A differential pressure measuring valve set for blow and measuring method

Abstract

The utility model relates to a kind of blow differential pressure measurement valve group and measurement method, relate to instrument blow pressure difference measurement field, standard three valve group, blow three valve group, differential pressure transmitter;Blow three valve group includes blow valve body, blow valve body is equipped with high pressure inlet channel, low pressure inlet channel, backflush inlet channel, high pressure backflush channel, low pressure backflush channel, purge backflush channel;Purge backflush channel is communicated with high pressure inlet channel and low pressure inlet channel, backflush inlet channel one end and the middle part of purge backflush channel are communicated, other end is communicated backflush gas import;Backflush inlet channel is sequentially provided with backflush gas filter core, blow three valve group bypass valve;High pressure backflush channel one end is communicated with high pressure inlet channel, other end is communicated with backflush inlet channel;High pressure backflush channel is sequentially provided with high pressure side orifice plate screw assembly, high pressure side pressure gauge, high pressure side blow valve.Differential pressure measurement precision is high, can effectively prevent that pressure pipe is jammed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of instrument blow washing differential pressure measurement, and particularly relates to a blow differential pressure measurement valve group and a measurement method. BACKGROUND

[0002] When differential pressure measurement is performed by using a differential pressure transmitter, if the measured medium is corrosive, viscous, crystalline, molten, precipitated, or contains solid matter, is toxic, or is dusty, a blow method needs to be used for measurement.

[0003] The existing blow differential pressure system mainly has the following disadvantages: 1. The blow system recommended in the existing specification is composed of an independent flow limiting orifice plate, a pressure gauge, a filter, a cut-off valve, a three-valve group, and the like, and is connected into a blow system by using external pipelines. The instrument is large in quantity and volume, and is complicated in connection. The installation and maintenance are inconvenient. 2. The existing integrated blow system uses a flow limiting capillary as a flow limiting orifice plate. In actual application, the capillary is prone to be blocked, and cannot be dredged after being blocked. The entire internal flow limiting assembly needs to be replaced, and the maintenance is difficult and the maintenance cost is high. SUMMARY

[0004] The present application solves the technical problem of overcoming the deficiencies of the prior art, and provides a blow differential pressure measurement valve group and a measurement method. The structure is compact, the installation and maintenance are convenient, the manufacturing cost is low, the differential pressure measurement precision is high, and the differential pressure measurement valve group can effectively prevent the pressure lead pipe from being blocked.

[0005] The technical solution of the present application is as follows:

[0006] In a first aspect, a blow differential pressure measurement valve group is provided, which comprises a standard three-valve group, a blow three-valve group, and a differential pressure transmitter. The standard three-valve group is provided with a standard high-pressure measurement channel and a standard low-pressure measurement channel. The differential pressure transmitter is in communication with one end of the standard high-pressure measurement channel and one end of the standard low-pressure measurement channel. The blow three-valve group comprises a blow valve body, which is provided with a high-pressure inlet channel, a low-pressure inlet channel, a back blow inlet channel, a high-pressure back blow channel, a low-pressure back blow channel, and a blow back blow channel. The standard high-pressure measurement channel and the high-pressure inlet channel are connected by a high-pressure side valve group connector. The blow back blow channel is connected between the high-pressure inlet channel and the low-pressure inlet channel. One end of the back blow inlet channel is in communication with the middle part of the blow back blow channel, and the other end is in communication with a back blow inlet. Along the direction from the back blow inlet to the blow back blow channel, a back blow filter element and a blow three-valve group bypass valve are sequentially arranged on the back blow inlet channel. One end of the high-pressure back blow channel is in communication with the high-pressure inlet channel, and the other end is in communication with the back blow inlet channel. The end of the high-pressure back blow channel in communication with the back blow inlet channel is located between the back blow filter element and the blow three-valve group bypass valve. Along the direction from the back blow inlet channel to the high-pressure inlet channel, a high-pressure side flow limiting orifice plate screw assembly, a high-pressure side pressure gauge, and a high-pressure side blow valve are sequentially arranged on the high-pressure back blow channel.

[0007] The standard low-pressure measurement channel and the low-pressure access channel are connected through a low-pressure side valve group connector; one end of the low-pressure backflush channel is connected to the low-pressure access channel, and the other end is connected to the backflush inlet channel, and the end connected to the backflush inlet channel is located between the backflush filter element and the bypass valve of the backflush three-valve group; along the direction from the backflush inlet channel to the low-pressure access channel, a low-pressure side flow-limiting orifice plate screw assembly, a low-pressure side pressure gauge, and a low-pressure side backflush valve are sequentially arranged on the low-pressure backflush channel.

