CN1632294A - A device for removing inhalable particulate matter from automobile exhaust - Google Patents

Abstract

A device used for removing particle matter capable of being inhaled in vehicle tail gas belongs to a removing device of superfine particles in vehicle tail gas. Said device consists of a group of thermophoresis working sections and upper and lower levels headers which are arranged in parallel, wherein said thermophoresis working sections are set between the upper and lower levels headers, with surfaces at the same side of each header being respectively connected with the inlet and outlet of adjacent two stage parallel thermophoresis working sections. By adopting freezing air outside vehicles to cool the thermophoresis working section pipe walls, affected by the thermophoresis effect caused by the temperature difference, the particle matter capable of being inhaled contained in tail gas will deposit at the tubular inner wall surface of the thermophoresis working sections. In accordance with the present invention, by taking advantage of the non-thorough progression flowing effect, affected by the thermophoresis effect, the thermophoresis deposition efficiency is gradually increased at each stage, and a higher total deposition efficiency is achieved finally. The invention has the advantages of low fabrication and operating cost, convenient embodyment and simple control; can realize highly effective removal of particle matter capable of being inhaled at different installation conditions.

Description

A device for removing inhalable particulate matter from automobile exhaust

technical field

The invention relates to a device for removing inhalable particulate matter from automobile exhaust, specifically, the cold air outside the automobile is used to cool the pipe wall passing through the exhaust gas, and the inhalable particulate matter contained in the exhaust gas is heated by temperature difference. Swimming effect, will be deposited on the inner wall surface of the working pipe section, a new type of device to realize the removal of inhalable particulate matter in automobile exhaust gas, belonging to the technical field of automobile exhaust gas purification or dust removal.

Background technique

With the increasing number of automobiles in big cities, inhalable particulate matter (PM2.5) in automobile exhaust has risen to become one of the main sources of environmental pollution. Its removal has also become an international problem. Some existing exhaust gas purifiers use adsorption or chemical reaction principles to remove harmful gases in the exhaust gas, but devices that remove inhalable particulate matter (PM2.5) in the exhaust gas are still rare. Thermophoresis is a hot topic in international research. The inhalable particulate matter (PM2.5) contained in the airflow with a higher temperature, when flowing in a pipeline with a lower wall temperature, will move to the direction of lower temperature due to the thermophoretic effect and deposit on the cold wall surface . According to the current foreign experimental and theoretical research results, the thermophoretic deposition efficiency caused solely by the thermophoretic effect is only 20% to 30%. The low efficiency of thermophoretic deposition is due to the fact that thermophoretic force is a short-range force and only works near the boundary layer. Moreover, existing studies have shown that when the length of the ordinary pipe is more than 2m, the thermophoretic deposition efficiency stops increasing. Moreover, in order to maintain a lower temperature on the wall, a related cooling system must be provided, which increases the complexity and operating costs of the system. Therefore, dust collectors made of thermophoretic effect are rarely reported. The only thing I saw was that in 2002, Byung Uk Lee and Sang Soo Kim in South Korea carried out experimental research on an impactor with a cold platen to capture particles (Byung UK Lee, Sang Soo Kim. (2003). New type ofimpactor with a cooled impact plate for capturing PM2.5 and other aerosols. Journal of Aerosol Science. (34) 957-967), they use the inertial collision and thermophoretic effect of particles on the cold copper plate, and coat the copper plate Butter, in the case of turbulent flow, can make the total deposition efficiency reach more than 50%. However, this method is very complicated and difficult to apply to engineering practice, especially to remove inhalable particulate matter in automobile exhaust.

Contents of the invention

The purpose of the present invention is to provide a novel device for removing inhalable particulate matter in automobile exhaust by using the principle of thermophoresis, that is, to develop a device with simple structure, high removal efficiency, stable performance, and specially suitable for removing automobile exhaust. Dust removal device for ultrafine particles.

The object of the present invention is achieved through the following technical solutions: it is characterized in that: the device is composed of a group of parallel arranged thermophoresis working sections and upper and lower cascade boxes; the thermophoresis working section is arranged between the upper and lower cascade boxes, The same side of each header is respectively connected with the inlet and outlet of two adjacent parallel thermophoresis working sections; each thermophoresis working section has 1 to 4 pieces, and the length of the thermophoresis working section is 0.5 to 2m. The inner diameter of the tube is 2-5 cm.

