CN102507274A - Intelligent air automatic sampler for occupational health - Google Patents

Abstract

The invention belongs to the technical field of automatic air sampling apparatuses, and particularly relates to an intelligent air automatic sampler for occupational health, which is program controlled, and can perform constant flow, continuous, equal time interval, absorption tube connected in series, and fixed-point real-time high-precision sampling. The intelligent air automatic sampler mainly comprises an air inlet connecting pipe, an air outlet connecting pipe, a control valve with air inlets and air outlets, absorption tubes, a flowrate control sensor, a single chip and a suction pump. The program set by the single chip is used for controlling the opening/closing of the suction pump, the flowrate of the flowrate control sensor, the connection between the air inlet connecting pipe and the air outlet connecting pipe and the air inlets and the air outlets, the opening/closing of each air inlet or each outlet, and sampling time. The sampler enables the two neighboring absorption tubes to be connected in series, so as to satisfy the collecting requirements of different types of occupational health samples.

Description

Smart Air Automatic Sampler for Occupational Hygiene

technical field

The invention belongs to the technical field of automatic air samplers, and in particular relates to an intelligent automatic air sampler for occupational hygiene that adopts program control and can perform constant flow, continuous, equal time intervals, series absorption tubes, fixed-point real-time and high-precision.

Background technique

As the occupational health department has higher and higher requirements for the production site and testing and evaluation work, the actual testing work in the daily testing or evaluation testing process of the production unit or technical service organization that has obtained self-inspection authorization needs to be carried out within a working day cycle. Continuous tracking detection or daily fixed-period detection on the same detection point. These samples are parallel samples, and the conditions should be exactly the same except for the sampling period. However, manual sampling cannot achieve the exact same parameters such as sampling flow rate, time, sampling point location, direction, and sampling volume, which will bring large errors to the detection results. At present, the occupational health air samplers used and sold at home and abroad are used for continuous sampling within a working day cycle, requiring the sampler to replace the absorption tube every 15 minutes, timing, starting and stopping the sampling pump, sealing the absorption tube, etc. Operation, one person can only sample one sampling point in a working day cycle, and the sampling direction, position, sampling flow rate, etc. of the sampler will inevitably change during the operation process, resulting in sampling errors. Chinese Invention Patent (Application No. 201010174255.1) discloses an atmospheric sampler that can use the same air path to collect multiple samples at different time periods. The sampler mainly realizes sampling by controlling the opening and closing of the air pump and solenoid valve The conversion of the branch gas circuit is used to complete the collection of multiple samples in one gas circuit in different time periods. However, there are many defects in using this atmospheric sampler for occupational health sample collection: one, the solenoid valve is a steel product controlled by an electromagnet, and the occupational health collection site is mostly a factory, a workshop, and there is a high concentration of acid or Alkaline gas corrodes the solenoid valve; second, the solenoid valve generally requires a high degree of cleanliness for the medium. When collecting dust samples, fine dust is easy to enter the solenoid valve and affect the airtightness of the gas circuit; third, the air sampler connected in parallel The multiple absorption bottles are connected by the same gas path in turn, and cross-contamination between the absorption bottles is easy, which affects the accuracy of sample collection. In addition, GB/T160.29-2004 "Determination of Inorganic Nitrogenous Compounds in Air Toxic Substances in the Workplace" issued by the Ministry of Health requires the use of two absorption bottles connected in series to complete sample collection, while the Chinese invention patent (application number 201010174255.1) discloses This atmospheric sampler cannot meet this requirement. Therefore, it is particularly urgent to design an atmospheric sampler that is really suitable for occupational health detection.

Contents of the invention

In view of the deficiencies in the prior art, the purpose of the present invention is to provide a real-time high-precision automatic sampler capable of constant flow, continuous, equal time interval, and non-equal time interval fixed-point. The airtightness of its system is better than other samplers, and the calibration point is set at the inlet of the absorption pipe, which can greatly reduce the uncertainty through flow calibration, making it more suitable for collecting occupational health air samples.

