Efficient combined type third-stage cyclone separator

Abstract

The utility model discloses an efficient combined third-stage cyclone separator which comprises a shell, the interior of the shell is of a hollow structure, the shell comprises a straight barrel section, a first conical section is fixedly arranged at the lower end of the straight barrel section, an end socket is fixedly arranged at the upper end of the straight barrel section, a partition hanging plate is installed in the end socket in the radial direction, and a gas outlet and a gas inlet are formed in the end socket. The gas inlet is provided with a central gas inlet pipe, the central gas inlet pipe extends into the shell, penetrates through the partition hanging plate and extends into the straight barrel section, a second conical section is arranged at the bottom end of the central gas inlet pipe, and a first-stage cyclone separator is arranged on the central gas inlet pipe through a pipeline and located in a space formed by the partition hanging plate and the straight barrel section. The outlet end of the first-stage cyclone separator is provided with two second-stage cyclone separators in parallel, the top ends of the second-stage cyclone separators are provided with second-stage cyclone separator exhaust pipes, and the second-stage cyclone separator exhaust pipes penetrate through the partition hanging plate and extend into the seal head. And the separation efficiency of small-particle-size solid particles is remarkably improved by changing the airflow rotation direction for multiple times.

Description

Technical Field

[0001] The utility model relates to the field of petroleum refining and chemical equipment, and particularly relates to an efficient combined third-stage cyclone separator. Background Art

[0002] Most domestic oil refining enterprises adopt a flue gas turbine (hereinafter referred to as a "smoke machine") to recover the energy of the regenerated flue gas. The higher the concentration of catalyst particles contained in the high-temperature flue gas at the inlet of the smoke machine and the larger the particle size of the catalyst particles, the easier it is to damage the smoke machine. It is necessary to install a third-stage cyclone separator (hereinafter referred to as a "three-cyclone") before the flue gas enters the smoke machine to meet the requirements that the mass concentration of gas dust at the inlet of the smoke machine is lower than 80-100 mg / m3 and basically does not contain particles larger than 10 μm, so as to ensure the long-term safe and stable operation of the smoke machine. At present, there are mainly two types of three-cyclones: multi-tube three-cyclones and large-whirl-fraction three-cyclones.

[0003] In order to meet the increasing demand for the processing capacity of FCC units and solve the problems existing in multi-tube three-cyclones, domestic engineering companies have developed large-whirl-fraction three-cyclones. By using a cyclone separator with a larger diameter as the separation element of the three-cyclone and replacing the countercurrent separation single tube of the traditional multi-tube three-cyclone, the structure and size of the three-cyclone are optimized and designed, and the service life of the three-cyclone is extended. The total efficiency of the large-whirl-fraction three-cyclone is generally 70%-80%, and the pressure drop is 15-20 kPa, which is larger than that of the multi-tube three-cyclone. Sometimes vibration will occur during operation, affecting the safe and stable operation of the FCC unit.

[0004] The multi-tube three-cyclone has the following problems: ① The distribution of the regenerated flue gas is uneven, and it is easy to have gas leakage, backmixing and scaling; ② The single tube has a complex structure, is difficult to manufacture and install, and is not easy to repair; ③ The exhaust pipe and the air inlet are on the same side, which limits the size design of the guide vane and the exhaust pipe to each other, and is not conducive to the uniform gas distribution of the whole three-cyclone.

[0005] Chinese patent document CN201006498Y discloses a third-stage cyclone separator. The third-stage cyclone separator of this utility model is a device for gas-solid separation in the energy recovery system of a petroleum refining catalytic cracking unit, including a shell, a flue gas outlet, a flue gas inlet, a central pipe, multiple single cyclones and a partition suspension plate. Its characteristics are that multiple single cyclones are installed in the shell; the multiple single cyclones are supported and suspended in the shell through a connection structure with the partition suspension plate and the central pipe; the interior of the shell is divided into three relatively independent spaces: an air inlet chamber, a gas collection chamber and a dust collection chamber. Since this three-cyclone adopts a shell-mounted three-cyclone with an overall suspension structure type using multiple single cyclone separators as separation elements, it can solve the problems of catalyst backmixing and comminution of the multi-tube three-cyclone and meet the requirements of the smoke machine for the separation efficiency of the three-cyclone; at the same time, it can effectively solve the problem of inconsistent thermal expansion deformation of internal components and improve the stress condition; moreover, it is more stable in operation, has a longer service life, is convenient for manufacturing, overhaul and replacement than the traditional multi-tube three-cyclone, and saves investment.

