CN110541743A - A spiral diesel engine tail gas purification device and its purification method - Google Patents

Abstract

The invention discloses a spiral type diesel engine tail gas purification device and a purification method thereof; it comprises an outer cylinder, a middle cylinder and an inner cylinder; they are combined to form a spiral flue gas purification chamber and a water supply chamber, and a layer of water film is formed on the wall of the water supply chamber ;The upper part of the flue gas purification chamber introduces the exhaust gas of the diesel engine through the exhaust gas inlet on the upper end plate; under the guide action of the spiral guide vane, the introduced exhaust gas spirals forward in the spiral flue gas purification chamber; the spiral advances During the process, the particles entrained in the exhaust gas are captured by the water film layer on the wall of the middle cylinder under the action of inertial centrifugal force, so that the particles are separated from the gas. After the water level of the water collection bin reaches the predetermined height, it is discharged from the water collection bin through the sewage pipe, and the purified gas is discharged to the atmosphere from the inner cylinder.

Description

A spiral diesel engine tail gas purification device and its purification method

technical field

The invention relates to a diesel engine tail gas purification device, in particular to a screw type diesel engine tail gas purification device and a purification method thereof.

Background technique

In recent years, with the rapid development of economy and technology, cars have become one of the main ways for people to travel, and global car production and ownership have increased year by year. While the extensive use of automobiles promotes the development of modern industry and economy, it also causes serious environmental pollution, which has become one of the main directions of environmental protection research. At present, the mainstream vehicle engines are gasoline engines and diesel engines. Gasoline engines have smaller volume and mass, and have higher liter power, which are suitable for various small vehicles. With its good power, economy and durability, diesel engines are getting more and more attention, and are widely used in various large passenger cars, trucks and various construction machinery.

The main emissions from diesel engines are carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx) and particulate matter (PM). Carbon monoxide (CO) will combine with hemoglobin in the body after being inhaled by the human body, hindering the blood from oxygen Transportation will make the human body hypoxic, causing dizziness, nausea and other symptoms, and in severe cases, it can cause coma or even death. Organic substances such as benzene (C6H6) in hydrocarbons (HC) have a strong carcinogenic effect, which greatly increases the incidence of cancer. Nitrogen oxides (NOx) enter the atmosphere and react with other substances in the atmosphere under the action of sunlight to form photochemical smog and acid rain, causing great harm and pollution to human health and the environment. Particulate matter (PM) not only directly affects the health of the human respiratory system, but also absorbs a large amount of soluble organic matter, many of which have strong carcinogenic effects.

Among the above-mentioned main emissions, the carbon monoxide (CO) and hydrocarbon (HC) emission levels of the diesel engine are significantly lower than those of the gasoline engine due to the higher excess air coefficient in the combustion process of the diesel engine and more oxygen participating in the reaction. However, in terms of particulate matter (PM) control, due to the limitation of the combustion mode and fuel properties of diesel engines, its emissions are much higher than those of gasoline engines.

Therefore, it is of great theoretical and practical significance to study the purification technology of particulate matter outside diesel engines, both in terms of environmental protection and human health.

Contents of the invention

In order to overcome the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a screw type diesel engine exhaust gas purification device and its purification method.

The present invention realizes through following technical scheme:

A spiral diesel engine exhaust gas purification device, comprising an outer cylinder 1, a middle cylinder 2 and an inner cylinder 3 which are sheathed together at intervals in sequence;

The upper edges of the outer cylinder 1, the middle cylinder 2 and the inner cylinder 3 are all sealed and connected by an upper end plate 31;

The lower end edges of the outer cylinder 1 and the middle cylinder 2 are sealed and connected through the lower end plate 32;

The lower port of the inner cylinder 3 directly communicates with the water collecting bin 4 located below the lower end plate 32;

A spiral deflector 5 is provided on the outer circumferential wall along the axial direction of the inner cylinder 3; the spiral deflector 5 is located in the gap formed between the inner cylinder 3 and the middle cylinder 2, and the gap constitutes a spiral smoke purification chamber;

