CN114923762A - Aerosol dilution system, aerosol dilution method and photometer calibration device - Google Patents

Abstract

The invention discloses an aerosol dilution system, a dilution method and a photometer calibration device. The dilution system comprises a mixing diluter, a first dilution gas path, a mixing gas path and a buffer box; the mixing and dilution device comprises a mixing cavity and a The first dilution gas inlet, the mixed gas inlet and the gas outlet communicated with the mixing chamber; the first dilution gas path is connected with the first dilution gas inlet, and is used to provide the first path of dilution gas into the mixing chamber; the mixed gas path is connected to the mixing chamber The gas inlet is connected, and the mixed gas path is respectively connected with the second dilution gas path and the aerosol gas path. The second path dilution gas and aerosol are mixed and flow into the mixing chamber through the mixed gas inlet under the action of the negative pressure of the inner cavity of the mixing diluter. The buffer box is connected with the air outlet through a pipeline; the flow rates of the first dilution air path, the second dilution air path and the aerosol air path can be adjusted. The dilution system can achieve accurate dilution ratio, the dilution ratio can be adjusted accurately, and the calibration accuracy of the photometer can be effectively improved.

Description

A kind of aerosol dilution system, dilution method and photometer calibration device

technical field

The invention relates to the technical field of aerosol detection, in particular to an aerosol dilution system, a dilution method and a photometer calibration device.

Background technique

Aerosol is a colloidal dispersion system formed by solid or liquid small particles dispersed and suspended in a gas medium, also known as a gas dispersion system. Its dispersed phase is solid or liquid small particles, its size is 0.001-100 microns, and the dispersion medium is gas. Aerosols are widely used in medicine, environmental science, and military science.

In many airborne particle measurements and particle concentration studies, aerosol photometers are used to detect particle mass concentrations in the monitored environment. At present, in the production and testing of filter materials such as masks and meltblown cloth, aerosol particles are used to detect the filtration efficiency of filter materials. Aerosol photometer is a simple optical measurement system, which can realize real-time detection of aerosol mass concentration by establishing the relationship between aerosol mass concentration and photoelectric signal of photodetector.

The calibration of the photometer requires an accurate photometer calibration device: the generated aerosol concentration is controllable (0-120 μg/L), mixed evenly, and its concentration stability is good.

As the key structure of the photometer calibration device, the aerosol dilution system can directly affect the accuracy and stability of the photometer calibration. Aerosol dilution systems can also be used with aerosol detection devices, such as condensation particle counters (CPCs), optical particle counters (OPCs), spectrometers, or other types of particle monitoring devices known in the art (including virtual impactors, Cascade Impactors, etc.).

The common aerosol dilution system in the prior art generally adopts one channel of dilution gas and one channel of aerosol to be directly mixed in the mixing box.

The above information disclosed in this Background is only for enhancement of understanding of the background of the application and therefore it may contain that it does not form the prior art that is already known to a person of ordinary skill in the art.

SUMMARY OF THE INVENTION

In view of the problems pointed out in the background art, the present invention proposes an aerosol dilution system, a dilution method and a photometer calibration device. The dilution system can realize an accurate dilution ratio, adjust the dilution ratio accurately, and effectively improve the calibration accuracy of the photometer.

In order to realize the above-mentioned purpose of the invention, the present invention adopts the following technical scheme to realize:

The present invention provides an aerosol dilution system, comprising:

A mixing and diluting device, which includes a mixing chamber and a first dilution gas inlet, a mixed gas inlet and an air outlet communicated with the mixing chamber;

a first dilution gas path, which is connected with the first dilution gas inlet, and is used for providing the first dilution gas into the mixing chamber;

A mixed gas path, which is connected to the mixed gas inlet, the mixed gas path is respectively connected with the second dilution gas path and the aerosol gas path, and the second dilution gas and the aerosol in the second dilution gas path The aerosol in the gas path is mixed, and flows into the mixing chamber through the mixed gas inlet under the action of the negative pressure of the inner cavity of the mixing and diluting device;

a buffer tank, which is connected with the air outlet through a pipeline;

Wherein, the flow rates of the first dilution gas path, the second dilution gas path and the aerosol gas path can be adjusted.