[0006] In the prior art, the central inlet pipe of the existing third-stage cyclone separator has no internal components. The dust-containing gas flow enters the three-stage cyclone and then directly enters the cyclone separator through the central inlet pipe. The mixed gas is separated by a single-stage and single-pipe method, and the separation effect is limited. Large particles will enter the expander, which is likely to damage the expander. Content of the Utility Model

[0007] Aiming at the deficiencies of the prior art, the present utility model provides an efficient combined third-stage cyclone separator. A spiral guide plate is provided in the central inlet pipe. The air flow rotation direction of the central pipe is opposite to that of the first-stage cyclone separator. The first-stage and the second-stage cyclone separators are connected in a series-parallel manner, that is, the first stage uses a cyclone separator with a larger diameter, and the second stage uses two cyclone separators with smaller diameters. The dust-containing gas enters through the central inlet pipe. After passing through the spiral guide plate, the air flow changes from moving downward parallel to the axial direction of the inlet pipe to moving downward in a spiral manner, and then enters the first-stage cyclone separator. The change in the rotation direction of the air flow can make the particle distribution at the inlet of the first-stage cyclone separator more regular: small-particle-size particles are close to the wall of the inlet, which is more conducive to recovery. Large particles are far from the wall, but due to the large centrifugal force on the large-particle-size particles, they can still be recovered, thus significantly improving the separation efficiency of the cyclone separator. The series-parallel connection method of the first- and second-stage cyclone separators can effectively improve the total separation efficiency without increasing the total pressure drop.

[0008] To achieve the above object, the present utility model adopts the following technical solutions:

[0009] An efficient combined third-stage cyclone separator, comprising a housing. The interior of the housing is a hollow structure. The housing includes a straight cylinder section. A first conical section is fixedly provided at the lower end of the straight cylinder section. A head is fixedly provided at the upper end of the straight cylinder section. A partition and suspension plate is radially installed inside the head. A gas outlet and a gas inlet are provided on the head. The gas inlet is provided with a central inlet pipe. The central inlet pipe extends into the interior of the housing through the partition and suspension plate and extends into the interior of the straight cylinder section. A second conical section is provided at the bottom end of the central inlet pipe. A first-stage cyclone separator is provided on the central inlet pipe through a pipeline. The first-stage cyclone separator is located in the space formed by the partition and suspension plate and the straight cylinder section. Two second-stage cyclone separators are arranged in parallel at the outlet end of the first-stage cyclone separator. A second-stage cyclone separator exhaust pipe is provided at the top end of the second-stage cyclone separator. The second-stage cyclone separator exhaust pipe extends through the partition and suspension plate and extends into the interior of the head;

[0010] As a preferred technical solution of the present utility model, a spiral guide plate is installed on the central inlet pipe, and the spiral guide plate rotates in the opposite direction to the first-stage cyclone separator;

[0011] As a preferred technical solution of the present utility model, at least 2 groups of first-stage cyclone separators are evenly arranged on the central inlet pipe; the dust discharge ports of the second-stage cyclone separators are evenly distributed on the partition and suspension plate;

[0012] As a preferred technical solution of the present utility model, the center of the partition suspension plate is a flat plate, and the periphery is a conical plate. The central air inlet pipe is installed at the gas inlet and the central axis of the housing;

[0013] As a preferred technical solution of the present utility model, a first-stage cyclone dust outlet is opened at the bottom end of the first-stage cyclone, and a second-stage cyclone dust outlet is opened at the bottom end of the second-stage cyclone;

