CN116718442B - Measuring range and flow regulating method of individual sampler - Google Patents
Measuring range and flow regulating method of individual sampler Download PDFInfo
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- CN116718442B CN116718442B CN202310980668.6A CN202310980668A CN116718442B CN 116718442 B CN116718442 B CN 116718442B CN 202310980668 A CN202310980668 A CN 202310980668A CN 116718442 B CN116718442 B CN 116718442B
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- 230000001105 regulatory effect Effects 0.000 title claims abstract description 51
- 238000000034 method Methods 0.000 title claims abstract description 47
- 238000005070 sampling Methods 0.000 claims abstract description 102
- 230000033228 biological regulation Effects 0.000 claims abstract description 15
- 230000007246 mechanism Effects 0.000 claims description 59
- 230000000903 blocking effect Effects 0.000 claims description 34
- 238000009423 ventilation Methods 0.000 claims description 16
- 238000004891 communication Methods 0.000 claims description 15
- 230000008859 change Effects 0.000 claims description 13
- 238000012544 monitoring process Methods 0.000 claims description 4
- 238000013459 approach Methods 0.000 claims description 3
- 239000007789 gas Substances 0.000 description 68
- 238000001514 detection method Methods 0.000 description 31
- 239000013618 particulate matter Substances 0.000 description 22
- 239000012528 membrane Substances 0.000 description 21
- 238000010521 absorption reaction Methods 0.000 description 19
- 238000011144 upstream manufacturing Methods 0.000 description 9
- 238000007789 sealing Methods 0.000 description 5
- 238000009434 installation Methods 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
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- 230000003139 buffering effect Effects 0.000 description 3
- 238000001914 filtration Methods 0.000 description 3
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- 238000013461 design Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
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- 230000009471 action Effects 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
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- 230000007547 defect Effects 0.000 description 1
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- 238000002474 experimental method Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K3/00—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing
- F16K3/02—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with flat sealing faces; Packings therefor
- F16K3/04—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with flat sealing faces; Packings therefor with pivoted closure members
- F16K3/06—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with flat sealing faces; Packings therefor with pivoted closure members in the form of closure plates arranged between supply and discharge passages
- F16K3/08—Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing with flat sealing faces; Packings therefor with pivoted closure members in the form of closure plates arranged between supply and discharge passages with circular plates rotatable around their centres
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B35/00—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for
- F04B35/04—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/20—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by changing the driving speed
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K31/00—Actuating devices; Operating means; Releasing devices
- F16K31/02—Actuating devices; Operating means; Releasing devices electric; magnetic
- F16K31/04—Actuating devices; Operating means; Releasing devices electric; magnetic using a motor
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/02—Devices for withdrawing samples
- G01N1/22—Devices for withdrawing samples in the gaseous state
- G01N1/2273—Atmospheric sampling
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/02—Devices for withdrawing samples
- G01N1/22—Devices for withdrawing samples in the gaseous state
- G01N1/24—Suction devices
Abstract
The invention discloses a measuring range and flow regulating method of an individual sampler, belonging to the technical field of gas sampling. According to the method, the total air outlet cross section of the buffer cavity is regulated by arranging the regulating structure in the buffer cavity, so that the measuring range and the flow can be flexibly regulated without increasing the volume of the individual sampler, and the regulation is simpler.
Description
Technical Field
The invention relates to the technical field of gas sampling, in particular to a measuring range and flow regulating method of an individual sampler.
Background
The individual sampler is a portable instrument for detecting the air quality around a carrier and is used for sampling and detecting harmful gases or particulate matters in the environment and the air. The individual sampler is special sampling equipment which can work for a long time, is small, exquisite and portable, is simple to operate, is convenient to use and has stable performance. The patent publication 202123450826.2 discloses a specific structure of an individual sampler, when in general use, an air inlet nozzle of the sampler is communicated with a harmful gas absorption bottle or a particulate matter absorption filter membrane device through a pipeline, the harmful gas absorption bottle or the particulate matter absorption filter membrane device can be clamped at the collar of an operator, thus the individual sampler can provide gas sampling power, gas enters from the vicinity of the nose and the mouth of the operator through the harmful gas absorption bottle or the particulate matter absorption filter membrane device, then is discharged after passing through the sampler, and is absorbed by a corresponding absorption material in the absorption bottle, or the particulate matter is filtered by the filter membrane, finally, the amount of the harmful gas absorbed in the absorption bottle is detected again or the particulate matter in the filter membrane is weighed to obtain the amount of a target object, and finally, the amount of the harmful gas or the particulate matter is divided by the gas flow sampled by the individual sampler, so that the accuracy of the sampling gas flow of the sampler directly determines the accuracy of the particulate matter or the harmful gas concentration.
The gas flow is generally detected by adopting an orifice plate flowmeter which is arranged at the upstream or downstream of a sampling pump of an individual sampler, the gas flow of a system is obtained through pressure difference, smaller sampling flow is needed when harmful gas is sampled, larger sampling flow is needed when the particulate matter is detected, the sampling power of the current individual sampler is generally provided by adopting a miniature diaphragm pump, the particulate matter in the sampled gas is not contacted with other parts in a pump body, the flow range of the diaphragm pump is fixed, the flow size can be changed only by adjusting the rotating speed of a motor, but the mode can only be adjusted in a narrow range, the miniature diaphragm pump of the current individual sampler is communicated with a constant flow buffer bin through a medium flow channel, the flow channel size of the current miniature diaphragm pump can not be changed, the pressure difference of flow measurement is small under the condition of small flow rate, the pressure change is insensitive, the medium flow rate is large under the condition of large flow rate, the resistance is increased, the current individual sampler cannot accurately detect the air leakage, and the air leakage of the system can not accurately detect the air leakage result once the sampling is detected.
In order to solve the above technical problems, the patent number is: 202011055615.6 discloses a miniature diaphragm pump with a precise flow regulating device, which is added with the flow regulating device on the basis of the original pump body, and the flow regulating device has a very complex structure and comprises a regulating motor, a speed regulating assembly and a regulating device. And the adjusting device comprises: the axle sleeve and axle core, the axle sleeve is inside to be equipped with circular recess, from the gaseous injection of mixing bin output circular recess, inside the axle core can get into circular recess, and run through the outer wall of axle sleeve with circular recess is equipped with a plurality of holes, adjusting device gets into the range size in the circular recess through the axle core to adjust the quantity that lets the hole of gaseous inflow or outflow, this kind of structure can solve foretell technical problem, but this scheme still has great technical defect:
first, in the 202011055615.6 patent document, the structure of the adjusting device is very complex, the transmission between the adjusting device and the adjusting motor is also very complex, the structures of the rotating inner shaft core, the telescopic shaft core and the shaft sleeve are all very complex, and the diaphragm pump is a micro pump, so that the overall size of the components is relatively small, the processing difficulty of the overall components is very high, and the processing cost is also very high.
Secondly, the use of a flow regulator to fix the diaphragm pump to each other increases the overall length and size of the diaphragm pump assembly, which in turn increases the size and weight of the individual sampler.