In some embodiments of the present application, the first diluent gas inlet and the gas outlet are oppositely disposed at both ends of the mixing and diluting device;

The inner cavity of the mixing and diluting device is provided with a communication section that communicates with the first dilution gas inlet and the mixing cavity, and the mixed gas inlet is communicated with the communication section;

An adjusting rod is arranged on the side wall of the mixing and diluting device, and one end of the adjusting rod extends into the communication section and faces the mixed gas inlet, and the end of the adjusting rod is connected to the mixed gas. The air outlet ends of the inlet are in conical fit, and the inflow amount of the mixed air in the mixed air passage is adjusted by the movement of the adjusting rod.

In some embodiments of the present application, an acceleration section is provided in the inner cavity of the mixing diluter, one end of the acceleration section is communicated with the first dilution gas inlet, and the other end is communicated with the communication section.

In some embodiments of the present application, the mixing chamber has a gradually expanding structure from the communication section to the air outlet.

In some embodiments of the present application, the second dilution gas path and the aerosol gas path are connected to the mixed gas path through a three-way structure, and a pipeline between the three-way structure and the mixed gas inlet is provided with There is a flow detection device.

In some embodiments of the present application, the first dilution gas path and the aerosol gas path provide clean gas from the same gas source system, and the second dilution gas path draws clean gas from the atmosphere through a dryer and a filter.

The present invention also provides an aerosol dilution method, comprising:

The aerosol is provided by the aerosol gas path, the first dilution gas is provided by the first dilution gas path, and the second dilution gas is provided by the second dilution gas path;

Use a mixing diluter to mix the aerosol and diluent gas by jet type;

The aerosol and the second diluting gas are mixed in the three-way structure and then flow into the inner cavity of the mixing and diluting device. The first diluting gas directly flows into the inner cavity of the mixing and diluting device. Negative pressure is generated in the process of gas flowing in the direction of the air outlet of the mixing and diluting device, and the mixed gas of the aerosol and the second diluting gas is sucked into the inner cavity of the mixing and diluting device, so that the first diluting gas is sucked into the inner cavity of the mixing and diluting device. Mixing with the mixed gas in the inner cavity of the mixing and diluting device;

The mixed gas flows to the downstream buffer tank through the gas outlet.

The present invention also provides a photometer calibration device, comprising:

Air supply system, calibration system and aerosol dilution system as described above;

the gas source system provides clean gas to the first dilution gas path and the aerosol gas path;

The calibration system includes a sampling cavity, the sampling cavity is connected with a photometer and a calibrated photometer, and the buffer box is communicated with the sampling cavity through a pipeline.

In some embodiments of the present application, the calibration system includes an upper fixture cavity and a lower fixture cavity, the upper fixture cavity and the lower fixture cavity move relatively to form the sampling cavity, and the upper fixture cavity is connected to the sampling cavity. A weighing filter membrane clamp and a shunt ring are arranged between the lower clamp cavities, the photometer and the calibrated photometer are connected to the shunt ring through pipelines, and the air outlet end of the lower clamp cavity is connected to an air pump.

In some embodiments of the present application, the air source system includes an air compressor, a steam drum, a refrigeration dryer, a dryer, and a high-efficiency filter that are connected in sequence.

Compared with the prior art, the advantages and positive effects of the present invention are:

In the aerosol dilution system disclosed in this application, two paths of dilution gas and one path of aerosol are used for mixing, and one path of dilution gas and aerosol are inhaled under the negative pressure of the mixing diluter. When adjusting the dilution ratio, , the first dilution gas path and aerosol gas path play the main adjustment role, and the second dilution gas path plays an auxiliary fine-tuning role, which helps to achieve accurate flow ratio to obtain accurate dilution ratio, and the dilution ratio is adjustable. Wide range.

The diluent gas and aerosol are mixed by jet flow through the mixing diluter, the aerosol is evenly mixed and diluted, and can be further mixed in the buffer box. The stability of the airflow improves the calibration accuracy.

The flow rates of the first dilution gas path, the second dilution gas path and the aerosol gas path can be adjusted, so that the mixing and dilution ratio can be precisely controlled to meet the needs of different calibration experiments.

