CN116988958A - Gas buffer device of individual sampler - Google Patents

Abstract

The invention discloses a gas buffering device of an individual sampler, which comprises a buffering chamber, wherein one chamber wall of the buffering chamber is an elastic diaphragm, an air inlet and a chamber air outlet are arranged on the buffering chamber, an air inlet pipe joint is arranged at the air inlet, and an adjusting mechanism for adjusting the cross section area of the chamber air outlet is arranged in the buffering chamber. The gas buffer device can convert the pulsating gas flow generated by the diaphragm pump into constant gas flow and can also detect gas leakage of the system, so that the gas leakage phenomenon of the system is avoided.

Description

Gas buffer device of individual sampler

Technical Field

The invention relates to the technical field of gas monitoring and sampling, in particular to a gas buffer device 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 disclosure of patent No. 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 absorbing bottle or a particulate matter absorbing filter membrane device through a pipeline, the harmful gas absorbing bottle or the particulate matter absorbing 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 absorbing bottle or the particulate matter absorbing filter membrane device, then is discharged after passing through the sampler, and is absorbed by a corresponding absorbing material in the absorbing bottle, or the particulate matter is filtered by the filter membrane, finally, the amount of the harmful gas absorbed in the absorbing bottle is detected again or the particulate matter in the filter membrane is weighed, and finally, the concentration of the harmful gas or the particulate matter can be obtained by dividing the amount of the harmful gas or the particulate matter 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.

The method is characterized in that a sampling flow requirement required by the detection of harmful gas and the detection of particulate matters is different, the detection gas flow is generally detected by adopting an orifice plate flowmeter, the orifice plate flowmeter is generally arranged at the downstream of a sampling pump of an individual sampler, the gas flow of a system is obtained through pressure difference, smaller sampling flow is required when the harmful gas is sampled, larger sampling flow is required when the particulate matters are detected, the sampling power of the current individual sampler is provided by adopting a miniature diaphragm pump, the flow measuring 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 be only 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 size of the flow channel can not be changed, the pressure difference of the flow measurement is small under the use condition of small flow, the pressure change is insensitive, the medium flow rate is large under the use condition of large flow, the received resistance is exponentially increased, the power consumption loss is large, and the current individual sampler cannot perform self-detection once the system has air leakage, and the air leakage can not accurately detect the sampling result.

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 rate adjustment device are integrally connected, in general, once the diaphragm pump is damaged, the diaphragm pump needs to be replaced together with the flow rate adjustment device during replacement, which results in great difficulty in maintenance and replacement and very high maintenance and replacement costs.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: the gas buffering device of the individual sampler can convert pulsating gas flow generated by the diaphragm pump into constant gas flow, and can detect gas leakage of a system at the same time, so that the gas leakage phenomenon of the system is avoided.

In order to solve the technical problems, the technical scheme of the invention is as follows: the utility model provides a gas buffer of individual sample thief, includes the buffering cavity, one of them chamber wall of buffering cavity is elastic diaphragm, be provided with air inlet and cavity gas outlet on the buffering cavity, air inlet department installs the air inlet pipe joint, the internally mounted of buffering cavity has the adjustment mechanism who is used for adjusting cavity gas outlet sectional area.

As a preferred solution, the adjusting mechanism comprises a blocking member slidably or rotatably mounted in the buffer chamber, and the blocking member is driven by a linear power device or a rotary power device to movably adjust between an opening station and a closing station.

As a preferable scheme, the buffer chamber is further provided with a normally open air port, the normally open air port and the chamber air outlet are both communicated with an air outlet channel, the air outlet channel is used for being communicated with an air outlet pipe connector, the sealing piece is in sealing fit with the corresponding chamber air outlet, and the buffer chamber is provided with a detection port for detecting the internal pressure of the buffer chamber.

As a preferable scheme, the plugging piece comprises a rotary disk, the rotary disk is rotatably installed in the buffer cavity, the rotary disk is in sealing fit with the cavity wall where the cavity air outlet is located, a plurality of vent holes with different apertures are formed in the rotary disk, and the rotary power device drives the rotary disk to rotate so that one vent hole corresponds to the air outlet position or the rotary disk plugs the cavity air outlet.