In this solution, since the diaphragm pump and the flow regulator are integrally connected, in general, once the diaphragm pump is damaged, the diaphragm pump needs to be replaced together with the flow regulator during replacement, which results in great maintenance and replacement difficulty and very high maintenance and replacement cost;
finally, paragraphs 0031 and 0032 of 202011055615.6 describe the sampling principle and flow of small-flow sampling and large-flow sampling, wherein during the small-flow sampling, the gas sample output by the air pump enters from the path a and then is discharged from the paths B and C, the path B is a normally open path, the path C is an actual sampling path, the gas flow of the path C can realize the control of small-flow, and then the individual sampler needs to be connected with a harmful gas absorbing bottle or a particulate matter absorbing filter membrane device, obviously, the harmful gas absorbing bottle or the particulate matter absorbing filter membrane device must be communicated with the discharge port of the path C to realize the sampling of small-flow, and the sampling mode makes the particulate matters or the harmful gases enter into the harmful gas absorbing bottle or the particulate matter absorbing filter membrane device through the sampling pump and the regulating device finally, so that the particulate matters and the harmful gases can be attached into the upstream paths of the sampling pump and the regulating device, resulting in inaccurate sampling result.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: the method adjusts the ventilation resistance by adjusting the total air outlet cross section of the buffer chamber, so that the range and the flow of the individual sampler can be flexibly adjusted without increasing the volume of the individual sampler, and the adjustment is simpler.
In order to solve the technical problems, the technical scheme of the invention is as follows: according to the method, an adjusting mechanism is arranged in a buffer cavity of an individual sampler, and the total air outlet cross section of the buffer cavity is adjusted by the adjusting mechanism to adjust the ventilation resistance of the buffer cavity, so that the range and the flow of the individual sampler are adjusted;
when the electronic flowmeter is used for detecting the flow, and small flow is needed, the regulating mechanism reduces the total air outlet cross section area of the buffer chamber, reduces the rotating speed of the sampling pump of the individual sampler, feeds back the real-time flow through the electronic flowmeter, and finishes regulating when the real-time flow reaches the specified flow; when the large flow is needed, the regulating mechanism increases the total air outlet sectional area of the buffer chamber, increases the rotating speed of the sampling pump of the individual sampler, feeds back the real-time flow through the electronic flowmeter, and finishes the regulation when the real-time flow reaches the specified flow;
When the orifice plate flowmeter is used for detecting the flow, the regulating mechanism reduces the total air outlet sectional area of the buffer chamber, so that the total air outlet sectional area is regulated to be a pre-calibrated small flow sectional area, the rotating speed of a sampling pump of the individual sampler is reduced, the real-time flow is detected by detecting the pressure difference between the inside and the outside of the buffer chamber, and the regulation is finished when the real-time flow reaches the specified flow; when the large flow is needed, the regulating mechanism increases the total air outlet sectional area of the buffer chamber, so that the total air outlet sectional area reaches the pre-calibrated large flow sectional area, the rotating speed of the sampling pump of the individual sampler is increased, the real-time flow is detected by detecting the pressure difference between the inside and the outside of the buffer chamber, and the regulation is finished when the real-time flow reaches the specified flow.
As a preferable scheme, the specific way of adjusting the total air outlet cross section area of the buffer chamber by the adjusting mechanism is as follows: the buffer chamber is internally provided with a normally open air port and at least one chamber air outlet, and the regulating mechanism realizes the change of the total air outlet sectional area by opening or closing the chamber air outlet. Therefore, the total air outlet cross section area can be changed by plugging or not plugging the air outlet of the cavity, so that the sampling flow and the measuring range of the individual sampler can be accurately regulated, when harmful gas is detected, the sampling pump of the individual sampler can operate at a lower rotating speed to control the sampling flow, so that the sampling flow is reduced, the air outlet of the cavity is plugged and the normally open air port is always opened, the air outlet cross section is smaller because only one normally open air port is opened at the moment, the air outlet cross section is smaller, the ventilation resistance is proper, the rotating speed of the sampling pump is not very low, the sampling pump is ensured to operate at a proper rotating speed, the condition that the rotating speed is unstable or not started due to the fact that the rotating speed is too low is avoided, meanwhile, the cross section area of the normally open air port is known, the flow under the cross section area can be calibrated in advance, and the accuracy of a flow detection result is ensured; when the particle detection is needed, the air outlet of the cavity is opened, the total air outlet sectional area of the buffer cavity is larger than that of a single outlet, the required sampling flow is larger, the sum of the total areas of the air outlet of the cavity and the normally open air outlet is also known and fixed, so that the flow calibration is also carried out under the air outlet sectional area, the accuracy of the detection result is finally ensured, the ventilation resistance is proper and cannot be too large because the total air outlet sectional area is larger, and the rotating speed of the sampling pump is not required to be too high, so that the large sampling flow can be still met, the rotating speed of the sampling pump is in a reasonable safety range, the sampling pump is ensured to be used under the safety working condition, and the service life is prolonged.
As a preferable scheme, the adjusting mechanism opens or closes the air outlet of the cavity in the following way: and the linear power device is used for driving the blocking piece which is arranged in the buffer cavity in a linear sliding manner to close or open the air outlet of the cavity.
As a preferable scheme, the linear power device is a speed reducing motor, the speed reducing motor drives the blocking piece to axially slide through a screw nut mechanism, the adjusting method further comprises a method for judging whether the blocking piece completely blocks the air outlet of the cavity by monitoring the blocking current of the speed reducing motor, when the speed reducing motor is closed, the speed reducing motor drives the blocking piece to axially slide to approach the air outlet of the cavity, when the blocking current of the speed reducing motor is increased to reach a set value, the motor stops, the blocking piece completely blocks the air outlet of the cavity, and by the detecting method, whether the blocking piece completely blocks the air outlet of the cavity can be accurately detected without detection of other sensors, so that the cost is saved.
As a preferable scheme, the specific way of adjusting the total air outlet cross section area of the buffer chamber by the adjusting mechanism is as follows: the buffer chamber is internally provided with a chamber air outlet, a rotary disk is rotatably arranged in the buffer chamber, the rotary disk is provided with a plurality of vent holes with different apertures, the rotary disk is driven by a rotary power device to enable the vent holes with different apertures to correspond to the chamber air outlet to finish the change of the total air outlet sectional area, the vent holes with different apertures are switched to correspond to the chamber air outlet through the rotation of the rotary disk in the mode, so that the total air outlet sectional area is changed, the flow and the measuring range of an individual sampler can be effectively adjusted, the adjustment is very convenient, meanwhile, the different aperture sizes of the vent holes are also known, and the air outlet sectional areas under different apertures are calibrated in advance, so that the detection requirement can be met.