[0008] In an implementation form of the first aspect, the high-pressure side flow-limiting orifice plate screw assembly includes a high-pressure side flow-limiting orifice plate screw body and a high-pressure side flow-limiting orifice plate; the backflush valve body is provided with a first connecting port for mounting the high-pressure side flow-limiting orifice plate screw assembly and a third connecting port for mounting the high-pressure side backflush valve; the high-pressure backflush channel includes a horizontal channel and a vertical channel, one end of the horizontal channel is connected to a lateral position of the first connecting port, and the other end is connected to the backflush inlet channel, one end of the vertical channel is connected to a bottom position of the first connecting port, and the other end is connected to the third connecting port; the high-pressure side flow-limiting orifice plate screw body presses the high-pressure side flow-limiting orifice plate against the bottom of the first connecting port, and the high-pressure side flow-limiting orifice plate screw body is provided with a communication hole, one end of the communication hole is connected to the horizontal channel, and the other end is connected to the vertical channel, so that the medium flows from the horizontal channel, through the communication hole and the high-pressure side flow-limiting orifice plate, and then enters the vertical channel.

[0009] In an implementation form of the first aspect, the part of the high-pressure side flow-limiting orifice plate screw body extending into the first connecting port is provided with a groove segment, the outer diameter of the groove segment is reduced, the groove segment is opposite to the horizontal channel, and one end of the communication hole is located on the outer wall of the groove segment.

[0010] In an implementation form of the first aspect, the communication hole includes horizontal holes and a vertical hole, the horizontal holes are arranged along the radial direction of the groove segment, the vertical hole extends to the end of the high-pressure side flow-limiting orifice plate screw body along the axial direction of the groove segment, and the horizontal holes are all connected to the vertical hole.

[0011] In an implementation form of the first aspect, the high-pressure side flow-limiting orifice plate screw body is provided with a threaded segment, and the threaded segment is used for threaded connection with the port position of the first connecting port of the backflush valve body.

[0012] In an implementation form of the first aspect, the high-pressure side flow-limiting orifice plate screw body is provided with a high-pressure side flow-limiting orifice plate screw sealing ring sleeved between the threaded segment and the groove segment, so as to seal the high-pressure side flow-limiting orifice plate screw body and the inner wall of the first connecting port.

[0013] In an implementation form of the first aspect, the edges of both ends of the high-pressure side flow-limiting orifice plate are respectively provided with a raised upper flange and a lower flange, the high-pressure side flow-limiting orifice plate top sealing ring is arranged in the upper flange, and the high-pressure side flow-limiting orifice plate bottom sealing ring is arranged in the lower flange.

[0014] In an implementation form of the first aspect, the blow valve body is provided with a second connecting port for mounting a high-pressure side pressure gauge, and a first communication channel is arranged between the second connecting port and the vertical channel.

[0015] In an implementation form of the first aspect, the high-pressure inlet channel is perpendicular to the vertical channel, and a second communication channel is arranged between the third connecting port and the high-pressure inlet channel.

[0016] In a second aspect, a blow differential pressure measurement method is provided, which uses any of the blow differential pressure measurement valve groups described above, and includes a normal measurement mode, a test mode, and a rapid back blow mode.

[0017] The normal measurement mode includes: connecting the back blow inlet to back blow, closing the blow three-valve group bypass valve, opening the high-pressure side blow valve and the low-pressure side blow valve, at this time, the back blow passes through the back blow filter, enters the high-pressure process measurement pressure pipeline through the high-pressure side flow limiting orifice plate screw assembly and the high-pressure side blow valve, and establishes a high-pressure side back blow pressure; the filtered back blow enters the low-pressure inlet channel, establishes a low-pressure side back blow pressure, and obtains the pressure difference between the media in the high-pressure inlet channel and the low-pressure inlet channel through a differential pressure transmitter.

[0018] The test mode includes: connecting the back blow inlet to back blow, closing the blow three-valve group bypass valve, closing the valves arranged on the high-pressure back blow channel and the low-pressure back blow channel, and displaying the back blow pressure of the pressure gauges connected to the high-pressure back blow channel and the low-pressure back blow channel; in the normal working mode, closing any one of the valves arranged on the high-pressure back blow channel and the low-pressure back blow channel, and judging the blockage degree of the flow limiting orifice plate screw assembly connected to the channel in the opening state of the high-pressure back blow channel or the low-pressure back blow channel according to the pressure rise speed of the pressure gauge connected to the channel in the closing state.

