A particle sampling device with rapid dilution and backwash cleaning and its use method

Abstract

The present invention belongs to the technical field of automobile exhaust particulate matter sampling and measurement, and specifically relates to a particle sampling device with rapid dilution and backwash cleaning and a method for using the same, comprising an exhaust dilution device, a dilution gas preheating device, a particle filtering device and a backwash device; the exhaust dilution device comprises a dilution gas convection duct, an exhaust pipe, a flow control meter and an air compression pump, the dilution gas convection duct is sleeved on the outer layer of the exhaust pipe, and a cavity I is formed between the dilution gas convection duct and the exhaust pipe, and a conical cavity II is formed between the front end of the dilution gas convection duct and the front end of the exhaust pipe. The particle sampling device and the method for using the same can ensure that the sample gas does not condense and the composition does not change during transportation, and the sample gas dilution efficiency is high. After the sampling is completed, the entire device can be backwashed and cleaned, the sampling results are accurate, the device structure is simple, and the design is ingenious and reasonable.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile exhaust particulate matter sampling and measurement, and in particular relates to a particle sampling device with rapid dilution and backwash cleaning and a method for using the same. Background Art

[0002] With the rapid development of my country's national economy and the continuous improvement of people's living standards, the number of cars on the road has increased year by year. The environmental problems caused by particulate matter pollution from vehicle exhaust emissions are becoming increasingly serious. Soot emissions also have a significant impact on human health. This is mainly because soot particles are small in size and contain strong carcinogens. They can enter the human lungs through the human respiratory tract, causing various respiratory diseases and endangering human physical and mental health. Furthermore, soot particles can deposit on the surface of snow and glaciers, enhancing their local melting and adversely affecting the global environment. Therefore, from the perspective of energy conservation and environmental protection, in-depth research on soot particles is urgently needed.

[0003] During the sampling process of automobile exhaust particulate matter, in order to make the particulate matter collected on the filter medium have the same composition as the particulate matter emitted by the vehicle when it is driving, the exhaust gas of the vehicle is generally diluted before being collected by the particle filter. The device that uses dilution gas to dilute the exhaust is usually called a dilution duct. The dilution duct dilutes all or part of the exhaust gas emitted by the vehicle with clean fresh air. Diluting all the exhaust gas and part of the exhaust gas are called full flow dilution and split flow dilution respectively. Full flow dilution requires a large amount of dilution air (200m 3 / min), and the dilution air duct diameter is relatively thick, requiring a large air pump flow rate, making the entire dilution device system bulky. Split dilution can overcome these shortcomings. Split dilution uses a sampling tube to directly extract a portion of the exhaust gas from the engine for dilution, and then filters the particles from the diluted exhaust gas. Current soot particle sampling devices have many drawbacks, such as uneven sample dilution, low sample dilution efficiency, and easy clogging of the particle filter and sampling port. In addition, factors such as temperature are not taken into account during sampling. In view of this, there is an urgent need to further improve the existing automobile exhaust soot particle sampling device to achieve efficient measurement and accurate analysis of soot particles in automobile exhaust. Summary of the Invention

[0004] The purpose of the present invention is to provide a particle sampling device with rapid dilution and backwash cleaning and a method for using the same. The particle sampling device and the method for using the same can ensure that the sample gas does not condense and its composition does not change during transportation, and the sample gas dilution efficiency is high. After the sampling is completed, the entire device can be backwashed and cleaned. The sampling results are accurate, the device structure is simple, and the design is ingenious and reasonable.

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

[0006] A particle sampling device for rapid dilution and back-flushing cleaning, comprising an exhaust dilution device, a dilution gas preheating device, a particle filtering device and a back-flushing device;

[0007] The exhaust dilution device includes a dilution gas convection pipe, an exhaust pipe, a flow control meter and an air compression pump. The dilution gas convection pipe is sleeved on the outer layer of the exhaust pipe, and a cavity I is formed between the dilution gas convection pipe and the exhaust pipe. The front end of the dilution gas convection pipe and the front end of the exhaust pipe form a conical cavity II. The compressed gas generated by the air compression pump is connected to the dilution gas convection pipe through a pipe. A three-way valve and a flow control meter are provided on the pipe. The compressed gas reaches the conical cavity II through the cavity I and dilutes the exhaust gas at the conical cavity II. One end of the sampling probe is inserted into the automobile exhaust pipe and fixed by a clip, and the other end is connected to the particle filter device and the backblowing device respectively through a three-way joint.