The aerosol dilution system can basically determine the dilution ratio of the dilution system in real time, constantly or periodically, so that the generated aerosol concentration is controllable (0-120 μg/L), and the aerosol concentration is stable.

During the entire dilution and calibration process, the aerosol is always in dynamic flow, which can effectively prevent the aerosol concentration from sudden increase and drop and other adverse effects when it is stationary, and ensure the calibration accuracy.

Other features and advantages of the present invention will become more apparent after reading the detailed description of the present invention in conjunction with the accompanying drawings.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of a photometer calibration device according to an embodiment;

Fig. 2 is the structural representation of the mixing diluter according to the embodiment;

3 is a top view of a mixing diluter according to an embodiment;

Fig. 4 is A-A sectional view in Fig. 3;

5 is a schematic structural diagram of a three-way structure according to an embodiment;

Fig. 6 is B-B in Fig. 5 sectional view;

Reference number:

100-air source system;

101-air compressor, 102-steam drum, 103-refrigeration dryer, 104-dryer, 105-high efficiency filter;

200 - dilution system;

201-first flow regulating valve, 202-first temperature sensor, 203-first differential pressure sensor, 204-first orifice flowmeter, 205-mixing diluter, 2051-first dilution gas inlet, 2052- Adjusting rod, 2053-connecting section, 2054-conical structure, 2055-acceleration section, 2056-mixed gas inlet, 2057-mixing chamber, 2058-air outlet, 206-second dilution gas filter, 207-second meter Temperature sensor, 208-Second orifice differential pressure sensor, 209-Second flow regulating valve, 210-Second orifice flowmeter, 211-Third orifice flowmeter, 212-Third orifice differential pressure sensor, 213 -Third thermometer sensor, 214-mixing tee, 2141-main line, 2142-branch line, 215-electrometer, 216-orifice plate restrictor, 217-aerosol regulating valve, 218-aerosol generator regulation Valve, 219-pressure gauge, 220-spray head, 221-aerosol generator liquid storage tank, 222-residual air filter, 223-air pressure balance filter, 224-buffer tank, 225-second dilution gas dryer;

300 - calibration system;

301- 5/2-way solenoid valve, 302- clamping cylinder, 303- gripper bracket, 304- shunt ring, 305- upper clamp cavity, 306- weighing filter clamp, 307- photometer, 308- calibrated Photometer, 309-pump front filter, 310-pump front-end temperature sensor, 311-pump front-end orifice flowmeter, 312-pump front-end differential pressure sensor, 313-air pump, 314-lower fixture cavity;

S1 - the first dilution gas path;

S2 - the second dilution gas path;

S3 - aerosol gas path;

S4-mixed gas path;

Q1-The first diluent gas;

Q2-The second diluent gas;

Q3 - Aerosol;

P-mixture.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", The orientation or positional relationship indicated by "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying The device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as a limitation of the present application.

The terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of this application, unless stated otherwise, "plurality" means two or more.

In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood in specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may include the first and second features in direct contact, or may include the first and second features Not directly but through additional features between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature has a lower level than the second feature.

The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are only examples and are not intended to limit the invention. Furthermore, the present disclosure may repeat reference numerals and/or reference letters in different instances for the purpose of simplicity and clarity and not in itself indicative of a relationship between the various embodiments and/or arrangements discussed. In addition, the present disclosure provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

This embodiment discloses a photometer calibration device, which uses an aerosol with a specific concentration to calibrate the photometer.

Referring to FIG. 1 , the photometer calibration apparatus includes a gas source system 100 , an aerosol dilution system 200 and a calibration system 300 .

The gas source system 100 is used to provide the gas source to the aerosol dilution system 200 and the calibration system 300 .

The aerosol dilution system 200 is used to dilute the aerosol to obtain a certain concentration of aerosol for the calibration system 300 to use.

The aerosol dilution system 200 mainly includes a mixing diluter 205 , a first dilution gas path S1 , a mixed gas path S4 , a buffer tank 224 and the like.

The mixing diluter 205 is the core key component of the aerosol dilution system 200 , and is used to mix and dilute the diluent gas and aerosol, and the mixed and diluted aerosol flows into the buffer tank 224 for use by the photometer calibration system 300 .

