CN110747003B

CN110747003B - Coke tower and delayed coking method using same

Info

Publication number: CN110747003B
Application number: CN201911078639.0A
Authority: CN
Inventors: 王宝石; 黄新龙; 岑友良; 王洪彬; 刘淑芳; 班新海; 户勇; 陈卫东; 马天军
Original assignee: China Petroleum and Chemical Corp; Sinopec Engineering Group Co Ltd
Current assignee: China Petroleum and Chemical Corp; Sinopec Engineering Group Co Ltd
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2021-04-27
Anticipated expiration: 2039-11-06
Also published as: CN110747003A

Abstract

The invention provides a coke tower and a delayed coking method using the same. The coke drum comprises: the coke tower comprises a top end enclosure, an upper cylinder, an upper cone, a lower cylinder and a bottom cone, wherein the upper cylinder, the upper cone and the lower cylinder are coaxially arranged, and the diameter of the upper cylinder of the coke tower is larger than that of the lower cylinder. The diameter of the upper cylinder of the coke tower is enlarged, the oil-gas linear velocity of oil gas on the upper part of the coke tower is reduced, the height of a foam layer in the coke tower is effectively reduced, and the heavy components such as colloid asphalt-like substances carried by the oil gas are obviously reduced, so that the coked wax oil separated from the fractionating tower has low density, viscosity, carbon residue value, asphaltene and the like, has good properties, and is beneficial to subsequent processing.

Description

Coke tower and delayed coking method using same

Technical Field

The invention relates to the technical field of petrochemical industry, in particular to a coke tower and a delayed coking method by utilizing the coke tower.

Background

The heavy oil processing technology can be divided into two types, one is hydrogenation, the other is decarburization, and the delayed coking process has the advantages of strong raw material adaptability, simple process flow, relatively mature technology, low device investment and the like, and becomes one of the important means for deep processing of the heavy oil. The relatively mature delayed coking technologies abroad are represented by the technologies of Foster Wheeler/UOP company, Conoco-Phillips company, ABB Lummus Crest company and KBR company, and most of the delayed coking devices abroad adopt the patent technologies of the companies. The domestic delayed coking technology is mainly developed by China petrochemicals, and comprises patent technologies of petrochemical engineering Research Institute (RIPP), China petrochemical engineering construction Inc. (SEI), China petrochemical industry Luoyang engineering Inc. (LPEC) and China petrochemical industry engineering (group) corporation Luoyang technology research and development center (SEGR), and colleges and research institutions such as China Petroleum university (east China) also develop some new technologies.

In the delayed coking process, the coking material heated to 450 deg.c in the heating furnace enters the coke tower and produces violent cracking and condensation reaction to produce great amount of oil gas and coke. During the reaction of the coking raw material, a lot of high-viscosity colloid asphalt-like substances are generated, and the colloid asphalt-like substances are continuously foamed and broken in a coke tower under the agitation of oil gas to form a stable foam layer. As the feed and reaction times increase, the coke drum head level continues to rise and the foam layer grows. Because the gas velocity in the coke tower is higher, when the coke layer in the coke tower rises to a certain height in the coking later stage, a large amount of coke powder contained in the foam layer can be carried by oil gas and enter a large oil-gas pipeline and a fractionating tower, so that the large oil-gas pipeline and the fractionating tower are coked. Further causing the blockage of a circulating filter at the bottom of the fractionating tower, a feeding filter at the radiation section and a feeding pump, coking of a furnace tube and influence on the safe production of the device. Therefore, to reduce the adverse effects of coke fines entrainment, a sufficient height of space must be left in the coke drum, which reduces the utilization of the coke drum. In order to reduce the adverse effect of the foam layer of the coke tower, a plurality of patent technologies are proposed at home and abroad to solve the problems, such as the problem that the entrainment of oil gas coke powder is reduced or reduced by adding an antifoaming agent to a delayed coking device which is commonly adopted in the industry at present.

In summary, in order to reduce the height of the foam layer in the coke drum, technicians mostly adopt methods such as adding a defoaming agent into the coke drum and arranging mechanical defoaming equipment, and the methods have certain effects on reducing the height of the foam layer of the delayed coking device, but have advantages and disadvantages.