[0008] The particle filtering device is composed of a particle filter, a valve, a vacuum pump and a connecting pipe 6a connected in series. The front end of the particle filter is connected to the joint through the connecting pipe 6a; the rear end of the particle filter is connected to the vacuum pump, and a valve is provided on the pipeline between the particle filter and the vacuum pump.

[0009] Furthermore, the compressed air generated by the air compression pump enters the connecting pipe 6b through the three-way valve, the particle filter is connected to the connecting pipe 6b, and the particle filter and the sampling pipeline are backwashed and cleaned by the compressed air.

[0010] Furthermore, two threaded holes are provided at the rear end of the particle filter and are respectively connected to the air compression pump and the vacuum pump through pipelines, and the two threaded holes are connected inside the particle filter.

[0011] Furthermore, the backflush device and the exhaust dilution device share an air compression pump, and the compressed air enters two different backflush and dilution parallel pipes by opening and closing the three-way valve, thereby realizing the backflush and dilution functions; the three-way valve is arranged at the branch of the two parallel pipes.

[0012] Furthermore, the two parallel pipelines for backflushing and dilution are detachable.

[0013] Furthermore, a dilution gas preheating device is evenly distributed on the outer wall of the dilution gas convection pipe. The dilution gas preheating device adopts a heating belt, which can freely heat up to a preset temperature to preheat the dilution gas in the cavity I, thereby preventing the exhaust gas from being rapidly cooled when it contacts the dilution gas in the conical cavity II and affecting the exhaust gas composition.

[0014] A method for using a particle sampling device for rapid dilution and backwash cleaning comprises the following steps:

[0015] Step 1: Turn on the heating belt switch to heat the dilution gas convection pipe;

[0016] Step 2: Turn on the air compressor pump. The compressed air generated by the air compressor pump enters cavity I and conical cavity II. The flow rate of the compressed air is adjusted by the flow controller according to the dilution ratio.

[0017] Step 3: Insert the sampling tube into the exhaust pipe of the car, secure it with a clip, turn on the vacuum pump to provide negative pressure for the device, and start pumping gas for sampling;

[0018] Step 4: When sampling is finished, close the vacuum pump and the valve on the pipeline, stop pumping, and remove the filter paper from the particle filter;

[0019] Step 5: By adjusting the three-way valve, the air compression pump is connected to the connecting pipe 6b, and the compressed air enters the particle filter through the connecting pipe to purge the residual particles attached to the particle filter and the inner wall of the entire pipeline.

[0020] The beneficial effects of the present invention are as follows: the particle sampling device for rapid dilution and backwashing and the method of using the same provided by the present invention have the following characteristics and advantages:

[0021] 1. A particle sampling device with rapid dilution and backwash cleaning of the present invention, through a sleeve-type exhaust dilution device, exhaust gas enters the conical cavity II from the sampling port and mixes with the dilution gas in the conical cavity II. The dilution gas does not directly enter the exhaust pipe to prevent the rapid cooling from affecting the particulate matter in the exhaust gas, and the flow rate of the dilution gas is controlled by a flow controller; a heating belt is evenly arranged on the outer wall of the dilution gas convection pipe to preheat the dilution gas entering the cavity I, to prevent the exhaust gas entering from the sampling port from being rapidly cooled when encountering the dilution gas in the conical cavity II, and to avoid condensation in the exhaust gas during the dilution process, which would affect the composition of the diluted sample gas; the device has the function of backwash cleaning, and the gas sources for backwash and dilution are both generated by an air compression pump, and the opening and closing of the two parallel pipelines of dilution and backwash are achieved by adjusting the three-way valve, which is flexible and convenient to operate, has a reasonable device structure design, and is fully functional;

[0022] 2. The backflush device and the exhaust dilution device in the present invention share an air compressor pump. A three-way valve is provided at the branch point of the two pipelines to control the opening and closing of the two parallel pipelines. This eliminates the need for an additional backflush air source required for backflush cleaning of the device, making the overall device compact, simplifying the operation process, and improving efficiency.