As shown in Fig. 1, the sampler of the present invention is mainly made of air inlet 1, air inlet connecting pipe 2, control valve 3, air outlet connecting pipe 4, absorption pipe (31,32,33,34,35,36,37, 38), a flow control sensor 5, an air pump 7 and a control system, the control system includes a single-chip microcomputer 6, a keyboard 61 and a display 62.

In the connecting pipe of the present invention, the inner and outer rubber layers can be made of natural rubber, styrene-butadiene rubber or butadiene rubber.

The control valve 3 of the present invention has a main body which is a cylinder made of polytetrafluoroethylene resin cold-pressed and sintered, which is wear-resistant, corrosion-resistant and has good sealing performance. The function of the control valve is to cut off and change the flow direction of the branch air path, so as to realize the purpose of continuous, equal time interval, series connection of absorption pipes, and fixed-point real-time sampling.

As shown in Figure 2, 8 pairs of 16 through-holes are drilled on the main body of the control valve 3, and the through-holes penetrate the upper and lower surfaces of the control valve 3, in pairs of two, and are respectively 8 air intake holes (311, 321, 331, 341 , 351, 361, 371, 381) and 8 air outlets (311', 321', 331', 341', 351', 361', 371', 381'), the inlet and outlet pipes of the eight absorption pipes are composed of The bottom end of the control valve 3 extends into the corresponding through hole and is sealed. One end of the air inlet connecting pipe 2 is airtightly connected with the sample air inlet 1, and the other end extends into one of the air inlets (311, 321, 331, 341, 351, 361, 371, 381) on the top of the control valve 3 and is airtight.

As shown in the virtual frame in Figure 2, inside the main body of the control valve 3, the air outlet 311' can be connected with the air inlet 321 through the channel, the air outlet 331' can be connected with the air inlet 341 through the channel, and the air outlet 351' can be connected with the air inlet 341 through the channel. It is connected with the air inlet 361 through a channel, and the air outlet 371 ′ can be connected with the air inlet 381 through a channel. Each air inlet and air outlet can be opened and closed independently, and the hole between the air outlet of the last absorption tube and the air inlet of the next absorption tube can also be opened and closed independently, so that each absorption tube can be used or closed independently. A series connection of two absorber tubes. The opening and closing of all channels are completed by the single-chip microcomputer controlling the rollers and the forward and reverse motors inside the control valve 3 (refer to the rotating device of patent CN101013070 for the specific working principle).

One end of the air outlet connecting pipe 4 according to the present invention stretches into one of the air outlet holes (311', 321', 331', 341', 351', 361', 371', 381') and is sealed, and the other end of the connecting pipe 4 One end is airtightly connected with the flow control sensor 5 .

The flow control sensor 5 described in the present invention is used to measure and control the flow rate of gas or liquid, so as to achieve the purpose of collecting samples at a constant flow rate under the condition of uneven air intake or liquid intake. One end of the flow control sensor 5 is airtightly connected with the connecting pipe 4 , and the other end is airtightly connected with the air suction pump 7 .

Atmospheric sampler of the present invention, its suction pump 7, flow control sensor 5, control valve 3, air intake connecting pipe 2, air outlet connecting pipe are all connected with single-chip microcomputer 6. Use the program set by the single-chip microcomputer 6 to control the opening and closing of the air pump 7, the flow rate of the flow control sensor 5, which air inlet the air intake connecting pipe 2 extends into, which air outlet the air outlet connecting pipe 4 extends into, and connect the air outlet and the air intake. The opening and closing of the channel between the holes, the closing or opening of each inlet or outlet hole, and the sampling time, etc.

The absorbing tube of the present invention can be a large bubble absorbing tube, a small bubble absorbing tube, a porous glass plate absorbing tube, or an impact type absorbing bottle. In the absorbing tube of the present invention, the outer diameters of the air inlet and the air outlet are 1.0±0.1mm.

