CN111450692A - Cement rotary kiln tail gas sulfur dioxide ultralow emission treatment device and process - Google Patents

Abstract

A cement rotary kiln tail gas ultra-low emission treatment device and process for sulfur dioxide, comprising a raw material mixing tank, a first storage tank, a second storage tank, a vertical mill, a raw material elevator and a flue; The first storage tank is connected, and a first valve is arranged on the first pipeline; the raw material mixing tank is communicated with the second storage tank through a second pipeline, and a second valve is arranged on the second pipeline; the first storage tank is connected through the third pipeline A nozzle is connected, a third valve is arranged on the third pipeline, and the nozzle is arranged on the flue; the second storage tank is connected to the feed port of the vertical mill through a fourth pipeline, and the fourth pipeline is provided with The fourth valve is provided with a fifth pipeline connected to the feed end of the raw meal elevator on the fourth pipeline, and the fifth pipeline is provided with a fifth valve; the third pipeline is provided with a first centrifugal pump, and the fourth pipeline is provided with a first centrifugal pump. There is a second centrifugal pump on it. The treatment process is to solidify the raw meal and the flue through the solid sulfur liquid, so as to improve the effect of solid sulfur.

Description

A kind of cement rotary kiln tail gas ultra-low emission treatment device and process of sulfur dioxide

technical field

The invention relates to a cement rotary kiln tail gas sulfur dioxide emission treatment device and a process, in particular to a cement rotary kiln tail gas ultra-low sulfur dioxide emission treatment device and a process.

Background technique

The cement industry is an important basic raw material industry in my country's national economy. It provides important support and guarantee for the development of construction, transportation, water conservancy and other related industries. It is an important pillar industry for the development of my country's national economy. The cement industry will play a vital role in accelerating the construction of a resource-saving and environment-friendly industrial system.

At present, the new dry process cement technology has become the mainstream of cement production in my country. It promotes the further development of the cement industry to large-scale due to its advanced technology, equipment reliability, production adaptability and excellent process performance. With the large-scale development of cement production, energy saving, emission reduction, recycling and low-carbon technologies are the reality faced by the cement industry. The greenhouse gas emitted by China's cement industry accounts for 50% of the world's total, and the dust particles that pollute the environment even more. Therefore, building a "low environmental load cement production model" has become a top priority for the cement industry. The reduction of the cement pollution index will promote the development of China's environmental protection cause, and is of great significance to improving the quality of people's living standards.

At present, the main processes of cement production are:

1. Crushing and pre-homogenization. In the process of cement production, most of the raw materials are crushed, such as limestone, clay, iron ore and coal. As the raw material with the largest amount of cement production, limestone is mined with large particle size and high hardness. The crushing of limestone is the most important step in material crushing. The pre-homogenization technology is to use the scientific stacking and reclaiming technology in the process of storage and retrieval of raw materials, so that the raw materials are initially homogenized, and the raw material yard has the ability to store and homogenize.

2. Raw meal preparation.

3. Homogenization of raw materials. In the production process of the new dry method cement, the stable composition of the raw meal entering the pit is the premise of stabilizing the thermal processing of clinker firing, and the raw meal homogenization system has the effect of stabilizing the composition of the raw meal entering the pit.

4. Preheat decomposition. The preheater completes the preheating and partial decomposition of the raw material, which replaces some of the functions of the rotary kiln, which can shorten the length of the return kiln. It also allows the kiln to carry out gas heat exchange in a stacked state, and moves it to the preheater to carry out in a suspended state, so that the The raw meal can be completely mixed with the hot gas discharged from the kiln, which increases the contact area of the gas and the material, and the heat transfer speed is fast and the heat exchange efficiency is high.

5. Cement clinker firing. After the raw meal is preheated and pre-decomposed in the cyclone preheater, it will enter the rotary kiln for clinker firing. In the rotary kiln, the carbonate is further rapidly decomposed and a series of solid-phase reactions are produced to produce minerals in the cement clinker. When the temperature of the material rises, the minerals will be in a liquid image, and they will dissolve in the liquid image and react to produce clinker. After the clinker is fired, the temperature gradually decreases. Finally, the cement clinker cooler cools the high-temperature clinker discharged from the rotary kiln to the temperature that the downstream transportation, storage and cement mill can bear, and recovers the sensible heat of the high-temperature clinker to improve the thermal efficiency and clinker quality of the system.