As a preferable scheme, the specific way of adjusting the total air outlet cross section area of the buffer chamber by the adjusting mechanism is as follows: the buffer chamber is fixedly provided with an air guide sleeve, an air outlet end of the air guide sleeve is communicated with an air outlet of the chamber, a piston is axially and slidably arranged in the air guide sleeve, the air guide sleeve is divided into an air outlet chamber and an adjusting chamber by the piston, the side wall of the air guide sleeve is provided with a plurality of air inlets which axially extend, the air inlets are communicated with the air outlet chamber and an inner cavity of the buffer chamber, the piston is driven by a linear power device, the linear power device drives the piston to axially slide to change the size of the air outlet chamber, so that the number of the air inlets communicated with the air outlet chamber and the inner cavity of the buffer chamber is changed, the size of the total air outlet sectional area is changed, and the adjusting method is very convenient to adjust and control by changing the position of the piston, so that the number of the air inlets communicated with the air outlet chamber and the inner cavity of the buffer chamber is changed.
Preferably, the specific way for the adjusting mechanism to adjust the total air outlet cross section of the buffer chamber is as follows: the outer part of the buffer chamber is fixedly provided with an outer sleeve, a piston cavity sleeve is fixedly arranged in the outer sleeve, a communication cavity is arranged between the piston cavity sleeve and the outer sleeve, a piston is axially and hermetically arranged in the piston cavity sleeve in a sliding manner, the piston separates the piston cavity sleeve into an air outlet cavity and an adjusting cavity, a plurality of axially distributed adjusting air holes are formed in the side wall of the piston cavity sleeve and are communicated with the communication cavity, the air outlet cavity is communicated with a cavity air outlet of the buffer chamber, an air outlet is formed in the outer sleeve, the piston is driven to axially slide by a linear power device, the volume of the air outlet cavity is changed, the number of the adjusting air holes between the air outlet cavity and the communication cavity is changed, and finally the size of the total air outlet cross section area is changed.
As a preferable scheme, the range and flow regulating method of the individual sampler further comprises a method for detecting whether the individual sampler leaks or not, before the individual sampler is used, the regulating mechanism closes the total air outlet of the buffer chamber, the sampling pump of the individual sampler is started, the locked rotor current of the driving motor of the sampling pump is monitored, when the locked rotor current gradually rises to a set value, the individual sampler is not leaked, and when the locked rotor current gradually rises and does not always reach the set value, the individual sampler leaks, because the whole system does not leak air, the resistance of the air outlet is gradually increased after the sampling pump of the individual sampler is started, the locked rotor current of the sampling pump rises, so that whether the whole system leaks air or not can be judged by monitoring the locked rotor current of the sampling pump, and once the leakage occurs, the air outlet resistance of the sampling pump is lower than the resistance in the air leakage state, and the locked rotor current of the sampling pump cannot reach the current in the air leakage state at the moment, and the system can influence the accuracy of flow detection, thereby the detection result of the individual sampler is inaccurate.
After the technical scheme is adopted, the invention has the following effects: because the method installs the regulating mechanism in the buffer chamber of the individual sampler, the regulating mechanism is used for regulating the total air outlet sectional area of the buffer chamber to regulate the measuring range and the flow of the individual sampler, when the electronic flowmeter is used for detecting the flow, the regulating mechanism reduces the total air outlet sectional area of the buffer chamber and reduces the rotating speed of the sampling pump of the individual sampler, the electronic flowmeter feeds back the real-time flow, and when the real-time flow reaches the specified flow, the regulating is finished; when the large flow is needed, the regulating mechanism increases the total air outlet sectional area of the buffer chamber, increases the rotating speed of the sampling pump of the individual sampler, feeds back the real-time flow through the electronic flowmeter, and finishes the regulation when the real-time flow reaches the specified flow;
When the orifice plate flowmeter is used for detecting the flow, the regulating mechanism reduces the total air outlet sectional area of the buffer chamber, so that the total air outlet sectional area is regulated to be a pre-calibrated small flow sectional area, the rotating speed of a sampling pump of the individual sampler is reduced, the real-time flow is detected by detecting the pressure difference between the inside and the outside of the buffer chamber, and the regulation is finished when the real-time flow reaches the specified flow; when the large flow is needed, the regulating mechanism increases the total air outlet sectional area of the buffer chamber, so that the total air outlet sectional area reaches the pre-calibrated large flow sectional area, the rotating speed of the sampling pump of the individual sampler is increased, the real-time flow is detected by detecting the pressure difference between the inside and the outside of the buffer chamber, and the regulation is finished when the real-time flow reaches the specified flow.
Compared with the existing structure and method at present, the method has the following advantages: 1. according to the method, the adjustment of the measuring range and the flow rate is concentrated in the buffer cavity, so that no extra space is occupied, the whole individual sampler is as small as possible, and the whole individual sampler is convenient to carry; 2. according to the adjusting method, different adjusting modes are selected according to the flowmeter for detecting the flow rate to change and adjust the total air outlet cross section of the buffer chamber, wherein when harmful gas is detected, small flow rate is needed, a sampling pump of an individual sampler can operate at a lower rotating speed to control the sampling flow rate, at the moment, an adjusting mechanism reduces the total air outlet cross section of an air outlet of the chamber, so that the individual sampler still can keep certain ventilation resistance under the condition of small flow rate, at the moment, under the condition of proper ventilation resistance, the sampling pump needs to properly increase the rotating speed to achieve rated sampling flow rate, the condition that the rotating speed of the sampling pump is unstable or the starting torque is too small under the condition of small flow rate can be avoided, when the particulate matter is detected, the air outlet cross section of the chamber can be increased, and thus, the air outlet area with enough large enough air outlet area is avoided to avoid the excessive rotating speed of the sampling pump, and the sampling requirements of different flow rates are met; 3. in the adjusting method, when the orifice plate flowmeter is used for detecting the flow, the adjusting mechanism adjusts the total air outlet sectional area to a pre-calibrated large flow sectional area or a pre-calibrated small flow sectional area, and the adjusted sectional areas are calibrated in advance, so that the flow detected by the orifice plate flowmeter is very accurate under the total air outlet sectional area, and the accurate flow detection can ensure the accurate detection result of the individual sampler. Of course, the ventilation resistance is changed by changing the total air outlet sectional area of the buffer chamber, so that the measuring range of the individual sampler is adjusted and expanded, the lowest measuring range of the individual sampler is lower than that of the existing structure, and the maximum measuring range is higher than that of the existing structure, so that the measuring range of detection is wider.
Drawings
The invention will be further described with reference to the drawings and examples.