In view of this, the invention is particularly proposed.

Disclosure of Invention

The present invention is directed to overcoming the above-mentioned drawbacks of the prior art and to providing a coke drum and a delayed coking method using the same.

The invention is realized by the following steps:

in a first aspect, embodiments of the present invention provide a coke drum comprising: the top end enclosure is connected with the top of the upper barrel, and the bottom of the upper barrel is connected with the top of the upper cone; the bottom of the upper cone is connected with the top of the lower cylinder, and the bottom of the lower cylinder is connected with the top of the bottom cone; the upper cylinder, the upper cone and the lower cylinder are coaxially arranged, and the diameter of the upper cylinder of the coke tower is larger than that of the lower cylinder.

In the delayed coking production process, the coking oil undergoes violent thermal reaction in the coking tower to generate a large amount of oil gas and coke. In the coking process, many of the intermediates are high viscosity colloidal asphaltic materials that, under the agitation of oil and gas, will form a stable foam layer within the coking drum. As feed and reaction times increase, the coke drum level continues to rise and the foam layer grows. Entrainment occurs when the foam layer is high due to the high gas velocity in the coking drum. At this point, the coke fines in the froth layer can be carried over into the large gas line and the fractionator, causing coking in the large gas line and the fractionator. Therefore, in order to reduce the adverse effects of fines entrainment, sufficient space height must be left in the coke drum, which reduces the coke drum utilization.

At present, technicians mostly adopt methods of adding a defoaming agent into a coke tower, arranging mechanical defoaming equipment and the like, and the methods have certain effects on reducing the height of a foam layer of a delayed coking device, but have various advantages and disadvantages, such as the fact that the defoaming agent needs to be added at regular time, and the overall economy and stability of the delayed coking device are improved to a certain extent. However, silicon-containing defoaming agents cause catalyst poisoning of downstream hydrogenation units, while non-silicon polyase composite defoaming agents have a certain defoaming effect, but are complex in raw material composition and high in cost. Set up the adverse effect that the defoaming agent added can not appear in mechanical defoaming equipment, but the inspiratory high temperature oil gas of centrifugal defoamer and coke powder easily coke on centrifugal defoamer and impeller, when this equipment breaks down or mechanical parts damages, overhauls the difficulty, influences the normal production of device.

In view of this, an embodiment of the present invention provides a coking tower, and a design idea of the coking tower is to provide a coking tower that has a small structural change for an original coking tower, can effectively reduce adverse effects of a foam layer, and can minimize the influence of intervention of external factors on a coking process, where an existing coking tower is composed of a top head, a straight cylinder and a bottom cone, generally, the height of the straight cylinder is 20m to 30m, the inner diameter of the straight cylinder is 6m to 10m, a coking raw material is subjected to a delayed coking reaction in the coking tower, and the inside of the coking tower sequentially includes, from a bottom layer to top: the feeding zone, the coke zone, the foam zone and the gas phase zone, the products obtained by delayed coking reaction are all distributed in the coking tower, the area of the foam zone above the coke zone is larger and larger along with the prolonging of time, oil gas quickly rises to the upper part of the coking tower, so that the area of the foam zone is further increased, and the foam zone is shown to be highly raised. The inventor has long practiced an improved coking tower, which is an improvement on the barrel structure of the coking tower, namely, the diameter of the upper barrel of the coking tower is enlarged, and the linear velocity of oil gas at the upper part of the coking tower is reduced. Therefore, the thickness of the foam layer in the coke tower is effectively reduced, the coke powder carried by the foam in the ascending air flow is reduced or avoided entering a large oil-gas pipeline and a fractionating tower, and the long-period safe production of the device is facilitated.

In an alternative embodiment, the method further comprises: the top end socket of the coke tower is provided with a coke drilling port and an oil gas outlet, and the bottom cone of the coke tower is provided with a feed inlet and a coke outlet.

In an optional embodiment, the diameter of the upper cylinder of the coke drum is 1.1-1.5 times of that of the lower cylinder, so that the linear velocity of oil gas in the coke drum can be reduced by 20% -60%, the oil gas velocity is reduced too much, the retention time of the oil gas in the coke drum is obviously prolonged, and the secondary reaction of the oil gas reduces the liquid yield.