[0014] As a preferred technical solution of the present utility model, a central pipe exhaust port is opened at the bottom end of the second conical section, and a flap valve is installed on the central pipe exhaust port;

[0015] As a preferred technical solution of the present utility model, the first-stage cyclone inlet is installed tangentially in the opposite direction to the central air inlet pipe;

[0016] As a preferred technical solution of the present utility model, a first opening is provided on the straight cylinder section; a second opening is provided on the first conical section;

[0017] As a preferred technical solution of the present utility model, the second-stage cyclones are of the same size, and the diameter of the second-stage cyclone is smaller than that of the first-stage cyclone.

[0018] Compared with the prior art, the present utility model has the following beneficial effects:

[0019] 1. A spiral guide plate is provided in the central air inlet pipe, which can force the dust-containing air flow to make a rotational movement. The solid particles in the air flow move towards the pipe wall under the action of centrifugal force. Some of the large particles are thrown to the pipe wall and move downward under the action of gravity to the bottom of the central cylinder. When the particles at the bottom accumulate to a certain weight, the flap valve at the bottom of the central air inlet pipe opens, and the particles enter the dust collection chamber for recovery, thereby achieving the effect of pre-separation. At the same time, when setting the spiral guide plate, the air flow can move according to the designed number of rotation circles, prolonging the residence time of the particles while also pre-sorting the particles, making the particle distribution entering the first-stage cyclone more regular.

[0020] 2. By changing the direction of the air flow rotation, the separation efficiency of small-particle-size solid particles is significantly improved. The dust-containing air flow forms a swirl after entering the three-stage cyclone. The solid particles move towards the wall of the device under the action of centrifugal force. The particle size in the central air inlet pipe shows a distribution from small to large from the center to the pipe wall. The first-stage cyclone is tangentially connected to the central air inlet pipe, and the air flow rotation directions before and after the connection are opposite. When the solid particles enter the cyclone from the first-stage cyclone inlet, the small-particle-size particles are close to the inlet wall, which is more conducive to recovery and separation. The large-particle-size particles are far from the wall, but due to the large centrifugal force they receive, they can still be recovered and separated. Such a reverse combination connection method can significantly improve the separation efficiency of small-particle-size particles while ensuring the original high separation efficiency for large-particle-size particles, thereby improving the overall separation efficiency.

[0021] 3. The first and second stage cyclone separators adopt a series-parallel connection method, which can improve the separation performance. The diameter of the second stage cyclone separator is directly connected to that of the first stage cyclone separator in a series-parallel connection method, and the diameter is slightly smaller than that of the first stage cyclone separator. The series-parallel connection method combines the advantages of both series and parallel connections. The series connection of cyclone separators can perform centrifugal separation on the particles not separated in the first stage again, further improving the separation efficiency. The parallel connection of cyclone separators can reduce the cylinder diameter of the cyclone separator while meeting the processing capacity. For a cyclone separator with a smaller diameter, the rotation radius is smaller, and the centrifugal force received by the particles is greater, which can achieve a better separation effect. Within a certain range of conditions, a higher pressure drop is accompanied by a higher separation efficiency. In actual industrial applications, the inlet concentration of the first stage cyclone separator is relatively high, and the average particle size of the particles is relatively large, making it easier to achieve separation. Therefore, most of the pressure drop can be allocated to the second stage cyclone separator to strengthen the separation and capture of fine particles, thereby obtaining better separation performance. Brief Description of the Drawings

[0022] Figure 1 is a schematic structural diagram of the third stage reverse combined cyclone separator of the present invention;

[0023] Figure 2 is a schematic diagram of the air flow rotation direction of the present invention;

[0024] Figure 3 is a schematic diagram of the gas-solid flow direction of the present invention.