Fig. 1 is a structural perspective view of embodiment 1 of the present invention;
FIG. 2 is a perspective view of another angular structure of embodiment 1 of the present invention;
FIG. 3 is an internal perspective view of embodiment 1 of the present invention;
FIG. 4 is a schematic side view of example 1 of the present invention;
FIG. 5 is a cross-sectional view of FIG. 4 at A-A;
FIG. 6 is an enlarged schematic view of FIG. 5 at B;
FIG. 7 is a perspective view of a buffer chamber;
FIG. 8 is a perspective view with the elastic membrane hidden;
FIG. 9 is another perspective view of an angle with the elastic membrane hidden;
FIG. 10 is a schematic side view of a buffer chamber;
FIG. 11 is a cross-sectional view of FIG. 10 at C-C;
FIG. 12 is a cross-sectional view of FIG. 10 at D-D;
FIG. 13 is a schematic view showing the structure of a buffer chamber according to embodiment 2 of the present invention;
fig. 14 is a schematic structural view of a rotary disk of embodiment 2 of the present invention;
FIG. 15 is a schematic view showing the structure of a buffer chamber according to embodiment 3 of the present invention;
FIG. 16 is a schematic view showing the structure of a buffer chamber according to embodiment 4 of the present invention;
in the accompanying drawings: 1. a housing 1; 101. the connecting air tap 101; 102. a pressure detecting nozzle 102; 103. an exhaust communication passage 103; 104. installing a sink 104; 2. an operation panel 2; 3. the air passage joint 3; 31. an air inlet nozzle 31; 32. An intake communication passage 32; 33. an outlet communication passage 33; 34. a filter membrane 34; 35. an exhaust port; 4. a hook 4; 5. a sampling pump 5; 51. an air inlet 51 of a sampling pump 55; 52. an air outlet of the sampling pump 55; 6. a buffer chamber 6; 61. an elastic diaphragm 61; 62. a press ring 62; 63. installing a countersink 63; 64. normally open port 64; 65. a chamber air outlet 65; 7. a differential pressure sensor 7; 8. an upstream differential pressure sensor 8; 9. an air guide block 9; 91. an air outlet channel 91; 92. a bypass passage 92; 93. an air outlet hole 93; 94. a large aperture orifice plate 94; 95. a small aperture orifice plate 95; 10. a chamber inlet 10; 11. an adjusting mechanism 11; 111. a speed reduction motor 111; 112. a driven gear 112; 113. a shutoff lever 113; 114. A screw sleeve 114; 115. a drive gear 115; 116. A rotating disc 116; 1161. a vent 1161; 117. a rotary power device 117; 118. an air guide sleeve 118; 119. a piston rod 119; 1110. a piston 1110; 1111. an air outlet chamber 1111; 1112. an air inlet 1112; 1113. an internal thread reduction motor 1113; 1114. an outer jacket 1114; 1115. a communication cavity 1115; 1116. a piston cavity 1116; 12. and detecting the mouth.
Detailed Description
The present invention will be described in further detail with reference to the following examples.
Example 1
According to the method, an adjusting mechanism 11 is arranged in a buffer chamber 6 of an individual sampler, and the ventilation resistance of the buffer chamber 6 is adjusted by adjusting the total air outlet cross section of the buffer chamber 6 through the adjusting mechanism 11, so that the measuring range and the flow of the individual sampler are adjusted;
when an electronic flowmeter is used for detecting the flow, and a small flow is needed, the regulating mechanism 11 reduces the total air outlet cross section area of the buffer chamber 6, reduces the rotating speed of the sampling pump 5 of the individual sampler, feeds back the real-time flow through the electronic flowmeter, and finishes the regulation when the real-time flow reaches the specified flow; when a large flow is needed, the regulating mechanism 11 increases the total air outlet sectional area of the buffer chamber 6, the rotating speed of the sampling pump 5 of the individual sampler is increased, the real-time flow is fed back through the electronic flowmeter, the regulation is finished when the real-time flow reaches the specified flow, and the electronic flowmeter is based on Faraday electromagnetic induction law, and is composed of a sensor and a converter and can be purchased from the market. Because the electronic flowmeter can directly detect the flow, the total air outlet sectional area can be adjusted in a stepless manner when the adjusting structure adjusts the total air outlet sectional area, and can also be adjusted according to the adjusting mode of the orifice plate flowmeter.
When the orifice plate flowmeter is used for detecting the flow, the regulating mechanism 11 reduces the total air outlet sectional area of the buffer chamber 6 to be adjusted to the pre-calibrated small flow sectional area when the flow is required, the rotating speed of the sampling pump 5 of the individual sampler is reduced, the real-time flow is detected by detecting the pressure difference between the inside and the outside of the buffer chamber 6, and the regulation is finished when the real-time flow reaches the designated flow; when a large flow is needed, the regulating mechanism 11 increases the total air outlet sectional area of the buffer chamber 6, so that the total air outlet sectional area reaches the pre-calibrated large flow sectional area, the rotating speed of the sampling pump 5 of the individual sampler is increased, the real-time flow is detected by detecting the pressure difference between the inside and the outside of the buffer chamber 6, and the regulation is finished when the real-time flow reaches the designated flow. In this embodiment, the buffer chamber 6 may be disposed upstream of the sampling pump or downstream of the sampling pump.
In this embodiment, the specific way for the adjusting mechanism 11 to adjust the total air outlet cross-sectional area of the buffer chamber 6 is as follows: a normally open air port 64 and at least one chamber air outlet 65 are arranged in the buffer chamber 6, and the adjusting mechanism 11 changes the size of the total air outlet cross section by opening or closing the chamber air outlet 65. Therefore, the total air outlet cross section area can be changed by plugging or not plugging the cavity air outlet 65, thereby changing the ventilation resistance, thus accurately adjusting the sampling flow and the measuring range of the individual sampler, when harmful gas detection is carried out, the sampling pump 5 of the individual sampler needs to operate at a lower rotating speed to control the sampling flow, the sampling flow is reduced, the cavity air outlet 65 can be plugged and the normally open air outlet 64 is always opened, only one normally open air outlet 64 is opened, the air outlet cross section is smaller, the ventilation resistance is properly increased due to the small air outlet cross section, the rotating speed of the sampling pump 5 can not be very low, the situation that the rotating speed is unstable or not started due to the fact that the rotating speed is too low can be avoided, the sampling low measuring range of the individual sampler is lower, when particulate matter detection is needed, the cavity air outlet 65 is opened, the total air outlet cross section area of the buffer cavity 6 is larger than that of a single outlet is needed, the ventilation resistance is also larger, the rotating speed of the sampling pump 5 can be satisfied without being too high, thereby the method that the rotating speed of the sampling pump 5 is reasonably switched to a high in a high range of the sampling pump is ensured, the sampling range is reasonably used, and the sampling of the individual sampler is reasonably high, and the method of the measuring range is realized. In this embodiment, the cross-sectional areas of the chamber air outlet 65 and the normally open air outlet 64 are fixed, so that the adjusting mechanism 11 adjusts the total air outlet cross-sectional area, and thus, when the orifice plate flowmeter is used for detecting, the flow rate under each different total air outlet cross-sectional area can be calibrated in advance, and according to the detection principle of the orifice plate flowmeter, after the buffer chamber 6 is filled with air, when the air flows through the normally open air outlet 64 or the chamber air outlet 65, the air outlet cross-section is contracted, and at the moment, the normally open air outlet 64 or the chamber air outlet 65 is actually under the action of the orifice plate, so that the air flow rate is increased, the static pressure is reduced, the pressure difference is generated before and after the orifice plate, the medium flow rate is larger, the pressure difference between the front and the back of the orifice plate is larger, and the flow rate is calculated by measuring the pressure difference. According to the Bernoulli equation and the fluid continuity equation in the fluid mechanics, a basic flow formula of the quantitative relation between the flow and the pressure difference of the orifice plate can be deduced, so that the flow can be accurately detected by using the orifice plate flowmeter through calibrating the quantitative corresponding relation between the pressure difference and the flow under three different total outlet cross-sectional areas, and thus, the various detection requirements of the individual sampler can be met.
