Anti-blocking quench tower of ethane cracking device

Abstract

The invention relates to the technical field of ethane cracking, in particular to an anti-blocking quench tower of an ethane cracking device, which comprises a tower body, two sections of random packing and one section of structured packing are sequentially arranged in the tower body from top to bottom, an angle steel tray is arranged below the structured packing, a vapor-liquid two-phase feeding distributor is arranged below the angle steel tray, and the gas-liquid two-phase feeding distributor is arranged below the angle steel tray. The invention has the following beneficial effects: the outlet pressure of the furnace tube of the cracking furnace is low, the cracking hydrocarbon pressure is low, the ethylene product selectivity of the cracking furnace is improved, and the material consumption is reduced; separation of heavy components and diluted steam in the quench tower is facilitated; low-level heat of pyrolysis gas can be recovered, and heat exchanger load between compressor sections can be reduced; mass transfer and heat transfer in the quench tower are facilitated, and the mass transfer and heat transfer efficiency of the tower is improved; heavy components, styrene and the like in the tower can be prevented from being subjected to polymerization reaction to generate a polymer to block a filler layer; the production of the device is not limited, and full-load or overload production can be met.

Description

Technical Field

[0001] The invention relates to the technical field of ethane cracking, and in particular to an anti-blocking quenching tower of an ethane cracking device. Background Art

[0002] In the field of ethane cracking technology, the function of the quench tower of the ethane cracking unit is to condense the cracked gas from the second quench heat exchanger by countercurrent contact cooling in the tower using circulating water. The condensed gasoline and heavy tar are separated in the tower bottom and sent out as by-products. The condensed water forms quench water and process water. The quench water is circulated to provide low-level heat for various process users of the device. The process water is sent to the ethane saturation tower for use after filtration, agglomeration and stripping treatment. The cracked gas cooled down from the top of the tower is sent to the compression section for compression and gradual separation.

[0003] like Figure 1 As shown in the figure, the quench tower uses two sections of random packing and one section of structured packing from top to bottom, the cracked gas is fed from bottom to top, the circulating water is fed from top to bottom, and the cracked gas and water are directly in contact for heat exchange. After the quench tower has been running at full load for 1.5 years, the pressure difference of the packing layer in the lower section has gradually increased from the original 0.8KPa to 8KPa. After calculation, this pressure difference has reached the flooding point of the quench tower. If the pressure difference continues to rise, it will cause the support beam inside the quench tower to collapse, affecting the operation of the device.

[0004] If the pressure difference of the quench tower needs to be controlled within a reasonable range, the operating load of the device must be reduced. Moreover, as the operation of the device is prolonged, the load can only be reduced lower and lower, and eventually it will become impossible to maintain production. This will cause the energy and material consumption of the device to increase, and the ethylene output will drop significantly.

[0005] In order to completely solve the problem of pressure difference in the quench tower, the internal parts of the quench tower are specially modified so that the pressure difference of the quench tower can meet the actual production needs within one operation cycle and the pressure difference is maintained within a reasonable range. Summary of the invention

[0006] The object of the present invention is to provide an anti-blocking quenching tower for an ethane cracking device, which has the characteristic of being able to reduce the operating pressure difference of the quenching tower.

[0007] The above technical purpose of the present invention is achieved through the following technical scheme: an anti-blocking quenching tower for an ethane cracking unit, comprising a tower body, in which two sections of random packing and one section of structured packing are arranged in sequence from top to bottom, an angle steel tower plate is arranged below the structured packing, and a vapor-liquid two-phase feed distributor is arranged below the angle steel tower plate.

[0008] Preferably, the random packing is a saddle ring metal packing.

[0009] Preferably, each unit of structured packing comprises a horizontal connecting plate, and packing pieces are obliquely arranged on both sides of the connecting plate. The packing pieces are parallel to each other, and the front faces of the packing pieces are triangular.

[0010] Preferably, two angle steel tower plates are arranged vertically.

[0011] Preferably, two vapor-liquid two-phase feed distributors are provided.

[0012] Preferably, the vapor-liquid two-phase feed distributor has a feed port at one end, the feed port extends to the outside of the tower body, the width of the vapor-liquid two-phase feed distributor gradually narrows in the direction away from the feed port, and the vapor-liquid two-phase feed distributor has a feed channel inside and outlets on both sides.

