Individual respirable dust concentration detection device and method

Abstract

The present invention relates to an individual respirable dust concentration detection device and method, belonging to the field of dust concentration detection. The device includes a respirable dust separator and a respirable dust detection device; the respirable dust separator is connected to a dust inlet channel provided on the respirable dust detection device; the respirable dust separator is detachable; the respirable dust detection device is composed of a laser detection unit and a constant flow control system; the cross-flow control system controls the vacuum pump to introduce the dust-laden airflow into the respirable dust separation device, and enters the measurement cavity from the air inlet, the light source, the optical lens, and the optical darkroom start working, the photoelectric sensor transmits the collected photoelectric signal to the main control board, completes the instantaneous concentration measurement of the respirable dust concentration, and the dust in the measurement cavity is discharged from the air outlet due to gravity and the suction of the vacuum pump. The tracking monitoring carried out by the present invention as the workers work, and the continuous sampling will inevitably be able to more objectively reflect the actual situation of dust at the work site and the actual dust exposure level of the miners.

Description

Technical Field

[0001] The invention belongs to the field of dust concentration detection, and relates to an individual respirable dust concentration detection device and method. Background Art

[0002] The individual respirable dust concentration detection device is an instrument that can continuously measure the respirable dust concentration. Its detection principle is to first use a respirable dust separator to separate the respirable components from the total dust, and then transmit the separated respirable components to the dust detection unit for concentration measurement.

[0003] At present, the individual respirable dust detection of workers usually adopts the method of continuous sampling and weighing of workers for a work shift by using individual respirable dust samplers. However, this method is cumbersome to operate and has a long detection cycle. The filter membrane needs to be dried and destaticized before and after sampling. Dust will fall off during the transportation of the filter membrane, resulting in detection errors. At present, there is no mature individual respirable dust concentration detector, which mainly faces the following difficulties: the common virtual impact, flat plate impact and horizontal ceramsite principles are difficult to achieve continuous separation of respirable dust; virtual impact has two channels of strong flow and weak flow, which makes the detector structure difficult to design, and the dust-containing airway is easily contaminated or blocked, making the detector unable to work normally and requiring frequent maintenance; pipeline cleaning is difficult, and there is a lack of continuous detection methods for individual respirable dust concentration, making it difficult to achieve continuous monitoring. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a device and method for detecting individual respirable dust concentration.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An individual respirable dust concentration detection device, the device comprising a respirable dust separator and a respirable dust detection device;

[0007] The respirable dust separator is connected to a dust inlet passage provided on the respirable dust detection device;

[0008] The respirable dust separator is removable;

[0009] The respirable dust detection device consists of a laser detection unit and a constant flow control system;

[0010] The laser detection unit is composed of a laser light source, an optical lens group, a measuring cavity, an optical darkroom, a concave condenser, a photoelectric sensor and a main control board. The laser light source is parallel to the optical lens group and the optical darkroom, and the laser light source, the optical lens group and the optical darkroom are distributed on both sides of the measuring cavity. An air inlet and an air outlet are provided on the measuring cavity. The photoelectric sensor is arranged above the measuring cavity at a certain angle to the incident light source and is connected to the main control board. The concave condenser is placed below the measuring cavity to gather scattered light onto the photoelectric detector.

[0011] The constant flow control system consists of a gas flow sensor, a constant flow control system and a vacuum pump. The gas flow sensor is connected to the main control board. The speed of the vacuum pump is adjusted by PID control technology to stabilize the flow at the set value, ensuring a constant vacuum flow.

[0012] An exhaust port is arranged on one side of the constant flow control system close to the laser detection unit, and a dust outlet channel is arranged on the other side.