Preferably, the lower drum diameter of the coke drum is from 5m to 10 m.

In an alternative embodiment, the total height of the coke drum is the sum of the heights of the upper drum, the upper cone, and the lower drum, and the total height of the coke drum is 20m to 30m,

preferably, the height of the upper cylinder of the coke tower is 3m-10m, and the height of the lower cylinder is 5m-15 m.

In a second aspect, embodiments of the present invention provide a delayed coking process using the above coke drum, comprising the steps of: introducing a raw material to be coked into a bottom cone of a coke tower, and carrying out delayed coking reaction in the coke tower.

In an optional embodiment, the raw material to be coked is obtained by heating a mixed material of raw coking oil and circulating coking oil, and mixing the heated mixed material with hydrogen and a sulfur reduction auxiliary agent again;

preferably, the coker feedstock comprises at least one of vacuum residuum, atmospheric residuum, heavy crude oil, vacuum wax oil, deoiled asphalt, deasphalted oil, residue hydrogenated heavy oil, thermally cracked residuum, lubricant refined extract oil, catalytically cracked cycle oil and decant oil, and ethylene cracked residuum and tar asphalt.

Preferably, the coker cycle oil comprises at least one of a light coker wax oil and a heavy coker wax oil; the cutting points of the light coking wax oil and the heavy coking wax oil are 400-500 ℃.

In an alternative embodiment, the mass ratio of the coking cycle oil to the coking raw oil is 0-0.5: 1;

preferably, when the light coking wax oil is used as the coking cycle oil, the mass ratio of the light coking wax oil to the coking raw oil is 0-0.1: 1.

preferably, when the heavy coking wax oil is used as the coking cycle oil, the mass ratio of the heavy coking wax oil to the coking raw oil is 0-0.4: 1.

the embodiment of the invention provides a delayed coking method, which comprises the following steps: before the mixed material of raw coking oil and circulating coking oil enters a coking tower, the mixed material is mixed with hydrogen and a sulfur reduction auxiliary agent again, the mixed material and the hydrogen can be subjected to hydrogenation reaction in the presence of the hydrogen, impurities such as sulfur, nitrogen, metal and the like in the mixed material are removed, the carbon residue value is reduced, a few light distillate oil is also produced at the same time, and the sulfur reduction auxiliary agent can reduce sulfur distributed in the top gas phase of the coking tower and in coke in the coking process of the coking raw material.

In an alternative embodiment, a mixed material of raw coking oil and cycle coking oil is heated in a heating furnace;

preferably, the temperature of the mixed material of the raw coking oil and the coking cycle oil after being heated by a heating furnace is 360-550 ℃;

more preferably, the outlet temperature of the convection chamber of the heating furnace is 360 ℃ to 460 ℃, and the outlet temperature of the radiation chamber of the heating furnace is 400 ℃ to 550 ℃, more preferably 480 ℃ to 510 ℃.

In an optional embodiment, the hydrogen and the sulfur reduction auxiliary agent are rapidly dispersed in a mixed material of the coking raw oil and the coking cycle oil by using a microbubble generator;

preferably, the addition amount of the sulfur reduction additive is 0.1-1% of the total mass of the coking raw oil, and the addition amount of the hydrogen is 0.01-0.2% of the total mass of the coking raw oil.

The delayed coking method provided by the embodiment of the invention comprises the following steps: the coking raw material and circulating oil are mixed and then enter a coking heating furnace to be heated, the coking material flow heated to the coking temperature enters a micro-bubble generator at a high speed, hydrogen and a sulfur reduction auxiliary agent are quickly and efficiently dispersed in the coking raw material by the micro-bubble generator, the mixed material flow enters a coke tower through an oil transfer line, delayed coking reaction is carried out in the coke tower, the generated coke remains in the coke tower, oil gas generated by the reaction enters a fractionating tower through a large oil gas pipeline on the top of the tower to be fractionated, and products such as gas, coking gasoline, coking wax oil and the like are obtained after the fractionation.