[0013] Preferably, an elastic airbag is arranged between two adjacent layers of regular packing, the outer surface of the elastic airbag has an air nozzle, the air nozzle has a valve 1, an air distribution pipe is arranged above the angle steel tower plate, each elastic airbag is connected to the air distribution pipe through a hose, and each hose is provided with a valve 2.

[0014] Preferably, the gas distribution pipe is connected to the inlet of the cracking gas.

[0015] Preferably, the gas distribution pipe is connected to the top gas outlet of the tower body.

[0016] In summary, the present invention has the following beneficial effects:

[0017] After the transformation of the internal parts of the quench tower, the operating pressure difference is basically reduced to 0KPa after starting, and the pressure difference of the tower does not change much during operation. In addition, an elastic airbag is used in this scheme. By inflating the elastic airbag to expand it, the structured packing is slightly tilted, so that the condensed gasoline and tar flow out faster. The pressure difference of the tower is within a controllable range during the entire operation cycle, which has the following benefits for the operation of the device: the outlet pressure of the cracking furnace tube is low, and the cracking hydrocarbon partial pressure is low, which helps to improve the selectivity of the cracking furnace ethylene product and reduce material consumption; it is beneficial to the separation of heavy components and dilution steam in the quench tower; it is beneficial to recover the low-level heat of cracking gas and reduce the load of the heat exchanger between compressor sections; it is beneficial to mass transfer and heat transfer inside the quench tower and improve the efficiency of mass transfer and heat transfer of the tower; it is beneficial to avoid polymerization reaction between heavy components and styrene in the tower to produce polymer blocking the packing layer; the production of the device is not limited, and it can meet full load or overload production, thereby increasing the output of ethylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the working principle of a quench tower in the background technology;

[0019] Figure 2 It is a schematic diagram of the structure of the tower;

[0020] Figure 3It is a front view of structured packing;

[0021] Figure 4 is a side view of a structured packing;

[0022] Figure 5 It is a structural diagram of the angle steel tower plate;

[0023] Figure 6 It is a schematic diagram of the shape of a vapor-liquid two-phase feed distributor;

[0024] Figure 7 is a schematic structural diagram of Example 2;

[0025] Figure 8 yes Figure 7 The enlarged schematic diagram of the middle A part;

[0026] Fig. 9 It is a structural schematic diagram of Example 3.

[0027] In the figure, 1. tower body; 2. random packing; 3. structured packing; 31. connecting plate; 32. packing sheet; 4. elastic airbag; 41. air nozzle; 42. hose; 43. air distribution pipe; 44. air pump; 5. angle steel tower plate; 6. vapor-liquid two-phase feed distributor; 61. feed inlet. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0029] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0030] Example 1: Figure 2 As shown, the quenching tower includes a tower body 1, in which two sections of random packing 2 and one section of structured packing 3 are arranged from top to bottom, two layers of angle steel tower plates 5 are arranged below the structured packing 3, and a vapor-liquid two-phase feed distributor 6 is arranged below the angle steel tower plates 5.

[0031] The random packing 2 is a rectangular saddle ring metal packing. The rectangular saddle ring is a known shape, for example, a Chinese patent with the publication number "CN305698362S" discloses a rectangular saddle ring.

[0032] like Figure 3 and Figure 4 As shown, the structured packing 3 is composed of a plurality of units. Each unit of the structured packing 3 includes a horizontal connecting plate 31. Both sides of the connecting plate 31 are obliquely provided with packing sheets 32. The packing sheets 32 are parallel to each other, and the front of the packing sheets 32 is triangular.

[0033] like Figure 5 As shown, the angle steel tower plate 5 is composed of a plurality of angle steels and is used to distribute the flow direction of the gas material in the tower body 1 .

[0034] like Figure 6 As shown, two vapor-liquid two-phase feed distributors 6 are provided, one end of which has a feed port 61, and the feed port 61 extends to the outside of the tower body 1. The width of the vapor-liquid two-phase feed distributor 6 gradually narrows in the direction away from the feed port 61, and has a feed channel inside and outlets on both sides.

