Gas dilution probe

Abstract

The utility model relates to a gas dilution probe which comprises a sampling probe rod which is provided with an internal flow channel allowing to-be-detected sample gas to flow through; the sampling cavity is in fluid communication with an internal flow channel of the sampling probe rod and is used for receiving to-be-detected sample gas drained by the sampling probe rod; the jet diluter is arranged outside the sampling cavity and is used for diluting the to-be-detected sample gas entering the jet diluter into a fixed dilution ratio; the sound velocity small hole is formed in the sampling cavity and is used for limiting the flow of to-be-detected sample gas entering the jet flow diluter; wherein the sampling cavity is provided with an accommodating part for accommodating the sound velocity small hole; and the sound velocity small hole is sealed and fixed in the accommodating part through a triple sealing structure comprising a first sealing structure, a second sealing structure and a third sealing structure. The triple sealing structure ensures that the flow of the sample gas to be detected entering the jet diluter is the designed flow, so that the accurate dilution ratio is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of gas dilution probes. BACKGROUND

[0002] The dilution probe is mainly applied to a continuous monitoring system for gaseous pollutant emission, for extracting and diluting the flue gas to be measured, so as to detect using a low-range and high-precision instrument.

[0003] The existing dilution probe has the following defects when extracting flue gas: first, the actual dilution ratio is lower than the designed dilution ratio, because the actual flue gas extraction flow is greater than the designed flue gas extraction flow; second, the failure rate of the heater is high and the service life is short. SUMMARY

[0004] In view of the defect that the actual dilution ratio of the existing dilution probe is lower than the designed dilution ratio, the embodiments of the utility model provide a gas dilution probe, which comprises:

[0005] a sampling probe rod having an internal flow passage allowing the flow of sample gas to be measured therethrough;

[0006] a sampling chamber in fluid communication with the internal flow passage of the sampling probe rod for receiving the sample gas to be measured flowing in through the sampling probe rod;

[0007] a jet diluter arranged outside the sampling chamber for diluting the sample gas to be measured entering the jet diluter to a fixed dilution ratio;

[0008] a sonic orifice arranged in the sampling chamber for limiting the flow of sample gas to be measured entering the jet diluter;

[0009] wherein the sampling chamber has a receiving portion for accommodating the sonic orifice;

[0010] and the sonic orifice is sealed and fixed in the receiving portion via a triple sealing structure comprising a first sealing structure, a second sealing structure and a third sealing structure.

[0011] In view of the problem that the actual dilution ratio is lower than the designed dilution ratio due to the actual flue gas extraction flow being greater than the designed flue gas extraction flow in the prior art, the triple sealing structure ensures that the flow of sample gas to be measured entering the jet diluter is the designed flow, thereby ensuring the accurate dilution ratio.

[0012] In some embodiments, the first sealing structure comprises:

[0013] a compression nut located at the opening side of the receiving portion and arranged between the outer wall of the sonic orifice and the inner wall of the receiving portion;

[0014] A sealing band is arranged between the outer wall of the compression nut and the inner wall of the accommodating portion to seal and fix the sonic orifice.

[0015] In some embodiments, the second sealing structure comprises a plastic sleeve arranged close to the bottom of the accommodating portion, and the sonic orifice is interference-fitted in the accommodating portion via the plastic sleeve to achieve the sealing and fixing effect.

[0016] In some embodiments, the third sealing structure comprises a sealing ring arranged at the joint of the plastic sleeve and the compression nut and surrounding the sonic orifice. The sealing ring is extruded and deformed to achieve the sealing and fixing effect.

[0017] In some embodiments, the gas dilution probe further comprises a sampling chamber filter arranged in the sampling chamber and located on the upstream side of the sonic orifice.

[0018] In some embodiments, the gas dilution probe further comprises a rod-shaped heater arranged substantially linearly along the sampling probe rod. Thus, the heater of the utility model will not be damaged due to excessive bending, reducing the failure rate of the heater and improving the service life of the heater.

[0019] In some embodiments, the sampling probe rod comprises a probe rod inner tube and a probe rod outer tube surrounding the probe rod inner tube; and the rod-shaped heater is arranged between the outer wall of the probe rod inner tube and the inner wall of the probe rod outer tube.

[0020] In some embodiments, the rod-shaped heater is arranged on the outer wall of the probe rod inner tube and extends substantially linearly along the length direction of the probe rod inner tube.

[0021] In some embodiments, the rod-shaped heater is fixed on the outer wall of the probe rod inner tube using fixing components at at least two fixing positions, and the spacing between adjacent fixing positions is equal. Thus, the heater of the utility model will not be damaged due to excessive bending, reducing the failure rate of the heater and improving the service life of the heater.

