A coke oven tail gas dehydration treatment device and treatment method thereof

Abstract

The present invention provides a coke oven tail gas dehydration treatment device and a treatment method thereof. Before the coke oven tail gas is used, the coke oven tail gas is firstly heat exchanged in a heat exchanger B, then sequentially enters a spray tower A and a spray tower B for cooling by spraying spray liquid, and finally sequentially enters a rotary dehumidifier A and a rotary dehumidifier B for dehumidification before entering a fuel gas pipeline network, thereby effectively controlling the temperature and moisture content of the coke oven tail gas, and can effectively reduce the potential safety hazards when the coke oven tail gas is used. The present invention uses a common heat exchanger B to exchange heat during the dehydration process and the water desorption process. At the same time, heat exchange is achieved between the fresh air introduced in the water desorption process and the exhausted air through the heat exchanger A, so that in the whole process, there is no need to introduce a new heat source to achieve water desorption of the rotary dehumidifier A and the rotary dehumidifier B, thereby achieving full utilization of the heat energy in the coke oven tail gas.

Description

Technical Field

[0001] The invention belongs to the technical field of coke oven tail gas treatment, and in particular relates to a coke oven tail gas dehydration treatment device and a treatment method thereof. Background Art

[0002] Coke oven exhaust gas has a high temperature, contains harmful gases such as sulfur dioxide, and contains a variety of recyclable gases. If it is discharged directly, it will not only pollute the environment, but also cause a waste of energy. Therefore, in order to solve the above technical problems, technical personnel in this field usually use coke oven exhaust gas for heat exchange and pass it into a roasting furnace for steam production and power generation. Some technical personnel also process coke oven exhaust gas into natural gas for use in order to make full use of the resources in coke oven exhaust gas. However, because the temperature of coke oven exhaust gas when discharged is as high as 180-200°C, it is very risky for circular mobile operation and poses a safety hazard. At the same time, the water content of coke oven exhaust gas is more than 35%. For the circular mobile operation of the roasting furnace, a large amount of water will accumulate at the end of the pipeline, blocking the pipeline, reducing the calorific value, and affecting the service life of the roasting furnace. Therefore, it is very necessary to dehydrate, cool and reduce the temperature of the coke oven exhaust gas before using it to reduce safety hazards. Summary of the invention

[0003] The purpose of the present invention is to provide a coke oven tail gas dehydration treatment device and a treatment method thereof, which can effectively reduce the safety hazards when using the coke oven tail gas by dehydrating and cooling the coke oven tail gas before using it.

[0004] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present invention is: a coke oven tail gas dehydration treatment device, comprising a spray tower A, a spray tower B, a rotary dehumidifier A, a rotary dehumidifier B and a heat exchanger B, the coke oven tail gas is connected to the fuel gas pipeline network after passing through the dehydration treatment device, characterized in that: the coke oven tail gas is connected to the heat exchanger B, the spray tower A and the spray tower B in sequence through a pipeline and then divided into two branches, one of which is connected to the fuel gas pipeline network through a pipeline after passing through the rotary dehumidifier A and a valve A1 is provided on the branch, and the other branch is connected to the fuel gas pipeline network through a pipeline after passing through the rotary dehumidifier B and a valve B1 is provided on the branch;

[0005] The water inlets of spray tower A and spray tower B are connected to the supplementary water source through a circulation pump, and the water outlets of spray tower A and spray tower B are commonly connected to the inlet of the cooling tower. The outlet of the cooling tower is connected to the water treatment device and the circulation pump in turn through pipes.

[0006] Furthermore, the dehydration treatment device also includes a heat exchanger A and a fan for introducing fresh air into the heat exchanger A. The fan is connected to the heat exchanger A and the heat exchanger B in sequence through pipelines and is divided into two branches. One branch is provided with a valve A2 and is connected to the rotary dehumidifier A after passing through the heat exchanger B. The other branch is provided with a valve B2 and is connected to the rotary dehumidifier B after passing through the heat exchanger B. The rotary dehumidifier A and the rotary dehumidifier B are connected to the exhaust gas treatment device after being connected to the heat exchanger A.

[0007] A method for treating a coke oven tail gas dehydration treatment device, comprising a dehydration method and a water desorption method.

[0008] Wherein, the dehydration method comprises the following steps:

[0009] Step 1: the coke oven tail gas first passes through the heat exchanger B for heat exchange, then enters the spray tower A and spray tower B in turn to be cooled by spraying spray liquid, and finally enters the rotary dehumidifier A and rotary dehumidifier B in turn for dehumidification before entering the fuel gas pipeline network;

[0010] Step 2: The spray liquid sprayed in the spray tower A and the spray tower B is collected and then enters the cooling tower for cooling. After cooling, it enters the water treatment device for treatment. After the treatment, it re-enters the spray tower A and the spray tower B through the circulation pump;

[0011] The water desorption method comprises the following steps:

[0012] Step 1: introducing fresh air into heat exchanger A through a fan;

[0013] Step 2: Open valve A2 and close valve A1. Fresh air is heat exchanged in heat exchangers A and B in turn and then enters rotary dehumidifier A to desorb moisture from the molecular sieve inside rotary dehumidifier A.