[0025] In the figure: 1. Shell; 2. Head; 3. Straight cylinder section; 4. First cone section; 5. Gas inlet; 6. Gas outlet; 7. Central inlet pipe; 8. Wing valve; 9. Spiral guide plate; 10. First stage cyclone separator; 11. Second stage cyclone separator; 12. Partition and suspension plate; 13. First stage cyclone separator inlet; 14. First stage cyclone separator exhaust pipe; 15. First stage cyclone separator dust discharge port; 16. Second stage cyclone separator inlet; 17. Second stage cyclone separator exhaust pipe; 18. Second stage cyclone separator dust discharge port; 19. Second cone section; 20. First opening; 21. Second opening. Detailed Embodiments

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] As Figures 1 - 3As shown in the figure, an efficient combined third-stage cyclone separator is provided. An efficient combined third-stage cyclone separator includes a housing. The interior of the housing is a hollow structure. The housing includes a straight cylinder section. A first conical section is fixedly provided at the lower end of the straight cylinder section. A head is fixedly provided at the upper end of the straight cylinder section. A partition and suspension plate is radially installed inside the head. A gas outlet and a gas inlet are provided on the head. A central intake pipe is provided at the gas inlet. The central intake pipe extends into the interior of the housing, penetrates through the partition and suspension plate, and extends into the interior of the straight cylinder section. A second conical section is provided at the bottom end of the central intake pipe. A first-stage cyclone separator is provided on the central intake pipe through a pipe. The first-stage cyclone separator is located in the space formed by the partition and suspension plate and the straight cylinder section. Two second-stage cyclone separators are arranged in parallel at the outlet end of the first-stage cyclone separator. A second-stage cyclone separator exhaust pipe is provided at the top of the second-stage cyclone separator. The second-stage cyclone separator exhaust pipe penetrates through the partition and suspension plate and extends into the interior of the head.

[0028] The housing 1 is composed of a head 2 at the top, a straight cylinder section 3, and a conical section 4. The gas inlet 5 and the outlet 6 are installed on the head. The partition and suspension plate 12 is installed inside the head. The center is a flat plate and the periphery is a conical plate. The central intake pipe 7 is installed at the gas inlet and on the central axis of the housing. The central intake pipe 7 passes through the partition and suspension plate 12. And thereby divides the interior space of the housing 1 into: an intake chamber A inside the central intake pipe 7, a gas collection chamber B between the housing 1 and the upper part of the partition and suspension 12 plate, and a dust collection chamber C between the housing 1 and the lower part of the partition and suspension plate 12. A first opening 20 is provided on the straight cylinder section 3. The first opening 20 is conducive to observing or overhauling the interior of the housing 1; a second opening 21 is provided on the first conical section 4. The first conical section 4 is conducive to discharging the particulate dust inside the housing 1. When the separator is working, the first opening 20 and the second opening 21 are in a normally closed state.

[0029] Inside the housing 1, the spiral direction of the spiral guide plate is opposite to the air flow rotation direction of the first-stage cyclone separator. After stress analysis of n groups of cyclone separators (n≥2), they are evenly arranged on the central intake pipe 7 and the partition and suspension plate 12. The inlet 13 of the first-stage cyclone separator is installed tangentially in the opposite direction to the central intake pipe 7. The exhaust pipe 14 of the first-stage cyclone separator is connected to the inlets 16 of the two second-stage cyclone separators. The exhaust pipe 17 of the second-stage cyclone separator passes through the partition and suspension plate 12.

[0030] The working process of the reverse combined third-stage cyclone separator provided by the present utility model is as Figure 3As shown in the figure: The dusty gas enters the central inlet pipe 7 from the gas inlet 5. Under the action of the spiral guide plate 9, the dusty gas flows downward in a spiral manner. Under the action of centrifugal force, some of the particles are preliminarily separated and accumulate at the bottom of the central inlet pipe 7. When the weight of the particles reaches the preset value, the flap valve 8 opens, and the particles enter the dust collection chamber through this and are recovered. The air flow then enters the first-stage cyclone separator 10 through the tangentially connected first-stage cyclone separator inlet 13. Under the action of centrifugal force, the particles are separated in the first-stage cyclone separator, and most of the particles are discharged from the dust discharge port 15 at the lower part of the cyclone separator. The remaining unseparated particles follow the air flow and enter the second-stage cyclone separator through the first-stage cyclone separator exhaust pipe 14.