The gas entering the mixing diluter 205 has three paths, namely the first path dilution gas, the second path dilution gas and the aerosol. The first path dilution gas is provided by the first dilution gas path S1, and the second path dilution gas is provided by the second path dilution gas. The dilution gas path S2 is provided, and the aerosol is provided by the aerosol gas path S3.

The second dilution gas path S2 and the aerosol gas path S3 are connected to the mixed gas path S4 at the same time. After the second path dilution gas and the aerosol are mixed in the mixed gas path S4, they flow into the mixing diluter 205 to be mixed with the first path dilution gas. Secondary mixing and dilution.

A mixing cavity 2057 is arranged inside the mixing and diluting device 205 , and a first dilution gas inlet 2051 , a mixed gas inlet 2056 and an air outlet 2058 are arranged on the walls of the mixing cavity 2057 .

The first dilution gas path S1 is connected to the first dilution gas inlet 2051 , and the dilution gas in the first dilution gas path S1 flows into the mixing chamber 2057 through the first dilution gas inlet 2051 .

The mixed gas path is connected to the mixed gas inlet 2056, and the diluted gas in the second dilution gas path S2 is mixed with the aerosol in the aerosol gas path S3, and is passed through the mixed gas inlet under the action of the negative pressure in the inner cavity of the mixing diluter 205. 2056 flows into the mixing chamber 2057.

The first diluent gas and the mixed gas are mixed and diluted in the mixing chamber 2057, and then flow to the buffer tank 224 through the air outlet 2058.

The diluent gas and the aerosol are jet-mixed by the mixing diluter 205, the aerosol is evenly mixed and diluted, and can be further mixed in the buffer box 224, on the one hand, the mixing uniformity is further improved, and on the other hand, the fluctuation of the air flow can be prevented from affecting the calibration of the photometer The stability of the airflow in the system 300 improves the calibration accuracy.

The flow rates of the first dilution gas path S1 , the second dilution gas path S2 and the aerosol gas path S3 can be adjusted, so that the mixing and dilution ratio can be precisely controlled to meet the needs of different calibration experiments.

Two paths of dilution gas and one path of aerosol are used for mixing, and one path of dilution gas and aerosol are inhaled under the action of negative pressure in mixing chamber 2057. When adjusting the dilution ratio, the first path of dilution gas S1 and aerosol gas are inhaled. Path S3 plays a main adjustment role, and the second dilution gas path S2 plays an auxiliary fine-tuning role, which helps to achieve accurate flow ratio to obtain accurate dilution ratio, and the dilution ratio can be adjusted in a wide range.

During the entire dilution and calibration process, the aerosol is always in dynamic flow, which can effectively prevent the aerosol concentration from sudden increase and drop and other adverse effects when it is stationary, and ensure the calibration accuracy.

In some embodiments of the present application, referring to FIG. 2 to FIG. 4 , the first dilution gas inlet 2051 and the gas outlet 2058 are oppositely disposed at both ends of the mixing and diluting device 205; A communication section 2053 connecting the dilution gas inlet 2051 and the mixing chamber 2057, the communication section 2053 is vertically arranged between the first dilution gas inlet 2051 and the mixing chamber 2057, and the mixed gas inlet 2056 is arranged on the side of the mixing diluter 205 The wall is in communication with the communication section 2053 at a position near the middle of the wall.

The first diluent gas flows in through the first diluent gas inlet 2051, and in the process of flowing to the mixing chamber 2057, it will pass through the communication section 2053, and a negative pressure will be generated at the communication section 2053. Using the Venturi principle, the mixed gas path S4 is composed of The mixed gas formed by mixing the second diluent gas and aerosol is inhaled through the mixed gas inlet 2056 , flows to the mixing chamber 2057 together with the first diluent gas, and then flows out through the air outlet 2058 .

The side wall of the mixing diluter 205 is provided with an adjusting rod 2052. The adjusting rod 2052 is arranged opposite to the mixed gas inlet 2056. One end of the adjusting rod 2052 extends into the communication section 2053 and faces the mixed gas inlet 2056. There is a conical fit between the end portion and the gas outlet end of the mixed gas inlet 2056 , and the amount of the mixed gas flowing into the mixed gas path S4 is adjusted by the movement of the adjusting rod 2052 .

