KR100890811B1 - Apparatus for cleaning heat exchanger of btx recovery equipment - Google Patents

Abstract

The present invention easily adheres to various heat exchangers and accumulates coal tar, pitch, etc. in the process of purifying and distilling benzene, toluene, and xylene, which are impurities in coke oven gas, which is a by-product gas generated when coke is dried by coal in coke oven. The present invention relates to a heat exchanger scrubber of a BTI distillation plant that is improved to maximize the efficiency of the heat exchanger. The benzene, toluene, and xylene contained in the coke oven gas generated during the coking of coal is manufactured. An apparatus for purifying distillation, comprising: a mixture separator connected to an end of a recovery pipe for discharging a cleaning liquid from a heat exchanger attached to a distillation equipment and arranged inclinedly; A pure B.T.X tank horizontally connected to an end of the cleaning pipe for supplying the cleaning liquid to the heat exchanger; A discharge pipe connecting the mixture separator and the pure B.T.X tank; A cooling heat exchanger installed on the discharge pipe to cool the washing liquid evaporated; It is configured to include a decanter facility for collecting and recovering coal tar, the pitch is connected to the mixture separator and discharged therefrom.

According to the present invention, only pure BTX, which is an organic solvent, can be recovered and reused as a cleaning liquid from the cleaning mixture, thereby maximizing the cleaning efficiency, improving the operating efficiency of the heat exchanger, improving the distillation efficiency of the BTX distillation unit, coal tar, Pitch can be obtained as a by-product.

Description

Heat exchanger cleaning device of BTI-EX distillation unit {APPARATUS FOR CLEANING HEAT EXCHANGER OF BTX RECOVERY EQUIPMENT}

1 is a heat exchanger cleaning and impurity treatment process diagram of a conventional B.T.X distillation unit,

2 is a heat exchanger cleaning and impurity treatment process diagram of the B.T.X distillation plant according to the present invention,

Figure 3 is an enlarged view of the main portion of the cleaning apparatus according to the present invention.

Explanation of symbols on the main parts of the drawings

100 ... water absorption tank 110 ... B.T.X absorption tower

120 ... water absorption tank 130 ... B.T.X distillation column

142,152,162 .... Heat exchanger 174 .... Cleaning piping

176 .... Recovery piping 200 .... Mixture separator

230 .... exhaust pipe 240 .... cooling heat exchanger

300 .... pure B.T.X tank

The present invention is attached to various heat exchangers in the process of purifying and distilling benzene, toluene, and xylene (hereinafter referred to as "BTX"), which are impurities in coke oven gas, which is a by-product gas generated when producing coke by distilling coal in a coke oven. The present invention relates to a heat exchanger cleaning device of an improved BTI distillation system to easily remove accumulated coal tar, pitch, and the like, thereby maximizing the efficiency of the heat exchanger.

Usually, B.T.X, an impurity in coke oven gas, which is a by-product gas generated when coke is dried by coal in coke oven, is absorbed by absorption oil in B.T.X absorption tower and then distilled in distillation equipment. The process is as follows.

Referring to FIG. 1, the coke oven gas containing BTX as an impurity is absorbed oil absorbing BTX from the absorption oil tank 100 while the coke oven gas is introduced from the lower portion 110a of the BTX absorption tower 110 and discharged to the upper portion 110b. After being supplied by the pump 100a, the BTX absorption tower 1100 flows from the top to the bottom to absorb the BTX, and is then introduced into the absorption oil storage tank 120 by the pump 110c.

The absorbing oil (containing B.T.X) is heated by passing through various heat exchangers 142, 152, and 162 by the pump 120a, and charged into the B.T.X distillation column 130.

At this time, the heating furnace 140 is installed to further increase the temperature of the absorbent oil containing BTX, and the heat medium oil circulates the heating furnace 140 through the pump 140a to perform heat exchange in the absorbent oil and the heat exchanger 152. Done.

Absorption oil charged in the BTX distillation column 130 is distilled by steam 134 and the BTX in the absorption oil is converted into a vapor state and then discharged through the BTX distillation tower 130, and after passing through the heat exchanger 132 It is recovered as a byproduct through a process.                         

The high temperature absorbent oil in which BTX is distilled off is lowered to the bottom of the BTX distillation column 130, and the temperature is dropped by the pump 130a through the heat exchangers 142 and 162. Will be.

In this process, oil of high temperature (80 ~ 180 ° C) is distributed to each heat exchanger (142, 152, 162). As absorption oil and absorbent oil containing BTX are distributed, coal tar and pitch are attached and fixed to the inside and outside of the tube type heat exchanger. It lowers the efficiency of the heat exchanger, so it is cleaned with liquid BTX.