The gap between the middle cylinder 2 and the outer cylinder 1 constitutes a water supply chamber 6, and the wall surface of the middle cylinder 2 is covered with water outlet holes 12, and the water in the water supply chamber 6 seeps out from the water outlet holes 12 and wets the middle cylinder 2 under pressure. Wall surface, forming a water film layer on the entire wall surface of the middle tube 2;

The lower part of the flue gas purification chamber communicates with the water collection bin 4 through the through hole on the lower end plate 32;

The upper part of the flue gas purification chamber introduces the exhaust gas of the diesel engine through the exhaust gas inlet 7 provided on the upper end plate 31; Forward; during the spiral forward process, the particles entrained in the tail gas are captured by the water film layer on the wall of the middle cylinder 2 under the action of inertial centrifugal force, so that the particles are separated from the gas, and the separated particles are brought together with the liquid flow to the collector under the action of air flow and gravity. In the water tank 4, when the water level of the water collecting tank 4 reaches a predetermined height, the water collecting tank 4 is discharged from the sewage pipe 8, and the purified gas is discharged to the atmosphere through the inner cylinder 3.

Each of the water outlet holes 12 has the same diameter, and the arrangement density is gradually sparse from top to bottom.

The diameter of the outlet hole 12 gradually decreases from top to bottom.

The exhaust gas inlet 7 of the upper end plate 31 is provided with an exhaust gas deflector 9 , and the exhaust gas deflector 9 is provided with an exhaust gas intake pipe 10 .

The exhaust gas inlet pipe 10 is installed on the side of the exhaust gas shroud 9 .

The upper side wall of the outer cylinder 1 is provided with a water inlet pipe 11 , and the water inlet pipe 11 communicates with the water supply chamber 6 .

An exhaust pipe 13 is installed on the inner cylinder 3 .

The side wall of the water collection bin 4 is provided with a sewage discharge pipe 8; the diameter of the sewage discharge pipe 8 is 1/4, 1/6, 1/10 or 1/20 of the diameter of the inner cylinder 3; The number of tubes 8 is one or more than two.

A method for purifying diesel exhaust gas, comprising the steps of:

Connect the water inlet pipe 11 on the side wall of the outer cylinder 1 to the water supply pump, the water from the water supply pump fills the water supply chamber 6, and seeps out from the water outlet hole 12 on the wall surface of the middle cylinder 2 to the spiral flue gas purification chamber under pressure, The seeped water forms a layer of water film layer flowing downward on the inner peripheral wall of the middle cylinder 2, and finally collects into the water collection chamber 4 through the through hole on the lower end plate 32;

Then the exhaust pipe of the diesel engine is connected to the exhaust gas intake pipe 10, and the exhaust gas enters the spiral flue gas purification chamber through the exhaust gas inlet 7 provided on the upper end plate 31; The spiral advances in the spiral flue gas purification chamber; during the spiral advance process, the particulate matter entrained in the exhaust gas is contacted and captured by the water film layer on the wall of the middle cylinder 2 under the action of inertial centrifugal force, so that the particulate matter is separated from the gas, and the separated particulate matter is in the air. Under the action of airflow and gravity, it is collected into the water collection bin 4 with the liquid flow. When the water level of the water collection bin 4 reaches a predetermined height, it is discharged from the water collection bin 4 through the sewage pipe 8; at the same time, the separated gas is purified by the spiral flue gas. The through hole at the bottom of the cavity enters the water collecting chamber 4, and the particles remaining in the gas entering the water collecting chamber 4 have a second contact and collision with the liquid surface in the water collecting chamber 4 to form a secondary capture, so that the gas is purified again; The exhausted gas returns to the inner cylinder 3, and then is discharged to the atmosphere through the exhaust pipe 13 connected to the inner cylinder 3; while the sewage mixed with particles continues to collect into the water collection bin 4, when the water level in the water collection bin 4 reaches After the predetermined height, the water collecting bin 4 is discharged from the sewage pipe 8 .