In some embodiments of the present application, an acceleration section 2055 is arranged in the inner cavity of the mixing diluter 205. One end of the acceleration section 2055 is communicated with the first dilution gas inlet 2051, and the other end is communicated with the communication section 2053. The first diluent gas is accelerated to improve the effect of generating negative pressure at the communication section 2053. At the same time, the first diluent gas flowing at a high speed has the effect of jet impact on the mixed gas flowing in from the mixed gas inlet 2056, improving the mixing. Effect.

In some embodiments of the present application, a tapered tapered structure 2054 is transitionally connected between the first dilution gas inlet 2051 and the acceleration section 2055, which plays a role in guiding the airflow.

In some embodiments of the present application, the mixing chamber 2057 has a gradually expanding structure from the communication section 2053 to the air outlet 2058, which improves the mixing effect of the first diluent gas and the mixed gas, and also facilitates the mixing of the diluted gas through the air outlet. 2058 flows downstream.

In some embodiments of the present application, the second dilution gas path S2 and the aerosol gas path S3 are connected to the mixed gas path S4 through a three-way structure 214, and a flow detection device is provided on the pipeline between the three-way structure 214 and the mixed gas inlet 2056, Marked as the third flow detection device, it is used to detect the flow of the mixed gas.

The third flow detection device includes a third orifice flowmeter 211, a third orifice differential pressure sensor 212, and a third temperature sensor 213. The third orifice differential pressure sensor 212 is used to measure the pressure difference before and after the orifice plate, and the third The thermometer sensor 213 is used to measure the pre-meter temperature of the orifice plate.

The three-way structure 214 is shown in FIG. 5 and FIG. 6 , the three-way structure 214 includes a main pipeline 2141 penetrating through both ends and a branch pipeline 2142 inserted on the main pipeline 2141. The branch pipeline 2142 has an L-shaped structure, and the branch pipeline 2142 is provided with On the side wall of the main pipe 2141 , the gas outlet end of the branch pipe 2142 extends along the gas flow direction in the main pipe 2141 .

The inner diameter of the main pipe 2141 is larger than that of the branch pipe 2142. One end of the main pipe 2141 is connected to the aerosol gas path S3, the other end is connected to the mixed gas path S4, and the branch pipe 2142 is connected to the second dilution gas path S2.

The aerosol and the second diluent gas are mixed in the main line 2141, and then flow together to the mixed gas line S4.

In some embodiments of the present application, the first dilution gas path S1 is provided with a first flow regulating valve 201 and a first flow detection device.

The first flow regulating valve 201 is used for regulating the flow of the first diluent gas.

The first flow detection device is used to detect the flow of the first diluent gas, which includes a first orifice flowmeter 204 , a first orifice differential pressure sensor 203 , a first temperature sensor 202 , and a first orifice differential pressure sensor 203 It is used to measure the pressure difference before and after the orifice plate, and the first thermometer sensor 202 is used to measure the pre-meter temperature of the orifice plate.

In some embodiments of the present application, the second dilution gas path S2 is provided with a second dilution gas dryer 225 , a second dilution gas filter 206 , a second flow regulating valve 209 and a second flow detection device.

The second flow regulating valve 209 is used for regulating the flow of the second diluent gas.

The second flow detection device is used to detect the flow of the second diluent gas, and includes a second orifice flowmeter 210 , a second orifice differential pressure sensor 208 , a second temperature sensor 207 , and a second orifice differential pressure sensor 208 It is used to measure the pressure difference before and after the orifice plate, and the second temperature sensor 207 is used to measure the pre-meter temperature of the orifice plate.

Under the negative pressure generated by the mixing diluter 205, the second diluent air is drawn through the second diluent air dryer 225 and the second diluent air filter 206 to filter out moisture and particulate matter in the air, and then passes through the second diluent air dryer 225 and the second diluent air filter 206. The second flow regulating valve 209 and the second flow detection device are mixed with the aerosol in the three-way structure 214 .

In some embodiments of the present application, the aerosol gas path S3 includes an aerosol generator regulating valve 218, a spray head 220, a liquid storage tank 221, a residual gas filter 222, an aerosol regulating valve 217 (using a ball valve), an orifice plate current limiting The device 216 , the aerosol electrometer 215 , and the electrometer 215 is arranged between the three-way structure 214 and the orifice plate current limiter 216 .