The adjusting mechanism 11 opens or closes the chamber air outlet 65 in the following manner: the blocking piece which is arranged in the buffer chamber 6 in a linear sliding way is driven by a linear power device to close or open the chamber air outlet 65.
The linear power device is a speed reducing motor 111, the speed reducing motor 111 drives the blocking piece to axially slide through a screw nut mechanism, the adjusting method further comprises a method for judging whether the blocking piece completely blocks the cavity air outlet 65 by monitoring the blocking current of the speed reducing motor 111, when the speed reducing motor 111 is closed, the blocking piece is driven to axially slide to approach the cavity air outlet 65, when the blocking current of the speed reducing motor 111 increases to a set value, the motor stops, the blocking piece completely blocks the cavity air outlet 65, and by the detecting method, whether the blocking piece completely blocks the cavity air outlet 65 can be accurately detected without detection of other sensors, so that the cost is saved.
As shown in fig. 1 to 12, the drawings disclose an individual sampler using the above measuring range and flow rate adjusting method, which comprises a housing 1, wherein a sampling pump 5 and a buffer chamber 6 are installed in the housing 1, the sampling pump 5 is a diaphragm pump, an air inlet nozzle 31 and an air outlet 35 are arranged on the housing 1, the air inlet nozzle 31 is used for being connected with a harmful gas absorbing bottle or a particulate matter absorbing filter membrane device, and in this embodiment, a hook 4 for facilitating the hooking of the sampler is further arranged on the housing 1. The hook 4 can be hooked on a belt or a special brace of a worker, the harmful gas absorption bottle or the particulate matter absorption filter membrane device is clamped at a neckline of the worker and is communicated with the air inlet nozzle 31 on the shell 1 through a hose, so that when the sampler is started, gas enters from the periphery of the mouth and the nose of the worker, enters into the sampler again after passing through the harmful gas absorption bottle or the particulate matter absorption filter membrane device, and is absorbed by an absorption medium in the absorption bottle, while particulate matters are filtered by a filter membrane in the particulate matter absorption filter membrane device, and finally, the total amount of the harmful gas can be obtained by detecting the harmful gas absorbed in the absorption medium, and the total amount of the particulate matters is obtained by weighing the filter membrane.
The utility model discloses a sampling pump, including sampling pump 5, buffer chamber, sampling pump 5, air inlet nozzle 311, buffer chamber, air inlet nozzle 311, buffer chamber, air inlet nozzle 5, air inlet nozzle, air outlet nozzle 35, pressure sensor 7 for detecting the differential pressure between buffer chamber 6 inside and the outside pressure is still installed to the shell 1, buffer chamber 6's inside is fixed with the adjustment mechanism 11 of the total air outlet cross-section area of adjusting chamber air outlet nozzle 65, be provided with the battery of supplying power for sampling pump 5 in the shell 1, this battery can provide the electric energy for whole sample thief, guarantees long-time operation.
In this embodiment, the casing 1 is further provided with an operation panel 2 for displaying and operating, and the operation panel 2 can display some parameters of the sampler and can be conveniently adjusted.
In this embodiment, the buffer chamber 6 is a rectangular chamber, the number of the elastic diaphragms 61 is two, the mounting countersink 63 is provided on two opposite chamber walls of the buffer chamber 6, the elastic diaphragms 61 are placed in the mounting countersink 63 and are detachably fixed through the pressing ring 62, wherein the pressing ring 62 is fixed on the mounting countersink 63 through screws to tightly press and fix the elastic diaphragms 61, the buffer chamber 6 can effectively store and adjust the gas flow, the elastic diaphragms 61 can expand when the internal gas pressure of the buffer chamber 6 is larger, and the elastic diaphragms 61 contract when the internal gas pressure is smaller, so that the stable gas flow discharged from the buffer chamber 6 can be ensured, and the pulsating gas flow characteristic of the diaphragm pump can be eliminated.
In this embodiment, the adjustment mechanism 11 comprises a blocking member slidably or rotatably mounted in the buffer chamber 6, the blocking member being driven by a linear or rotary power means 117 to move between an open position and a closed position. The sealing piece is in sealing fit with the corresponding chamber air outlet 65, a detection port 12 for detecting the internal pressure of the buffer chamber 6 is arranged on the buffer chamber 6, and one detection end of the differential pressure sensor 7 is communicated with the detection port 12.
However, in the present embodiment, the individual sampler can adjust the ventilation resistance of the individual sampler by adjusting the sectional area of the chamber air outlet 65.
In this embodiment, still be provided with a normally open gas port 64 on the buffering cavity 6, normally open gas port 64 and cavity gas outlet 65 all communicate with gas outlet channel 91, gas outlet channel 91 with communicate between the gas vent 35, normally open gas port 64's aperture is less than with the aperture of cavity gas outlet 65, and in the embodiment, the outside of buffering cavity 6 is fixed with air guide block 9 through the bolt can be dismantled, air guide block 9's position corresponds with cavity gas outlet 65 and normally open gas port 64 position, gas outlet channel 91 sets up on air guide block 9, be provided with on air guide block 9 with cavity gas outlet 65 and normally open gas port 64 with the branch road channel 92 of gas outlet channel 91 intercommunication, demountable installation has the orifice plate with cavity gas outlet 65 and normally open gas port 64 one-to-one between air guide block 9 and the buffering cavity 6, each orifice plate is located between corresponding branch road channel 92 and cavity gas outlet 65, branch road channel 92 and normally open gas port 64 respectively, still is provided with air outlet 93 on air guide block 9, and communicates with gas outlet channel 91 and then communicates it with gas vent 35.
In the present embodiment, in the above-described structure, the normally open air port 64 and the chamber air outlet 65 may actually form an orifice plate throttle structure, and therefore, the pressure difference between the inside and outside of the buffer chamber 6 may be detected by the differential pressure sensor 7, thereby detecting the air outlet flow rate of the buffer chamber 6.
The number of the orifice plates in the embodiment is two, wherein the orifice plates arranged between the normally open air port 64 and the branch passage 92 are small-aperture orifice plates 95, the orifice plates arranged between the chamber air outlet 65 and the branch passage 92 are large-aperture orifice plates 94, and the orifice plates are specifically arranged in a manner of being clamped and fixed by the air guide block 9 and the buffer chamber 6, and can be also arranged at the air outlet in a threaded manner. The size of the air outlet section can be changed by changing pore plates with different apertures, so that the flow interception is convenient to adjust.