The atmospheric sampler of the present invention can realize the switching between different absorption tubes and the series and non-serial switching between two absorption tubes during sampling. This sampler can realize sequential sampling of 8 absorption tubes once set up.

Atmospheric sampler of the present invention can be used for NH ₃ (using large bubble absorption tube, sampling in series), HCl (using porous glass plate absorption tube, non-serial sampling), SO ₂ (using porous glass plate absorption tube, non-serial sampling) sampling), H ₂ S (sampling in series using a porous glass absorption tube), Hg (sampling in series using a large bubble absorption tube), O ₃ (sampling in series using a large bubble absorption tube), H ₂ O ₂ (using a large bubble absorption tube Bubble absorption tube, non-serial sampling), Cl ₂ (using large-bubble absorption tube, non-serial sampling), ClO ₂ (using large-bubble absorption tube, non-serial sampling), Cr (using impact absorption bottle, non-serial sampling), Sn (use a porous glass absorption tube, non-serial sampling), NO (use a porous glass absorption tube, non-serial sampling), NO ₂ (use a porous glass absorption tube, serial sampling), CN (use a small bubble absorption tube, Series sampling), NaN ₃ (use porous glass absorption tube, non-serial sampling), H ₃ P (use porous glass absorption tube, non-serial sampling), P ₂ O ₅ (use porous glass absorption tube, non-serial sampling ), P ₂ S ₅ (use a porous glass absorption tube, non-serial sampling), thionyl chloride (use a porous glass absorption tube, non-serial sampling), HF (use a porous glass absorption tube, non-serial sampling), Collection of gases such as TDI (using impact absorbing bottle, series sampling), MDI (using impact absorbing bottle, series sampling).

Description of drawings

Fig. 1: the structural representation of intelligent air automatic sampler for occupational health of the present invention (the absorption tube shown in the accompanying drawing is a porous glass plate absorption tube);

Fig. 2: the structural representation of intelligent air automatic sampler control valve for occupational health of the present invention (the absorption pipe shown in the accompanying drawing is a porous glass plate absorption pipe);

Fig. 3: the software flowchart of the intelligent air automatic sampler control system for occupational hygiene according to the present invention.

As shown in Figure 1, the names of the components are: air inlet 1 located at the center of the control valve, air inlet connecting pipe 2, control valve 3, air outlet connecting pipe 4, absorption pipes (31, 32, 33, 34, 35, 36, 37, 38), flow control sensor 5, air pump 7, single-chip microcomputer 6, keyboard 61 and display 62.

As shown in Figure 2, wherein (a) is a top view of the control valve, 8 air inlet holes (311, 321, 331, 341, 351, 361, 371, 381) and 8 air outlet holes ( 311', 321', 331', 341', 351', 361', 371', 381'), the air inlet and the air outlet are in pairs, that is, 311 and 311', 321 and 321'.... .. A pair; the air inlet 1 is located in the middle of the control valve, and the air inlet connecting pipe 2 can be switched to different air inlets under the control of the control system.

As shown in Figure 2 (b), the air inlet and outlet pipes of the absorption pipe 31 extend into the control valve from the bottom end of the control valve 3 and communicate with the through holes 311 and 311' and are sealed. The bottom end extends into the control valve and communicates with the through holes 321, 321' and seals it...; the air outlet hole 311' and the air inlet hole 321 are connected through a channel. This figure corresponds to the channel disconnected state, that is, the absorption tubes are independent Work; as shown in Figure 2 (c), the outlet hole 311' is connected with the air inlet hole 321 through a channel, and this figure corresponds to the closed state of the channel, that is, the absorption pipe works in series;

As shown in FIG. 3 , it is a software flowchart of the sample control system of the present invention, and its working process is as described in the embodiment. Before collecting atmospheric samples, insert the absorbing tube into the air inlet and air outlet of the control valve 3 in turn, and set the program of the single-chip microcomputer 6 according to the actual situation.