[0013] An individual respirable dust concentration detection method based on the device, the method is:

[0014] Assume the starting calculation time is t0 and the ending calculation time is t s , t n Unit measurement time for calculating the cumulative exposure to respirable dust;

[0015] When t s -t0≤t n -t0:

[0016] At t0-t s Time period, individual respirable dust concentration sampling m0-m s s group of respirable dust measurement values, using s group of data, fit the measurement time and respirable dust concentration relationship function f(t), integrate to get individual respirable dust concentration cumulative exposure M, average respirable dust concentration m;

[0017]

[0018]

[0019] When t s -t0>t n -t0:

[0020] At t0-t n The individual respirable dust concentration is sampled n groups of respirable dust measurement values, and the relationship function f1(′) between time and respirable dust concentration is fitted using n groups of data to obtain t0-t n The cumulative exposure to respirable dust between n1 ;

[0021]

[0022] As the sampling time increases, t n As unit time, fit each n groups of collected data separately, and integrate the function of the relationship between time and dust concentration obtained by fitting to obtain the cumulative exposure to respirable dust in the current time period; for the last group of sampling time that does not reach t n The m groups of data actually sampled are fitted; at t0-t s The cumulative dust exposure is the sum of the respirable dust exposure in n periods of time, and the average respirable dust concentration is m.

[0023] The beneficial effect of the present invention is that the individual respirable dust continuous monitoring equipment can reflect the cumulative amount of respirable dust that workers are exposed to in the workplace and the instantaneous dust concentration. Tracking monitoring can be carried out as the workers work, and continuous sampling can inevitably reflect the actual situation of dust at the work site and the actual dust exposure level of miners more objectively. It is more scientific and reliable than full dust monitoring, and is more conducive to measuring the dust exposure of workers and ensuring the safety of operators.

[0024] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0026] Figure 1 It is a structural diagram of the device of the present invention;

[0027] Figure 2 The figure is a flow chart of the method of the present invention.

[0028] Figure numerals: 1. Respirable dust separator, 2. Dust inlet channel, 3. Main control board, 4. Photoelectric sensor, 5. Laser light source, 6. Optical lens group, 7. Measuring cavity, 8. Optical darkroom, 9. Air inlet, 10. Air outlet, 11. Concave condenser, 12. Constant flow control system, 13. Gas flow sensor, 14. Constant flow control system, 15. Vacuum pump, 16. Dust outlet channel, 17. Exhaust port. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0031] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] like Figure 1 and Figure 2 As shown, the device of the present invention comprises a respirable dust separator 1 and a respirable dust detection device. The respirable dust separator 1 is connected to a dust inlet channel 2 of the respirable dust detection device.

[0033] The respirable dust separator 1 is a cyclone separator, which is detachable and replaceable and can separate the respirable dust.

[0034] When in use, the respirable dust separator 1 is close to the user's breathing port, which is beneficial to improving the collection accuracy and facilitating maintenance.

[0035] The respirable dust detection device is suitable for personal wear.

[0036] The respirable dust detection device is composed of a laser detection unit based on optical principles and a constant flow control system 12.

[0037] The laser detection unit is composed of a laser light source 5, an optical lens group 6, a measuring cavity 7, an optical darkroom 8, a concave condenser 11, a photoelectric sensor 4 and a main control board 3. The laser light source 5 is parallel to the optical lens group 6 and the optical darkroom 8, and the laser light source 5, the optical lens group 6 and the optical darkroom 8 are distributed on both sides of the cavity of the measuring cavity 7; the measuring cavity 7 is provided with an air inlet 9 and an air outlet 10; the photoelectric sensor 4 is arranged above the cavity of the measuring cavity 7 at a certain angle to the incident light source, and is connected to the main control board 3; the concave condenser 11 is placed below the cavity of the measuring cavity 7 to gather more scattered light to the photoelectric detector 4. The entire unit is encapsulated in a light-shielded cavity.

[0038] The constant flow control system 12 is composed of a gas flow sensor 13, a constant flow control system 14 and an air pump 15. The gas flow sensor 13 is connected to the main control board 3. The rotation speed of the air pump is automatically adjusted through the PID control technology so that the flow rate is always stable near the set value, thereby ensuring the constancy of the air flow rate.

[0039] An exhaust port 17 is provided on one side of the constant flow control system 12 close to the laser detection unit, and a dust outlet channel 16 is provided on the other side.