[0022] In some embodiments, the sampling probe rod further comprises:

[0023] A rubber plug for plugging the space between the outer wall of the probe rod inner tube and the inner wall of the probe rod outer tube at the inlet end;

[0024] A threaded cap for compressing and fixing the rubber plug on the sampling probe rod.

[0025] The heater is isolated from the corrosive gas by a rubber plug and a threaded cap structure, so that the heater is not corroded by the corrosive substances in the sample gas, thereby reducing the failure rate of the heater and prolonging the service life of the heater.

[0026] As can be seen from the above embodiments, the gas dilution probe can ensure that the actual dilution ratio reaches the designed dilution ratio, and the failure rate of the heater is reduced and the service life of the heater is prolonged.

[0027] The various aspects, features, advantages and the like of the embodiments of the present application will be described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic diagram showing an application example of the gas dilution probe according to the embodiment of the present application.

[0029] Figure 2 is a schematic diagram showing the overall structure of the gas dilution probe according to the embodiment of the present application.

[0030] Figure 3 is a schematic diagram showing the mounting structure of the sonic orifice according to the embodiment of the present application.

[0031] Figure 4 is a schematic diagram showing the overall structure of the gas dilution probe according to another embodiment of the present application. DETAILED DESCRIPTION

[0032] In the following, exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0033] The terms "comprise", "include" and "have" as used in the specification designate the presence of stated features, steps, operations, elements, and / or components but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or collections thereof. Unless the context clearly indicates otherwise, the terms "first", "second", and other similar terms do not imply a sequence or order.

[0034] The terms "generally", "approximately", "substantially", "about", and similar terms are used as approximate terms and are intended to account for inherent variations in measurement or calculation values that would be recognized by one of ordinary skill in the art.

[0035] The embodiments of the present application relate to a gas dilution probe, which is mainly applied to continuous monitoring of gaseous pollutant emissions. Figure 1 As shown in the figure, one end of the gas dilution probe 200 extends into the flue 100 to extract and dilute the sample flue gas from the flue 100, and the arrows in the figure represent the direction of the gas flow.

[0036] As shown in the exemplary embodiment, the gas dilution probe 200 includes a sampling probe stem 210, a sampling chamber 220, a jet diluter 230, and an acoustic velocity orifice 240. Figure 2

[0037] The sampling probe stem 210 has an internal flow passage that allows the flow of the sample gas to be measured. As shown in the exemplary embodiment, the sampling probe stem 210 is adapted to extend into the flue 100 to draw the sample gas, such as flue gas, from the flue 100. The sampling probe stem 210 draws the sample gas into the sampling chamber 220. Figure 1

[0038] The sampling chamber 220 is in fluid communication with the internal flow passage of the sampling probe stem 210 for receiving the sample gas drawn in through the sampling probe stem 210. For example, the flue gas in the flue 100 enters the sampling probe stem 210 through the sample gas inlet 211, passes through the internal flow passage of the sampling probe stem 210, and enters the sampling chamber 220. In the sampling chamber 220, the sample gas flows through the acoustic velocity orifice 240, which allows a prescribed flow of the sample gas to pass through and into the jet diluter 230.

[0039] The acoustic velocity orifice 240 is disposed in the sampling chamber 220 and is configured to limit the flow of the sample gas into the jet diluter 230 and can maintain the flow constant.

[0040] The jet diluter 230 is disposed outside of the sampling chamber 220 and is configured to dilute the sample gas entering the jet diluter 230 to a fixed dilution ratio. In some embodiments, as shown in the exemplary embodiment, dilution gas enters the jet diluter 230 through a dilution gas inlet 231. In the jet diluter 230, the dilution gas mixes with the sample gas in a prescribed ratio, thereby diluting the sample gas to a dilution gas of a fixed dilution ratio. The dilution gas exits the jet diluter 230 through a dilution gas outlet 232 for passage through a heated line (not shown) to an instrument analyzer. Figure 2

[0041] In some embodiments, as shown in the exemplary embodiment, the sampling chamber 220 has a receiving portion 222 for receiving the acoustic velocity orifice 240. The acoustic velocity orifice 240 is received in the receiving portion 222 through a triple seal structure including a first seal structure, a second seal structure, and a third seal structure. Figure 3

[0042] ​​​​In some embodiments, the first sealing structure includes a compression nut 241 and a sealing band 242. The compression nut 241 is located at the opening side of the accommodating portion 222 between the outer wall of the sonic orifice 240 and the inner wall of the accommodating portion 222 so as to fix the sonic orifice 240 in the accommodating portion 222. The sealing band 242 is arranged between the outer wall of the compression nut 241 and the inner wall of the accommodating portion 222.