[0023] 3. The dilution gas used in the exhaust dilution device and the back-flushing gas used in the back-flushing device of the present invention are both compressed air generated by an air compression pump. The air is easy to obtain, and the use of an air compression pump replaces the dilution gas storage tank device, which simplifies the overall structure of the device and broadens the application scenarios of the device.

[0024] 4. The cavity structure formed by the front end of the dilution gas convection pipe and the front end of the exhaust pipe in the present invention is a conical structure, and the sampling port is a through hole at the front end of the dilution gas convection pipe, which facilitates uniform mixing of the sample gas and the dilution gas, and the dilution rate is faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the overall structure of the particle sampling device for rapid dilution and backwash cleaning of the present invention;

[0026] Figure 2 Schematic diagram of the structure of the exhaust dilution device in the present invention;

[0027] Figure 3 for Figure 2 Schematic diagram of the enlarged structure at A in the middle;

[0028] Figure 4 for Figure 2 Schematic diagram of the enlarged structure at B in the middle;

[0029] Figure 5 Schematic diagram of the structure of the backflush device in the present invention;

[0030] Figure 6 Schematic diagram of the structure of the particle filter in the present invention;

[0031] Figure 7 Schematic diagram of the structure of the particle filter device of the present invention;

[0032] Figure 8 is a side view schematic diagram of the particle filter of the present invention;

[0033] The numbers in the figure are: 1-dilution gas convection pipe, 2-clamp, 3-tee joint, 4-exhaust pipe, 5-combination joint, 6a-connecting pipe 6a, 6b-connecting pipe 6b, 6c-connecting pipe 6c, 7-particle filter, 8-valve, 9-vacuum pump, 10-tee valve, 11-flow control meter, 12-air compression pump, 13-heating belt, 14-cavity I, 15-conical cavity II, 16-filter paper. DETAILED DESCRIPTION

[0034] Specific embodiment 1: The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. It should be noted that: in the present invention, unless otherwise specified, all the implementation methods and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution. In the present invention, unless otherwise specified, all the technical features and preferred features mentioned herein can be combined with each other to form a new technical solution. Unless otherwise specified, the professional and scientific terms used in this article have the same meaning as those familiar to those skilled in the art.

[0035] As the appended specification of this invention Figure 1 , Instruction Manual Figure 2 , Instruction Manual Figure 5 As shown, the present invention provides a rapid dilution and backwash cleaning particle sampling device, which mainly includes an exhaust dilution device, a dilution gas preheating device, a particle filtering device and a backwash device; the exhaust dilution device includes a dilution gas convection pipe 1, an exhaust pipe 4, a flow control meter 11 and an air compression pump 12;

[0036] As the appended specification of this invention Figure 2 , Instruction Manual Figure 3 , Instruction Manual Figure 4 As shown, the dilution gas convection pipe 1 is sleeved on the outer layer of the exhaust pipe 4, and a cavity I14 is formed between the dilution gas convection pipe 1 and the exhaust pipe 4. The cavity structure formed by the front end of the dilution gas convection pipe 1 and the front end of the exhaust pipe 4 is conical (i.e., a conical cavity II15). The sampling port is a through hole at the front end of the dilution gas convection pipe 1. The above-mentioned sleeve structure design of the dilution gas convection pipe 1 and the exhaust pipe 4 and the cavity I14 and the conical cavity II15 formed therebetween are very convenient for uniform mixing of the sample gas and the dilution gas. The release rate is fast. When installed and used, the air compression pump 12 is connected to the dilution gas convection pipe 1 through a pipe. A three-way valve 10 and a flow control meter 11 are provided on the pipe. The compressed gas reaches the conical cavity II15 through the cavity I14, and the exhaust is diluted at the conical cavity II15. The dilution gas convection pipe 1 and the exhaust pipe 4 constitute a sampling probe. One end of the sampling probe is inserted into the exhaust pipe of the automobile and fixed by a clamp 2. The other end is connected to the particle filter device and the backflush device respectively through a three-way joint 3.