6. Cement grinding. The final process in the cement process is also the largest power consumption. Its main function is to grind the cement clinker to a suitable particle size, generate the corresponding particle gradation, increase the hydration area, speed up the hydration speed, and meet the needs of cement slurry coagulation and hardening.

In the above process, sulfur dioxide emissions will occur, and because of the country's environmental requirements, there are emission standards for sulfur dioxide emissions. Therefore, many people are now studying how to reduce sulfur dioxide emissions. For example, the Chinese patent application number is 201620175396.8 The patent document with the application date of 2016.3.8 and the authorization announcement date of 2016.7.27 discloses a composite solid-sulfur desulfurization system for a new dry-process cement production line. The system adopts a solid-liquid combination to achieve desulfurization. The desulfurization effect is good, but the solid desulfurizer is used at the input end of the raw meal, and the desulfurization effect needs to be further improved.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a treatment device and process for ultra-low emission of sulfur dioxide in the tail gas of a cement rotary kiln, and the treatment device and process of the present invention have a good desulfurization effect.

In order to achieve the above purpose, a cement rotary kiln tail gas ultra-low emission treatment device for sulfur dioxide includes a raw material mixing tank, a first storage tank, a second storage tank, a vertical mill, a raw material elevator and a flue; A pipeline is communicated with the first storage tank, and a first valve is arranged on the first pipeline; the raw material mixing tank is communicated with the second storage tank through a second pipeline, and a second valve is arranged on the second pipeline; the first storage tank passes through The third pipe is connected with a spray head, the third pipe is provided with a third valve, and the flue is provided with the spray head; the vertical mill has a feeding port, and the second storage tank is connected to the vertical mill through the fourth pipe The feeding port is provided with a fourth valve on the fourth pipeline, a fifth pipeline connected to the feeding end of the raw meal elevator on the fourth pipeline, and a fifth valve on the fifth pipeline; on the third pipeline A first centrifugal pump is provided, and a second centrifugal pump is provided on the fourth pipeline on the input end side of the fifth pipeline.

The processing technology of the above-mentioned processing device is:

(1) 5-50:100 raw materials by weight of urea and water are put into the raw material stirring tank, and the urea and water are mixed through the raw material stirring tank until the urea is dissolved to form a solid sulfur liquid.

(2) Open the first valve to allow the solid sulfur liquid in the raw material stirring tank to be input into the first storage tank. If the second invention is opened, the solid sulfur liquid in the raw material stirring tank is input into the second storage tank.

(3) Open the fourth valve and the second centrifugal pump, and let the solid sulfur liquid in the second storage tank spray onto the surface of the raw meal through the fourth pipe.

(4) The raw meal sprayed with the solid sulfur liquid enters the vertical mill, and the raw meal and the solid sulfur liquid are ground together so that the raw meal and the solid sulfur liquid are mixed evenly; store.

(5) The raw meal in the raw meal silo is lifted into the C1 and C2 cyclones by the raw meal elevator; the third valve and the first centrifugal pump are opened at the same time, so that the solid sulfur liquid in the first storage tank is sprayed through the nozzle. The sulfur dioxide is oxidized and solidified into the flue.

(6) When the fourth valve is opened, the amount of sulfur dioxide discharged is adjusted by opening or closing the fifth valve to control the solid sulfur liquid injected into the feed end of the raw meal elevator.

The above-mentioned cement rotary kiln tail gas ultra-low sulfur dioxide emission treatment device and treatment process, the sulfur-fixing raw materials are stirred and mixed in the raw material mixing tank, if the first valve is opened, the sulfur-fixing liquid will be input into the first storage tank for storage. If there are two valves, the solid sulfur liquid is input into the second storage tank for storage. In the present invention, the first storage tank and the second storage tank are used to store the solid sulfur liquid separately for use. When using the treatment device, by opening the fourth valve, the solid sulfur liquid is sprayed into the raw material at the feed port of the vertical mill through the fourth pipeline. The raw meal of the sulfur liquid enters the vertical mill for grinding, so that the raw meal is pulverized and fully mixed with the solid sulfur liquid. In the process of grinding the raw meal, because the present invention uses a mixture of urea and water as the liquid, and the grinding temperature is about 200 degrees, the above-mentioned sulfur-fixing liquid does not react in this process, so as to fully stimulate the potential vitality of the raw material and provide a basis for the subsequent sulfur-fixing. When the ground raw meal enters the raw meal silo, the raw meal is lifted into the C1 and C2 grade cyclones by the raw meal elevator, and then the third valve is opened, and the third pipe is sent to the C1 grade cyclone and C2 grade cyclone. The flue between the cyclones sprays the solid sulfur liquid, so that the double action of the solid sulfur liquid mixed in the raw meal and the solid sulfur liquid sprayed into the flue oxidizes the sulfur dioxide and solidifies the sulfur dioxide, so that the solid Sulfur works well.