Before a mixed material of raw coking oil and circulating coking oil enters a coking tower, the mixed material is mixed with hydrogen and a sulfur reduction auxiliary agent again, in order to enable the hydrogen and the sulfur reduction auxiliary agent to be better mixed with the mixed material of the raw coking oil and the circulating coking oil, a micro-interface strengthening technology is applied to a coking process, a micro-bubble generator can be used for greatly strengthening the mixing of the hydrogen, the sulfur reduction auxiliary agent and a coking raw material, the transfer rate of the hydrogen in a multiphase reaction process is enhanced, the micro-interface hydrodesulfurization effect of the coking raw material is strengthened, the sulfur content of a coking product, particularly petroleum coke, is reduced, and the property of the coking product is improved.

In an alternative embodiment, the coking reaction conditions in the coke drum are: the coking temperature is 450-500 ℃, the coke charging time is 12-36 h, and the pressure at the top of the tower is 0.01-0.3 MPa;

preferably, the coking temperature is 460-480 ℃, the coke charging time is 18-24 h, and the pressure at the top of the tower is 0.05-0.15 MPa;

preferably, the number of coke drums is 2 or more, and a plurality of coke drums are arranged in parallel.

The embodiment of the invention provides a delayed coking method, which is characterized in that the coking tower is utilized for delayed coking, products such as gas, coking gasoline, coking diesel oil, coking wax oil and the like are obtained by fractionation, wherein the properties of the coking wax oil are obviously improved, and the linear velocity of oil gas at the upper part of the coking tower is lower, so that the heavy components such as colloid asphaltic substances carried by the oil gas are obviously reduced, the contents of density, viscosity, residual carbon value, asphaltic substances and the like of the coking wax oil separated from the fractionating tower are low, the properties of the coking wax oil are good, and the subsequent processing of the coking wax oil is facilitated.

The invention has the following beneficial effects:

the invention provides a coke tower and a delayed coking method using the same. The coke tower comprises a coke tower top end socket, an upper barrel, an upper cone, a lower barrel and a bottom cone, wherein the upper barrel, the upper cone and the lower barrel are coaxially arranged, and the diameter of the upper barrel of the coke tower is larger than that of the lower barrel. The diameter of the upper cylinder of the coke tower is enlarged, and the oil gas linear velocity of the oil gas at the upper part of the coke tower is reduced. Therefore, the thickness of the foam layer in the coke tower is effectively reduced, the coke powder carried by the foam in the ascending air flow is reduced or avoided entering a large oil-gas pipeline and a fractionating tower, and the long-period safe production of the device is facilitated.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

The left diagram in fig. 1 is a schematic structural diagram of a coke drum according to an embodiment of the present invention, and the right diagram is a schematic structural diagram of a conventional coke drum;

FIG. 2 is a schematic process flow diagram of an embodiment of the present invention.

Numbering in the figures: 1-heating a furnace; 2a/2 b-coke drum; 3-a fractionation column; 4a/4 b-microbubble generator; 5-hydrogen; 6-a sulfur reduction aid; 100-top end enclosure; 200-upper cylinder; 300-upper cone; 400-lower cylinder; 500-bottom cone; 600-a feed inlet; 700-coke outlet; 800-oil gas outlet; 900-drilling a coke opening; 1000-safety valve port; others are pipelines.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

Referring to the left diagram in fig. 1, a coke drum comprises: the coke drum comprises a top seal head 100, an upper cylinder 200, an upper cone 300, a lower cylinder 400 and a bottom cone 500, wherein the upper cylinder 200 is positioned between the top seal head 100 and the upper cone 300, the top surface of the upper cylinder 200 is connected with the top seal head 100, the bottom surface of the upper cylinder 200 is connected with the upper cone 300, the lower cylinder 400 is positioned between the upper cone 300 and the bottom cone 500, the top surface of the lower cylinder 400 is connected with the upper cone 300, the bottom surface of the lower cylinder 400 is connected with the bottom cone 500, the upper cylinder 200, the upper cone 300 and the lower cylinder 400 are coaxially arranged, the diameter of the upper cylinder 200 of the coke drum is 1.25 times that of the lower cylinder 400, the top seal head of the coke drum is provided with a coke drilling port 900, an oil-gas outlet 800 and a safety valve port.

