Preliminary separation and dehydration device for crude benzene

Abstract

The utility model discloses a crude benzene preliminary separation and dehydration device which comprises a rectifying tower, a condenser and an oil-water separator which are communicated, a plurality of tower plates are arranged in the rectifying tower, a closed heating cavity is arranged below the tower plates, a return pipe and a plurality of upper air pipes are arranged on the tower plates, and a plurality of branch pipes are uniformly distributed on the upper air pipes above the tower plates in the circumferential direction. The condenser is divided into an air inlet chamber, a condensation chamber and a liquid outlet chamber through two vertical plates, a plurality of baffle plates are arranged in the condensation chamber in an up-down spaced mode, a spiral pipe is arranged in a circulation channel formed by the baffle plates, and the two ends of the spiral pipe are communicated with the air inlet chamber and the liquid outlet chamber respectively. A water outlet of the oil-water separator is communicated with the bottom of the condensation chamber, and the top of the condensation chamber is communicated with the heating cavity through a hot water pipe. In conclusion, the device disclosed by the utility model has the advantages of high separation efficiency, capability of reducing energy consumption and good purification effect.

Description

TECHNICAL FIELD

[0001] The utility model relates to crude benzol separation dehydration technical field, concretely relates to a crude benzol preliminary separation and dehydration device. BACKGROUND

[0002] Crude benzol is one of the products in the crude coal gas generated by coal pyrolysis, and is mainly benzene among the benzene series compounds recovered from the coke oven gas after deamination. Crude benzol needs to be rectified for purification, and the principle is to use the difference in volatility of each component in the mixture, through the reflux of liquid and gas phases, to make the gas and liquid phases contact reversely in multiple stages, under the constraints of heat energy driving and phase equilibrium, so that the easily volatile light components are continuously transferred from the liquid phase to the gas phase, while the difficultly volatile components are transferred from the gas phase to the liquid phase, so that the mixture is continuously separated and purified.

[0003] In the refining process of crude benzol, a rectifying tower is used, and a plurality of trays are arranged in the tower. The crude benzol raw material is fed into the rectifying tower, and the crude benzol raw material is continuously heated from the bottom through a reboiler to make the crude benzol raw material vaporize to form steam rising upwards. The higher the steam goes, the lower the temperature of the tray it encounters, and at the same time, the steam gradually approaches the temperature of the reflux liquid due to the influence of the surrounding temperature, so that a large amount of steam is cooled by the tray and the reflux liquid before entering the condenser, forming reflux liquid that is recombined into the reboiler of the rectifying tower. This process has the following problems: the gas-liquid two-phase balance is broken, the reflux liquid temperature rises, the gas-liquid two-phase temperature difference is small, the effect of gas-liquid two-phase convection is not obvious, and the material containing light components also flows into the reboiler again with the reflux liquid, which prolongs the separation and purification time of light and heavy components in the crude benzol raw material, reduces the separation efficiency of crude benzol, and increases the heating energy consumption of the reboiler for crude benzol. Therefore, it is an objective need to develop a crude benzol preliminary separation and dehydration device with high separation efficiency, low energy consumption and good purification effect. SUMMARY

[0004] The utility model aims at providing a crude benzol preliminary separation and dehydration device with high separation efficiency, low energy consumption and good purification effect.

[0005] The utility model discloses a rectifying tower, condenser and oil -water separator are connected, and the rectifying tower is provided with a plurality of trays, the lower portion of tray is provided with the sealed heating cavity, is provided with one return flow pipe and a plurality of upper air pipes on the tray, and the lower end of upper air pipe penetrates heating cavity and is communicated with the rectifying tower below heating cavity, and the upper end of upper air pipe is blocked after extending to the upper portion of tray, and the upper air pipe on the upper portion of tray is uniformly distributed with a plurality of branch pipes, and the branch pipe is arranged horizontally after bending downward, and a plurality of air injection holes are arranged on the branch pipe, the condenser is divided into the air inlet chamber, condensing chamber and liquid outlet chamber through two vertical boards, the air inlet chamber is communicated with the exhaust port of the top of rectifying tower, the liquid outlet chamber is communicated with oil -water separator, and a plurality of baffles are arranged in condensing chamber and are spaced apart up and down, and the spiral pipe is arranged in the flow passage formed by baffle, and the both ends of spiral pipe are communicated with air inlet chamber and liquid outlet chamber respectively, the drain outlet of oil -water separator is communicated with the bottom of condensing chamber, and the top of condensing chamber is communicated with heating cavity through hot water pipe.