As a preferable scheme, the blocking piece comprises a blocking rod, the blocking rod is axially and slidably arranged in the buffer cavity, the end part of the blocking rod is in sealing fit with the air outlet of the cavity, and the linear power device is arranged in the buffer cavity and is in transmission fit with the blocking rod.

As a preferable scheme, the linear power device comprises a speed reducing motor, a driving gear is fixed on an output shaft of the speed reducing motor, a driven gear meshed with the driving gear is fixed on the plugging rod, a screw sleeve is fixed on the buffering cavity, the plugging rod is installed in the screw sleeve in a threaded mode, and the driving gear drives the driven gear to rotate so as to drive the plugging rod to axially move in a spiral mode.

As a preferable scheme, be fixed with the air guide sleeve on the buffering cavity, the air outlet end of air guide sleeve with the cavity gas outlet intercommunication, the shutoff piece includes the piston rod and installs in the piston rod tip, piston axial seal slidable mounting is in the air guide sleeve, the piston separates the air guide sleeve into air outlet cavity and regulation cavity, the lateral wall of air guide sleeve is provided with a plurality of axially extending inlet port, and this inlet port will give vent to anger cavity and buffering cavity's inner chamber intercommunication, the piston rod is by linear power device drives.

As a preferred scheme, the outside of buffering cavity is fixed with the overcoat, overcoat internal fixation has the piston chamber cover, be provided with the intercommunication chamber between piston chamber cover and the overcoat, the shutoff piece includes the piston rod and installs in the piston of piston rod tip, piston axial seal slidable mounting is in the piston chamber cover, the piston separates into the piston chamber cover and gives vent to anger cavity and adjust the cavity, the lateral wall of piston chamber cover is provided with the regulation gas pocket of a plurality of axial distribution, and this regulation gas pocket communicates piston chamber cover and intercommunication chamber, give vent to anger the cavity with the cavity gas outlet intercommunication of buffering cavity, be provided with the gas outlet on the overcoat, the piston rod is by the drive of sharp power device.

As a preferred scheme, the outside of buffering cavity can be dismantled and be fixed with the air guide block, the position of air guide block corresponds with cavity gas outlet and normally open gas port position, the passageway of giving vent to anger sets up on the air guide block, be provided with the branch road passageway with cavity gas outlet and normally open gas port and the passageway intercommunication of giving vent to anger on the air guide block, demountable installation has the orifice plate with cavity gas outlet and normally open gas port one-to-one between air guide block and the buffering cavity, and each orifice plate is located between corresponding branch road passageway and cavity gas outlet, branch road passageway and the normally open gas port respectively.

As a preferable scheme, the number of the elastic diaphragms is two, mounting sunk openings are formed in two opposite chamber walls of the buffer chamber, and the elastic diaphragms are arranged in the mounting sunk openings and are detachably fixed through compression rings.

After the technical scheme is adopted, the invention has the following effects: because the gas buffering device of the individual sampler comprises a buffering chamber, one chamber wall of the buffering chamber is an elastic diaphragm, an air inlet and a chamber air outlet are formed in the buffering chamber, an air inlet pipe joint is installed at the air inlet, and an adjusting mechanism for adjusting the sectional area of the chamber air outlet is installed in the buffering chamber, the adjusting mechanism of the gas buffering device is arranged in the buffering chamber, and the size of the buffering chamber is not integrally increased, so that the gas buffering device has the following advantages: 1. the elastic diaphragm of the buffer chamber can expand when the internal air pressure of the buffer chamber is high, and the elastic diaphragm contracts when the internal air pressure is low, so that the stable flow of the air flow discharged from the buffer chamber can be ensured, and the pulsating air flow characteristic of the diaphragm pump of the individual sampler can be eliminated; 2. the adjusting mechanism is arranged in the buffer chamber, the size of the buffer chamber is not integrally increased, so that the whole size of the individual sampler is not influenced, meanwhile, the air resistance can be adjusted because the adjusting mechanism can adjust the sectional area of the air outlet of the chamber, when harmful gas is detected, the diaphragm pump of the individual sampler needs to be operated at a lower rotating speed to control the sampling flow, at the moment, the sectional area of the air outlet of the chamber is reduced by the adjusting mechanism, the individual sampler still can keep a certain air resistance under the condition of small flow, in order to ensure that the flow reaches the specified flow, the diaphragm pump needs to increase the rotating speed to reach the rated sampling flow because the air outlet sectional area is reduced, the unstable rotating speed of the diaphragm pump or the condition that the starting torque is too small can be avoided when the particle detection needs to be carried out, the sectional area of the air outlet of the chamber can be increased when the particle detection needs to be carried out at a large flow, so that the sufficiently large air outlet area is needed, the rotating speed of the diaphragm pump can be avoided to be too fast, the sampling requirements of different flow can be met, and the volume of the individual sampler can be as small as possible.