[0019] The rapid back blow mode includes: connecting the back blow inlet to back blow, opening the blow three-valve group bypass valve, closing the valves arranged on the high-pressure back blow channel and the low-pressure back blow channel, and blowing the high-pressure inlet channel and the low-pressure inlet channel through the blow back blow channel.

[0020] In summary, the present application at least has the following beneficial technical effects:

[0021] 1. The present application embeds the flow limiting orifice plate in the valve group, simplifies the complex blow differential pressure measurement system into a three-valve group, and can effectively ensure the measurement accuracy by arranging a reasonable flow limiting orifice plate.

[0022] 2. The blow differential pressure measurement valve group designed in the present patent integrates the complex blow pipeline outside into an integrated valve group, which can be directly connected to a differential pressure transmitter for use.

[0023] 3. The application has small volume, compact structure, convenient to assemble and disassemble, easy to use, maintain and repair, reduces production cost and improves economic benefit. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The structural principle diagram of the differential pressure measuring valve group for blowing and the differential pressure transmitter cooperation used according to the application;

[0025] Figure 2 The overall schematic diagram of the differential pressure measuring valve group for blowing and the differential pressure transmitter cooperation used according to the application;

[0026] Figure 3 The structural schematic diagram of the differential pressure measuring valve group for blowing and the differential pressure transmitter cooperation used according to the application; Figure 2 The structural schematic diagram of the differential pressure measuring valve group for blowing and the differential pressure transmitter cooperation used according to the application;

[0027] Figure 4 The cooperation schematic diagram of the differential pressure measuring valve group for blowing and the differential pressure transmitter cooperation used according to the application;

[0028] Figure 5 The sectional view of the blowing valve body;

[0029] Figure 6 The structural schematic diagram of the high-pressure side flow orifice plate screw body;

[0030] Figure 7 The schematic diagram of the high-pressure side flow orifice plate screw body assembled in the first connecting port;

[0031] Figure 8 The structural schematic diagram of the high-pressure side flow orifice plate.

[0032] Figure: 1, differential pressure transmitter; 2, standard three valve group balance valve; 3, standard three valve group high pressure side stop valve; 4, blow three valve group high pressure side flow restriction orifice screw assembly; 5, standard three valve group high pressure side blow-off; 6, high pressure side valve group connector; 7, blow three valve group high pressure side pressure gauge; 8, high pressure process connection; 9, blow three valve group high pressure side blow valve; 10, blow three valve group low pressure side blow valve; 11, low pressure process connection; 12, blow three valve group low pressure side pressure gauge; 13, low pressure side valve group connector; 14, standard three valve group low pressure side blow-off; 15, blow three valve group low pressure side flow restriction orifice screw assembly; 16, standard three valve group low pressure side stop valve; 17, blow three valve group bypass valve; 18, back blow inlet; 19, back blow filter element; 20, high pressure side flow restriction orifice screw seal ring; 21, high pressure side flow restriction orifice top seal ring; 22, high pressure side flow restriction orifice; 23, high pressure side flow restriction orifice bottom seal ring; 24, low pressure side flow restriction orifice bottom seal ring; 25, low pressure side flow restriction orifice; 26, low pressure side flow restriction orifice top seal ring; 27, low pressure side flow restriction orifice screw seal ring; 28, standard three valve group; 29, blow three valve group.

[0033] 281, standard valve body; 282, standard high pressure measurement channel; 283, standard low pressure measurement channel; 284, balance channel.

[0034] 151, low pressure side flow restriction orifice screw body; 41, high pressure side flow restriction orifice screw body.

[0035] 411, threaded section; 412, recessed section; 413, communication hole; 4131, horizontal hole; 4132, vertical hole.

[0036] 291, blow valve body; 292, high pressure inlet channel; 293, low pressure inlet channel; 294, back blow inlet channel; 295, high pressure back blow channel; 2951, horizontal channel; 2952, vertical channel; 296, low pressure back blow channel; 297, purge back blow channel.