[0006] Further, the bottom of the heating cavity is provided with a plurality of inwardly recessed grooves.

[0007] Further, the jet direction of the air injection hole is downward.

[0008] Further, a heat insulation layer is arranged between the tray and the heating cavity.

[0009] Further, a reflux pipe is arranged on the oil discharge pipe of the oil -water separator, and the reflux pipe is communicated with the top of the rectifying tower.

[0010] Further, the flow direction of the cold water in the condensing chamber is opposite to the flow direction of the steam in the spiral pipe.

[0011] Further, a heater is arranged on the hot water pipe.

[0012] The utility model discloses a crude benzene raw material is passed into rectifying tower in operation, and the crude benzene raw material is heated through the reboiler setting at rectifying tower bottom, and the crude benzene raw material is heated gasification and rises, and the steam produced flows upwards, and in turn passes through each heating cavity and tray, when the steam passes through the heating cavity, first contacts the bottom of heating cavity, and the hot water in heating cavity heats the steam, and then enters the upper air pipe, and again exchanges heat with the hot water in heating cavity in the upper air pipe, and is heated again, and the steam after heating enters each branch pipe, and then is sprayed into the reflux liquid on the tray from the air injection hole, so that the rising steam can wrap the light component and rise together, and the heavy component in the steam mixes into the reflux liquid, and with the reflux liquid continuing to flow downwards, by analogy, the steam continuously contacts the heating cavity and the reflux liquid, and continuously separates the light component and the heavy component in it, to reach the crude benzene raw material preliminary separation purpose, and finally the steam is discharged from the top of rectifying tower, enters the condenser, and flows reversely with the cold water in the spiral pipe, and after condensing into liquid, enters the oil-water separator, and after separation, obtains cold water and crude benzene fraction, and the cold water is passed into the condensing chamber of condenser to condense the steam, and after the cold water absorbs the steam heat, temperature rises, and it is passed into the heating cavity to heat the steam, and the steam temperature is improved. In the utility model, the steam is heated and heated again by the heating cavity, so that the steam rising to the upper part of rectifying tower will not be condensed by the interference of the tray, and the steam and the reflux liquid flowing downwards form effective contact, in the process of contact, the light component continues to move upwards with the steam, and the heavy component mixes into the reflux liquid, avoiding the problem that the steam temperature reduces in advance and the gas-liquid two-phase countercurrent effect is not obvious, improving the separation efficiency and purification effect of the steam, and also preventing the light component from continuing to flow to the bottom of rectifying tower and increasing the heating energy consumption of reboiler. Secondly, after the steam enters the condenser, the cold water discharged from the oil-water separator is used to cool the steam, and after the cold water is heated to hot water, the hot water is passed into the heating cavity to heat the steam, improving the purification effect, and forming the recycling of heat, playing the role of energy saving. In summary, the utility model has the advantages of high separation efficiency, low energy consumption and good purification effect. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is the whole structure schematic diagram of the utility model;

[0014] Figure 2 It is Figure 1 It is the amplification structure schematic diagram of node A;

[0015] In the drawing: 1-rectifying tower, 2-condenser, 3-oil-water separator, 4-tray, 5-heating cavity, 6-reflux pipe, 7-upper air pipe, 8-branch pipe, 9-air inlet chamber, 10-condensing chamber, 11-liquid outlet chamber, 12-spiral pipe, 13-hot water pipe, 14-groove, 15-heat insulation layer, 16-backflow pipe, 17-heater. DETAILED DESCRIPTION

[0016] The utility model makes further illustration in combination with the drawings below, but not in any way to the utility model add restriction, based on the utility model made, any change or improvement, all belong to the protection scope of the utility model.