The air outlet cross-sectional area of the chamber air outlet 65 of the conventional buffer chamber 6 of the existing individual sampler is not adjustable, so that the chamber air outlet 65 cannot meet the sampling requirement of very low flow or very high flow, that is, the range of the existing individual sampler is relatively narrow, because after the air outlet cross-sectional area of the chamber air outlet 65 is fixed, the flow can be adjusted only by controlling the rotating speed of the diaphragm pump within a certain range, for example, when the flow requirement is very small, the rotating speed of the diaphragm pump can be reduced, and the rotating speed of the diaphragm pump is very low, so that the following problems exist: 1. the rotational speed of the diaphragm pump may be too low to start; 2. the rotating speed of the diaphragm pump is low, so that the fluctuation of the air flow is large, and the air flow stability is influenced; 3. the rotation speed of the diaphragm pump is lower, the whole flow is lower, the pressure difference between the pressure of the buffer chamber 6 and the external pressure is smaller, thus the differential pressure detection precision of the orifice plate flowmeter is not high, and the detection result is also inaccurate, therefore, when the individual sampler is suitable for sampling and detecting harmful gas, the aperture of the chamber air outlet 65 can only be set to be smaller when leaving the factory, but the chamber air outlet 65 can not be suitable for the sampling requirement of large flow when being smaller, because when the sampling of large flow is needed, the aperture of the chamber air outlet 65 is smaller, the ventilation resistance is very large, the rotation speed needs to be increased to increase the flow speed, and the rotation speed of the diaphragm pump possibly exceeds the rated rotation speed to damage the diaphragm pump, so the range of the current individual sampler is narrow.
In the individual sampler in this embodiment, the above adjustment method is adopted, when the sampling detection of the harmful gas is required, the sampling requirement of the small flow is required at this time, the normally open air port 64 is opened, and the chamber air port 65 is closed, at this time, the cross-sectional area of the channel flowing out of the buffer chamber 6 is reduced, so that in order to achieve the set flow, the flow rate needs to be increased, and the rotation speed of the diaphragm pump needs to be increased, so that the rotation speed is prevented from being close to or lower than the starting rotation speed of the diaphragm pump during the sampling of the small flow, and the phenomenon of shutdown or unstable rotation speed of the diaphragm pump caused by the too low rotation speed can be avoided; in addition, when the small flow is sampled, only the normally open air port 64 is opened, the caliber is smaller, so that the pressure difference between the inside and the outside of the buffer chamber 6 is relatively larger, the accuracy of the orifice plate flowmeter is higher when the pressure difference is detected, and the detection result is also more accurate.
When the particulate matter sampling detection is needed, the detection flow of the particulate matter is generally larger, the sampling flow can reach 10 times of the sampling flow of the harmful gas sometimes, the air outlet 65 of the cavity can be opened at the moment, the total air outlet sectional area is increased at the moment, the ventilation resistance is not excessively large, and thus the diaphragm pump can meet the requirement of large flow of the particulate matter sampling as long as the rotating speed is properly increased, and therefore the diaphragm pump can also operate at a safe rotating speed, and the sampling sustainability and the reliability of the individual sampler are ensured.
As shown in fig. 5, 8, 9, 11 and 12, the blocking member for blocking the air outlet 65 of the chamber comprises a blocking rod 113, the blocking rod 113 is axially slidably mounted in the buffer chamber 6, the end of the blocking rod 113 is in sealing engagement with the air outlet 65 of the chamber, and the linear power device is mounted in the buffer chamber 6 and is in driving engagement with the blocking rod 113.
In this embodiment, the number of the chamber air outlets 65 is one, and the number of the normally open air outlets 64 is also one, however, it is also possible to have two chamber air outlets 65, and the apertures of the two chamber air outlets 65 are different, and two sets of plugging rods 113 are also provided, and each set of plugging rods 113 is driven by a corresponding linear power device, so that more combinations can be formed. In combination, normally open port 64 is open and both chamber air outlets 65 are closed; in the second combination, the normally open air port 64 is opened, the small-aperture chamber air outlet 65 is opened, and the large-aperture chamber air outlet 65 is closed; in the third combination, the normally open air port 64 is opened, the small-aperture chamber air outlet 65 is closed, and the large-aperture chamber air outlet 65 is opened; in combination four, normally open port 64 is open and both chamber vents 65 are open.
In this embodiment, the linear power device includes a gear motor 111, a driving gear 115 is fixed on an output shaft of the gear motor 111, a driven gear 112 meshed with the driving gear 115 is fixed on the plugging rod 113, a threaded sleeve 114 is fixed on the buffer chamber 6, the plugging rod 113 is threadedly mounted in the threaded sleeve 114, the driving gear 115 drives the driven gear 112 to rotate, the driven gear 112 rotates to drive the plugging rod 113 to spiral and simultaneously axially move, and further plugging or opening of the chamber air outlet 65 can be completed.
And as shown in fig. 5 and 6, the air inlet nozzle 31 and the air outlet 35 are integrated on the air passage joint 3, the air passage joint 3 is provided with an installation sink 104, one of the connectors of the upstream differential pressure sensor 8 is connected with the pressure detection nozzle 102, the other connector is communicated with the outside of the individual sampler, and thus the upstream differential pressure sensor 8 can detect the pressure difference between the air inlet communication channel 32 and the outside, so as to detect the flow of the upstream gas, the connection nozzle 101 is communicated with the air inlet nozzle 101 through a pipeline, the pressure detection nozzle 102 is also arranged on the casing 1, the pressure detection nozzle 102 is communicated with the air inlet communication channel 32, the corresponding casing 1 is internally provided with an upstream differential pressure sensor 8, one of the connectors of the upstream differential pressure sensor 8 is connected with the pressure detection nozzle 102, and the other connector is communicated with the outside of the individual sampler, and thus the connection nozzle 101 is communicated with the differential pressure sensor 33 of the air outlet 5 through a pipeline, the buffer chamber 65 is communicated with the air outlet 6, and the buffer chamber 5 is communicated with the air outlet chamber 51.
The installation sink 104 is also internally provided with a filtering membrane 34, the filtering membrane 34 is extruded and fixed in the installation sink 104 by the gas circuit connector 3, and the filtering membrane 34 can filter external particles when not connected with a harmful gas absorption bottle or a particulate matter absorption filter membrane device, so that the large particles are prevented from entering the sampling pump 5 to cause damage.
Example 2
The method of this embodiment is basically the same as the method of embodiment 1, except that the specific adjustment manner of the adjustment mechanism 11 is different, and the specific manner of adjusting the total air outlet cross-sectional area of the buffer chamber 6 by the adjustment mechanism 11 is as follows: the buffer chamber 6 is internally provided with a chamber air outlet 65, a rotary disk 116 is rotatably installed in the buffer chamber 6, a plurality of vent holes 1161 with different apertures are arranged on the rotary disk 116, the rotary disk 116 is driven by a rotary power device 117 to enable the different vent holes 1161 to be corresponding to the chamber air outlet 65 to finish the change of the total air outlet sectional area, and in the mode, the vent holes 1161 with different apertures are switched to be corresponding to the chamber air outlet 65 by the rotation of the rotary disk 116, so that the total air outlet sectional area is changed, the flow and the measuring range of an individual sampler can be effectively adjusted, and the regulation is also very convenient.