The clean compressed gas flows to the spray head 20 through the aerosol generator regulating valve 218, and the spray head 220 is immersed in the solution in the liquid storage tank 221 of the aerosol generator. Under the action of the compressed gas, the spray head 220 generates aerosol, so the The generated aerosol is divided into two paths, one aerosol is discharged through the residual air filter 222, and the other aerosol is passed through the aerosol regulating valve 217 and the orifice restrictor under the action of the negative pressure generated by the mixing diluter 205. 216 flows to the three-way structure 214, and is mixed with the second diluent gas, and the mixed gas flows into the mixing diluter 205 through the mixed gas path S4 and the third flow detection device.

An example of the calculation of the dilution ratio is as follows:

The electrometer 215 measures the aerosol concentration through the orifice plate restrictor 216 to be 1ug/L, the first orifice flowmeter 204 measures the flow rate of the first dilution gas to be 100L/min, and the adjusting rod 2052 of the mixing diluter is adjusted. Set the flow rate of the third orifice flowmeter 211 to 1L/min, adjust the second flow regulating valve 209 to make the flow rate of the second dilution gas passing through the second orifice flowmeter 210 be 0.5L/min, then pass through the orifice plate restrictor 216 The flow rate of the aerosol entering the tee structure 214 is 1-0.5=0.5L/min, then the concentration of the aerosol entering the mixing and diluting device 205 is 0.5*1/1=0.5ug/L. After the mixing diluter 205 enters the buffer box 224, the concentration is: 0.5*1/(100+1)=0.00495ug/L, then the dilution ratio at this time is 1:0.00495, which is close to the dilution ratio of 202 times. A larger dilution ratio can be obtained through the adjustment rod 2052 and the second flow adjustment valve 209 .

The dilution system in this embodiment can basically determine the dilution ratio of the dilution system in real time, constantly or periodically, so that the generated aerosol concentration is controllable (0-120 μg/L), and the aerosol concentration is stable .

In some embodiments of the present application, an air pressure balance filter 223 is connected to the buffer tank 224. After the gas flowing out of the mixing diluter 205 flows into the buffer tank 224, the buffer tank 224 exhibits a certain positive pressure, and the air pressure balance filter 223 passes through the air pressure balance filter 223. To balance the air pressure in the buffer tank 224, it is helpful to improve the air pressure stability in the calibration system 300 and improve the calibration accuracy.

In some embodiments of the present application, the first dilution gas path S1 and the aerosol gas path S3 provide clean compressed gas from the same gas source system 100, and the second dilution gas path S2 draws clean gas from the atmosphere through a dryer and a filter.

The air source system 100 has few air paths and stable air flow, which helps to improve the stability and accuracy of the entire system.

In some embodiments of the present application, the air source system 100 includes an air compressor 101 , a steam drum 102 , a refrigeration dryer 103 , a dryer 104 , and a high-efficiency filter 105 , which are connected in sequence.

The air compressor 101 inflates the steam drum 102, and stops inflating after the air pressure reaches a certain pressure. The compressed air passes through the refrigerating machine 103 to remove the water vapor in the gas, and then passes through the dryer 104 to adsorb the small water droplets that have not been removed, and then passes through the high-efficiency filtration. The device 105 filters out the particulate matter in the air source to obtain clean compressed air.

The clean compressed gas is divided into three paths, one is supplied to the first dilution gas path S1 , the other is supplied to the aerosol gas path S3 , and the other is supplied to the calibration system 300 .

In some embodiments of the present application, the calibration system 300 includes an upper fixture cavity 305 and a lower fixture cavity 314, the upper fixture cavity 305 and the lower fixture cavity 314 move relatively to form a sampling cavity, and the upper and lower fixture cavity 305 and the lower fixture cavity 314 The relative movement is realized by the clamping cylinder 302 , and the compressed air drawn out from the air source system 100 provides power for the clamping cylinder 302 . Between the upper clamp cavity 305 and the lower clamp cavity 314, a weighing filter clamp 306 and a shunt ring 304 are arranged, the photometer 307 and the calibrated photometer 308 are connected to the shunt ring 304 through pipelines, and the air outlet end of the lower clamp cavity 314 Connected to the air pump 313, the photometer 307 and the calibrated photometer 308 have their own power sources respectively.