In particular, since the absorbent oil is coal tar-based absorbent oil, the absorbent oil itself has a coal tar component, so that coal tar and pitch are more attached to the inner and outer tubes of the tubular heat exchanger.

In the cleaning operation, the liquid BTX stored in the cleaning tank 170 is pumped by the pump 170a to be supplied to the cleaning pipe 174 connected to each heat exchanger 142, 152, 162, and the coal tar or pitch attached to the inside and the outside of the tube of the heat exchanger is collected. After dissolving, washing is performed through a circulation to recover the cleaning tank 170 through the recovery pipe 176, and the cleaning time is continuously performed for about 72 hours.

However, this continuous cleaning operation removes impurities such as coal tar and pitch, which are attached to the heat exchanger, but is not quickly and completely discharged to the outside, but still circulates in a mixed state in the liquid BTX. The more the problem is that the cleaning efficiency is lowered.

In addition, since the waste discharged from the cleaning tank 170 is collected in the slop tank 180 and then sent back to the absorption oil storage tank 120 to be reused, the distillation efficiency is not completely discharged to the outside of the circulation line. Of course, the lowering of both cleaning efficiency is indispensable.

In addition, when coal tar or pitch is accumulated in the bottom of the absorbent oil tank 100, the absorbent oil storage tank 120, and the slop tank 180, the operation of the equipment is stopped. Problems such as the trouble of having to go directly into the tank and discharging these residues and the risk of safety accidents exist constantly.

The present invention has been made in view of the above-described problems of the prior art, and it was created to solve this problem. During the cleaning process, only the pure BTX can be used as the cleaning liquid, which allows the complete discharge process to the outside to be recovered as a by-product, thereby improving the cleaning efficiency and at the same time maximizing the efficiency of the equipment. It is an object to provide a cleaning device.

The above object of the present invention is to purify and distill benzene, toluene and xylene contained in the coke oven gas generated in the process of producing coke by distilling coal, and the cleaning liquid is discharged from the heat exchanger installed in the distillation facility. A mixture separator connected to an end of the recovery pipe and inclinedly disposed; A pure B.T.X tank horizontally connected to the end of the cleaning pipe for supplying the cleaning liquid to the heat exchanger; A discharge pipe connecting the mixture separator and the pure B.T.X tank; A cooling heat exchanger installed on the discharge pipe to cool the washing liquid evaporated; It is achieved by providing a heat exchanger cleaning apparatus of the BTI-X distillation equipment, characterized in that it comprises a decanter facility for collecting and recovering coal tar, discharged from the mixture separator.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

Figure 2 is a heat exchanger cleaning and impurity treatment process diagram of the B.T.X distillation plant according to the present invention, Figure 3 is an enlarged view of the main part of the cleaning apparatus according to the present invention.

2 to 3, the mixture separator 200 installed with a slight inclination at the end of the recovery pipe 176 through which the cleaning liquid is discharged from each heat exchanger 142, 152, 162 is connected, and the mixture separator 200 is installed. The lower portion of the heat source supply 210 of the type that can supply heat by using steam or a heater is installed to be configured to heat the inside, and also inside the temperature sensor 220 for temperature control is built therein. .

The other side of the mixture separator 200, that is, the opposite side to which the recovery pipe 176 is connected, is connected to a discharge pipe 230 through which BTX is discharged in a vapor state, and the discharge pipe 230 is horizontally extended after the pure BTX tank ( 300 is connected to the cooling heat exchanger 242 is part of.

In addition, the lower side of the mixture separator 200 is provided with a liquid level gauge 202 for measuring the liquid level of coal tar, pitch, the pump 204 is installed on one side thereof, which is controlled by the liquid level meter 202 The liquid level control valve 206 is provided, and the discharged through the coal tar or pitch to the decanter facility (400).

In addition, the cooling heat exchanger 242 is provided with a temperature detector 242a for controlling the cooling temperature and a temperature control valve 242b operated thereby.

On the other hand, the pure BTX tank 300 is provided with an indirect heat supply 310, such as a heater that can apply heat, is provided with a temperature detector 320 for its control, the pump 330 and the flow meter 350 Flow control valve 340 is controlled by the installed on the cleaning pipe 174 connected to each heat exchanger (142, 152, 162).

The operating relationship of the present invention made of such a configuration is as follows.

First, the B.T.X distillation process in the coke oven gas is made of the same process as described in the prior art with reference to Figure 1, the present invention relates to the control process of the deposits generated in the heat exchanger during this distillation process will be described.