The method further comprises a method for detecting whether the individual sampler leaks air, wherein before the individual sampler is used, the regulating mechanism 11 closes the total air outlet of the buffer chamber 6, specifically, the rotating power device 117 can drive the solid part of the rotating disc 116 to seal the chamber air outlet 65, at the moment, the whole system is sealed, the sampling pump 5 of the individual sampler is started, the locked-rotor current of the driving motor of the sampling pump 5 is monitored, when the locked-rotor current gradually rises to a set value, the individual sampler is not leaked, and when the locked-rotor current gradually rises to a set value, the individual sampler is not leaked. The set value can be determined through experiments before delivery, a pressure sensor can be connected before delivery to judge whether the gas circuit system of the individual sampler has gas leakage or not, the locked-rotor current of the driving motor of the sampling pump 5 at the moment is recorded, the locked-rotor current value can be used as the set value, when the locked-rotor current reaches the set value, the gas circuit system of the whole individual sampler determines that the gas is not leaked, and once the gas is leaked, the locked-rotor current can not reach the set value.
In this embodiment, as shown in fig. 13 and 14, the blocking member includes a rotary disc 116, the rotary disc 116 is rotatably installed in the buffer chamber 6, the rotary disc 116 is in sealing fit with a chamber wall where the chamber air outlet 65 is located, a plurality of air holes 1161 with different apertures are provided on the rotary disc 116, and the rotary power device 117 drives the rotary disc 116 to rotate so that one of the air holes 1161 corresponds to the position of the chamber air outlet 93 or the rotary disc 116 blocks the chamber air outlet 65. In this embodiment, the ventilation holes 1161 with different apertures on the rotary disk 116 are directly utilized to change and adjust the air outlet cross-sectional area without providing the normally open air port 64, wherein the rotary power device 117 can be realized by adopting a speed reduction servo motor. As for the rotation angle at which the speed reduction motor 111 drives the rotary disk 116, this can be positioned by an existing position detection structure, for example, a hall sensor can be used.
Example 3
The method of this embodiment is basically the same as that of embodiment 2, except that the adjustment manner of the adjustment mechanism 11 is different, and this embodiment also has a method for detecting whether the individual sampler leaks, in this embodiment, the specific manner in which the adjustment mechanism 11 adjusts the total outlet cross-sectional area of the buffer chamber 6 is as follows: the buffer chamber 6 is fixedly provided with an air guide sleeve 118, an air outlet end of the air guide sleeve 118 is communicated with the chamber air outlet 65, a piston 1110 is axially and hermetically installed in the air guide sleeve 118 in a sliding manner, the air guide sleeve 118 is divided into an air outlet chamber 1111 and an adjusting chamber by the piston 1110, a plurality of axially extending air inlets 1112 are formed in the side wall of the air guide sleeve 118, the air outlet chamber 1111 is communicated with the inner cavity of the buffer chamber 6, the piston 1110 is driven by the linear power device, the linear power device drives the piston 1110 to axially slide to change the size of the air outlet chamber 1111, so that the number of air inlets 1112 communicating the air outlet chamber 1111 with the inner cavity of the buffer chamber 6 is changed, the size of the total air outlet sectional area is changed, and the adjusting method is very convenient to adjust and control by changing the position of the piston 1110, so that the number of the air inlets 1112 communicating the air outlet chamber 1111 with the inner cavity of the buffer chamber 6 is changed.
In this embodiment, as shown in fig. 15, an air guide sleeve 118 is fixed on the buffer chamber 6, the air guide sleeve 118 is fixed on the outside of the buffer chamber 6 by a bolt, the air outlet end of the air guide sleeve 118 is communicated with the air outlet 65 of the chamber, the blocking member comprises a piston 1110 rod 119 and a piston 1110 installed at the end of the piston 1110 rod 119, the piston 1110 is axially and slidably installed in the air guide sleeve 118, the piston 1110 separates the air guide sleeve 118 into an air outlet chamber 1111 and an adjusting chamber, a plurality of air inlet holes 1112 extending axially are arranged on the side wall of the air guide sleeve 118, the air inlet holes 1112 are communicated with the air outlet chamber 1111 and the inner cavity of the buffer chamber 6, and the piston 1110 rod 119 is driven by the linear power device.
The linear power device in this embodiment adopts the internal thread gear motor 1113, wherein the internal thread gear motor 1113 includes an internal thread sleeve and a gear motor 111 driving the internal thread sleeve to rotate, and the internal thread sleeve is in threaded connection with the piston 1110 shaft 119 to form the principle of a screw nut mechanism, so that when the gear motor 111 drives the internal thread sleeve to rotate, the piston 1110 shaft 119 is driven to axially move, and the piston 1110 shaft 119 is driven to axially move to change the size of the air outlet chamber 1111, so as to change the number of air inlet holes 1112 correspondingly communicated with the air outlet chamber 1111, thereby changing the size of the communication cross section between the buffer chamber 6 and the air outlet chamber 1111, and also realizing the adjustment of flow and measuring range. When the air leakage detection is needed, the piston 1110 directly moves to the air outlet end of the air guide sleeve 118, so that the number of air inlets 1112 between the air outlet chamber 1111 of the air guide sleeve 118 and the buffer chamber 6 is 0, thereby completing the blocking and meeting the air leakage detection.
Example 4
As shown in fig. 16, the structure of this embodiment is basically the same as that of embodiment 3, except that an outer jacket 1114 is fixed outside the buffer chamber 6, a piston chamber jacket 1116 is fixed inside the outer jacket 1114, a communication chamber 1115 is provided between the piston chamber jacket 1116 and the outer jacket 1114, the sealing member includes a piston 1110 shaft 119 and a piston 1110 mounted at the end of the piston 1110 shaft 119, the piston 1110 is axially and slidably mounted in the piston chamber jacket 1116, the piston 1110 separates the piston chamber jacket 1116 into an air outlet chamber 1111 and an adjusting chamber, a plurality of axially distributed adjusting air holes are provided on the side wall of the piston chamber jacket 1116, the adjusting air holes communicate the piston chamber jacket 1116 with the communication chamber 1115, the air outlet chamber 1111 communicates with the chamber air outlet 65 of the buffer chamber 6, an air outlet is provided on the outer jacket 1114, and the piston 1110 shaft 119 is driven by the linear power device. After the jacket 1114 is arranged outside the buffer chamber 6, the jacket 1114 can be located in the free space of the housing 1, and the piston 1110 shaft 119 and the internal thread gear motor 1113 are located in the buffer chamber 6, so that the volume of the buffer chamber 6 can be further reduced, and the whole sampler can be smaller.