The buffer chamber is further provided with a normally open air port, the normally open air port and the chamber air outlet are communicated with the air outlet channel, the air outlet channel is used for being communicated with the air outlet pipe connector, the sealing fit is realized between the sealing piece and the corresponding chamber air outlet, the buffer chamber is provided with a detection port for detecting the internal pressure of the buffer chamber, therefore, the sealing piece is used for sealing or not sealing the chamber air outlet, the total air outlet sectional area can be changed, the sampling flow of the individual sampler can be accurately regulated, the small flow is required when harmful gas is detected, the isolating pump of the individual sampler can operate at a lower rotating speed to control the sampling flow, at the moment, the normally open air port is always opened when the chamber air outlet is sealed, and because only one normally open air port is opened, the section of the individual sampler is smaller, the individual sampler still can keep a certain differential pressure under the condition of small flow, so that the flow is accurately detected by the flow meter, in order to ensure that the flow reaches the specified flow, the diaphragm pump needs to be increased to improve the sampling flow speed, the condition that the diaphragm pump is unstable or not started when the harmful gas is detected, the whole air outlet is required to be opened at a large rotating speed, the same time, the volume of the whole air pump is not required to be fully opened, and the air outlet is required to be fully opened, and the volume of the air is not required to be high, and the air flow is required to be rapidly detected, and the whole volume is required to be rapidly, and the air is not required to be opened.

Because the plugging piece comprises a rotary disk, the rotary disk is rotatably arranged in the buffer cavity, the rotary disk is in sealing fit with the cavity wall where the cavity air outlet is positioned, a plurality of vent holes with different apertures are formed in the rotary disk, the rotary power device drives the rotary disk to rotate so that one vent hole corresponds to the air outlet hole or the rotary disk plugs the cavity air outlet, the rotary disk can be driven to rotate through the rotary power device, thus the vent holes with different apertures on the rotary disk correspond to the cavity air outlet, the size of the whole air outlet section can be changed, and the sampling flow can be adjusted.

And the blocking piece comprises a blocking rod, the blocking rod is axially and slidably arranged in the buffer cavity, the end part of the blocking rod is in sealing fit with the air outlet of the cavity, and the linear power device is arranged in the buffer cavity and is in transmission fit with the blocking rod. The linear power device comprises a gear motor, a driving gear is fixed on an output shaft of the gear motor, a driven gear meshed with the driving gear is fixed on the plugging rod, a screw sleeve is fixed on the buffer cavity, the plugging rod is installed in the screw sleeve in a threaded mode, the driving gear drives the driven gear to rotate so as to drive the plugging rod to axially move in a spiral mode, therefore, the plugging rod drives the axial movement to plug a cavity air outlet through the gear motor to also plug or open the cavity air outlet, flow can be adjusted, meanwhile, the driving structure of the plugging rod is simple, the gear motor can drive the plugging rod to be stably located at an opening or closing position, and the structure is more reliable.

And because the air guide sleeve is fixed on the buffer chamber, the air outlet end of the air guide sleeve is communicated with the air outlet of the chamber, the plugging piece comprises a piston rod and a piston arranged at the end part of the piston rod, the piston is axially and slidably arranged in the air guide sleeve in a sealing way, the piston separates the air guide sleeve into an air outlet chamber and a regulating chamber, a plurality of axially extending air inlets are arranged on the side wall of the air guide sleeve, the air inlets are communicated with the air outlet chamber and the inner cavity of the buffer chamber, and the piston rod is driven by the linear power device. Therefore, the linear power device is utilized to drive the piston rod to axially move, the piston rod drives the piston to axially move so as to change the size of the air outlet chamber, and then the number of air inlets correspondingly communicated with the air outlet chamber is changed, so that the size of the communication sectional area between the buffer chamber and the air outlet chamber is changed, the flow is regulated, and the requirements of different sampling conditions are met.