[0017] As Figures 1-2 Indicated, the utility model includes rectifying column 1, condenser 2 and oil water separator 3, rectifying column 1 is prior art equipment, is used for the separation and purification of crude benzene raw material, its bottom is provided with reboiler, carries out heating to crude benzene raw material and forms steam and rises, simultaneously its inside is provided with several trays 4, for making the counterflow of reflux liquid and steam, separates the light and heavy components in steam, rectifying column 1 is provided with several trays 4, the lower portion of tray 4 is provided with airtight heating cavity 5, is provided with a reflux pipe 6 and several upper air pipes 7 on tray 4, reflux pipe 6 is used for the downward flow of reflux liquid, its upper end protrudes tray 4 certain height, when the liquid level height of reflux liquid on tray 4 is higher than the upper end port of reflux pipe 6, enters reflux pipe 6 and flows down, the reflux pipe 6 on adjacent two trays 4 is arranged staggeredly, the lower end of upper air pipe 7 is communicated with rectifying column 1 below heating cavity 5 after penetrating heating cavity 5, the upper end of upper air pipe 7 protrudes to the upper side of tray 4 and is blocked, the upper air pipe 7 on the upper side of tray 4 is uniformly distributed with several branch pipes 8, branch pipe 8 is arranged horizontally after downward bending, is provided with several air injection holes on branch pipe 8, condenser 2 is divided into gas inlet chamber 9, condensing chamber 10 and liquid outlet chamber 11 by two vertical boards, gas inlet chamber 9 is communicated with the exhaust port on the top of rectifying column 1, liquid outlet chamber 11 is communicated with oil water separator 3, multiple baffles are arranged in condensing chamber 10 and are spaced apart, the baffle structure is the baffle structure in prior heat exchanger, for the flow guiding of liquid, increase the flow time and path of liquid, is provided with spiral pipe 12 in the flow passage formed by baffle, the both ends of spiral pipe 12 are communicated with gas inlet chamber 9 and liquid outlet chamber 11 respectively, the steam discharged from the top of rectifying column 1 enters gas inlet chamber 9, then is shunted into multiple strands, respectively enters each spiral pipe 12, exchanges heat with cold water in spiral pipe 12, condenses into liquid and enters liquid outlet chamber 11, is discharged into oil water separator 3 again, the drain outlet of oil water separator 3 is communicated with the bottom of condensing chamber 10, the top of condensing chamber 10 is communicated with heating cavity 5 through hot water pipe 13.

[0018] The utility model discloses a crude benzene raw material is passed into rectifying column 1 when running, and the crude benzene raw material is heated through the reboiler of rectifying column 1 bottom setting, and the crude benzene raw material is heated gasification and rises, and the steam produced flows upwards, and in turn passes through each heating cavity 5 and tray 4, when the steam passes through heating cavity 5, first contact the bottom of heating cavity 5, and the hot water in heating cavity 5 heats the steam, then enters upper air pipe 7, and again exchanges heat with the hot water in heating cavity 5 in upper air pipe 7, and is heated again, and the steam after heating enters each branch pipe 8, and then is sprayed into the reflux liquid on tray 4 from the air injection hole, so that the steam rising can wrap the light component and rise together, and the heavy component in the steam mixes into the reflux liquid, and with the reflux liquid continuing to flow downwards, by analogy, the steam continuously contacts the heating cavity 5 and the reflux liquid, and continuously separates the light component and the heavy component in it, reaches the crude benzene raw material preliminary separation purpose, and finally the steam is discharged from the top of rectifying column 1, enters condenser 2, and flows reversely with the cold water in spiral pipe 12, and after condensing into liquid, enters oil-water separator 3, and after separating, obtains cold water and crude benzene fraction, and the cold water is passed into the condensing chamber of condenser 2 to condense the steam, and after the cold water absorbs the steam heat, the temperature rises, and it is passed into heating cavity 5 to heat the steam, and the steam temperature is improved.

[0019] In the utility model, the heating cavity 5 is used to heat the steam twice, so that the steam rising to the upper part of rectifying column 1 will not be condensed by the interference of tray 4, and the steam and the reflux liquid flowing downwards form effective contact, in the process of contact, the light component continues to move upwards with the steam, and the heavy component mixes into the reflux liquid, avoiding the problem that the steam temperature reduces in advance and the gas-liquid two-phase counterflow effect is not obvious, improving the separation efficiency and purification effect of the steam, and also preventing the light component from continuing to flow to the bottom of rectifying column 1 and increasing the heating energy consumption of the reboiler.

[0020] The bottom of heating cavity 5 is provided with a plurality of inward recessed grooves 14, and in the process of steam rising, first contact the lower surface of heating cavity 5, and then continue to rise through upper air pipe 7, and the grooves 14 at the bottom of heating cavity 5 can increase the contact area between the lower surface of heating cavity 5 and the steam, so that the heating efficiency of the steam can be improved, and the steam can be effectively heated.

[0021] The jet direction of the jet hole is towards the lower side, during the operation of the utility model, the heavy components in the steam will mix into the reflux liquid on the tower plate 4, during the actual operation process, it is found that certain deposition may be generated on the tower plate 4, and the deposition thickness will also increase along with the extension of the use time, thereby affecting the normal operation of the equipment, in order to prevent this situation, the jet direction of the jet hole is arranged towards the lower side, the effect of pneumatic agitation is generated, the reflux liquid is agitated, and the impurities and other substances in the reflux liquid are prevented from depositing.