Detailed ways

Example 1:

Detect the content of hydrogen chloride in the atmosphere: when working, insert the absorption tube into the air inlet and air outlet on the control valve 3 in sequence, and under the control of the single-chip microcomputer 6, the program starts to run. After the data initialization is completed, the air inlet connecting pipe 2 is automatically switched To (the switching process is completed by the single-chip microcomputer by controlling the roller and the forward and reverse motor inside the control valve 3) the air inlet 311, the air outlet connecting pipe 4 is automatically switched to the air outlet 311 ', and the single-chip microcomputer 6 controls the opening of the air inlet 311 to start The air pump 7 (JH-606 electric air pump) collects data, while collecting atmospheric samples, the flow sensor 5 (JKY/4008-50SLpm/314724 flow sensor) is used to calculate and control the sampling flow rate to 0.5L/min, after 15 minutes of sample collection , stop the air pump 7, so as to obtain the sampling sample in the absorption pipe 31; then, the single-chip microcomputer 6 controls the air inlet 311 and the air outlet 311' to close, the air inlet 321 and the air outlet 321' to open, and the air inlet connecting pipe 2 to automatically switch To the air inlet 321, the air outlet connecting pipe 4 is automatically switched to the air outlet 321', and the air pump 7 is turned on to collect data. While collecting samples, the flow sensor 5 is used to calculate and control the sampling flow to 0.5L/min. After 15 minutes of atmospheric sample collection, Stop air pump 7, thereby obtain sampling sample in absorption pipe 32; Then, single-chip microcomputer 6 controls air inlet 321 and air outlet 321 ' to close, air inlet 331 and air outlet 331 ' to open, and air inlet connecting pipe 2 automatically switches to The air inlet hole 331, the air outlet connecting pipe 4 is automatically switched to the air outlet hole 331', the air pump 7 is turned on to collect data, and the flow sensor 5 is used to calculate and control the sampling flow rate to 0.5L/min while collecting samples. After 15 minutes of atmospheric sample collection, stop Aspirate the pump 7, so as to obtain the sampling sample in the absorption pipe 33; then, the control valve controls the air inlet 331 and the air outlet 331' to close, the air inlet 341 and the air outlet 341' to open, and the air inlet connecting pipe 2 automatically switches to the air inlet Hole 341, the air outlet connecting pipe 4 is automatically switched to the air outlet 341', the air pump 7 is turned on to collect data, and the flow sensor 5 is used to calculate and control the sampling flow to 0.5L/min while collecting samples. After 15 minutes of atmospheric sample collection, the air pump is stopped 7, so that the sampling sample is obtained in the absorption pipe 34; then, the control valve controls the air inlet 341 and the air outlet 341' to close, the air inlet 351 and the air outlet 351' to open, and the air inlet connecting pipe 2 to automatically switch to the air inlet 351, the air outlet connecting pipe 4 is automatically switched to the air outlet 351', and the air pump 7 is turned on to collect data. While collecting samples, the flow sensor 5 is used to calculate and control the sampling flow to 0.5L/min. After the atmospheric sample is collected for 15 minutes, the air pump 7 is stopped , so as to obtain sampling samples in the absorption pipe 35; then, the control valve controls the air inlet 351 and the air outlet 351' to close, the air inlet 361 and the air outlet 361' to open, and the air inlet connecting pipe 2 to automatically switch to the air inlet 361 , the air outlet connecting pipe 4 is automatically switched to the air outlet 361', and the air pump 7 is turned on Collect data, use the flow sensor 5 to calculate and control the sampling flow rate to 0.5L/min while collecting the sample, stop the air pump 7 after the atmospheric sample is collected for 15 minutes, so as to obtain the sampling sample in the absorption pipe 36; then, the control valve controls the intake air The hole 361 and the air outlet 361' are closed, the air inlet 371 and the air outlet 371' are opened, the air inlet connecting pipe 2 is automatically switched to the air inlet 371, the air outlet connecting pipe 4 is automatically switched to the air outlet 371', and the air pump 7 is turned on to collect Data, while collecting samples, use the flow sensor 5 to calculate and control the sampling flow rate to 0.5L/min. After the atmospheric sample is collected for 15 minutes, stop the air pump 7, thereby obtaining the sampling sample in the absorption pipe 37; then, the control valve controls the air inlet 371 and the air outlet 371' are closed, the air inlet 381 and the air outlet 381' are opened, the air inlet connecting pipe 2 is automatically switched to the air inlet 381, the air outlet connecting pipe 4 is automatically switched to the air outlet 381', and the air pump 7 is turned on to collect data , while collecting samples, use flow sensor 5 to calculate and control the sampling flow rate to be 0.5L/min. After collecting atmospheric samples for 15 minutes, stop air pump 7, thereby obtaining sampling samples in absorption pipe 38; finally, the control valve controls air inlet 381 And the air outlet 381' is closed, and the program stops running. The uncertainty of the hydrogen chloride content measured by the eight absorption tubes is less than 5%, while the uncertainty of the sampling volume of the conventional sampler is usually about 15% due to system air leakage.