[0037] 298, first connection; 299, second connection; 2911, third connection; 2912, fourth connection; 2913, fifth connection. DETAILED DESCRIPTION

[0038] The application will be further described in detail below in conjunction with the drawings and specific embodiments:

[0039] The embodiments of the application disclose a blow differential pressure measurement valve group, such as Figure 1 、 Figure 2 、 Figure 3 and Figure 4As shown, it comprises a standard three-valve group 28, a blowing three-valve group 29, a high-pressure side valve group connector 6, a low-pressure side valve group connector 13, and a differential pressure transmitter 1. The blowing three-valve group 29 and the standard three-valve group 28 are connected through the high-pressure side valve group connector 6 and the low-pressure side valve group connector 13. The blowing differential pressure measurement valve group of the present application adds a blowing three-valve group to the original three-valve group, overcoming the function of the standard three-valve group 28 that cannot realize blowing.

[0040] The standard three-valve group 28 comprises a standard valve body, and a balance valve 2, a high-pressure side stop valve 3, a low-pressure side stop valve 16, a high-pressure side drain 5, and a low-pressure side drain 14 connected to the standard valve body.

[0041] As shown in Figure 1 and Figure 5 , the standard valve body 281 is provided with a standard high-pressure measurement channel 282, a standard low-pressure measurement channel 283, and a balance channel 284. The balance channel 284 is communicated between the standard high-pressure measurement channel 282 and the standard low-pressure measurement channel 283, the balance valve 2 is arranged in the balance channel 284 for controlling the opening and closing of the balance channel 284, the high-pressure side stop valve 3 is communicated with the standard high-pressure measurement channel 282 for isolating the high-pressure end process connection, one end of the high-pressure side drain 5 is communicated with the standard high-pressure measurement channel 282 so that the medium in the standard high-pressure measurement channel 282 can flow out through the high-pressure side drain 5, the low-pressure side stop valve 16 is communicated with the standard low-pressure measurement channel 283 for isolating the low-pressure end process connection, and one end of the low-pressure side drain 14 is communicated with the standard low-pressure measurement channel 283 so that the medium in the standard low-pressure measurement channel 283 can flow out through the low-pressure side drain 14. The differential pressure transmitter 1 is communicated with one end of the standard high-pressure measurement channel 282 and one end of the standard low-pressure measurement channel 283 for measuring the differential pressure of the medium in the standard high-pressure measurement channel 282 and the standard low-pressure measurement channel 283.

[0042] The blowing three-valve group 29 comprises a blowing valve body 291, and a high-pressure side flow-restricting orifice plate screw assembly 4, a high-pressure side pressure gauge 7, a high-pressure process connection port 8, a high-pressure side blowing valve 9, a low-pressure side flow-restricting orifice plate screw assembly 15, a low-pressure side pressure gauge 12, a low-pressure process connection port 11, a low-pressure side blowing valve 10, a blowing three-valve group bypass valve 17, a back blowing inlet 18, and a back blowing filter element 19 connected to the blowing valve body 291.

[0043] As shown in Figure 1 and Figure 5As shown, the blow valve body 291 is provided with high pressure access channel 292, low pressure access channel 293, back flushing inlet channel 294, high pressure back flushing channel 295, low pressure back flushing channel 296, blow back flushing channel 297. High pressure side valve group connector 6 is used to connect one end of standard high pressure measurement channel 282 and one end of high pressure access channel 292, low pressure side valve group connector 13 is used to connect one end of standard low pressure measurement channel 283 and one end of low pressure access channel 293, the other end of high pressure access channel 292 is connected to high pressure process connection port 8, the other end of low pressure access channel 293 is connected to low pressure process connection port 11. Blow back flushing channel 297 is communicated between high pressure access channel 292 and low pressure access channel 293, one end of back flushing inlet channel 294 is communicated with the middle part of blow back flushing channel 297, and the other end is communicated with back flushing gas inlet 18. In the direction from back flushing gas inlet 18 to blow back flushing channel 297, back flushing filter element 19 and blow three valve group bypass valve 17 are arranged on back flushing inlet channel 294 in sequence. One end of high pressure back flushing channel 295 is communicated with high pressure access channel 292, and the other end is communicated with back flushing inlet channel 294, and the end communicated with back flushing inlet channel 294 is located between back flushing filter element 19 and blow three valve group bypass valve 17. One end of low pressure back flushing channel 296 is communicated with low pressure access channel 293, and the other end is communicated with back flushing inlet channel 294, and the end communicated with back flushing inlet channel 294 is located between back flushing filter element 19 and blow three valve group bypass valve 17. On high pressure back flushing channel 295, in the direction from back flushing inlet channel 294 to high pressure access channel 292, high pressure side flow restricting orifice plate screw assembly 4, high pressure side pressure gauge 7, high pressure side blow valve 9 are arranged in sequence. On low pressure back flushing channel 296, in the direction from back flushing inlet channel 294 to low pressure access channel 293, low pressure side flow restricting orifice plate screw assembly 15, low pressure side pressure gauge 12, low pressure side blow valve 10 are arranged in sequence.