The total height H of the coke drum is 25.0m (height not counting top and bottom cones 500), the diameter D of the lower barrel 400 of the coke drum is 6.0m, the height H is 15.0m, the diameter of the upper barrel 200 of the coke drum is 7.5m, the height of the upper barrel 200 is 8.0m, and the height above the upper cone 300 is 2.0 m.

Example 2

The delayed coking process for coking feedstock using a coking drum as in the left diagram of fig. 1 (i.e., the coke drum of example 1) comprises the following specific steps:

referring to fig. 2, the coker feed oil and cycle oil were mixed in a ratio of 1: 0.2 (mass ratio) of the mixed materials are sent into a coking heating furnace 1 for heating, the coking material flow heated to the coking temperature enters a coke tower 2a through an oil transfer line at a high speed, delayed coking reaction is carried out in the coke tower, the coke generated by the reaction remains in the coke tower, oil gas enters a fractionating tower 3 through a large oil gas pipeline at the top of the tower for fractionation, and products such as gas, coking gasoline, coking diesel oil, coking wax oil and the like are obtained after fractionation.

Example 3

referring to fig. 2, the coker feed oil and cycle oil were mixed in a ratio of 1: 0.2 (mass ratio) of the mixed material obtained by mixing is sent into a coking heating furnace 1 for heating, the coking material flow heated to the coking temperature enters a micro-bubble generator at a high speed, hydrogen 5 (0.05 percent of the coking raw material) and a sulfur reduction additive 6 (0.5 percent of the coking raw material) are quickly and efficiently dispersed in the mixed material by utilizing the micro-bubble generator 4a/4b, the material flow after re-mixing enters a coke tower 2a through an oil transfer line, delayed coking reaction is carried out in the coke tower, the coke generated by the reaction remains in the coke tower, oil gas enters a fractionating tower 3 through a large oil gas pipeline at the top of the tower for fractionating, and products such as gas, coking gasoline, coking diesel oil, coking wax oil and the like are obtained after fractionating.

Comparative example

The delayed coking process for coking feedstock is carried out using a coking drum (i.e., a conventional coke drum) as in the right hand diagram of fig. 1. the delayed coking process used in the comparative example is the same as that used in example 2 of the present invention, with the main differences being that: 1) the structure of the coke drum of the comparative example is different, the coke drum of the comparative example is a conventional coke drum (shown in the right diagram of fig. 1), namely the conventional coke drum consists of a top head 100, a straight cylinder and a bottom cone 500, the height of the straight cylinder is 25m, the inner diameter is 6.0m, and the conventional coke drum is seen to have no upper expanding section and no upper cone 300; 2) and the comparative example is not provided with a microbubble generator, and is not injected with hydrogen and the sulfur reduction auxiliary agent.

The raw oil used in each example and comparative example was the same vacuum residue feed and the properties are shown in table 1.

TABLE 1 Main physical Properties of vacuum residuum

The delayed coking processes provided in the examples and comparative examples treat the same weight of coker feedstock and the operating parameters and product distribution of the examples and comparative examples are shown in table 2.

TABLE 2 operating conditions and product distribution for the examples and comparative examples

As can be seen from table 2 above: the vacuum residue is used as coking feed, and the sulfur reduction auxiliary agent and hydrogen are added in the embodiment 3, so that the liquid yield is increased, and the mild hydrogenation effect is realized under the combined action of the sulfur reduction auxiliary agent and the hydrogen, so that the liquid yield of the device can be increased, and the coke yield is reduced. Meanwhile, the linear velocity of the oil gas at the upper part of the coke tower of the comparative example is 0.144m/s, while the linear velocity of the oil gas at the upper part of the coke tower in the embodiment 2 of the invention is only 0.095m/s, and although a certain amount of hydrogen is additionally injected in the embodiment 3, the linear velocity of the oil gas at the upper part of the coke tower is only 0.126m/s, and the linear velocity of the oil gas of the two embodiments is smaller than that of the comparative example, so that the embodiment of the invention can reduce the height of a foam layer in the coking tower, reduce the coke powder carrying amount of the oil gas, and better property of the coking wax.