Because the outside of buffering cavity can be dismantled and is fixed with the air guide block, the position of air guide block corresponds with cavity gas outlet and normally open gas port position, the passageway of giving vent to anger sets up on the air guide block, be provided with on the air guide block with cavity gas outlet and normally open gas port and the branch road passageway of the passageway intercommunication of giving vent to anger, demountable installation has the orifice plate with cavity gas outlet and normally open gas port one-to-one between air guide block and the buffering cavity, and each orifice plate is located between corresponding branch road passageway and cavity gas outlet, branch road passageway and normally open gas port respectively, utilizes this air guide block can be better setting and installing the orifice plate, also can conveniently set up the branch road passageway and communicate each cavity gas outlet.

Drawings

The invention will be further described with reference to the drawings and examples.

Fig. 1 is a perspective view of embodiment 1 of the present invention;

FIG. 2 is a perspective view of the elastic membrane of FIG. 1, with the elastic membrane hidden;

FIG. 3 is a perspective view of another angle with the elastic membrane hidden;

FIG. 4 is a top view of example 1;

FIG. 5 is a cross-sectional view of FIG. 4 at A-A;

FIG. 6 is a cross-sectional view of FIG. 4 at B-B;

fig. 7 is a schematic structural view of embodiment 2;

fig. 8 is a schematic structural view of the rotary disk of embodiment 2;

fig. 9 is a schematic structural view of embodiment 3;

fig. 10 is a schematic structural view of embodiment 4;

in the accompanying drawings: 1. a buffer chamber; 11. a normally open air port; 12. a chamber air outlet; 13. installing a sinking port; 2. an air guide block; 21. a bypass channel; 22. an air outlet channel; 23. an air outlet hole; 24. a large aperture orifice plate; 25. a small aperture orifice plate; 3. a compression ring; 4. an elastic diaphragm; 5. an adjusting mechanism; 51. a linear power device; 52. a drive gear; 53. a plugging rod; 54. a screw sleeve; 55. a driven gear; 56. a rotating disc; 561. a vent hole; 57. a rotary power device; 58. an air guide sleeve; 59. a piston rod; 510. a piston; 511. an air outlet chamber; 512. an air inlet hole; 513. an internal thread speed reducing motor; 514. regulating the air holes; 515. a jacket; 516. a communication chamber; 517. a piston cavity sleeve; 6. an inner cavity; 7. detecting a pipe joint; 8. an air inlet pipe joint.

Detailed Description

The present invention will be described in further detail with reference to the following examples.

Example 1

As shown in fig. 1 to 6, a gas buffer device of an individual sampler is used for an individual to carry around the air of a user, so as to detect whether the surrounding air particulate matter or harmful gas meets the standards, and the individual sampler generally comprises a box body, wherein a sampling pump, a buffer chamber 1, a storage battery, an orifice flowmeter and a plurality of connecting pipelines are generally arranged in the box body, and the specific connecting modes are as follows: the particle filtering device (the filter membrane device) or the harmful gas absorbing bottle is connected to the air inlet nozzle of the box body of the individual sampler in a threaded manner, the air inlet nozzle is communicated with the air inlet of the sampling pump, the air outlet 12 of the chamber of the sampling pump is communicated with the air inlet of the buffer chamber 1, the air outlet 12 of the chamber of the buffer chamber 1 is connected with the orifice plate flowmeter, and finally gas is discharged, wherein the sampling pump provides power for sampling, the storage battery provides power for the sampling pump, the purpose of the buffer chamber 1 is to convert pulse air flow of the sampling pump into constant air flow to flow out, the accuracy of air flow detection is guaranteed, and the orifice plate flowmeter reflects the flow of gas by detecting differential pressure on two sides of the orifice plate.