[0044] Figure 5 In the machining process of high pressure back flushing channel 295 and blow back flushing channel 297, in order to facilitate machining, a transverse through hole will be machined from the end of blow valve body 291, but finally the two ends of the through hole will be blocked to obtain high pressure back flushing channel 295 or blow back flushing channel 297. This design effectively reduces the machining cost, but the blow valve body 291 is not suitable for machining. Figure 5 In the cross section A-A view, the blocking of both ends of high pressure back flushing channel 295 is not shown. Similarly, in the cross section B-B view, the blocking of both ends of blow back flushing channel 297 is not shown. Figure 5

[0045] The blow three valve group pressure gauge is installed in the blow circuit after the flow restricting orifice plate, and by opening and closing the back flushing valve, the pressure gauge can be used to measure the process pressure and the blow pressure. The blow three valve group blow inlet is provided with a filter element, which can filter the blow gas to prevent the flow restricting orifice plate from being blocked.​

[0046] As Figure 6 , Figure 7 and Figure 8 shown, the flow restriction orifice screw assembly (high pressure side flow restriction orifice screw assembly 4 and low pressure side flow restriction orifice screw assembly 15) is the key to realize back flushing measurement and ensure the accuracy of differential pressure measurement, and the structure is the same. Among them, the low pressure side flow restriction orifice screw assembly 15 includes a low pressure side flow restriction orifice screw body 151, a low pressure side flow restriction orifice screw sealing ring 27, a low pressure side flow restriction orifice top sealing ring 26, a low pressure side flow restriction orifice 25, and a low pressure side flow restriction orifice bottom sealing ring 24. The high pressure side flow restriction orifice screw assembly 4 includes a high pressure side flow restriction orifice screw body 41, a high pressure side flow restriction orifice screw sealing ring 20, a high pressure side flow restriction orifice top sealing ring 21, a high pressure side flow restriction orifice 22, and a high pressure side flow restriction orifice bottom sealing ring 23.

[0047] Because the high pressure side flow restriction orifice screw assembly 4 and the low pressure side flow restriction orifice screw assembly 15 have the same structure, only the structure of the high pressure side flow restriction orifice screw assembly 4 is described in detail. Specifically, the blow valve body 291 is provided with a first connecting port 298 for installing the high pressure side flow restriction orifice screw assembly 4, a third connecting port 2911 for installing the high pressure side blow valve 9, and a second connecting port 299 for installing the high pressure side pressure gauge 7. The high pressure back flushing channel 295 includes a horizontal channel 2951 and a vertical channel 2952, one end of the horizontal channel is communicated to the lateral position of the first connecting port 298, the other end is communicated to the back flushing inlet channel 294, one end of the vertical channel is communicated to the bottom position of the first connecting port 298, the other end is communicated to the third connecting port 2911. The high pressure inlet channel 292 is perpendicular to the vertical channel 2952. A second communication channel is provided between the third connecting port 2911 and the high pressure inlet channel 292, and a first communication channel is provided between the second connecting port 299 and the vertical channel.

[0048] The blow valve body 291 is also provided with a fourth interface 2912 for installing the blow three valve group bypass valve 17, and a fifth interface 2913 for installing the back blow inlet 18.