[0031] The rotation direction of its air flow is as Figure 2 shown. A small part of the solid particles not separated by the first-stage cyclone separator are carried by the air flow and enter the second-stage cyclone separator 11 from the second-stage cyclone separator inlet 16 to make a rotational motion. The two second-stage cyclone separators are of the same size and have a diameter slightly smaller than that of the first-stage cyclone separator. Under the action of centrifugal force, most of the solid particles are thrown towards the wall of the separator, and the air flow moving downward near the wall of the cylinder takes them to the dust discharge port 18 of the cyclone separator. The gas that has been separated and purified is discharged through the exhaust pipe 17 into the gas collection chamber and is discharged from the gas outlet 7.

[0032] The technical concept of the present utility model is illustrated by the above embodiments, but the present utility model is not limited to the above embodiments, that is, it does not mean that the present utility model must rely on the above embodiments to be implemented. Those skilled in the art should understand that the relevant improvements to the present utility model all fall within the protection scope and the disclosure scope of the present utility model.

Claims

1. A high-efficiency combined third-stage cyclone separator, comprising a housing (1), the interior of the housing (1) being a hollow structure, characterized in that: The shell (1) comprises a straight section (3), a first cone section (4) is fixedly provided at the lower end of the straight section (3), a head (2) is fixedly provided at the upper end of the straight section (3), a partition plate (12) is radially installed inside the head (2), a gas outlet (6) and a gas inlet (5) are provided on the head (2), the gas inlet (5) is provided with a central air inlet pipe (7), the central air inlet pipe (7) extends into the interior of the shell (1), passes through the partition plate (12), and extends into the interior of the straight section (3), a second cone section (19) is provided at the bottom end of the central air inlet pipe (7), a first-stage cyclone (10) is provided on the central air inlet pipe (7) through a pipeline, and the first-stage cyclone (10) is located at the partition plate (12) and the straight section (3), two second-stage cyclones (11) are arranged in parallel at the outlet end of the first-stage cyclone (10), and a second-stage cyclone exhaust pipe (17) is arranged at the top end of the second-stage cyclone (11), and the second-stage cyclone exhaust pipe (17) penetrates the partition plate (12) and extends into the interior of the head (2); a spiral guide plate (9) is installed on the central air inlet pipe (7), and the spiral guide plate (9) rotates in the opposite direction to the first-stage cyclone (10); there are at least two groups of first-stage cyclones (10), which are evenly arranged on the central air inlet pipe (7); and the dust exhaust ports (18) of the second-stage cyclones are evenly distributed on the partition plate (12).

2. The high-efficiency combined third-stage cyclone separator according to claim 1, characterized in that: The center of the partition plate (12) is a flat plate, and the periphery is a conical plate. The central air inlet pipe (7) is installed at the central axis of the gas inlet (5) and the shell (1).

3. The high-efficiency combined third-stage cyclone separator according to claim 1 is characterized in that: A first-stage cyclone dust discharge port (15) is provided at the bottom end of the first-stage cyclone (10), and a second-stage cyclone dust discharge port (18) is provided at the bottom end of the second-stage cyclone (11).

4. The high-efficiency combined third-stage cyclone separator according to claim 1, characterized in that: A central pipe exhaust port is provided at the bottom end of the second cone section (19), and a wing valve (8) is installed on the central pipe exhaust port.

5. The high-efficiency combined third-stage cyclone separator according to claim 1, characterized in that: The first-stage cyclone inlet (13) is installed in a reverse tangential direction to the central air inlet pipe (7).

6. The high-efficiency combined third-stage cyclone separator according to claim 1, characterized in that: The straight tube section (3) is provided with a first opening (20); the first cone section (4) is provided with a second opening (21).

7. The high-efficiency combined third-stage cyclone separator according to claim 1, characterized in that: The sizes of the second-stage cyclones (11) are all the same, and the diameter of the second-stage cyclones (11) is smaller than that of the first-stage cyclones (10).

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