[0040] The cross-flow control system controls the vacuum pump to introduce the dust-laden airflow into the respirable dust separation device. After the dust is separated by the separation device, only the respirable dust enters the measuring chamber from the air inlet 9 through the hose connecting the separation device and the measuring chamber. The light source, optical lens, and optical darkroom start working. The photoelectric sensor transmits the collected photoelectric signal to the main control board to complete the instantaneous concentration measurement of the respirable dust. The dust in the measuring chamber is discharged from the air outlet 9 due to gravity and the suction force of the vacuum pump.

[0041] Assume the starting calculation time is t0 and the ending calculation time is t s , t n Unit measurement time for calculating the cumulative exposure to respirable dust;

[0042] When t s -t0≤t n -t0:

[0043] At t0-t s Time period, individual respirable dust concentration sampling m0-m s s group of respirable dust measurement values, using s group of data, fit the measurement time and respirable dust concentration relationship function f(t), integrate to get individual respirable dust concentration cumulative exposure M, average respirable dust concentration m;

[0044]

[0045]

[0046] When t s- t0>t n -t0:

[0047] At t0-t n The individual respirable dust concentration is sampled n groups of respirable dust measurement values, and the relationship function f1(t) between time and respirable dust concentration is fitted using n groups of data to obtain t0-t n The cumulative exposure to respirable dust between n1 ;

[0048]

[0049] As the sampling time increases, t n As unit time, fit each n groups of collected data separately, and integrate the function of the relationship between time and dust concentration obtained by fitting to obtain the cumulative exposure to respirable dust in the current time period; for the last group of sampling time that does not reach t n The m groups of data actually sampled are fitted; at t0-t s The cumulative dust exposure is the sum of the respirable dust exposure in n periods of time, and the average respirable dust concentration is m.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. An individual respirable dust concentration detection device, characterized in that: The device includes a respirable dust separator and a respirable dust detection device; The respirable dust separator is connected to a dust inlet passage provided on the respirable dust detection device; The respirable dust separator is detachable and can be moved according to the wearer's needs; The respirable dust detection device consists of a laser detection unit and a constant flow control system; The laser detection unit is composed of a laser light source, an optical lens group, a measuring cavity, an optical darkroom, a concave condenser, a photoelectric sensor and a main control board. The laser light source is parallel to the optical lens group and the optical darkroom, and the laser light source, the optical lens group and the optical darkroom are distributed on both sides of the measuring cavity. An air inlet and an air outlet are provided on the measuring cavity. The photoelectric sensor is arranged above the measuring cavity at a certain angle to the incident light source and is connected to the main control board. The concave condenser is placed below the measuring cavity to gather scattered light onto the photoelectric detector. The constant flow control system consists of a gas flow sensor, a constant flow control system and a vacuum pump. The gas flow sensor is connected to the main control board. The speed of the vacuum pump is adjusted by PID control technology to stabilize the flow at the set value, ensuring a constant vacuum flow. The constant flow control system is provided with an exhaust port on one side close to the laser detection unit, and a dust outlet channel on the other side; The individual respirable dust concentration detection method based on the device comprises the following steps: Assume the starting calculation time is t0 and the ending calculation time is t s , t n Unit measurement time for calculating the cumulative exposure to respirable dust; When t s -t0≤t n -t0: At t0-t s Time period, individual respirable dust concentration sampling m0-m s s group of respirable dust measurement values, using s group of data, fit the measurement time and respirable dust concentration relationship function f(t), integrate to get individual respirable dust concentration cumulative exposure M, average respirable dust concentration m; When t s -t0>t n -t0: At t0-t n The individual respirable dust concentration is sampled n groups of respirable dust measurement values, and the relationship function f1(t) between time and respirable dust concentration is fitted using n groups of data to obtain t0-t n The cumulative exposure to respirable dust between n1 ; As the sampling time increases, t n As unit time, fit each n groups of collected data separately, and integrate the function of the relationship between time and dust concentration obtained by fitting to obtain the cumulative exposure to respirable dust in the current time period; for the last group of sampling time that does not reach t n The m groups of data actually sampled are fitted; at t0-t s The cumulative dust exposure is the sum of the respirable dust exposure in n periods of time, and the average respirable dust concentration is m.

Images