[0049] The high-pressure side flow restriction orifice screw body is provided with a threaded segment 411 for threaded connection with the mouth position of the first connecting port 298 of the blow valve body 291. The part of the high-pressure side flow restriction orifice screw body extending into the first connecting port 298 is provided with a recessed segment 412 with a reduced outer diameter. The recessed segment 412 is opposite the transverse channel. The recessed segment 412 is provided with a communication hole 413. One end of the communication hole 413 is in communication with the transverse channel 2951, and the other end is in communication with the vertical channel 2952. Specifically, the communication hole 413 includes a plurality of transverse holes 4131 and a vertical hole 4132. The transverse holes 4131 are arranged along the radial direction of the recessed segment 412. The vertical hole 4132 extends along the axis direction of the recessed segment 412 to the end of the high-pressure side flow restriction orifice screw body. The transverse holes 4131 are in communication with the vertical hole 4132. The recessed segment 412 with a reduced outer diameter forms an annular recess at this position. The medium flowing through the transverse channel 2951 can be uniformly distributed in the annular recess and then flow into the end of the plurality of transverse holes 4131. The high-pressure side flow restriction orifice screw sealing ring 20 is sleeved on the outside of the high-pressure side flow restriction orifice screw body and located between the threaded segment 411 and the recessed segment 412, so as to prevent the medium flowing into the first connecting port 298 from leaking out of the first connecting port 298. The edge of the end surface of the high-pressure side flow restriction orifice 22 is respectively protruded to form an upper convex edge and a lower convex edge. The high-pressure side flow restriction orifice top sealing ring 21 is placed in the upper convex edge, and the high-pressure side flow restriction orifice bottom sealing ring 23 is placed in the lower convex edge. When the high-pressure side flow restriction orifice screw body is tightened in the first connecting port 298, the high-pressure side flow restriction orifice screw body presses the high-pressure side flow restriction orifice top sealing ring 21 and the high-pressure side flow restriction orifice bottom sealing ring 23, so as to realize the sealing between the high-pressure side flow restriction orifice 22 and the bottom of the first connecting hole and the sealing between the high-pressure side flow restriction orifice 22 and the end of the high-pressure side flow restriction orifice screw body, so that the medium stably flows into the vertical channel from the vertical hole 4132.

[0050] The pressure screw sealing ring is nested on the flow restriction orifice guide pressure screw, and a sealed cavity is formed with the atmosphere. The flow restriction orifice guide pressure screw is provided with a straight thread, which is connected with the blowback valve body through the thread. The thread is screwed in to press the upper sealing ring of the flow restriction orifice. The flow restriction orifice is provided with a sealing groove at both ends, and a sealing ring is respectively installed in the inner part of the groove. The orifice sealing channel is formed by screwing in the flow restriction orifice guide pressure screw. The orifice opening specification can be calculated according to the actual working condition.

[0051] Working principle:

[0052] The blow differential pressure measuring valve group has three working modes, namely normal measuring mode, test mode and rapid blowback mode.

[0053] The standard three valve group 28 is put into operation and stopped according to the standard operation process, which will not be described here. The following only describes the different working modes of the blowing three valve group 29.

[0054] Normal working mode (for measuring the pressure of medium in 8 and 11): the reverse blowing inlet 18 is connected to the reverse blowing, the blowing three valve group bypass valve 17 is closed, the high-pressure side blowing valve 9 and the low-pressure side blowing valve 10 are opened, at this time, the reverse blowing is filtered through the reverse blowing filter element 19, and then enters the high-pressure process measurement pressure pipeline through the high-pressure side flow limiting orifice plate screw 4 and the high-pressure side blowing valve 9, thereby establishing the high-pressure side reverse blowing pressure, at this time, the high-pressure side pressure gauge 7 displays the process pressure of the high-pressure side. The filtered reverse blowing enters the low-pressure channel 293 through the low-pressure side flow limiting orifice plate screw 15 and the low-pressure side blowing valve 10, thereby establishing the low-pressure side reverse blowing pressure, at this time, the low-pressure side pressure gauge 12 displays the process pressure of the low-pressure side.

[0055] Test mode: the reverse blowing inlet 18 is connected to the reverse blowing, the blowing three valve group bypass valve 17 is closed, the high-pressure side blowing valve 9 and the low-pressure side blowing valve 10 are closed, at this time, the high-pressure side pressure gauge 7 and the low-pressure side pressure gauge 12 display the reverse blowing pressure.

[0056] In the normal working mode, any one of the high-pressure side blowing valve 9 and the low-pressure side blowing valve 10 is switched from the open state to the closed state, at this time, the pressure displayed by the high-pressure side pressure gauge 7 or the low-pressure side pressure gauge 12 will gradually rise to the reverse blowing pressure (the orifice plate on the side in the open state has gas passing through continuously, but the gas flow through the orifice plate is very small, so the pressure loss caused by the gas passing through the orifice plate on the side in the open state can be ignored, so the pressure displayed by the high-pressure side pressure gauge 7 or the low-pressure side pressure gauge 12 on the side in the closed state can rise to the reverse blowing pressure), the rising rate of the pressure is very important, which can be used to characterize the gas flow rate of the high-pressure side flow limiting orifice plate 22 and the high-pressure side flow limiting orifice plate 25, so the rising rate of the pressure can be used to judge whether the flow limiting orifice plate is blocked, and if it is blocked, the flow limiting orifice plate can be dredged or replaced in time.