In this embodiment, the gas buffering device includes a buffering chamber 1, one chamber wall of the buffering chamber 1 is an elastic diaphragm 4, an inner cavity 6 is provided in the buffering chamber 1, the elastic diaphragm 4 can expand when the internal air pressure of the buffering chamber 1 is large, and the elastic diaphragm 4 contracts when the internal air pressure is small, so that the flow of the air discharged from the buffering chamber 1 can be ensured to be stable, and the pulsating air flow characteristic of the diaphragm pump can be eliminated. In this embodiment, the number of the elastic diaphragms 4 is two, the two opposite chamber walls of the buffer chamber 1 are provided with mounting notches 13, and the elastic diaphragms 4 are placed in the mounting notches 13 and are detachably fixed by bolts through the compression ring 3.

The buffer chamber 1 is provided with an air inlet and a chamber air outlet 12, an air inlet pipe joint 8 is arranged at the air inlet, the chamber air outlet 12 communicates the buffer chamber 1 with the external environment, and an adjusting mechanism 5 for closing or opening the chamber air outlet 12 is fixed in the buffer chamber 1.

The adjusting mechanism 5 comprises a blocking piece which is slidably or rotatably installed in the buffer chamber 1, and the blocking piece is driven by the linear power device 51 or the rotary power device 57 to movably adjust between an opening station and a closing station, in this embodiment, the opening or closing of the chamber air outlet 12 is realized through the adjusting mechanism 5, when the chamber air outlet is opened, the normal air flow requirement of the air sampler can be met, and when the chamber air outlet is closed, whether the pipeline system leaks or not can be detected.

In this embodiment, it is further preferred that a normally open air port 11 is further provided on the buffer chamber 1, the normally open air port 11 and the chamber air outlet 12 are both communicated with the air outlet channel 22, the air outlet pipe joint is communicated with the air outlet channel 22, the sealing member is in sealing fit with the corresponding chamber air outlet 12, a detection port for detecting the internal pressure of the buffer chamber 1 is provided on the buffer chamber 1, and a detection pipe joint 7 convenient for connecting a pipeline is installed at the detection port. In the above structure, the normally open air port 11 and the chamber air outlet 12 may actually form an orifice plate throttling structure, so that the pressure inside the buffer chamber 1 and the pressure difference outside the buffer chamber 1 may be detected by a differential pressure sensor, thereby detecting the air outlet flow of the buffer chamber 1.

In this embodiment, the aperture of the normally open air port 11 is smaller than the aperture of the chamber air outlet 12, the blocking piece includes a blocking rod 53, the blocking rod 53 is axially slidably mounted in the buffer chamber 1, the end of the blocking rod 53 is in sealing fit with the chamber air outlet 12, the linear power device 51 is mounted in the buffer chamber 1 and is in driving fit with the blocking rod 53, in this embodiment, the number of the chamber air outlets 12 is one, the number of the normally open air ports 11 is also one, of course, the number of the chamber air outlets 12 is two, the apertures of the two chamber air outlets 12 are different, and two sets of blocking rods 53 are also provided, each set of blocking rods 53 is driven by a corresponding linear power device 51, so that more combinations can be formed. In combination, a normally open air port 11 is opened, and air outlets 12 of two chambers are closed; in the second combination, a normally open air port 11 is opened, a small-aperture cavity air outlet 12 is opened, and a large-aperture cavity air outlet 12 is closed; the combination III, the normally open air port 11 is opened, the small-aperture chamber air outlet 12 is closed, and the large-aperture chamber air outlet 12 is opened; and in the fourth combination, the normally open air port 11 is opened, and the air outlets 12 of the two chambers are opened.

In this embodiment, the linear power device 51 includes a gear motor, a driving gear 52 is fixed on an output shaft of the gear motor, a driven gear 55 meshed with the driving gear 52 is fixed on the blocking rod 53, a threaded sleeve 54 is fixed on the buffer chamber 1, the blocking rod 53 is threadedly mounted in the threaded sleeve 54, the driving gear 52 drives the driven gear 55 to rotate, and the driven gear 55 rotates to drive the blocking rod 53 to axially move in a spiral manner, so that blocking or opening of the air outlet 12 of the chamber can be completed.