Further, a raw material elevator is provided at the feeding port of the raw material stirring tank. With this structure, it is convenient to lift the raw material into the raw material stirring tank.

Further, the volume of the first storage tank is greater than the volume of the second storage tank.

Further, the nozzle is installed on the flue between the C1-level cyclone and the C2-level cyclone. This way the sulfur fixation effect is better.

Further, there are 12 nozzles. In this way, the injection area to the flue is large, and the effect of fixing sulfur is good.

Further, shells are provided on the raw material stirring tank, the first storage tank and the outer cover of the second storage tank. In this way, the raw material stirring tank, the first storage tank and the second storage tank can be integrated together, which facilitates integration.

Further, it also includes a central control operating mechanism that controls the valve and displays the capacity. Control the valve and display the capacity of the raw material mixing tank, the first storage tank and the second storage tank through the central control operating mechanism. In this structure, the valve, flow, etc. in the casing can be controlled by the central control operation mechanism, and the capacity of the raw material stirring tank, the first storage tank and the second storage tank can also be directly displayed.

Further, a third centrifugal pump is arranged on the first pipeline, and a fourth centrifugal pump is arranged on the second pipeline. In this way, it is convenient to actively input the mixed liquid in the raw material stirring tank into the first storage tank through the third centrifugal pump, and input the mixed liquid in the raw material stirring tank into the second storage tank through the fourth centrifugal pump.

Description of drawings

Figure 1 is a schematic diagram of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figure 1, a cement rotary kiln tail gas ultra-low emission treatment device for sulfur dioxide includes a raw material elevator 1, a raw material mixing tank 2, a first storage tank 3, a second storage tank 4, a vertical mill 5, and a raw material elevator 6 and flue 7.

It also includes a base 10 on which a casing 11 is arranged.

The raw material stirring tank 2 is communicated with the first storage tank 3 through a first pipeline 21 , and a first valve 22 and a third centrifugal pump 23 are arranged on the first pipeline 21 . The raw material stirring tank 2 is communicated with the second storage tank 4 through a second pipeline 24 , and a second valve 25 and a fourth centrifugal pump 26 are arranged on the second pipeline 24 . The first storage tank 3 is connected with the nozzles 32 through the third pipeline 31. In this example, there are 12 nozzles 32. The third pipeline 31 is provided with a third valve 33 and a first centrifugal pump 34. The nozzle 7 is provided with the nozzle, and the flue 7 is the flue between the C1-level cyclone and the C2-level cyclone. The vertical mill 5 has a feeding port 51, and the second storage tank 4 is connected to the feeding port of the vertical mill through a fourth pipeline 35. A fourth valve 36 and a second centrifugal pump 37 are arranged on the fourth pipeline 35. Two centrifugal pumps are arranged at the input end of the fifth pipeline; the fourth pipeline 35 is provided with a fifth pipeline 38 connected to the feed end of the raw meal elevator 6 , and a fifth valve 39 is arranged on the fifth pipeline 38 .

In this embodiment, the volume of the first storage tank 3 is greater than the volume of the second storage tank 4, the volume of the first storage tank 3 is 50 m³, and the volume of the second storage tank 4 is 20 m³.

The raw material elevator 1, the raw material mixing tank 2, the first storage tank 3, the second storage tank 4, the first valve, the second valve, the third valve, the fourth valve, the first centrifugal pump, the second centrifugal pump , the third centrifugal pump, the fifth centrifugal pump and part of the pipeline are arranged in the casing to form an integrated body.

It also includes a central control operating mechanism that controls the valve and displays the capacity. The central control operating mechanism controls the valve and displays the capacity of the raw material mixing tank, the first storage tank and the second storage tank, that is, the central control operating mechanism can directly control the first and second storage tanks. Second, third and fourth valves, therefore, the first, second, third and fourth valves are all electronic valves, and there are capacity meters, flow meters, etc. in the central control operating mechanism. This facilitates centralized control and display.

