 has a built-in Proportional-Integral-Derivative (PID) block for changing the pressure value in the controller 110,
When the sample inlet and outlet pressure exceeds or decreases based on the pressure limit set in the controller 110, the controller 110 issues a command in the form of a current to the servo motor 120 to open or close the sample pressure reducing valve characterized in that
Automated sample decompression system.

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