[0022] The heat insulation layer 15 is arranged between the tower plate 4 and the heating cavity 5, the heat insulation layer 15 is made of existing heat insulation materials, the hot water in the heating cavity 5 can be prevented from heating the tower plate 4 and the reflux liquid on the tower plate 4, so that the steam and the tower plate 4 and the steam and the reflux liquid have obvious temperature difference, thereby improving the effect of the gas-liquid two-phase flow, preventing the light component substances from flowing into the reboiler again along with the reflux liquid, shortening the separation and purification time of the light and heavy components, and reducing the heating energy consumption.

[0023] The backflow pipe 16 is arranged on the oil discharge pipe of the oil-water separator 3 and communicates with the top of the rectifying tower 1, the steam is condensed into liquid in the condenser 2 and then is introduced into the oil-water separator 3 to separate oil and water, so that the crude benzene fraction and cold water are obtained, the separation and dehydration of the crude benzene raw material are completed, and it is found in the actual operation process that there are certain heavy components and impurities in the crude benzene fraction, in order to improve the purity of the crude benzene fraction, the heavy components and impurities can be returned to the top of the rectifying tower 1 through the backflow pipe 16 and mixed into the reflux liquid after flowing to the tower plate 4, and then the purification is continuously carried out.

[0024] In order to improve the heat exchange efficiency of the cold water and the steam, the flow direction of the cold water in the condensing chamber 10 is opposite to the flow direction of the steam in the spiral pipe 12, so that the cold water and the steam always have a large temperature difference, high heat exchange efficiency and good heat exchange effect are ensured.

[0025] The heater 17 is arranged on the hot water pipe 13, the heater 17 is an existing device, an electric heating device can be used, and the heater 17 is a standby device, when an accident such as operation error occurs and the temperature of the hot water is too low to heat the steam to the required temperature, the heater 17 can be started to heat the cold water, so that the device can normally operate, and when the system returns to normal, the heater 17 can be closed.

Claims

1. A crude benzene preliminary separation and dehydration device, comprising a rectifying tower (1), a condenser (2) and an oil-water separator (3), a plurality of tower plates (4) are arranged in the rectifying tower (1), characterized in that The lower part of the tower plate (4) is provided with a closed heating cavity (5), the tower plate (4) is provided with a reflux pipe (6) and a plurality of gas pipes (7), the lower end of the gas pipe (7) penetrates the heating cavity (5) and is communicated with the rectifying tower (1) below the heating cavity (5), the upper end of the gas pipe (7) is blocked after extending above the tower plate (4), a plurality of branch pipes (8) are uniformly distributed on the gas pipe (7) above the tower plate (4), the branch pipe (8) is arranged horizontally after being bent downward, a plurality of air injection holes are arranged on the branch pipe (8), the condenser (2) is divided into an air inlet chamber (9), a condensing chamber (10) and a liquid outlet chamber (11) by two vertical plates, the air inlet chamber (9) is communicated with the exhaust port at the top of the rectifying tower (1), the liquid outlet chamber (11) is communicated with the oil-water separator (3), a plurality of baffles are arranged in the condensing chamber (10) in a spaced manner, a spiral pipe (12) is arranged in the flow channel formed by the baffles, the two ends of the spiral pipe (12) are communicated with the air inlet chamber (9) and the liquid outlet chamber (11) respectively, the water outlet of the oil-water separator (3) is communicated with the bottom of the condensing chamber (10), and the top of the condensing chamber (10) is communicated with the heating cavity (5) through a hot water pipe (13).

2. A crude benzol primary separation and dehydration device according to claim 1, characterized in that: The bottom of the heating cavity (5) is provided with a plurality of inwardly recessed grooves (14).

3. A crude benzol primary separation and dehydration device according to claim 1, characterized in that: The air injection direction of the air injection hole is downward.

4. The crude benzol preliminary separation and dehydration device according to claim 1, characterized in that: A heat insulation layer (15) is arranged between the tower plate (4) and the heating cavity (5).

5. A crude benzol primary separation and dehydration device according to claim 1, characterized in that: The oil outlet pipe of the oil-water separator (3) is provided with a reflux pipe (16), and the reflux pipe (16) is communicated with the top of the rectifying tower (1).

6. A crude benzol primary separation and dehydration device according to claim 1, characterized in that: The flow direction of the cold water in the condensing chamber (10) is opposite to the flow direction of the steam in the spiral pipe (12).

7. A crude benzol primary separation and dehydration device according to claim 1, characterized in that: A heater (17) is arranged on the hot water pipe (13).

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