Compared with the prior art, the present invention has the following advantages and prominent effects: The thermophoresis dust removal device for automobiles provided by the present invention uses the principle of thermophoresis to remove inhalable particulate matter, that is, the air outside the tube caused by the speed of the vehicle is relatively Movement to cool the pipe wall without additional energy consumption. At present, automobile dust collectors mainly deal with harmful gases in exhaust gas, but have little effect on removing fine particles. Foreign experiments have shown that the thermophoretic deposition efficiency caused solely by the thermophoretic effect is only 20% to 30%. However, with the device provided by the present invention, the thermophoretic deposition efficiency is improved by using the thermophoretic effect under the multi-stage non-fully developed flow, and the removal efficiency can reach 70%-90%. Moreover, the utility model has the advantages of convenient implementation, low cost, reliable performance and extremely low operating cost. It can be effectively used in various types of automobiles, and has an outstanding effect on controlling environmental pollution caused by inhalable particles emitted by automobile exhaust. Has broad market prospects.

Description of drawings

Figure 1 is a schematic diagram of the structure of a device for removing inhalable particulate matter from automobile exhaust.

Fig. 2 is the right side view of Fig. 1 .

Detailed ways

The specific structure, working process and best implementation mode of the present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a structural schematic diagram of a device for removing inhalable particulate matter from automobile exhaust provided by the present invention. The device is composed of a group of thermophoresis working sections 1 and upper and lower cascade boxes 2 arranged in parallel; The inlet and outlet of the two parallel thermophoresis working sections are connected; the outer wall of the thermophoresis working section is cooled by cold air to maintain a lower wall temperature of the tube wall, and the inhalable particles in the high-temperature exhaust gas in the tube will be heated Deposited on the wall of the thermophoresis working tube under the action of swimming. Exhaust gas containing respirable particles enters the first-stage thermophoresis working section. Under the action of the temperature difference with the air-cooled wall surface, the respirable particles are deposited on the pipe wall according to the law of thermophoresis. After passing through the upper-stage header, they enter The next-stage thermophoretic deposition pipe section continues to deposit; and so on, through the multi-stage thermophoretic deposition pipe section, a higher deposition efficiency is achieved. The header can play the role of changing the exhaust gas flow field, making the exhaust gas flow a non-fully developed flow, improving the thermophoretic deposition efficiency, and at the same time using turbulent flow to improve the total deposition efficiency. The device can efficiently remove inhalable particulate matter for different types of automobiles. There are two ways to arrange the device: first, the thermophoresis working pipe section is in the same direction as the car, and the air flow outside the pipe and the inner flow of the pipe move in opposite directions; secondly, the thermophoresis working pipe section is perpendicular to the moving direction of the car. The air flow outside the tube and the flow inside the tube are in a cross-flow direction. In addition, there is a dust cleaning hole 3 with a lock nut on the other side of the header, which corresponds to the inlet and outlet of the thermophoresis working section, so that the lock nut can be opened regularly, the cleaning brush can be used and the clean air can be introduced. Remove the inhalable particles deposited on the inner wall of the working section. Then the clean air is blown into the filter bag to collect the inhalable particulate matter under sweeping.

The thermophoresis working pipe section and the header of the present invention are all made of metal, and the length of each thermophoresis working pipe section is generally 0.5-2m. A single pipe is used, and the inner diameter of the pipe is 2m according to the cars with different displacements. ~5cm. The total number of working sections at all levels is generally 4 to 10 sections. Considering the exhaust flow of different types of automobiles, the number of thermophoresis working pipe sections 1 in each stage may be 1-4. The arrangement of the thermophoresis working pipe sections adopts two types: straight row or fork row, and the fork row structure is preferably used. The thermophoresis working pipe section and the header can be connected by argon arc welding or threaded with high temperature resistant gasket.

Claims (3)

1. A device for removing inhalable particulate matter from automobile exhaust, characterized in that: the device is composed of a group of parallel arranged thermophoresis working sections (1) and upper and lower cascade boxes (2); said thermophoresis working section is set Between the upper and lower cascade headers, the same side of each header is respectively connected with the inlet and outlet of two adjacent parallel thermophoresis working sections; each stage has 1 to 4 thermophoresis working sections, The length of the segment is 0.5-2m, and the inner diameter of the tube is 2-5cm. 2. The vehicle exhaust inhalable particle remover device according to claim 1, characterized in that: the thermophoresis working section adopts a fork structure. 3. According to claim 1 or 2 described automobile exhaust inhalable particle remover device, it is characterized in that: on the other side of the header, there is a cleaning hole (3) with a lock nut, the cleaning hole It corresponds to the import and export of the thermophoresis working section.