[0037] As the appended specification of this invention Figure 6 , Instruction Manual Figure 7 And the instruction manual Figure 8As shown, the particle filtering device is composed of a particle filter 7, a valve 8, a vacuum pump 9 and a connecting pipe 6a in series. The front end of the particle filter 7 is connected to the joint 5 through the connecting pipe 6a; the rear end of the particle filter 7 is connected to the vacuum pump 8, and a valve 8 is provided on the connecting pipe; the backflush device and the exhaust dilution device share an air compression pump 12, and a three-way valve 10 is provided at the branch of the two pipelines. The opening and closing of the two parallel pipelines are controlled by the three-way valve 10. The compressed air generated by the air compression pump 12 enters the connecting pipe 6b through the three-way valve 10, and the particle filter 7 is connected to the connecting pipe 6b. The particle filter 7 and the sampling pipeline are backflush cleaned by compressed air. This design eliminates the external backflush air source required for backflush cleaning of the device, making the overall device compact, simplifying the operation process, and high efficiency.

[0038] The specific operation steps of the particle sampling device for rapid dilution and backwashing provided by the present invention are as follows:

[0039] First, the operator can turn on the dilution gas preheating device (i.e., the heating belt arranged on the outer wall of the convection duct) to allow it to heat freely to a preset temperature, thereby preheating the dilution gas entering the cavity 1. The air compression pump 12 is then turned on, and the three-way valve 10 is adjusted to allow the dilution gas to enter the cavity (cavity I14, tapered cavity II15) between the dilution gas convection duct 1 and the exhaust pipe 4 through the connecting pipe 6c. The sampling tube is inserted into the vehicle exhaust pipe (the insertion distance is not less than 400 mm) and clamped and fixed using the clamp 2. The vacuum pump 9 is connected to the particulate filter 7 via a pipe, and a valve 8 is arranged on the pipe. The particulate filter 7 is connected to the exhaust pipe 4 via the connecting pipe 6a and the joint 5. When the vacuum pump 9 is started, negative pressure is provided at the end of the system to control the flow of air to the end. The sampling port at the front end of the sampling tube can extract airflow carrying carbon soot particles from the vehicle exhaust pipe. When the airflow flows through the filter paper in the particulate filter 7, the carbon soot particles are trapped on the filter paper. At the end of sampling, close the valve 8 and the vacuum pump 9, take out the filter paper in the particle filter 7, adjust the three-way valve 10 so that the air compression pump 12 is connected to the particle filter 7 through the connecting pipe 6b, and the compressed air begins to backwash and clean the particle filter 7 and the inner wall of the sampling pipeline. In general, when the particle sampling device for rapid dilution and backwash cleaning of the present invention is in use, the automobile exhaust enters the conical cavity II15 from the sampling port at the front end of the sampling tube, and is mixed with the dilution gas in the conical cavity II15. The dilution gas does not directly enter the exhaust pipe 4, so as to prevent the rapid cooling from affecting the particulate matter in the exhaust gas, and the flow rate of the dilution gas is controlled by a flow controller; a heating belt is evenly distributed on the outer wall of the dilution gas convection pipe 1, so as to preheat the dilution gas entering the cavity I14, so as to prevent the exhaust gas entering from the sampling port from being rapidly cooled when encountering the dilution gas in the conical cavity II15, and to avoid condensation in the exhaust gas during the dilution process, which affects the composition of the diluted sample gas; the device of the present invention has the function of backwash cleaning when in use, and the gas sources for backwash and dilution are both generated by the air compression pump 12, and the opening and closing of the two parallel pipelines of dilution and backwash are realized by adjusting the three-way valve 10. The operation is flexible and convenient, the device structure is reasonably designed, and the functions are complete.