Liquid BTX from the pure BTX tank 300 is sent to the heat exchanger (142, 152, 162) along the cleaning pipe 174 by the pump 330, the flow rate of the flow control valve 340 in accordance with the flow rate set value of the flow meter (350) Will work automatically

Since the cleaning liquid passing through the inner and outer tubes of the tubular heat exchanger 142, 152 and 162 dissolves the coal tar and the pitch attached to the inner and outer tubes, the coal liquid and the pitch are naturally included in the cleaning liquid.

Coal tar, pitch, and the mixed liquid is introduced into the mixture separator 200 through the recovery pipe 176.

In the interior of the mixture separator 200, steam or heated heat is passed through the heat source air supply 210 to the inside of the mixture separator 200 according to the temperature set value of the temperature sensor 220, thereby causing the internal temperature of the mixture separator 200 to be adjusted. Will be adjusted.

At this time, the boiling point of the BTX is 80.1 ℃, so that if managed at an appropriate temperature of more than 80.1 ℃ pure BTX of the mixed liquid introduced into the mixture separator 200 is boiled to be introduced into the cooling heat exchanger 242 while evaporating to the discharge pipe 230. do.

The cooling heat exchanger 242 cools the pure water B.T.X, and the cooled pure water B.T.X is moved and stored in the pure water B.T.X tank 300 through the other end of the discharge pipe 230.

In this state, the cooling temperature is automatically adjusted to a desired temperature in the process by automatically operating the temperature control valve 242b according to the set value of the temperature detector 242a installed in the discharge pipe 230.

On the other hand, after the pure B.T.X is separated from the mixture separator 200, coal tar and pitch are accumulated in the mixture separator 200, but the fluidity is high because the temperature is high.

Therefore, the coal tar and pitch accumulated at the bottom are sent to the decanter facility 400 collecting coal tar by the pump 204 and recovered as a by-product.

In addition, the liquid level control valve 206 is operated in accordance with the set value of the liquid level gauge 202 installed in the mixture separator 200 to manage the liquid level of coal tar and pitch layer.

In addition, the liquid B.T.X introduced into the pure B.T.X tank 300 is reused for the heat exchanger cleaning by the pump 330.

The internal temperature of the pure B.T.X tank 300 adjusts the internal temperature of the pure B.T.X tank 300 by adjusting the heating amount or the steam amount by the indirect heat supply 310 according to the temperature set value of the temperature detector 320.

This operation is repeated repeatedly.

As described in detail above, the present invention provides the following effects.

First, since only pure B.T.X, an organic solvent, can be recovered from the cleaning mixture and reused as the cleaning solution, the cleaning efficiency is maximized.

Second, the operating efficiency of the heat exchanger is improved.

Third, the distillation efficiency of the B.T.X distillation plant is also improved.

Fourth, coal tar or pitch can be obtained as a by-product.

Fifth, since the tank does not need to be cleaned, manpower reduction and safety accidents can be prevented.

Claims (4)

In the equipment for purifying and distilling benzene, toluene and xylene contained in the coke oven gas generated in the process of producing coke by distilling coal, A mixture separator 200 connected to an end of the recovery pipe 176 for discharging the cleaning liquid from the heat exchanger 142, 152 and 162 installed in the distillation unit and inclinedly disposed; Pure B.T.X tank 300 is connected to the end of the cleaning pipe (174) for supplying the cleaning liquid to the heat exchanger (142, 152, 162) and installed horizontally; A discharge pipe 230 connecting the mixture separator 200 and the pure B.T.X tank 300; A cooling heat exchanger (242) installed on the discharge pipe (230) to cool the cleaning liquid that evaporates; The decanter facility connected to the mixture separator 200 and discharged from the coal tar, the pitch is collected from the decanter equipment, characterized in that it comprises a decanter distillation equipment heat exchanger cleaning device. The method according to claim 1, A temperature sensor 220 and a temperature detector 320 are installed in the mixture separator 200 and the pure BTX tank 300, respectively, and the internal temperature is constant by the temperature sensor 220 and the temperature detector 320. Heat exchanger cleaning apparatus of the BTI-X distillation equipment, characterized in that the heat source supply 210 and the indirect heat supply 310 to control the heating is installed. The method according to claim 1, A liquid level gauge 202 is attached to the downward inclined end of the mixture separator 200, and a liquid level control valve 206 for controlling discharge of coal tar and pitch accumulated by the liquid level gauge 202 to the decanter facility 400 is provided. Heat exchanger cleaning apparatus of the BTI-X distillation equipment, characterized in that the. The method according to claim 1, The cooling heat exchanger 242, the temperature detector for adjusting the cooling temperature (242a) and the temperature control valve (242b) controlled by this is installed, the heat exchanger cleaning device of the BTI-X distillation equipment.

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