[0057] Fast blowing mode: the reverse blowing inlet 18 is connected to the reverse blowing, the blowing three valve group bypass valve 17 is opened, the high-pressure side blowing valve 9 and the low-pressure side blowing valve 10 are closed, at this time, the high-pressure side pressure gauge 7 and the low-pressure side pressure gauge 12 display the reverse blowing pressure. At this time, the high-pressure reverse blowing directly blows the high and low pressure side process pipelines without limiting the flow, and this mode is used to remove the deposits that may exist in the process connection pipeline.

[0058] The present application is described in detail above in connection with specific embodiments and exemplary examples, but the description is not to be construed to limit the present application. It will be understood by those skilled in the art that various equivalents, modifications and substitutions can be made to the present application and its embodiments without departing from the spirit and scope of the present application, and these are to be construed to fall within the scope of the present application. The scope of the present application is defined by the appended claims.

[0059] The contents not described in detail in the specification of the present application are known to those skilled in the art.

Claims

1. A differential pressure measuring valve set for blow, characterized by: The differential pressure transmitter (1) is connected with one end of the standard high-pressure measuring channel (282) and one end of the standard low-pressure measuring channel (283). The standard three-valve group (28) comprises a standard valve body (281) provided with a standard high-pressure measuring channel (282) and a standard low-pressure measuring channel (283), and the differential pressure transmitter (1) is connected with one end of the standard high-pressure measuring channel (282) and one end of the standard low-pressure measuring channel (283). The blowing three-valve group (29) comprises a blowing valve body (291) provided with a high-pressure inlet channel (292), a low-pressure inlet channel (293), a back blowing inlet channel (294), a high-pressure back blowing channel (295), a low-pressure back blowing channel (296) and a blowing back blowing channel (297). The standard high-pressure measuring channel (282) and the high-pressure inlet channel (292) are connected through a high-pressure side valve group connector (6). The blowing back blowing channel (297) is connected between the high-pressure inlet channel (292) and the low-pressure inlet channel (293), one end of the back blowing inlet channel (294) is connected with the middle part of the blowing back blowing channel (297), and the other end is connected with the back blowing gas inlet (18); along the direction from the back blowing gas inlet (18) to the blowing back blowing channel (297), the back blowing inlet channel (294) is sequentially provided with a back blowing gas filter element (19) and a blowing three-valve group bypass valve (17); one end of the high-pressure back blowing channel (295) is connected with the high-pressure inlet channel (292), and the other end is connected with the back blowing inlet channel (294), and the end connected with the back blowing inlet channel (294) is located between the back blowing gas filter element (19) and the blowing three-valve group bypass valve (17); along the direction from the back blowing inlet channel (294) to the high-pressure inlet channel (292), the high-pressure back blowing channel (295) is sequentially provided with a high-pressure side flow limiting orifice plate screw assembly (4), a high-pressure side pressure gauge and a high-pressure side blowing valve; the low-pressure back blowing channel (296) is sequentially provided with a low-pressure side flow limiting orifice plate screw assembly (15), a low-pressure side pressure gauge (12) and a low-pressure side blowing valve (10); the low-pressure side flow limiting orifice plate screw assembly (15) and the high-pressure side flow limiting orifice plate screw assembly have the same structure. The high-pressure side flow limiting orifice plate screw assembly comprises a high-pressure side flow limiting orifice plate screw body and a high-pressure side flow limiting orifice plate (22). The blowing valve body (291) is provided with a first connecting port (298) for mounting the high-pressure side flow limiting orifice plate (22) screw assembly and a third connecting port (2911) for mounting the high-pressure side blowing valve, the high-pressure back blowing channel (295) comprises a horizontal channel (2951) and a vertical channel (2952), one end of the horizontal channel (2951) is connected with the lateral position of the first connecting port (298), and the other end is connected with the back blowing inlet channel (294), one end of the vertical channel (2952) is connected with the bottom position of the first connecting port (298), and the other end is connected with the third connecting port (2911). The high-pressure side flow-restricting orifice plate (22) is pressed against the bottom of the first connecting port (298) by a high-pressure side flow-restricting orifice plate screw body, the high-pressure side flow-restricting orifice plate screw body is provided with a communication hole (413), one end of the communication hole (413) is in communication with the horizontal channel (2951), and the other end of the communication hole (413) is in communication with the vertical channel (2952), so that the medium flows into the vertical channel (2952) from the horizontal channel (2951) and then through the communication hole (413) and the high-pressure side flow-restricting orifice plate (22); the high-pressure inlet channel (292) is perpendicular to the vertical channel (2952); the horizontal channel (2951) and the blowback channel (297) linearly pass through the blow valve body (291), and both ends of the horizontal channel (2951) and the blowback channel (297) are blocked. The part of the high-pressure side flow-restricting orifice plate screw body extending into the first connecting port (298) is provided with a groove section (412), the outer diameter of the groove section (412) is reduced, the groove section (412) is opposite to the horizontal channel (2951), and one end of the communication hole (413) is located on the outer wall of the groove section (412). The edges of both ends of the high-pressure side flow-restricting orifice plate (22) are respectively provided with a protruding upper convex edge and a protruding lower convex edge, the high-pressure side flow-restricting orifice plate top sealing ring is arranged in the upper convex edge, and the high-pressure side flow-restricting orifice plate bottom sealing ring is arranged in the lower convex edge.