Example 2:

Detect the content of _NH3 in the atmosphere: when working, insert the absorption pipe into the air inlet and air outlet on the control valve 3 in turn, under the control of the single-chip microcomputer 6, the air inlet connecting pipe 2 is not connected with the air inlet 321, 341, 361 , 381 are connected, and the air inlets 321, 341, 361, 381 are connected with the air outlets 311', 331', 351' and 371' respectively, and the air outlets 311', 331', 351' and 371' are connected with the atmosphere closed. The program starts to run, and after the data initialization is completed, the air inlet connecting pipe 2 automatically switches to the air inlet 311, the air outlet connecting pipe 4 automatically switches to the air outlet 321', and the control valve 3 controls the opening of the air inlet 311 and the air outlet 321' to absorb The pipe 31 and the absorption pipe 32 are connected in series, start the suction pump 7 to collect data, and use the flow sensor 5 to calculate and control the sampling flow rate to be 0.5L/min while collecting atmospheric samples. Then, the control valve 3 controls the air inlet 311 and the air outlet 321 ' to close, the air inlet 331 and the air outlet 341 ' to open, and the air inlet connecting pipe 2 automatically switches to the air inlet 331, The air outlet connecting pipe 4 is automatically switched to the air outlet 341', the absorption pipe 33 and the absorption pipe 34 are connected in series, the air pump 7 is started to collect data, and the flow sensor 5 is used to calculate and control the sampling flow at 0.5 L/min while collecting samples. After 15min, stop the suction pump 7, thereby obtain sampling sample in the absorption pipe 33 and the absorption pipe 34; The air connecting pipe 2 is automatically switched to the air inlet 351, the air outlet connecting pipe 4 is automatically switched to the air outlet 361', the absorption pipe 35 and the absorption pipe 36 are connected in series, the air pump 7 is turned on to collect data, and the flow sensor 5 is used to calculate and Control the sampling flow rate to 0.5L/min, and stop the air pump 7 after the atmospheric sample is collected for 15 minutes, thereby obtaining the sampling sample in the absorption pipe 35 and the absorption pipe 36; then, the control valve controls the air inlet 351 and the air outlet 361' to close, The air inlet 371 and the air outlet 381' are opened, the air inlet connecting pipe 2 is automatically switched to the air inlet 371, the air outlet connecting pipe 4 is automatically switched to the air outlet 381', the absorption pipe 37 and the absorption pipe 38 are connected in series, and the air pump 7 is turned on to collect Data, while collecting samples, use flow sensor 5 to calculate and control the sampling flow rate to be 0.5L/min. After the atmospheric sample is collected for 15 minutes, stop the air pump 7, thereby obtaining sampling samples in the absorption pipe 37 and the absorption pipe 38; finally, the control valve Control the air inlet hole 371 and the air outlet hole 381' to close, and the program stops running. Sampling is performed with a common sampler, and the absorption efficiency of a single tube is 80% to 90%. In this example, the absorption liquid in the front and back absorption tubes connected in series in pairs (the absorption liquid is in the absorption tube and is used to absorb the collected atmospheric samples. In this example, the specific absorption liquid is a sulfuric acid solution with a concentration of 0.01mol/L), etc. Volume mixing is used for measurement, and the absorption efficiency of serial sampling can reach 96% to 99%.