[0040] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the present profession can make slight changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A particle sampling device for rapid dilution and backwash cleaning, characterized in that: It includes exhaust dilution device, dilution gas preheating device, particle filtering device and back-blowing device; The exhaust dilution device comprises a dilution gas convection pipe (1), an exhaust pipe (4), a flow control meter (11) and an air compression pump (12), wherein the dilution gas convection pipe (1) is sleeved on the outer layer of the exhaust pipe (4), and a cavity I (14) is formed between the dilution gas convection pipe (1) and the exhaust pipe (4), and a conical cavity II (15) is formed between the front end of the dilution gas convection pipe (1) and the front end of the exhaust pipe (4), and the air compression pump (12) is connected to the dilution gas convection pipe (1) through a pipe, and a three-way valve (10) and a flow control meter (11) are provided on the pipe. The compressed gas generated by the air compression pump (12) passes through the pipe (6c) from the cavity I (14) to the conical cavity II (15), and the exhaust gas is diluted in the conical cavity II (15). One end of the sampling probe is inserted into the exhaust pipe of the automobile and fixed by a clamp (2), and the other end is connected to the particle filter device and the back-blowing device respectively through a three-way joint (3); The particle filtering device is composed of a particle filter (7), a valve (8), a vacuum pump (9), and a connecting pipe (6a) connected in series. The front end of the particle filter (7) is connected to the joint connector (5) via the connecting pipe (6a); the rear end of the particle filter (7) is connected to the vacuum pump (9), and a valve (8) is provided on the pipe. Compressed air generated by the air compression pump (12) enters the connecting pipe (6b) through the three-way valve (10), and the particle filter (7) is connected to the connecting pipe (6b), and the particle filter (7) and the sampling pipeline are backwashed and cleaned by the compressed air; The particle filter (7) has two threaded holes at the rear end thereof, which are connected to the air compression pump (12) and the vacuum pump (9) through pipelines, respectively, and the two threaded holes are connected inside the particle filter (7); The backflush device and the exhaust dilution device share an air compression pump (12), and the compressed air enters two different parallel pipelines for backflush and dilution by opening and closing the three-way valve (10), thereby realizing the backflush and dilution functions; the three-way valve (10) is arranged at the branch of the two parallel pipelines.

2. A particle sampling device for rapid dilution and backwashing according to claim 1, characterized in that: The two parallel pipelines for backflushing and dilution are detachable.

3. The particle sampling device for rapid dilution and backwashing according to claim 1, characterized in that: A heating belt (13) is evenly distributed on the outer wall of the dilution gas convection pipe (1). The heating belt (13) is used to preheat the dilution gas in the cavity I (14) to prevent the exhaust gas from being rapidly cooled when it contacts the dilution gas in the conical cavity II (15) and thus affecting the exhaust gas composition.

4. A method for using a particle sampling device for rapid dilution and backwashing according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: Turn on the heating belt (13) to heat the dilution gas convection pipe (1); Step 2: Turn on the air compressor pump (12), adjust the three-way valve (10), and allow the compressed air generated by the air compressor pump (12) to enter the pipe (6c). According to the dilution factor, the flow rate of the compressed air is adjusted by the flow controller (11); Step 3: Insert the sampling tube into the exhaust pipe of the car, fix it with a clip (2), open the valve (8) and the vacuum pump (9), and the vacuum pump (9) provides negative pressure for the device to start pumping gas for sampling; Step 4: When sampling is finished, close the vacuum pump (9) and valve (8), stop pumping, and remove the filter paper from the particle filter (7); Step 5: By adjusting the three-way valve (10), the air compression pump (12) is connected to the pipeline (6b), and the compressed air enters the particle filter (7) through the pipeline (6b), and the residual particles attached to the particle filter (7) and the inner wall of the pipeline are purged.

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