[0014] Step 3: Open valve B2 and close valve B1. Fresh air is sequentially heat exchanged in heat exchanger A and heat exchanger B before entering rotary dehumidifier B to desorb moisture from the molecular sieve inside rotary dehumidifier B.

[0015] Step 4: After the water desorption is completed, the air is discharged after being heat exchanged by the heat exchanger A and treated by the exhaust gas treatment device.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. Before the coke oven tail gas is used, the coke oven tail gas is firstly heat exchanged in the heat exchanger B, then sequentially enters the spray tower A and the spray tower B to be cooled by spraying the spray liquid, and finally sequentially enters the rotary dehumidifier A and the rotary dehumidifier B to be dehumidified before entering the fuel gas pipeline network, thereby effectively controlling the temperature and moisture content of the coke oven tail gas, and can effectively reduce the safety hazards when the coke oven tail gas is used;

[0018] 2. The present invention includes a dehydration process and a moisture desorption process of coke oven exhaust gas, wherein the heat exchanger B plays a role of cooling during the dehydration process, and the heat exchanger A and the heat exchanger B play a role of heating the fresh air introduced by the fan during the moisture desorption process. The present invention uses the common heat exchanger B to exchange heat during the dehydration process and the moisture desorption process. At the same time, heat exchange is achieved between the fresh air introduced in the moisture desorption process and the exhausted air through the heat exchanger A. Therefore, in the whole process, there is no need to introduce a new heat source to achieve moisture desorption of the rotary dehumidifier A and the rotary dehumidifier B, thereby achieving full utilization of the thermal energy in the coke oven exhaust gas, and no need to provide a separate heat source, thereby saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The utility model is a principle block diagram of a coke oven tail gas dehydration treatment device. DETAILED DESCRIPTION

[0020] In order to make the purpose, 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 in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] A coke oven tail gas dehydration treatment device, such as Figure 1As shown, it includes a spray tower A, a spray tower B, a rotary dehumidifier A, a rotary dehumidifier B and a heat exchanger B. After passing through the dehydration treatment device, the coke oven exhaust gas is connected to the fuel gas pipeline network. The coke oven exhaust gas is connected to the heat exchanger B, the spray tower A and the spray tower B in sequence through pipelines and is divided into two branches. One branch is connected to the fuel gas pipeline network through a pipeline after passing through the rotary dehumidifier A, and a valve A1 is arranged on the branch. The other branch is connected to the fuel gas pipeline network through a pipeline after passing through the rotary dehumidifier B, and a valve B1 is arranged on the branch. Before the coke oven exhaust gas is used, the coke oven exhaust gas is firstly heat exchanged through the heat exchanger B, and then enters the spray tower A and the spray tower B in sequence to be cooled by spraying spray liquid, and finally enters the rotary dehumidifier A and the rotary dehumidifier B in sequence for dehumidification before entering the fuel gas pipeline network, thereby effectively controlling the temperature and moisture content of the coke oven exhaust gas, and can effectively reduce the safety hazards when the coke oven exhaust gas is used.

[0022] The water inlets of spray tower A and spray tower B are connected to the supplementary water source through a circulation pump, and the water outlets of spray tower A and spray tower B are commonly connected to the inlet of the cooling tower. The outlet of the cooling tower is connected to the water treatment device and the circulation pump in turn through pipes. Part of the tap water is added to spray tower A and spray tower B through the supplementary water source to make up for the lost water.

[0023] In order to fully utilize the thermal energy in the coke oven exhaust gas, the dehydration treatment device also includes a heat exchanger A and a fan for introducing fresh air into the heat exchanger A. The fan is connected to the heat exchanger A and the heat exchanger B in sequence through pipelines and is divided into two branches. One branch is provided with a valve A2 and the branch is connected to the rotary dehumidifier A after passing through the heat exchanger B. The other branch is provided with a valve B2 and the branch is connected to the rotary dehumidifier B after passing through the heat exchanger B. The rotary dehumidifier A and the rotary dehumidifier B are connected to the heat exchanger A together and then connected to the exhaust gas treatment device.

[0024] The present invention includes a dehydration process and a moisture desorption process of coke oven tail gas, wherein the heat exchanger B plays a role of cooling in the dehydration process, and the heat exchanger A and the heat exchanger B play a role of heating the fresh air introduced through the fan in the moisture desorption process. The present invention uses the common heat exchanger B to exchange heat in the dehydration process and the moisture desorption process. At the same time, heat exchange is achieved between the fresh air introduced in the moisture desorption process and the exhausted air through the heat exchanger A. Therefore, in the whole process, there is no need to introduce a new heat source to achieve moisture desorption of the rotary dehumidifier A and the rotary dehumidifier B, thereby achieving full utilization of the thermal energy in the coke oven tail gas, and no need to provide a separate heat source, thereby saving energy.

[0025] A method for treating a coke oven tail gas dehydration treatment device, comprising a dehydration method and a water desorption method.