Compared with the prior art, the present invention has the following advantages and effects:

In the present invention, the outer cylinder 1, the middle cylinder 2 and the inner cylinder 3 are organically combined, and a spiral guide vane 5 is arranged on the outer circumferential wall of the inner cylinder 3 along the axial direction; the spiral guide vane 5 is located between the inner cylinder 3 and the middle In the gap formed between the cylinders 2, the gap constitutes the spiral flue gas purification chamber; the gap between the middle cylinder 2 and the outer cylinder 1 constitutes the water supply chamber 6, and the wall surface of the middle cylinder 2 is covered with water outlet holes 12, and the water supply chamber 6 Under the action of pressure, water seeps out from the water outlet hole 12 and wets the wall surface of the middle cylinder 2, forming a water film layer on the entire wall surface of the middle cylinder 2.

With this combination of structures, the introduced exhaust gas is guided by the spiral deflector 5, and the exhaust gas spirals forward in the spiral flue gas purification chamber in a spiral manner; Under the action, it is contacted and captured by the water film layer on the wall of the middle cylinder 2, so that the particles are separated from the gas. After reaching the predetermined height, the water collection bin 4 is discharged from the sewage pipe 8; at the same time, the separated gas enters the water collection bin 4 through the through hole at the bottom of the spiral flue gas purification chamber, and the residual particulate matter in the gas entering the water collection bin 4 is separated from the water collection bin 4 again. The liquid surface in the water collection chamber 4 produces a secondary contact and collision, forming a secondary capture, so that the gas is purified again; Discharge to the atmosphere; and the sewage mixed with particulate matter continues to collect into the water collection bin 4, and when the water level in the water collection bin 4 reaches a predetermined height, it is discharged from the water collection bin 4 through the sewage pipe 8.

Compared with the traditional cyclone particle separation device, the invention not only has a simpler structure and principle, but also has a better separation effect on the particles mixed in the tail gas.

The actual function of the wall surface of the middle cylinder of this device is to pass through the water outlet holes distributed in the array, and the water seeping out of the water outlet holes finally wets the wall surface of the middle cylinder 2, forming a water film layer; the arrangement density of the water outlet holes adopts a top-to-bottom Gradually sparse, or an arrangement in which the pore size gradually decreases from top to bottom. This arrangement method cleverly uses the principle of fluid mechanics. The present invention adopts the principle that the pore size and pore arrangement density are proportional to the flow rate under the same pressure, so that the distribution of the water film layer on the wall surface of the entire middle cylinder is more uniform and stable.

This device generally uses water to adsorb particulate matter in the exhaust gas. According to the principle of selective catalytic reduction (SCR) technology, it can also use a liquid containing a certain amount of reducing agent such as urea. During the flow of exhaust gas, relevant harmful gases will also come into contact with the adsorption liquid to remove harmful gases such as nitrogen oxides (NOx) in the exhaust gas and realize multi-effect utilization.

The outer cylinder, middle cylinder, inner cylinder, upper and lower end plates, exhaust gas deflector and water collection bin of this device can be made into a split structure through flange connection, which is convenient for maintenance.

At present, the diesel engine exhaust treatment system is generally composed of multiple purification devices. This device mainly filters and purifies the particulate matter in the exhaust gas, and can be combined with other treatment devices to form a complete diesel engine exhaust treatment system.

Description of drawings

Fig. 1 is a structural schematic diagram of a screw-type diesel engine tail gas purification device of the present invention.

Fig. 2 is a schematic diagram of the exhaust gas flow path in the spiral flue gas purification chamber.

Fig. 3 is a schematic diagram 1 of the array distribution of water outlet holes on the wall surface of the middle cylinder.

Fig. 4 is a second schematic diagram of the array distribution of water outlet holes on the wall surface of the middle cylinder.

Detailed ways

The present invention will be described in further detail below in conjunction with specific embodiments.