In the calibration system 300, the compressed air is connected to the two-position, five-way solenoid valve 301, which controls the clamping cylinder 302 to move, and then controls the upper clamp cavity 305 to move up and down. The clamping cylinder 302 and the lower clamp cavity 314 are respectively fixed on the holder bracket. 303 upper and lower. The upper clamp cavity 305 and the lower clamp cavity 314 are respectively placed with a shunt ring 304 and a weighing filter membrane clamp 306 from top to bottom, two air outlet nozzles are symmetrically arranged on the shunt ring 304, and the air outlet nozzles are respectively connected to the precision aerosol photometer 307 and The aerosol photometer 308 to be calibrated, the lower end of the lower fixture cavity 314 is sequentially connected to the filter 309 at the front end of the pump, the orifice flowmeter 311 at the front end of the pump, and the air pump 313, and the front end of the orifice plate and the two sides of the orifice plate are respectively Set the pump front-end temperature sensor 310 and the pump front-end orifice differential pressure sensor 312, the pump front-end temperature sensor 310 measures the orifice temperature of the pump front-end orifice flowmeter 311, and the pump front-end orifice differential pressure sensor 312 measures the pump The pressure difference before and after the orifice plate of the front orifice flowmeter 311 is used to calculate the air flow of the air pump 313. By adjusting the rotation speed of the air pump 313, the flow measured by the orifice flowmeter 311 at the front end of the pump is the same as that of the precision aerosol photometer 307, The sample flow rate of the calibrated aerosol photometer 308 remains consistent.

The buffer box 224 is communicated with the sampling chamber in the calibration system 300 through a pipeline, and the aerosol in the buffer box 224 flows into the upper fixture cavity 305 under the action of the air pump 313, the precision aerosol photometer 307, and the calibrated aerosol photometer 308 , the lower clamp cavity 314, the weighing filter clamp 306, and the cavity formed by the shunt ring 304 (ie, the sampling cavity), due to the suction flow rate of the air pump 313, the precision aerosol photometer 307, and the calibrated aerosol photometer 308 Consistent to ensure even distribution of the aerosol within the chamber. When the photometer is calibrated, a weighing filter is placed on the weighing filter holder 306, and the air pump 313, the precision aerosol photometer 307, and the calibrated aerosol photometer 308 are simultaneously pumped. Since the aerosol is evenly distributed, In this way, the total amount of aerosol entering the precision aerosol photometer 307, the calibrated aerosol photometer 308, and the total amount of aerosol captured by the filter membrane can ensure good consistency, and the precision aerosol photometer 307 is used to display the value. The concentration is used to calibrate the calibrated aerosol photometer 308, and the aerosol captured by the filter membrane can be used as the traceability of the calibration result.

In some embodiments of the present application, the system shown in FIG. 1 is used for aerosol dilution, and the dilution method is:

The aerosol is provided by the aerosol gas path, the first dilution gas is provided by the first dilution gas path S1, and the second dilution gas is provided by the second dilution gas path S2;

Utilize the mixing diluter 205 to carry out jet mixing to the aerosol and the dilution gas;

The aerosol and the second diluent gas are mixed in the tee structure 214 and then flow into the inner cavity of the mixing and diluting device 205, the first diluting gas directly flows into the inner cavity of the mixing and diluting device 205, and the first diluting gas Negative pressure is generated in the process of flowing in the direction of the air outlet of the mixing and diluting device 205, and the mixed gas of the aerosol and the second diluent gas is sucked into the inner cavity of the mixing and diluting device 205, so that the first diluting gas and the mixed gas are Mixing is carried out in the inner cavity of the mixing diluter 205;

The mixed gas flows to the downstream buffer tank 224 through the gas outlet.