The results of measuring the properties of the coker gas oil obtained in the above examples and comparative examples in table 2 are shown in table 3.

TABLE 3 results of investigating properties of coker gas oils of example 2 and comparative examples

As can be seen from table 3 above: the coker gas oil obtained in inventive example 2 had a density of 0.9878g/cm, compared to the comparative example³Reduced to 0.9722g/cm³The carbon residue value is reduced from 0.21% to 0.11%, the sulfur content is reduced from 1.32% to 1.09%, the asphaltene is reduced from 0.16% to 0.08%, the molecular weight is reduced from 355g/mol to 341g/mol, and the 95% point of the distillation range is reduced from 476.4 ℃ to 449.8 ℃.

Table 4 below is a property analysis of the petroleum cokes of example 3 and the comparative example.

Table 4 analysis of properties of petroleum coke of example 3 and comparative example

As can be seen from table 4 above: compared with the comparative example, the volatile content of the petroleum coke obtained in the example 3 of the invention is reduced from 11.59% to 10.28%, the most obvious change is that the sulfur content of the petroleum coke is reduced from 2.39% to 1.55%, and the sulfur content is reduced by more than 30%. Therefore, the properties of the coking wax oil and the petroleum coke obtained by the coke tower and the delayed coking method provided by the embodiment of the invention are obviously improved, and the subsequent processing and utilization of the coking wax oil and the petroleum coke are facilitated.

In summary, embodiments of the present invention provide a coke drum and a delayed coking method using the same. The coke drum comprises: the top end enclosure is connected with the top of the upper barrel, and the bottom of the upper barrel is connected with the top of the upper cone; the bottom of the upper cone is connected with the top of the lower cylinder, and the bottom of the lower cylinder is connected with the top of the bottom cone; the upper cylinder, the upper cone and the lower cylinder are coaxially arranged, and the diameter of the upper cylinder of the coke tower is larger than that of the lower cylinder. The diameter of the upper cylinder of the coke tower is enlarged, and the oil gas linear velocity of the oil gas at the upper part of the coke tower is reduced. Therefore, the thickness of the foam layer in the coke tower is effectively reduced, the coke powder carried by the foam in the ascending air flow is reduced or avoided entering a large oil-gas pipeline and a fractionating tower, and the long-period safe production of the device is facilitated.

Compared with the prior art, the embodiment of the invention has the following beneficial effects:

(1) the properties of the coker gas oil are obviously improved, and the linear velocity of the oil gas at the upper part of the coke tower is low, so that the heavy components such as colloid asphalt-like substances carried by the oil gas are obviously reduced, and the coker gas oil separated from the fractionating tower has low density, viscosity, carbon residue value, asphaltene content and the like, has good properties, and is beneficial to subsequent processing.

(2) Because the diameter of the upper barrel of the coke tower is larger, the oil gas linear velocity of oil gas on the upper part of the coke tower can be reduced, so that the thickness of a foam layer in the coke tower is effectively reduced, coke powder carried by foam in ascending air flow is reduced or avoided from entering a large oil gas pipeline and a fractionating tower, and the long-period safety production of the device is facilitated.

(3) Greatly reduces or completely avoids the using amount of the defoaming agent, not only can reduce the cost and improve the economic efficiency, but also can not generate adverse effect on the subsequent processing of the coking liquid product.

(4) The micro-interface strengthening technology is applied to the coking process, the mixing of hydrogen, the sulfur reduction auxiliary agent and the coking raw material can be greatly strengthened by using the micro-bubble generator, the transfer rate of the hydrogen in the multiphase reaction process is enhanced, the micro-interface hydrodesulfurization effect of the coking raw material is strengthened, and the sulfur content of a coking product, particularly petroleum coke, is reduced.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A coke drum, comprising: the top end socket is connected with the top of the upper barrel, and the bottom of the upper barrel is connected with the top of the upper cone; the bottom of the upper cone is connected with the top of the lower cylinder, and the bottom of the lower cylinder is connected with the top of the bottom cone; the upper cylinder, the upper cone and the lower cylinder are coaxially arranged, and the diameter of the upper cylinder of the coke tower is larger than that of the lower cylinder.