The air path system, the actuating device such as a servo motor, a gear transmission mechanism and a screw nut mechanism are all conventional technologies at present, the specific structure and principle of an air cylinder, a motor and other transmission mechanisms and other designs are disclosed in detail in a mechanical design manual fifth edition printed twenty-eight times in a fifth edition of Beijing, 4 th month, 2008, the structure is clear, a vacuum element, an air loop and program control are disclosed in detail in an SMC training teaching material of 3 rd edition of a modern practical pneumatic technology published by a mechanical industry publishing company in a period of 08 month 01, the air path structure in the embodiment is also the prior art, and the control and a travel switch of the motor are also described in detail in a motor driving and speed regulating book published by a chemical industry publishing company in a period of 07 month 01, 2015, so that the circuit and the air path connection are clear. The above examples are merely illustrative of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and adaptations of the technical solution of the present invention should and are intended to fall within the scope of the present invention as defined in the claims.
Claims (8)
1. A measuring range and flow regulating method of individual sampler is characterized in that: according to the method, an adjusting mechanism is arranged in a buffer cavity of an individual sampler, and the total air outlet cross section of the buffer cavity is adjusted by the adjusting mechanism to adjust the ventilation resistance of the buffer cavity, so that the measuring range and the flow of the individual sampler are adjusted;
when the electronic flowmeter is used for detecting the flow, and small flow is needed, the regulating mechanism reduces the total air outlet cross section area of the buffer chamber, reduces the rotating speed of the sampling pump of the individual sampler, feeds back the real-time flow through the electronic flowmeter, and finishes regulating when the real-time flow reaches the specified flow; when the large flow is needed, the regulating mechanism increases the total air outlet sectional area of the buffer chamber, increases the rotating speed of the sampling pump of the individual sampler, feeds back the real-time flow through the electronic flowmeter, and finishes the regulation when the real-time flow reaches the specified flow;
when the orifice plate flowmeter is used for detecting the flow, the regulating mechanism reduces the total air outlet sectional area of the buffer chamber, so that the total air outlet sectional area is regulated to be a pre-calibrated small flow sectional area, the rotating speed of a sampling pump of the individual sampler is reduced, the real-time flow is detected by detecting the pressure difference between the inside and the outside of the buffer chamber, and the regulation is finished when the real-time flow reaches the specified flow; when the large flow is needed, the regulating mechanism increases the total air outlet sectional area of the buffer chamber, so that the total air outlet sectional area reaches the pre-calibrated large flow sectional area, the rotating speed of the sampling pump of the individual sampler is increased, the real-time flow is detected by detecting the pressure difference between the inside and the outside of the buffer chamber, and the regulation is finished when the real-time flow reaches the specified flow.
2. The method for adjusting the range and flow rate of an individual sampler according to claim 1, wherein: the specific mode of adjusting the total air outlet sectional area of the buffer chamber by the adjusting mechanism is as follows: the buffer chamber is internally provided with a normally open air port and at least one chamber air outlet, and the regulating mechanism realizes the change of the total air outlet sectional area by opening or closing the chamber air outlet.
3. The method for adjusting the range and the flow rate of an individual sampler according to claim 2, wherein: the mode of opening or closing the air outlet of the cavity by the adjusting mechanism is as follows: and the linear power device is used for driving the blocking piece which is arranged in the buffer cavity in a linear sliding manner to close or open the air outlet of the cavity.
4. A method of range and flow adjustment for an individual sampler as claimed in claim 3 wherein: the linear power device is a speed reducing motor, the speed reducing motor drives the blocking piece to axially slide through a screw nut mechanism, the adjusting method further comprises a method for judging whether the blocking piece completely blocks the air outlet of the cavity by monitoring the blocking current of the speed reducing motor, when the speed reducing motor is closed, the speed reducing motor drives the blocking piece to axially slide to approach the air outlet of the cavity, when the blocking current of the speed reducing motor increases to reach a set value, the motor stops, and the blocking piece completely blocks the air outlet of the cavity.
5. The method for adjusting the range and flow rate of an individual sampler according to claim 1, wherein: the specific mode of adjusting the total air outlet sectional area of the buffer chamber by the adjusting mechanism is as follows: the buffer chamber is internally provided with a chamber air outlet, a rotary disk is rotatably arranged in the buffer chamber, a plurality of vent holes with different apertures are arranged on the rotary disk, and the rotary disk is driven by a rotary power device to correspondingly complete the change of the total air outlet sectional area of the different vent holes and the chamber air outlet.
6. The method for adjusting the range and flow rate of an individual sampler according to claim 1, wherein: the specific mode of adjusting the total air outlet sectional area of the buffer chamber by the adjusting mechanism is as follows: the buffer chamber is fixedly provided with an air guide sleeve, an air outlet end of the air guide sleeve is communicated with an air outlet of the chamber, a piston is axially and slidably arranged in the air guide sleeve, the air guide sleeve is divided into an air outlet chamber and a regulating chamber by the piston, the side wall of the air guide sleeve is provided with a plurality of air inlets which axially extend, the air inlets are communicated with an inner cavity of the air outlet chamber and the buffer chamber, the piston is driven by a linear power device, the linear power device drives the piston to axially slide to change the size of the air outlet chamber, so that the number of the air inlets communicated with the air outlet chamber and the inner cavity of the buffer chamber is changed, and the total air outlet sectional area is changed.
7. The method for adjusting the range and flow rate of an individual sampler according to claim 1, wherein: the specific mode of adjusting the total air outlet sectional area of the buffer chamber by the adjusting mechanism is as follows: the outer part of the buffer chamber is fixedly provided with an outer sleeve, a piston cavity sleeve is fixedly arranged in the outer sleeve, a communication cavity is arranged between the piston cavity sleeve and the outer sleeve, a piston is axially and hermetically arranged in the piston cavity sleeve in a sliding manner, the piston separates the piston cavity sleeve into an air outlet cavity and an adjusting cavity, a plurality of axially distributed adjusting air holes are formed in the side wall of the piston cavity sleeve and are communicated with the communication cavity, the air outlet cavity is communicated with a cavity air outlet of the buffer chamber, an air outlet is formed in the outer sleeve, the piston is driven to axially slide by a linear power device, the volume of the air outlet cavity is changed, the number of the adjusting air holes between the air outlet cavity and the communication cavity is changed, and finally the size of the total air outlet cross section area is changed.
8. A method of range and flow adjustment for an individual sampler as claimed in claim 1 or 5 or 6 or 7, wherein: the measuring range and flow regulating method of the individual sampler further comprises a method for detecting whether the individual sampler leaks or not, before the individual sampler is used, the regulating mechanism closes the total air outlet of the buffer chamber, the sampling pump of the individual sampler is started, the locked rotor current of the driving motor of the sampling pump is monitored, when the locked rotor current gradually rises to a set value, the individual sampler is free from leaking, and when the locked rotor current gradually rises and does not always reach the set value, the individual sampler is free from leaking.
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Citations (11)
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