In the foregoing description of the embodiments, the particular features, structures, materials or characteristics may be combined in any suitable manner in any one or more of the embodiments or examples.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered. within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (10)

1. an aerosol dilution system, is characterized in that, comprises: A mixing and diluting device, which includes a mixing chamber and a first dilution gas inlet, a mixed gas inlet and an air outlet communicated with the mixing chamber; a first dilution gas path, which is connected with the first dilution gas inlet, and is used for providing the first dilution gas into the mixing chamber; A mixed gas path, which is connected to the mixed gas inlet, the mixed gas path is respectively connected with the second dilution gas path and the aerosol gas path, and the second dilution gas and the aerosol in the second dilution gas path The aerosol in the gas path is mixed, and flows into the mixing chamber through the mixed gas inlet under the action of the negative pressure of the inner cavity of the mixing and diluting device; a buffer tank, which is connected with the air outlet through a pipeline; Wherein, the flow rates of the first dilution gas path, the second dilution gas path and the aerosol gas path can be adjusted. 2. aerosol dilution system according to claim 1, is characterized in that, The first dilution gas inlet and the gas outlet are oppositely arranged at both ends of the mixing and diluting device; The inner cavity of the mixing and diluting device is provided with a communication section that communicates with the first dilution gas inlet and the mixing cavity, and the mixed gas inlet is communicated with the communication section; An adjusting rod is arranged on the side wall of the mixing and diluting device, and one end of the adjusting rod extends into the communication section and faces the mixed gas inlet, and the end of the adjusting rod is connected to the mixed gas. The air outlet ends of the inlet are in conical fit, and the inflow amount of the mixed air in the mixed air passage is adjusted by the movement of the adjusting rod. 3. aerosol dilution system according to claim 2, is characterized in that, An acceleration section is arranged in the inner cavity of the mixing and diluting device, one end of the acceleration section is communicated with the first dilution gas inlet, and the other end is communicated with the communication section. 4. The aerosol dilution system according to claim 2, characterized in that, The mixing chamber is in a gradually expanding structure from the communication section to the air outlet. 5. The aerosol dilution system according to any one of claims 1 to 4, characterized in that, The second dilution gas path and the aerosol gas path are connected to the mixed gas path through a three-way structure, and a flow detection device is provided on the pipeline between the three-way structure and the mixed gas inlet. 6. The aerosol dilution system according to any one of claims 1 to 4, wherein The first dilution gas path and the aerosol gas path provide clean gas from the same air source system, and the second dilution gas path draws clean gas from the atmosphere through a dryer and a filter. 7. an aerosol dilution method, is characterized in that, comprises: The aerosol is provided by the aerosol gas path, the first dilution gas is provided by the first dilution gas path, and the second dilution gas is provided by the second dilution gas path; Use a mixing diluter to mix the aerosol and diluent gas by jet type; The aerosol and the second diluting gas are mixed in the three-way structure and then flow into the inner cavity of the mixing and diluting device. The first diluting gas directly flows into the inner cavity of the mixing and diluting device. Negative pressure is generated in the process of gas flowing in the direction of the air outlet of the mixing and diluting device, and the mixed gas of the aerosol and the second diluting gas is sucked into the inner cavity of the mixing and diluting device, so that the first diluting gas is sucked into the inner cavity of the mixing and diluting device. Mixing with the mixed gas in the inner cavity of the mixing and diluting device; The mixed gas flows to the downstream buffer tank through the gas outlet. 8. A photometer calibration device, characterized in that, comprising: A gas source system, a calibration system, and an aerosol dilution system as claimed in any one of claims 1 to 6; the gas source system provides clean gas to the first dilution gas path and the aerosol gas path; The calibration system includes a sampling cavity, the sampling cavity is connected with a photometer and a calibrated photometer, and the buffer box is communicated with the sampling cavity through a pipeline. 9. The photometer calibration device according to claim 8, characterized in that, The calibration system includes an upper clamp cavity and a lower clamp cavity, the upper clamp cavity and the lower clamp cavity move relatively to form the sampling cavity, and there is a space between the upper clamp cavity and the lower clamp cavity. The filter membrane clamp and the shunt ring are weighed, the photometer and the calibrated photometer are connected to the shunt ring through pipelines, and the air outlet end of the lower clamp cavity is connected to an air pump. 10. The photometer calibration device according to claim 8, characterized in that, The air source system includes an air compressor, a steam drum, a refrigeration dryer, a dryer and a high-efficiency filter which are connected in sequence.

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