The process steps of using the ultra-low emission treatment device for sulfur dioxide in the tail gas of the cement rotary kiln to treat the sulfur dioxide are as follows:

(1) 5-50:100 raw materials by weight of urea and water are put into the raw material stirring tank, and the urea and water are mixed through the raw material stirring tank until the urea is dissolved to form a solid sulfur liquid.

(2) Open the first valve to allow the solid sulfur liquid in the raw material stirring tank to be input into the first storage tank. If the second invention is opened, the solid sulfur liquid in the raw material stirring tank is input into the second storage tank.

(3) Open the fourth valve and the second centrifugal pump, and let the solid sulfur liquid in the second storage tank spray onto the surface of the raw meal through the fourth pipe.

(4) The raw meal sprayed with the solid sulfur liquid enters the vertical mill, and the raw meal and the solid sulfur liquid are ground together so that the raw meal and the solid sulfur liquid are mixed evenly; store.

(5) The raw meal in the raw meal silo is lifted into the C1 and C2 cyclones by the raw meal elevator; the third valve and the first centrifugal pump are opened at the same time, so that the solid sulfur liquid in the first storage tank is sprayed through the nozzle. The sulfur dioxide is oxidized and solidified into the flue.

(6) When the fourth valve is opened, the amount of sulfur dioxide discharged is adjusted by opening or closing the fifth valve to control the solid sulfur liquid injected into the feed end of the raw meal elevator.

The above-mentioned cement rotary kiln tail gas ultra-low sulfur dioxide emission treatment device and treatment process, the sulfur-fixing raw materials are stirred and mixed in the raw material mixing tank, if the first valve is opened, the sulfur-fixing liquid will be input into the first storage tank for storage. If there are two valves, the solid sulfur liquid is input into the second storage tank for storage. In the present invention, the first storage tank and the second storage tank are used to store the solid sulfur liquid separately for use. When using the treatment device, by opening the fourth valve, the solid sulfur liquid is sprayed into the raw material at the feed port of the vertical mill through the fourth pipeline. The raw meal of the sulfur liquid enters the vertical mill for grinding, so that the raw meal is pulverized and fully mixed with the solid sulfur liquid. In the process of grinding the raw meal, because the present invention uses a mixture of urea and water as the liquid, and the grinding temperature is about 200 degrees, the above-mentioned sulfur-fixing liquid does not react in this process, so as to fully stimulate the potential vitality of the raw material and provide a basis for the subsequent sulfur-fixing. When the ground raw meal enters the raw meal silo, the raw meal is lifted into the C1 and C2 grade cyclones by the raw meal elevator, and then the third valve is opened, and the third pipe is sent to the C1 grade cyclone and C2 grade cyclone. The flue between the cyclones sprays the solid sulfur liquid, so that the double action of the solid sulfur liquid mixed in the raw meal and the solid sulfur liquid sprayed into the flue oxidizes the sulfur dioxide and solidifies the sulfur dioxide, so that the solid Sulfur works well.

Claims (10)

1. The utility model provides a cement rotary kiln tail gas sulfur dioxide minimum discharge processing apparatus which characterized in that: comprises a raw material stirring tank, a first storage tank, a second storage tank, a vertical mill, a raw material hoister and a flue; the raw material stirring tank is communicated with the first storage tank through a first pipeline, and a first valve is arranged on the first pipeline; the raw material stirring tank is communicated with a second storage tank through a second pipeline, and a second valve is arranged on the second pipeline; the first storage tank is connected with a spray head through a third pipeline, a third valve is arranged on the third pipeline, and the spray head is arranged on the flue; the vertical mill is provided with a feeding port, the second storage tank is connected to the feeding port of the vertical mill through a fourth pipeline, a fourth valve is arranged on the fourth pipeline, a fifth pipeline connected to the feeding end of the raw material hoister is arranged on the fourth pipeline, and a fifth valve is arranged on the fifth pipeline; the third pipeline is provided with a first centrifugal pump, and the fourth pipeline is provided with a second centrifugal pump at the input end side of the fifth pipeline.

2. The ultra-low emission treatment device for tail gas sulfur dioxide of the cement rotary kiln as claimed in claim 1, is characterized in that: and a raw material lifting machine is arranged at a feeding port of the raw material stirring tank.