As shown in fig. 2 and fig. 5, the air guide block 2 is detachably fixed to the outside of the buffer chamber 1, the position of the air guide block 2 corresponds to the positions of the chamber air outlet 12 and the normally open air port 11, the air outlet channel 22 is arranged on the air guide block 2, one end of the air outlet channel 22 is plugged by plugging screws, an air outlet hole 23 communicated with the air outlet channel 22 is arranged on the air guide block 2, the air guide block 2 is provided with a branch channel 21 for communicating the chamber air outlet 12 and the normally open air port 11 with the air outlet channel 22, pore plates corresponding to the chamber air outlet 12 and the normally open air port 11 are detachably arranged between the air guide block 2 and the buffer chamber 1, each pore plate is respectively arranged between the corresponding branch channel 21 and the chamber air outlet 12, the branch channel 21 and the normally open air port 11, the pore plates in the embodiment are two, the pore plates 25 are arranged between the normally open air port 11 and the branch channel, the pore plates 24 are arranged between the chamber air outlet 12 and the branch channel, the specific pore plates can be clamped and fixed by the air guide block 2 and the buffer chamber 1, and the air outlet 12 can also be fixedly arranged at the positions of the screw threads. The size of the air outlet section can be changed by changing pore plates with different apertures, and the adjustment is very convenient.

The air outlet cross-sectional area of the air outlet 12 of the conventional buffer chamber of the existing individual sampler is not adjustable, so that the air outlet 12 of the chamber cannot meet the requirement of very low flow or very high flow, that is, the range of the existing isolation sampler is relatively narrow, because when the air outlet cross-sectional area of the air outlet 12 of the chamber is fixed, the flow can be regulated 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 is 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 cavity 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 cavity air outlet=can only be set to be smaller when leaving the factory, but the cavity air outlet is smaller, the requirement of large-flow sampling cannot be met, because when large-flow sampling is needed, the aperture of the cavity air outlet is smaller, the larger flow speed is needed, the resistance of the air outlet end of the diaphragm pump is also very large, the rotation speed is increased to increase the flow speed, and the diaphragm pump is damaged due to the fact that the rotation speed of the diaphragm pump exceeds the rated rotation speed, so the range of the current isolation sampler is small.

When the gas buffer device in this embodiment is installed in an individual sampler and a sampling requirement of a small flow is needed at this time, the normally open gas port 11 is opened and the chamber gas outlet 12 is closed, at this time, the cross-sectional area of the channel flowing out of the buffer chamber 1 is reduced, so that in order to achieve a 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 sampling of the small flow, and the phenomenon that the diaphragm pump stops or the rotation speed is unstable due to the too low rotation speed can be avoided; in addition, when the small flow is sampled, only the normally open air port 11 is opened, the caliber is smaller, and therefore the pressure difference is relatively larger, and the accuracy of the orifice plate flowmeter is higher when the pressure difference is detected, and the detection result is 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 12 of the cavity can be opened at the moment, the total air outlet sectional area is increased at the moment, so that the diaphragm pump can meet the requirement of large flow of the particulate matter sampling as long as the rotating speed is properly increased, the diaphragm pump can also operate at the safe rotating speed, and the sampling sustainability and reliability of the individual sampler are ensured.

Example 2

As shown in fig. 7 and 8, the structure of this embodiment is basically the same as that of embodiment 1, except that the plugging member includes a rotary disc 56, the rotary disc 56 is rotatably mounted in the buffer chamber 1, the rotary disc 56 is in sealing fit with the chamber wall where the chamber air outlet 12 is located, the rotary disc 56 is provided with a plurality of air holes 561 with different apertures, and the rotary power device 57 drives the rotary disc 56 to rotate so that one of the air holes 561 corresponds to the air outlet 23 or the rotary disc 56 plugs the chamber air outlet 12. In this embodiment, the ventilation holes 561 with different apertures on the rotary disk 56 may be directly used to change and adjust the air outlet cross-sectional area without providing the normally open air port 11, and of course, a normally open air port 11 may be provided, and the change of the air outlet cross-sectional area may also be realized. Wherein the rotation power means 57 may be realized by a gear motor.