2. The differential pressure measuring valve set for blow according to claim 1, wherein: The communication hole (413) comprises horizontal holes (4131) and vertical holes (4132), a plurality of horizontal holes (4131) are arranged along the radial direction of the groove section (412), the vertical holes (4132) extend to the end of the high-pressure side flow-restricting orifice plate screw body along the axis direction of the groove section (412), and the horizontal holes (4131) are in communication with the vertical holes (4132).

3. The differential pressure measuring valve set for blow according to claim 1, wherein: The high-pressure side flow-restricting orifice plate screw body is provided with a threaded section (411), and the threaded section (411) is used for being threadedly connected with the port position of the first connecting port (298) of the blow valve body (291).

4. The differential pressure measuring valve set for blow according to claim 3, wherein: The high-pressure side flow-restricting orifice plate screw body is provided with a high-pressure side flow-restricting orifice plate screw sealing ring (20) arranged between the threaded section (411) and the groove section (412), so as to seal the high-pressure side flow-restricting orifice plate screw body and the inner wall of the first connecting port (298).

5. The differential pressure measuring valve set for blow according to claim 1, wherein: The blow valve body (291) is provided with a second connecting port (299) for mounting a high-pressure side pressure gauge, and a first communication channel is arranged between the second connecting port (299) and the vertical channel (2952).

6. The differential pressure measuring valve set for blow according to claim 1, wherein: A second communication channel is arranged between the third connecting port (2911) and the high-pressure inlet channel (292).

7. A differential pressure measurement method for blow molding, characterized by: The blow valve group is used for differential pressure measurement, and comprises a normal measurement mode, a test mode and a rapid blowback mode. Normal measurement mode includes: the back blowing gas inlet (18) accesses back blowing gas, the blow gas three valve group bypass valve (17) is closed, the high pressure side blow gas valve and the low pressure side blow gas valve are opened, at this time, the back blowing gas is filtered after passing through the back blowing gas filter (19), enters the high pressure process measurement pressure pipeline via the high pressure side flow limiting orifice plate (22) screw assembly, the high pressure side blow gas valve, establishes the high pressure side back blowing pressure; The filtered back blowing gas enters the low pressure access channel (293), establishes the low pressure side back blowing pressure, and the pressure difference of the medium in the high pressure access channel (292) and the low pressure access channel (293) is obtained by the differential pressure transmitter (1); Test mode includes: the back blowing gas inlet (18) accesses back blowing gas, the blow gas three valve group bypass valve (17) is closed, the valve arranged on the high pressure back blowing channel (295) and the low pressure back blowing channel (296) is closed, and the pressure gauge arranged on the high pressure back blowing channel (295) and the low pressure back blowing channel (296) displays the back blowing gas pressure; In normal working mode, any one valve arranged on the high pressure back blowing channel (295) or the low pressure back blowing channel (296) is closed, and according to the pressure rising speed of the pressure gauge connected to the channel in the closed state in the high pressure back blowing channel (295) or the low pressure back blowing channel (296), the blockage degree of the flow limiting orifice plate screw assembly connected to the channel in the open state in the high pressure back blowing channel (295) or the low pressure back blowing channel (296) is judged; Fast back blowing mode includes: the back blowing gas inlet (18) accesses back blowing gas, the blow gas three valve group bypass valve (17) is opened, the valve arranged on the high pressure back blowing channel (295) and the low pressure back blowing channel (296) is closed, and the back blowing gas is blown through the blow back blowing channel (297) to the high pressure access channel (292) and the low pressure access channel (293).

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