3. The ultra-low emission treatment device for tail gas sulfur dioxide of the cement rotary kiln as claimed in claim 1, is characterized in that: the volume of the first storage tank is greater than the volume of the second storage tank.

4. The ultra-low emission treatment device for tail gas sulfur dioxide of the cement rotary kiln as claimed in claim 1, is characterized in that: the spray head is arranged on a flue between the C1 grade cyclone cylinder and the C2 grade cyclone cylinder.

5. The rotary cement kiln tail gas sulfur dioxide ultralow emission treatment device as claimed in claim 1 or 4, is characterized in that: the number of the spray heads is 12.

6. The ultra-low emission treatment device for tail gas sulfur dioxide of the cement rotary kiln as claimed in claim 1, is characterized in that: the shell is arranged outside the raw material stirring tank, the first storage tank and the second storage tank.

7. The rotary cement kiln tail gas sulfur dioxide ultralow emission treatment device as claimed in claim 6, is characterized in that: the device also comprises a control valve and a central control operating mechanism for displaying the capacity.

8. The ultra-low emission treatment device for tail gas sulfur dioxide of the cement rotary kiln as claimed in claim 1, is characterized in that: the first pipeline is provided with a third centrifugal pump, and the second pipeline is provided with a fourth centrifugal pump.

9. The rotary cement kiln tail gas sulfur dioxide ultralow emission treatment process is characterized by comprising the following steps of: the method comprises the following steps of treating sulfur dioxide by using a tail gas sulfur dioxide ultralow emission treatment device of the cement rotary kiln, wherein the tail gas sulfur dioxide ultralow emission treatment device of the cement rotary kiln comprises a raw material stirring tank, a first storage tank, a second storage tank, a vertical mill, a raw material hoister and a flue; the raw material stirring tank is communicated with the first storage tank through a first pipeline, and a first valve is arranged on the first pipeline; the raw material stirring tank is communicated with a second storage tank through a second pipeline, and a second valve is arranged on the second pipeline; the first storage tank is connected with a spray head through a third pipeline, a third valve is arranged on the third pipeline, and the spray head is arranged on the flue; the vertical mill is provided with a feeding port, the second storage tank is connected to the feeding port of the vertical mill through a fourth pipeline, a fourth valve is arranged on the fourth pipeline, a fifth pipeline connected to the feeding end of the raw material hoister is arranged on the fourth pipeline, and a fifth valve is arranged on the fifth pipeline; a first centrifugal pump is arranged on the third pipeline, and a second centrifugal pump is arranged on the fourth pipeline and positioned on the input end side of the fifth pipeline;

the process for treating sulfur dioxide by using the ultra-low emission treatment device for the sulfur dioxide in the tail gas of the cement rotary kiln comprises the following steps:

(1) adding the raw materials of 5-50:100 by weight of urea and water into a raw material stirring tank, and mixing the urea and the water through the raw material stirring tank until the urea is completely dissolved to form a sulfur-fixing liquid;

(2) opening the first valve to input the sulfur-fixing liquid in the raw material stirring tank into the first storage tank, and if the second invention is opened, inputting the sulfur-fixing liquid in the raw material stirring tank into the second storage tank;

(3) opening a fourth valve and a second centrifugal pump, and spraying the sulfur fixing liquid in a second storage tank onto the surface of the raw material through a fourth pipeline;

(4) the raw material sprayed with the solid sulfur solution enters a vertical mill to be ground together with the solid sulfur solution, so that the raw material and the solid sulfur solution are uniformly mixed; inputting the ground raw materials into a raw material bin for storage;

(5) raw materials in the raw material bin are lifted to C1 and C2 level cyclones by a raw material lifter; opening the third valve and the first centrifugal pump at the same time, and spraying the sulfur fixing liquid in the first storage tank into the flue through the spray head to oxidize and fix sulfur in the sulfur dioxide;

(6) and the fourth valve is opened and the fifth valve is opened or closed to control the solid sulfur liquid sprayed into the feed end of the raw material hoister to regulate the amount of the discharged sulfur dioxide.

10. The ultra-low emission treatment process for sulfur dioxide in tail gas of a cement rotary kiln as claimed in claim 9, is characterized in that: the device also comprises a control valve and a central control operation mechanism for displaying the capacity, and the valve and the capacity of the raw material stirring tank, the first storage tank and the second storage tank are controlled by the central control operation mechanism.

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