Example

As shown in Figure 1-4. The invention discloses a spiral diesel engine tail gas purification device, which comprises an outer cylinder 1, a middle cylinder 2 and an inner cylinder 3 which are sheathed together at intervals in sequence;

The upper edges of the outer cylinder 1, the middle cylinder 2 and the inner cylinder 3 are all sealed and connected by an upper end plate 31;

The lower end edges of the outer cylinder 1 and the middle cylinder 2 are sealed and connected through the lower end plate 32;

The lower port of the inner cylinder 3 directly communicates with the water collecting bin 4 located below the lower end plate 32;

A spiral deflector 5 is provided on the outer circumferential wall along the axial direction of the inner cylinder 3; the spiral deflector 5 is located in the gap formed between the inner cylinder 3 and the middle cylinder 2, and the gap constitutes a spiral smoke purification chamber;

The gap between the middle cylinder 2 and the outer cylinder 1 constitutes a water supply chamber 6, and the wall surface of the middle cylinder 2 is covered with water outlet holes 12, and the water in the water supply chamber 6 seeps out from the water outlet holes 12 and wets the middle cylinder 2 under pressure. Wall surface, forming a water film layer on the entire wall surface of the middle tube 2;

The lower part of the flue gas purification chamber communicates with the water collection bin 4 through the through hole on the lower end plate 32;

The upper part of the flue gas purification chamber introduces the exhaust gas of the diesel engine through the exhaust gas inlet 7 provided on the upper end plate 31; Forward; during the spiral forward process, the particles entrained in the tail gas are captured by the water film layer on the wall of the middle cylinder 2 under the action of inertial centrifugal force, so that the particles are separated from the gas, and the separated particles are brought together with the liquid flow to the collector under the action of air flow and gravity. In the water tank 4, when the water level of the water collecting tank 4 reaches a predetermined height, the water collecting tank 4 is discharged from the sewage pipe 8, and the purified gas is discharged to the atmosphere through the inner cylinder 3.

Each of the water outlet holes 12 has the same diameter, and the arrangement density is gradually sparse from top to bottom. The diameter of the outlet hole 12 gradually decreases from top to bottom. According to the principle of fluid mechanics, when the water outlet holes on the wall of the middle cylinder 2 are equal in diameter, the smaller the diameter of the lower one, the greater the pressure and the greater the flow rate. It is more evenly watered from top to bottom.

The exhaust gas inlet 7 of the upper end plate 31 is provided with an exhaust gas deflector 9 , and the exhaust gas deflector 9 is provided with an exhaust gas intake pipe 10 .

The exhaust gas inlet pipe 10 is installed on the side of the exhaust gas shroud 9 .

The upper side wall of the outer cylinder 1 is provided with a water inlet pipe 11 , and the water inlet pipe 11 communicates with the water supply chamber 6 .

An exhaust pipe 13 is installed on the inner cylinder 3 . The diameter of the exhaust pipe 13 can be equal to that of the inner cylinder 3 ; it can also be smaller than the diameter of the exhaust pipe 13 in practical applications, such as one-half or one-third of the diameter of the inner cylinder 3 .

The side wall of the water collection bin 4 is provided with a sewage discharge pipe 8; the diameter of the sewage discharge pipe 8 is 1/4, 1/6, 1/10 or 1/20 of the diameter of the inner cylinder 3; The number of tubes 8 is one or more than two. Of course, the above are just examples, and may be determined according to specific situations in practical applications.

The outer cylinder 1, the middle cylinder 2 and the inner cylinder 3 are generally metal circular cylinder structures. The spiral deflector 5 of the present invention is connected with the inner cylinder 3 by welding, the outer edge of the spiral deflector 5 is only in contact with the wall surface of the middle cylinder 2, and no fixed connection is required to facilitate disassembly.

The size of the gap between the outer cylinder 1 and the middle cylinder 2 can be flexibly changed according to the required volume of the water supply chamber 6; the size of the gap between the middle cylinder 2 and the inner cylinder 3 (spiral smoke purification chamber) can be adjusted according to the displacement of the diesel engine Depends on size.