[0026] Wherein, the dehydration method comprises the following steps:

[0027] Step 1: The coke oven tail gas is firstly heat exchanged in the heat exchanger B, and the temperature after heat exchange is reduced to below 195°C, and then it enters the spray tower A and the spray tower B from the bottom in turn and is cooled by spraying the spray liquid. The cooled coke oven tail gas is discharged from the top of the spray tower B, at which time, the temperature is reduced to below 50°C, and finally enters the rotary dehumidifier A and the rotary dehumidifier B in turn for dehumidification before entering the fuel gas pipeline network. The moisture content of the coke oven tail gas after dehumidification is less than 5%;

[0028] Step 2: The spray liquid sprayed in the spray tower A and the spray tower B is collected and then enters the cooling tower for cooling. After cooling, it enters the water treatment device for treatment. After the treatment, it re-enters the spray tower A and the spray tower B through the circulation pump;

[0029] The water desorption method comprises the following steps:

[0030] Step 1: fresh air is introduced into the heat exchanger A through a fan, and the amount of fresh air introduced is about 1 / 20 of the amount of coke oven tail gas;

[0031] Step 2: Open valve A2 and close valve A1. Fresh air is heat exchanged in heat exchangers A and B in turn and then enters rotary dehumidifier A to desorb moisture from the molecular sieve inside rotary dehumidifier A.

[0032] Step 3: Open valve B2 and close valve B1. Fresh air is sequentially heat exchanged in heat exchanger A and heat exchanger B before entering rotary dehumidifier B to desorb moisture from the molecular sieve inside rotary dehumidifier B.

[0033] Here, it should be noted that the moisture desorption process of the rotary dehumidifier A and the rotary dehumidifier B is carried out alternately, wherein the temperature of the fresh air after heat exchange in the heat exchanger A reaches about 112°C, and the temperature of the fresh air after heat exchange in the heat exchanger B reaches about 195°C. The fresh air after heat exchange enters the corresponding rotary dehumidifier to complete the moisture desorption process of the molecular sieve in the rotary dehumidifier;

[0034] Step 4: After the water desorption is completed, the air is discharged after being heat exchanged by the heat exchanger A and treated by the exhaust gas treatment device.

[0035] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coke oven tail gas dehydration treatment device, comprising a spray tower A, a spray tower B, a rotary dehumidifier A, a rotary dehumidifier B and a heat exchanger B. The coke oven tail gas is connected to the fuel gas pipeline network after passing through the dehydration treatment device, characterized in that: The coke oven tail gas is connected to the heat exchanger B, the spray tower A and the spray tower B in sequence through a pipeline and then divided into two branches, one of which is connected to the fuel gas pipeline network through a pipeline after passing through the rotary dehumidifier A and a valve A1 is provided on the branch, and the other branch is connected to the fuel gas pipeline network through a pipeline after passing through the rotary dehumidifier B and a valve B1 is provided on the branch; The water inlets of spray tower A and spray tower B are connected to the supplementary water source through a circulation pump, and the water outlets of spray tower A and spray tower B are connected to the inlet of the cooling tower. The outlet of the cooling tower is connected to the water treatment device and the circulation pump in sequence through pipelines; The dehydration treatment device also includes a heat exchanger A and a fan for introducing fresh air into the heat exchanger A. The fan is connected to the heat exchanger A and the heat exchanger B in sequence through a pipeline and then divided into two branches, one of which is provided with a valve A2 and connected to the rotary dehumidifier A after passing through the heat exchanger B, and the other branch is provided with a valve B2 and connected to the rotary dehumidifier B after passing through the heat exchanger B. The rotary dehumidifier A and the rotary dehumidifier B are connected to the heat exchanger A together and then connected to the exhaust gas treatment device; The interiors of both rotary disk dehumidifier A and rotary disk dehumidifier B are filled with molecular sieves.

2. A method for dehydrating coke oven tail gas, characterized in that: The coke oven tail gas dehydration treatment device according to claim 1 comprises a dehydration method and a water desorption method. Wherein, the dehydration method comprises the following steps: Step 1: the coke oven tail gas first passes through the heat exchanger B for heat exchange, then enters the spray tower A and spray tower B in turn to be cooled by spraying spray liquid, and finally enters the rotary dehumidifier A and rotary dehumidifier B in turn for dehumidification before entering the fuel gas pipeline network; Step 2: The spray liquid sprayed in the spray tower A and the spray tower B is collected and then enters the cooling tower for cooling. After cooling, it enters the water treatment device for treatment. After the treatment, it re-enters the spray tower A and the spray tower B through the circulation pump; The water desorption method comprises the following steps: Step 1: introducing fresh air into heat exchanger A through a fan; Step 2: Open valve A2 and close valve A1. Fresh air is heat exchanged in heat exchangers A and B in turn and then enters rotary dehumidifier A to desorb moisture from the molecular sieve inside rotary dehumidifier A. Step 3: Open valve B2 and close valve B1. Fresh air is sequentially heat exchanged in heat exchanger A and heat exchanger B before entering rotary dehumidifier B to desorb moisture from the molecular sieve inside rotary dehumidifier B. Step 4: After the water desorption is completed, the air is discharged after being heat exchanged by the heat exchanger A and treated by the exhaust gas treatment device.

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