[0043] In an alternative embodiment, the outer wall of the compression nut 241 has a first thread, and the inner wall of the accommodating portion 222 has a second thread that cooperates with the first thread. The sealing band 242 includes a raw band that is wound on the outer wall of the compression nut 241. The sonic orifice 240 passes through the inner passage of the compression nut 241, and the compression nut 241 is screwed into the accommodating portion 222 by the cooperation of the first thread and the second thread, so that the raw band is squeezed between the outer wall of the compression nut 241 and the inner wall of the accommodating portion 222 to seal the gap between the outer wall of the compression nut 241 and the inner wall of the accommodating portion 222. It should be understood that the present application is not limited thereto, and the sealing band 242 can be a band made of any other suitable material known in the art that can be used for sealing.

[0044] In some embodiments, the second sealing structure includes a plastic sleeve 243 that is arranged near the bottom of the accommodating portion 222, and a portion of the sonic orifice 240 is interference-fitted in the accommodating portion 222 via the plastic sleeve 243.

[0045] In an alternative embodiment, the plastic sleeve 243 includes a PTFE sleeve that is sleeved around the sonic orifice 240. The sonic orifice 240 sleeved with the PTFE sleeve is inserted into the accommodating portion 222, and the compression nut 241 is tightened to squeeze the sleeve 243 by the compression nut, thereby achieving the interference fit between the plastic sleeve 243 and the accommodating portion 222 and the interference fit between the plastic sleeve 243 and the sonic orifice 240. The squeezed PTFE sleeve seals the gap between the outer wall of the sonic orifice 240 and the inner wall of the accommodating portion 222, thereby achieving the sealing and fixing effect. It should be understood that the present application is not limited thereto, and the plastic sleeve 243 can be a sleeve made of any other suitable material known in the art.

[0046] In some embodiments, the third sealing structure includes a sealing ring 244 that is arranged at the junction of the plastic sleeve 243 and the compression nut 241 and surrounds the sonic orifice 240.

[0047] In an optional embodiment, the sealing ring 244 comprises an O-ring, which is sleeved on the outer periphery of the sonic orifice 240 at the position where the plastic sleeve 243 meets the compression nut 241. Through the sealing ring 244, the sample gas to be measured can be prevented from flowing into the downstream channel through the gap between the inner wall of the compression nut 241 and the outer wall of the sonic orifice 240, and entering the jet diluter 230.

[0048] In some embodiments, the tail section of the sonic orifice 240 in the gas flow direction is inserted into the internal channel of the compression nut 241, and then the sealing ring 244 is sleeved, followed by the plastic sleeve 243, so that the sealing ring 244 is located at the position where the plastic sleeve 243 meets the compression nut 241. The sealing tape 242 is wound outside the compression nut 241. Then, the sonic orifice 240 provided with the compression nut 241, the sealing tape 242, the sealing ring 244 and the plastic sleeve 243 is inserted into the accommodating portion 222 of the sampling chamber 220 as a whole, and the compression nut 241 is tightened. Thus, the sonic orifice 240 and the accommodating portion 222 have a triple sealing structure: first, the sealing tape 242 seals the gap between the outer wall of the compression nut 241 and the inner wall of the accommodating portion 222; second, the plastic sleeve 243 seals the gap between the outer wall of the tail section of the sonic orifice 240 and the inner wall of the accommodating portion 222, and at the same time, through interference fit, increases the friction force to fix the sonic orifice 240; third, the sealing ring 244 seals the gap between the outer wall of the sonic orifice 240 and the inner wall of the compression nut 241, and at the same time, the sealing ring 244 is extruded and deformed, which also can fix the sonic orifice. Through the triple sealing structure, the sonic orifice 240 is sealed and fixed, so that the sample gas to be measured entering the sampling chamber 220 can only enter the jet diluter 230 through the sonic orifice 240, so as to accurately control the flow rate entering the jet diluter 230 through the sonic orifice 240, and ensure that the designed dilution ratio is achieved. It should be understood that although the triple sealing structure is described in the tail section of the sonic orifice 240 in the utility model, the utility model is not limited to this, and the triple sealing structure can be provided at any other suitable position of the sonic orifice 240.

[0049] In some embodiments, the gas dilution probe 200 further comprises a sampling chamber filter 250, which is arranged in the sampling chamber 220 and located on the upstream side of the sonic orifice 240. The sampling chamber filter 250 can filter the particles in the sample gas to be measured, so as to prevent the particles from blocking the sonic orifice 240.