The purification process of diesel engine tail gas of the present invention is as follows:

Connect the water inlet pipe 11 on the side wall of the outer cylinder 1 to the water supply pump, the water from the water supply pump fills the water supply chamber 6, and seeps out from the water outlet hole 12 on the wall surface of the middle cylinder 2 to the spiral flue gas purification chamber under pressure, The seeped water forms a layer of water film layer flowing downward on the inner peripheral wall of the middle cylinder 2, and finally collects into the water collection chamber 4 through the through hole on the lower end plate 32;

Then the exhaust pipe of the diesel engine is connected to the exhaust gas intake pipe 10, and the exhaust gas enters the spiral flue gas purification chamber through the exhaust gas inlet 7 provided on the upper end plate 31; The spiral advances in the spiral flue gas purification chamber; during the spiral advance process, the particulate matter entrained in the exhaust gas is contacted and captured by the water film layer on the wall of the middle cylinder 2 under the action of inertial centrifugal force, so that the particulate matter is separated from the gas, and the separated particulate matter is in the air. Under the action of airflow and gravity, it is collected into the water collection bin 4 with the liquid flow. When the water level of the water collection bin 4 reaches a predetermined height, it is discharged from the water collection bin 4 through the sewage pipe 8; at the same time, the separated gas is purified by the spiral flue gas. The through hole at the bottom of the cavity enters the water collecting chamber 4, and the particles remaining in the gas entering the water collecting chamber 4 have a second contact and collision with the liquid surface in the water collecting chamber 4 to form a secondary capture, so that the gas is purified again; The exhausted gas returns to the inner cylinder 3, and then is discharged to the atmosphere through the exhaust pipe 13 connected to the inner cylinder 3; while the sewage mixed with particles continues to collect into the water collection bin 4, when the water level in the water collection bin 4 reaches After the predetermined height, the water collecting bin 4 is discharged from the sewage pipe 8 .

As described above, the present invention can be preferably carried out.

The implementation of the present invention is not limited by the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods, and are all included in within the protection scope of the present invention.

Claims (9)

1. The utility model provides a spiral diesel engine tail gas cleanup unit which characterized in that: comprises an outer cylinder (1), a middle cylinder (2) and an inner cylinder (3) which are sleeved together at intervals in sequence;

the upper end edges of the outer cylinder (1), the middle cylinder (2) and the inner cylinder (3) are hermetically connected through an upper end plate (31);

The lower end edges of the outer cylinder (1) and the middle cylinder (2) are hermetically connected through a lower end plate (32);

The lower port of the inner cylinder (3) is directly communicated with a water collecting bin (4) arranged below the lower end plate (32);

a spiral flow deflector (5) is arranged on the outer circumferential wall surface along the axial direction of the inner cylinder (3); the spiral flow deflector (5) is positioned in a gap formed between the inner cylinder (3) and the middle cylinder (2), and the gap forms a spiral flue gas purification cavity;

a water supply cavity (6) is formed by a gap between the middle cylinder (2) and the outer cylinder (1), water outlet holes (12) are fully distributed on the wall surface of the middle cylinder (2), water in the water supply cavity (6) seeps out of the water outlet holes (12) under the action of pressure and wets the wall surface of the middle cylinder (2), and a water film layer is formed on the whole wall surface of the middle cylinder (2);

The lower part of the flue gas purification cavity is communicated with the water collecting bin (4) through a through hole on the lower end plate (32);

the upper part of the flue gas purification cavity introduces the tail gas of the diesel engine through a tail gas inlet (7) arranged on an upper end plate (31); leading the introduced tail gas to spirally advance in the spiral flue gas purification cavity under the flow guiding action of the spiral flow guiding sheet (5); in the spiral advancing process, particulate matters carried in the tail gas are captured by a water film layer on the wall surface of the middle cylinder (2) under the action of inertial centrifugal force, so that the particulate matters are separated from the gas, the separated particulate matters are collected into the water collecting bin (4) along with liquid flow under the action of air flow and gravity, the water collecting bin (4) is discharged out of the water collecting bin (4) through the blow-off pipe (8) after the water level of the water collecting bin (4) reaches a preset height, and the purified gas is discharged to the atmosphere through the inner cylinder (3).