Example 3

As shown in fig. 9, the structure of this embodiment is basically similar to that of embodiment 1, except that the opening mechanism is different, in this embodiment, an air guide sleeve 58 is fixed on the buffer chamber 1, the air outlet end of the air guide sleeve 58 is communicated with the air outlet 12 of the chamber, the blocking member includes a piston rod 59 and a piston 510 mounted at the end of the piston rod 59, the piston 510 is axially and slidably mounted in the air guide sleeve 58, the piston 510 separates the air guide sleeve 58 into an air outlet chamber 511 and an adjusting chamber, a plurality of air inlet holes 512 extending axially are provided on the side wall of the air guide sleeve 58, the air inlet holes 512 communicate the air outlet chamber 511 with the inner cavity of the buffer chamber 1, and the piston rod 59 is driven by the linear power device 51. The linear power device 51 in this embodiment adopts an internal thread gear motor, wherein the internal thread gear motor includes an internal thread sleeve and a gear motor for driving the internal thread sleeve to rotate, and the internal thread sleeve and the piston rod 59 are in threaded connection to form a principle of a screw nut mechanism, so that when the gear motor drives the internal thread sleeve to rotate, the piston rod 59 is driven to axially move, and the piston rod 59 drives the piston 510 to axially move to change the size of the air outlet chamber 511, so as to change the number of air inlet holes 512 correspondingly communicated with the air outlet chamber 511, thereby changing the size of the communication sectional area between the buffer chamber 1 and the air outlet chamber 511, and also realizing adjustment of flow measurement range.

Example 4

As shown in fig. 10, the structure of this embodiment is basically similar to that of embodiment 3, a jacket 515 is fixed outside the buffer chamber, a piston chamber sleeve 517 is fixed inside the jacket 515, a communication chamber 516 is provided between the piston chamber sleeve 517 and the jacket 515, the blocking member includes a piston rod 59 and a piston 58 mounted at the end of the piston rod 59, the piston 58 is axially and slidably mounted in the piston chamber sleeve 517, the piston 58 separates the piston chamber sleeve 517 into an air outlet chamber 511 and an adjusting chamber, a plurality of axially distributed adjusting air holes 514 are provided on the side wall of the piston chamber sleeve 517, the adjusting air holes 514 communicate the piston chamber sleeve 517 with the communication chamber 516, the air outlet chamber 511 is communicated with the chamber air outlet of the buffer chamber, and an air outlet is provided on the jacket 515, and the piston rod is driven by the linear power device. The linear power device is driven by the internal thread speed reduction motor 513 in embodiment 3, and in this embodiment, after the outer sleeve 515 is disposed outside the buffer chamber, the outer sleeve 515 may be located in an empty space outside the buffer chamber, and the piston rod and the internal thread speed reduction motor 513 are both located in the buffer chamber, so that the volume of the buffer chamber can be further reduced, and the volume of the whole sampler can be smaller.

The air path system, the motor and other executing devices and the screw nut mechanism mentioned in the embodiment are all conventional technologies at present, the specific structure and principle of the motor and other driving mechanisms and other designs are disclosed in the fifth edition of the mechanical design manual printed twenty-eighth edition of the fifth edition of Beijing 4 in 2008, the structure is clear and clear, the above embodiment is only a description of the preferred embodiments of the present invention, and is not used as a limitation of the scope of the present invention, and various modifications and improvements made to the technical scheme of the present invention should fall within the protection scope determined by the claims of the present invention on the basis of not departing from the design spirit of the present invention.

Claims (10)

1. The utility model provides a gaseous buffer of individual sample thief, includes the buffering cavity, one of them chamber wall of buffering cavity is elastic diaphragm, be provided with air inlet and cavity gas outlet on the buffering cavity, air inlet department installs air inlet pipe joint, its characterized in that: and an adjusting mechanism for adjusting the sectional area of the air outlet of the chamber is arranged in the buffer chamber.

2. A gas buffering means for an individual sampler as claimed in claim 1 wherein: the adjusting mechanism comprises a blocking piece which is slidably or rotatably arranged in the buffer cavity, and the blocking piece is driven by a linear power device or a rotary power device to movably adjust between an opening station and a closing station.