[0050] In some embodiments, the sample gas to be tested first flows through the internal flow channel of the sampling probe 210 and then flows through the sampling chamber 220. In the sampling chamber 220, the sample gas to be tested is divided into two paths: one path flows through the drainage channel and is exhausted from the drainage gas outlet 221; the other path flows through the sampling chamber filter 250, is throttled by the sonic orifice 240, and enters the jet diluter 230. In the jet diluter 230, the dilution gas flows in from the dilution gas inlet 231 and mixes with the sample gas to be tested, diluting the sample gas to be tested into a diluted sample gas with a fixed dilution ratio. The diluted sample gas flows out from the diluted sample gas outlet 232 and finally enters the instrument analysis device through the heat tracing pipeline.

[0051] In some embodiments, the gas dilution probe further comprises a rod-shaped heater disposed along a straight line or substantially a straight line of the sampling probe. Thus, the heater of the present invention will not be damaged by excessive bending, thereby reducing the failure rate of the heater and increasing the service life of the heater.

[0052] In some embodiments, as Figure 4 As shown, the sampling probe 210 includes an inner probe tube 213 and an outer probe tube 212 surrounding the inner probe tube 213. A rod-shaped heater 260 is provided between the outer wall of the inner probe tube 213 and the inner wall of the outer probe tube 212. In some embodiments, the rod-shaped heater 260 includes a metal armored heater.

[0053] In some embodiments, the rod-shaped heater 260 is disposed on the outer wall of the probe inner tube 213 and extends linearly or substantially linearly along the length of the probe inner tube 213. In some embodiments, the rod-shaped heater 260 is fixed to the outer wall of the probe inner tube 213 using fixing members 270 at at least two fixed positions. Optionally, the spacing between adjacent fixing positions is equal. In some embodiments, the fixing members 270 may include metal ties for fixing the rod-shaped heater 260 to the probe inner tube 213 in a naturally flattened manner. This ensures that the rod-shaped heater will not be damaged by excessive bending.

[0054] In some embodiments, the probe inner tube 213 is coaxially arranged with the probe outer tube 212, wherein the probe inner tube 213 has a sample gas inlet 211, and the gap between the probe inner tube 213 and the probe outer tube 212 is sealed by a sealing structure, isolating the rod-shaped heater 260 from contact with corrosive gas.

[0055] In some embodiments, the sealing structure includes a rubber plug 214 and a threaded cap 215. The rubber plug 214 is used to seal the space between the outer wall of the inner tube 213 of the sampling probe and the inner wall of the outer tube 212 of the sampling probe at the inlet end. The threaded cap 215 is used to press and fix the rubber plug 214 on the sampling probe 210. The sealing structure including the rubber plug 214 and the threaded cap 215 isolates the heater from the corrosive gas, so that the heater is not corroded by the corrosive substances in the sample gas. Thus, the failure rate of the heater is reduced, and the service life of the heater is improved.

[0056] The gas dilution probe according to the embodiments of the present application not only ensures that the actual dilution ratio reaches the designed dilution ratio, but also reduces the failure rate of the heater and improves the service life of the heater.

[0057] It should be understood that the above disclosed embodiments are only examples of the present application, and cannot limit the scope of the patent protection claimed in the present application. The present application can also be embodied by the following embodiments.

[0058] In some embodiments, the embodiments of the present application provide a gas dilution probe, which comprises:

[0059] a sampling probe having an internal flow passage allowing the sample gas to flow therethrough;

[0060] a sampling chamber in fluid communication with the internal flow passage of the sampling probe, for receiving the sample gas flowing in through the sampling probe;

[0061] a jet diluter arranged outside the sampling chamber, for diluting the sample gas entering the jet diluter to a fixed dilution ratio;

[0062] a sonic orifice arranged in the sampling chamber, for limiting the flow rate of the sample gas entering the jet diluter, and can keep the flow rate constant;

[0063] a rod-shaped heater arranged substantially linearly along the sampling probe. Thus, the heater of the present application will not be damaged due to excessive bending, and the failure rate of the heater is reduced, and the service life of the heater is improved.

[0064] In some embodiments, the sampling probe includes an inner tube and an outer tube surrounding the inner tube; and the rod-shaped heater is arranged between the outer wall of the inner tube and the inner wall of the outer tube.

[0065] In some embodiments, the rod-shaped heater is arranged on the outer wall of the inner tube and extends substantially linearly along the length direction of the inner tube.

[0066] In some embodiments, the rod-shaped heater is fixed on the outer wall of the inner tube of the probe rod by using fixing components at at least two fixing positions, and the distance between adjacent fixing positions is equal.