[0035] Embodiment 2: This embodiment is basically the same as Embodiment 1, except that Figure 7 and Figure 8 As shown, the structured packing 3 has multiple layers, and each layer has multiple units of structured packing 3. An elastic airbag 4 is arranged between two adjacent layers of structured packing 3, and the outer surface of the elastic airbag 4 has a gas nozzle 41, and the gas nozzle 41 has a valve 1. A gas distribution pipe 43 is arranged above the angle steel tower plate 5, and each elastic airbag 4 is connected to the gas distribution pipe 43 through a hose 42, and each hose 42 is provided with a valve 2. Valve 1 and valve 2 are not drawn in the figure. The gas distribution pipe 43 is connected to the gas inlet of the cracked gas.

[0036] During operation, by opening valve 2 of the elastic airbag 4 on one side, the cracked gas is passed into the corresponding elastic airbag 4 to expand it, thereby slightly lifting a portion of the structured packing 3, so that the condensed gasoline and heavy tar in the structured packing 3 can flow out smoothly under the self-generated gravity. Then, valve 2 is closed, valve 1 is opened, the elastic airbag 4 contracts, and the cracked gas inside it is discharged. In the process of being discharged, the cracked gas slightly purges the structured packing 3, and this purging action further blows the gasoline and heavy tar on the structured packing 3, thereby alleviating the blockage in the structured packing 3.

[0037] Embodiment 3: This embodiment is substantially the same as Embodiment 2, except that Fig. 9 The air distribution pipe 43 is connected to the top outlet of the tower body 1, and an air pump 44 is arranged between the two. During operation, the top outlet of the tower body 1 is extracted into the elastic airbag 4 to replace the cracking gas in the embodiment to prevent the air nozzle 41 from being blocked.

Claims

1. An anti-blocking quenching tower for an ethane cracking unit, comprising a tower body (1), characterized in that: Two sections of random packing (2) and one section of structured packing (3) are arranged in sequence from top to bottom in the tower body (1); an angle steel tray (5) is arranged below the structured packing (3); and a vapor-liquid two-phase feed distributor (6) is arranged below the angle steel tray (5).

2. The anti-blocking quenching tower of an ethane cracking device according to claim 1, characterized in that: The random packing (2) is a square saddle ring metal packing.

3. The anti-blocking quenching tower of an ethane cracking device according to claim 1, characterized in that: Each unit of structured packing (3) comprises a horizontal connecting plate (31), and packing sheets (32) are arranged obliquely on both sides of the connecting plate (31). The packing sheets (32) are parallel to each other, and the front faces of the packing sheets (32) are triangular.

4. The anti-blocking quenching tower of an ethane cracking device according to claim 1, characterized in that: Two angle steel tower plates (5) are arranged one above the other.

5. The anti-blocking quenching tower of an ethane cracking device according to claim 1, characterized in that: The number of vapor-liquid two-phase feed distributors (6) is 2.

6. The anti-blocking quenching tower of an ethane cracking device according to claim 1, characterized in that: One end of the vapor-liquid two-phase feed distributor (6) has a feed port (61), the feed port (61) extends to the outside of the tower body (1), the width of the vapor-liquid two-phase feed distributor (6) gradually narrows in a direction away from the feed port (61), and the vapor-liquid two-phase feed distributor (6) has a feed channel inside and outlets on both sides.

7. The anti-blocking quenching tower of an ethane cracking device according to claim 1, characterized in that: An elastic airbag (4) is arranged between two adjacent layers of structured packing (3), the outer surface of the elastic airbag (4) is provided with an air nozzle (41), the air nozzle (41) is provided with a valve 1, an air distribution pipe (43) is arranged above the angle steel tower plate (5), each elastic airbag (4) is connected to the air distribution pipe (43) via a hose (42), and each hose (42) is provided with a valve 2.

8. The anti-blocking quenching tower of an ethane cracking device according to claim 7, characterized in that: The gas distribution pipe (43) is connected to the gas inlet of the cracked gas.

9. The anti-blocking quenching tower of an ethane cracking device according to claim 7, characterized in that: The gas distribution pipe (43) is connected to the gas outlet at the top of the tower body (1).

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