2. The coke drum of claim 1, wherein the upper drum diameter of the coke drum is 1.1 to 1.5 times the lower drum diameter.

3. The coke drum of claim 2, wherein the lower barrel of the coke drum has a diameter of 5m to 10 m.

4. The coke drum of claim 1 or 2, wherein the total height of the coke drum is the sum of the heights of the upper drum, the upper cone and the lower drum, and the total height of the coke drum is 20m to 30 m.

5. The coke drum of claim 4, wherein the upper barrel of the coke drum has a height of 3m to 10m and the lower barrel of the coke drum has a height of 5m to 15 m.

6. The coke drum of claim 1, further comprising: the coke drum is characterized in that a coke drilling port and an oil gas outlet are formed in a top seal head of the coke drum, and a feed inlet and a coke outlet are formed in a bottom cone of the coke drum.

7. A delayed coking process utilizing the coke drum of any of claims 1-6, characterized by the steps of: and introducing the raw material to be coked into a bottom cone of the coke tower, and carrying out delayed coking reaction in the coke tower.

8. The delayed coking process of claim 7, wherein the raw material to be coked is obtained by heating a mixed material of raw coking oil and cycle coking oil, and mixing the heated mixed material with hydrogen and a sulfur reduction auxiliary agent again.

9. The delayed coking process of claim 8, wherein the coker feedstock oil comprises at least one of vacuum residuum, atmospheric residuum, heavy crude oil, vacuum wax oil, deoiled bitumen, deasphalted oil, residue hydrogenated heavy oil, thermally cracked residuum, lube oil refined draw oil, catalytically cracked cycle oil, decant oil, ethylene cracked residuum, and tar pitch.

10. The delayed coking process of claim 8, wherein the coker cycle oil comprises at least one of a light coker gas oil and a heavy coker gas oil having cut points from 400 ℃ to 500 ℃.

11. The delayed coking process of claim 8, wherein the mass ratio of the coking cycle oil to the coking feedstock oil is from 0 to 0.5: 1.

12. the delayed coking process according to claim 11, wherein the mass ratio of the light coker gas oil as the coker recycle oil to the coker feedstock oil is from 0 to 0.1: 1.

13. the delayed coking process according to claim 11, wherein the mass ratio of the heavy coker gas oil as the coker recycle oil to the coker feedstock oil is from 0 to 0.4: 1.

14. the delayed coking process of claim 8, wherein the mixture of raw coker oil and cycle coker oil is heated in a furnace.

15. The delayed coking process of claim 14, wherein the temperature of the mixture of raw coker oil and cycle coker cycle oil heated in a furnace is from 360 ℃ to 550 ℃.

16. The delayed coking process of claim 14, wherein the furnace convection chamber exit temperature is from 360 ℃ to 460 ℃ and the furnace radiant chamber exit temperature is from 400 ℃ to 550 ℃.

17. The delayed coking process of claim 16, wherein the furnace radiant chamber exit temperature is in the range of 480 ℃ to 510 ℃.

18. The delayed coking process of claim 8, wherein the hydrogen gas and the sulfur reduction aid are rapidly dispersed in the mixed material of the raw coking oil and the cycle coking oil by using the microbubble generator.

19. The delayed coking process of claim 18, wherein the sulfur reduction aid is added in an amount of 0.1-1% of the total mass of the coker feedstock, and the hydrogen is added in an amount of 0.01-0.2% of the total mass of the coker feedstock.

20. The delayed coking process of any of claims 7-19, wherein the conditions of the coking reaction in the coke drum are: the coking temperature is 450-500 ℃, the coke charging time is 12-36 h, and the pressure at the top of the tower is 0.01-0.3 MPa.

21. The delayed coking process of claim 20, wherein the coking temperature is from 460 ℃ to 480 ℃, the coke charging time is from 18h to 24h, and the overhead pressure is from 0.05MPa to 0.15 MPa.

22. The delayed coking process of claim 20, wherein the number of coke drums is 2 or more, and a plurality of coke drums are arranged in parallel.