2. The spiral diesel engine exhaust purification device according to claim 1, characterized in that: the diameters of the water outlet holes (12) are equal, and the arrangement density is gradually sparse from top to bottom.

3. The spiral diesel engine exhaust purification device according to claim 1, characterized in that: the aperture of the water outlet hole (12) is gradually reduced from top to bottom.

4. the spiral diesel engine exhaust purification device according to claim 2, characterized in that: a tail gas guide sleeve (9) is arranged on a tail gas inlet (7) of the upper end plate (31), and a tail gas inlet pipe (10) is arranged on the tail gas guide sleeve (9).

5. The spiral diesel engine exhaust purification device according to claim 4, characterized in that: the tail gas inlet pipe (10) is arranged on the side part of the tail gas guide sleeve (9).

6. The spiral diesel engine exhaust purification device according to claim 5, characterized in that: the upper side wall of the outer barrel (1) is provided with a water inlet pipe (11), and the water inlet pipe (11) is communicated with the water supply cavity (6).

7. the spiral diesel engine exhaust purification device according to claim 6, characterized in that: an exhaust pipe (13) is arranged on the inner cylinder (3).

8. A spiral diesel engine exhaust purification device according to any one of claims 1 to 7, characterized in that: a drain pipe (8) is arranged on the side wall of the water collecting bin (4); the diameter of the sewage discharge pipe (8) is one fourth, one sixth, one tenth or one twentieth of the diameter of the inner cylinder (3); the number of the sewage discharge pipes (8) is one or more than two.

9. A method for purifying exhaust gas from a diesel engine, which is implemented by using the spiral type diesel engine exhaust gas purifying apparatus according to claim 8, comprising the steps of:

a water inlet pipe (11) on the side wall of the outer barrel (1) is connected to a water supply pump, water from the water supply pump is filled in a water supply cavity (6) and seeps out from a water outlet hole (12) on the wall surface of the middle barrel (2) to the spiral flue gas purification cavity under the action of pressure, the seeped water forms a downward flowing water film layer on the inner circumferential wall surface of the middle barrel (2), and finally the water film layer is collected to the water collecting bin (4) through a through hole on a lower end plate (32);

then, the exhaust pipe of the diesel engine is connected into an exhaust gas inlet pipe (10), and exhaust enters a spiral flue gas purification cavity through an exhaust gas inlet (7) formed in an upper end plate (31); under the flow guiding action of the spiral flow guiding sheet (5), tail gas spirally advances in the spiral flue gas purification cavity in a spiral mode; in the spiral advancing process, particulate matters carried in the tail gas are contacted and captured by a water film layer on the wall surface of the middle cylinder (2) under the action of inertial centrifugal force, so that the particulate matters are separated from gas, the separated particulate matters are converged into the water collecting bin (4) along with liquid flow under the action of gas flow and gravity, and the particulate matters are discharged out of the water collecting bin (4) through a discharge pipe (8) when the water level of the water collecting bin (4) reaches a preset height; meanwhile, the separated gas enters the water collecting bin (4) from a through hole at the bottom of the spiral flue gas purification cavity, and the residual particulate matters in the gas entering the water collecting bin (4) generate secondary contact collision with the liquid level in the water collecting bin (4) again to form secondary capture, so that the gas is purified again; the gas purified again returns to the inner cylinder (3) and is exhausted to the atmosphere through an exhaust pipe (13) connected to the inner cylinder (3); and the sewage mixed with the particulate matters is continuously collected to the water collecting bin (4), and is discharged out of the water collecting bin (4) by the blow-off pipe (8) after the water level in the water collecting bin (4) reaches a preset height.