3. A gas buffering means for an individual sampler as claimed in claim 2 wherein: the buffer chamber is further provided with a normally open air port, the normally open air port and the chamber air outlet are communicated with an air outlet channel, the air outlet channel is communicated with an air outlet pipe connector, the sealing piece is in sealing fit with the corresponding chamber air outlet, and the buffer chamber is provided with a detection port for detecting the internal pressure of the buffer chamber.

4. A gas buffering means for an individual sampler as claimed in claim 2 wherein: the plugging piece comprises a rotary disc, the rotary disc is rotatably installed in the buffer cavity, the rotary disc is in sealing fit with the cavity wall where the air outlet of the cavity is located, a plurality of vent holes with different apertures are formed in the rotary disc, and the rotary power device drives the rotary disc to rotate so that one vent hole corresponds to the position of the air outlet hole or the rotary disc plugs the air outlet of the cavity.

5. A gas buffering means for an individual sampler as claimed in claim 3 wherein: the blocking piece comprises a blocking rod, the blocking rod is axially slidably mounted in the buffer cavity, the end portion of the blocking rod is in sealing fit with the air outlet of the cavity, and the linear power device is mounted in the buffer cavity and in transmission fit with the blocking rod.

6. The gas buffering mechanism of an individual sampler of claim 5 wherein: the linear power device comprises a speed reducing motor, a driving gear is fixed on an output shaft of the speed reducing motor, a driven gear meshed with the driving gear is fixed on the plugging rod, a screw sleeve is fixed on the buffer cavity, the plugging rod is installed in the screw sleeve in a threaded mode, and the driving gear drives the driven gear to rotate so as to drive the plugging rod to axially move in a spiral mode.

7. A gas buffering means for an individual sampler as claimed in claim 2 wherein: the air guide sleeve is fixed on the buffer chamber, the air outlet end of the air guide sleeve is communicated with the air outlet of the chamber, the plugging piece comprises a piston rod and a piston arranged at the end part of the piston rod, the piston is axially and slidably arranged in the air guide sleeve in a sealing manner, the piston separates the air guide sleeve into an air outlet chamber and a regulating chamber, a plurality of air inlet holes which axially extend are formed in the side wall of the air guide sleeve, the air inlet holes are communicated with the inner cavity of the air outlet chamber and the buffer chamber, and the piston rod is driven by the linear power device.

8. A gas buffering means for an individual sampler as claimed in claim 2 wherein: the outside of buffering cavity is fixed with the overcoat, overcoat internal fixation has the piston chamber cover, be provided with the intercommunication chamber between piston chamber cover and the overcoat, the shutoff piece includes the piston rod and installs in the piston of piston rod tip, piston axial seal slidable mounting is in the piston chamber cover, the piston separates into the piston chamber cover and gives vent to anger cavity and adjust the cavity, the lateral wall of piston chamber cover is provided with the regulation gas pocket of a plurality of axial distribution, and this regulation gas pocket communicates piston chamber cover and intercommunication chamber, give vent to anger the cavity gas outlet intercommunication of cavity with be provided with the gas outlet on the overcoat, the piston rod is by sharp power device drives.

9. A gas buffering means for an individual sampler as claimed in claim 3 wherein: the outside of buffering cavity can be dismantled and is fixed with the air guide piece, the position of air guide piece corresponds with cavity gas outlet and normally open gas port position, the passageway of giving vent to anger sets up on the air guide piece, be provided with on the air guide piece with cavity gas outlet and normally open gas port and the branch road passageway of the passageway intercommunication of giving vent to anger, demountable installation has the orifice plate with cavity gas outlet and normally open gas port one-to-one between air guide piece and the buffering cavity, each orifice plate is located between corresponding branch road passageway and cavity gas outlet, branch road passageway and the normally open gas port respectively.

10. A gas buffering means for an individual sampler as claimed in claim 9 wherein: the number of the elastic diaphragms is two, mounting sunk openings are formed in two opposite chamber walls of the buffer chamber, and the elastic diaphragms are placed in the mounting sunk openings and are detachably fixed through the compression rings.