Claims (6)

1. An intelligent air automatic sampler for occupational hygiene, characterized in that: Composed of air inlet (1), air inlet connecting pipe (2), control valve (3), air outlet connecting pipe (4), absorption pipe (31, 32, 33, 34, 35, 36, 37, 38), flow Control sensor (5), air pump (7) and control system; control system includes single-chip microcomputer (6), keyboard (61) and display (62); The control valve (3) is drilled with 8 pairs of 16 through-holes, and the through-holes run through the upper and lower surfaces of the control valve (3), in pairs, and are respectively 8 air intake holes (311, 321, 331, 341, 351, 361 . , 36, 37, 38) the air inlet and outlet pipes are stretched into the corresponding through holes by the bottom end of the control valve (3) and sealed; One end of the air inlet connecting pipe (2) is airtightly connected with the sample air inlet (1), and the other end extends into the air inlet (311, 321, 331, 341, 351, 361, 371, 381) on the top of the control valve (3). ) and sealed; one end of the air outlet connecting pipe (4) stretches into one of the air outlets (311', 321', 331', 341', 351', 361', 371', 381') and sealed, the other end It is airtightly connected with the flow control sensor (5), and the other end of the flow control sensor (5) is airtightly connected with the air pump (7); The air intake connecting pipe (2), control valve (3), air outlet connecting pipe (4), flow control sensor (5) and suction pump (7) are all connected with the single-chip microcomputer (6), and the program set by the single-chip microcomputer (6) Control the opening and closing of the suction pump (7), the flow rate of the flow control sensor (5), the connection between the inlet connecting pipe (2) and the outlet connecting pipe (4) and the inlet and outlet holes, each inlet or outlet Closure or opening of stomata and sampling time. 2. a kind of occupational hygiene intelligent air automatic sampler as claimed in claim 1 is characterized in that: between the air outlet of previous absorbing pipe and the air inlet of next absorbing pipe, duct is arranged, and duct is in single-chip microcomputer ( 6) It can be turned on or off separately under the control of the control, so as to realize the series connection of the absorption tubes. 3. A kind of occupational hygiene intelligent automatic air sampler as claimed in claim 1 or 2, is characterized in that: the material of air inlet connecting pipe (2) and air outlet connecting pipe (4) is natural rubber, styrene-butadiene rubber or Butadiene rubber. 4. An intelligent automatic air sampler for occupational health as claimed in claim 1 or 2, characterized in that: the control valve (3) is a cylinder formed by cold pressing and sintering of polytetrafluoroethylene resin. 5. An intelligent automatic air sampler for occupational health as claimed in claim 1 or 2, characterized in that it is used for NH ₃ , HCl, SO ₂ , H ₂ S, Hg, O ₃ , H ₂ O ₂ , Acquisition of Cl ₂ , ClO ₂ , Cr, Sn, NO, NO ₂ , CN, NaN ₃ , H ₃ P, P ₂ O ₅ , P ₂ S ₅ , thionyl chloride, HF, TDI or MDI. 6. An intelligent automatic air sampler for occupational health as claimed in claim 5, wherein the absorber is a large bubble absorber, a porous glass plate absorber, an impact absorber or a small bubble absorber.

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