[0067] In some embodiments, the sampling probe further comprises:

[0068] A rubber plug for sealing the space between the outer wall of the inner tube of the probe rod and the inner wall of the outer tube of the probe rod at the inlet end;

[0069] A threaded cap for pressing and fixing the rubber plug on the sampling probe.

[0070] The rubber plug and the threaded cap structure isolate the heater from the corrosive gas, so that the heater is not corroded by the corrosive substances in the sample gas.

[0071] In some embodiments, the sampling chamber has a receiving portion for receiving the sonic orifice; and the sonic orifice is received in the receiving portion via a triple sealing structure comprising a first sealing structure, a second sealing structure and a third sealing structure.

[0072] The triple sealing structure ensures that the flow rate of the sample gas entering the jet diluter is the designed flow rate, thereby ensuring accurate dilution ratio.

[0073] In some embodiments, the first sealing structure comprises:

[0074] A compression nut located at the opening side of the receiving portion and arranged between the outer wall of the sonic orifice and the inner wall of the receiving portion;

[0075] A sealing band arranged between the outer wall of the compression nut and the inner wall of the receiving portion.

[0076] In some embodiments, the second sealing structure comprises a plastic sleeve arranged close to the bottom of the receiving portion, and the sonic orifice is interference-fitted in the receiving portion via the plastic sleeve.

[0077] In some embodiments, the third sealing structure comprises a sealing ring arranged at the joint of the plastic sleeve and the compression nut and surrounding the sonic orifice.

[0078] In some embodiments, the gas dilution probe further comprises a sampling chamber filter element arranged in the sampling chamber and located at the upstream side of the sonic orifice.

[0079] It should be understood that various changes, modifications, etc. can be made to any one of the aforementioned embodiments by those skilled in the art without departing from the scope defined by the claims of the present application. The technical solutions obtained by making various changes, modifications, etc. to any one of the aforementioned embodiments still fall within the scope defined by the claims of the present application.

Claims

1. A gas dilution probe comprising: a sampling probe stem having an internal flow passage allowing a flow of a sample gas to pass therethrough; a sampling chamber in fluid communication with the internal flow passage of the sampling probe stem for receiving the sample gas flowing in through the sampling probe stem; a jet diluter disposed outside the sampling chamber for diluting the sample gas entering the jet diluter to a fixed dilution ratio; a sonic orifice disposed in the sampling chamber for limiting the flow of the sample gas entering the jet diluter; wherein the sampling chamber has a receiving portion for receiving the sonic orifice; and the sonic orifice is received in the receiving portion via a triple seal structure comprising a first seal structure, a second seal structure and a third seal structure.

2. The gas dilution probe of claim 1, wherein, The first seal structure comprises: a compression nut located at an opening side of the receiving portion and disposed between an outer wall of the sonic orifice and an inner wall of the receiving portion; a sealing band disposed between an outer wall of the compression nut and the inner wall of the receiving portion.

3. The gas dilution probe of claim 2, wherein, The second seal structure comprises a plastic collar disposed proximate to a bottom of the receiving portion, the sonic orifice being interference fit in the receiving portion via the plastic collar.

4. The gas dilution probe of claim 3, wherein, The third seal structure comprises a sealing ring disposed at an interface of the plastic collar and the compression nut and surrounding the sonic orifice.

5. The gas dilution probe of claim 1, wherein, The gas dilution probe further comprises a sampling chamber filter disposed in the sampling chamber and located at an upstream side of the sonic orifice.

6. The gas dilution probe of claim 1, wherein, The gas dilution probe further comprises a rod heater disposed substantially linearly along the sampling probe stem.

7. The gas dilution probe of claim 6, wherein, The sampling probe stem comprises a probe stem inner tube and a probe stem outer tube surrounding the probe stem inner tube; The rod heater is disposed between an outer wall of the probe stem inner tube and an inner wall of the probe stem outer tube.

8. The gas dilution probe of claim 7, wherein, The rod heater is disposed on the outer wall of the probe stem inner tube and extends substantially linearly along a length direction of the probe stem inner tube.

9. The gas dilution probe of claim 8, wherein, The rod heater is secured to the outer wall of the probe stem inner tube using securing members at at least two securing locations, and a spacing between adjacent securing locations is equal.

10. The gas dilution probe of claim 7, wherein, The sampling probe stem further comprises: a rubber plug for sealing a space between the outer wall of the probe stem inner tube and the inner wall of the probe stem outer tube at an inlet end; a threaded cap for compressing and securing the rubber plug to the sampling probe stem.

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