CN204768126U - Charcoal kiln flue gas treatment system - Google Patents

Abstract

A charcoal kiln flue gas treatment system, belonging to the technical field of flue gas treatment, including a graded dust removal device connected to the exhaust port of a charcoal kiln, a flue gas discharge chimney, and a power distribution cabinet. The structure of the graded dust removal device includes condensation treatment device, electrostatic adsorption device and the burner installed at the exit of the chimney, the gas inlet and outlet of the condensation treatment device are respectively connected with the exhaust port of the charcoal kiln and the gas inlet of the electrostatic adsorption device, and the gas outlet of the electrostatic adsorption device is connected with the induced draft fan and pipeline Connects to chimney inlet. The key to the electrostatic charcoal kiln flue gas treatment equipment of the present invention is the coordinated use of the three processes and the strict control of the sequence. The condensation device is used as the first process, the electrostatic adsorption device is used as the second process, and the flue gas combustion device As the third process, the flue gas from the charcoal kiln goes through these three processes in sequence, and finally the flue gas from the charcoal kiln is completely purified.

Description

A charcoal kiln flue gas treatment system

technical field

The utility model belongs to the technical field of flue gas treatment, and relates to a charcoal kiln flue gas treatment system, in particular to a charcoal kiln flue gas treatment system.

Background technique

The production and application of charcoal in our country has a history of hundreds of years. The thick smoke from the charcoal kiln causes air pollution and endangers the health and living environment of nearby residents. Analyze the properties of charcoal kiln flue gas:

1. Thermal decomposition of wood: thermal decomposition of wood and its main components

The main components of wood: cellulose, hemicellulose and lignin.

1) Thermal decomposition of cellulose

When the cellulose is heated to 100 degrees, only some physical changes occur, and when the temperature reaches 162 degrees, gas begins to be released. When the temperature reaches 275 degrees, there is a significant exothermic effect. The heat energy released can raise its own temperature to more than 80 degrees. When the temperature rises to 400-475 degrees, almost all the volatiles are separated.

2) Thermal decomposition of hemicellulose

When heated to 180 degrees, thermal decomposition begins, heat release begins at 220 degrees, and reaction ends at 270 degrees.

3) Thermal decomposition of lignin

Lignin is heated to 250 degrees and begins to decompose, producing a small amount of carbon dioxide and carbon monoxide gas. When the temperature rises to 320-340 degrees, it begins to produce a large amount of steam gas products, including acetic acid, wood tar and other lignin decomposition products, and gas contains hydrocarbons. At about 400-450 degrees, the thermal decomposition reaction of lignin is most significant.

2. Charcoal pyrolysis products

1) Solid product: charcoal. Charcoal is a loose, porous black solid. Its specific gravity is 1.4-1.6, volumetric weight is 0.6-0.8, and stacking weight is 0.3.

2) Liquid products: The liquid products of wood carbonization are composed of many different substances, and their yields vary with the type, quality and carbonization conditions of wood. There are more than 180 different substances in the liquid products of wood charring. These substances can be divided into 11 classes: acids, alcohols, esters, ketones, aldehydes, ethers, phenols, lactones, hydrocarbons, carbohydrates and heterocyclic compounds. Generally known as crude wood vinegar, it is divided into clarified wood vinegar and precipitated wood tar. Clarified wood vinegar is a yellow to reddish-brown liquid with a special smell of burnt smoke and a specific gravity of 1.02-1.05, which contains 80%-90% water and 10%-20% organic matter. Precipitated wood tar is a black viscous oily liquid with a specific gravity of 1.01-1.1.

3 The original governance measures:

(1) In order to improve the production environment of workers, charcoal manufacturers use combustion methods to reduce smoke emissions. Combustion method: that is, when the carbon monoxide can meet the combustion conditions in the late stage of charcoal thermal decomposition, it is ignited, and the carbon monoxide is burned to generate carbon dioxide. The disadvantage is that the smoke generated in the early stage of the thermal decomposition reaction cannot be treated.

Chemical formula: 2CO+O ₂ ＝2CO ₂ (condition is ignition)

(2) There are also some other charcoal producers who use the method of spray tower cooling and bag dust removal to solve the flue gas generated in the early stage of charcoal thermal decomposition. The working principle of the spray tower is to use water pump as the power and water as the medium The water is introduced into the spray tower through the pipeline, and under the action of high pressure, the water quickly passes through the pipeline and collides with the nozzle installed at the outlet of the pipeline in the tower to produce tiny mist droplets. The mist droplets collide with the flue gas at high speed when passing through the tower. When it gets bigger and bigger under constant collision, due to its own gravity, it falls into the pool at the bottom of the tower, and the purified flue gas enters the bag filter through the gas outlet and pipe on the top of the tower. Under the microporous structure of the bag, the tiny dust particles in the air and The mist is blocked and captured by the cloth bag fiber, and then passes through the air outlet through the pipe and induced draft fan, and then is discharged through the high chimney.

This design has the following disadvantages:

a. The dust removal efficiency of the spray tower depends on the "liquid-gas ratio" (the ratio of the sprayed water to the flue gas), the water consumption is large, the dust removal efficiency is low, and it is difficult to capture tiny dust particles.

b. After the atomized droplets are sufficiently lowered in the flue gas temperature, the liquefied wood vinegar and tar and other liquid products are captured by water and flow into the pool to cause water pollution.

c. Sewage circulation is bad. After the collision of sewage droplets and high-temperature flue gas, polluted water vapor is easily generated, causing secondary pollution.

d. Tiny dust particles, tar and water vapor are likely to block the pores of the bag and reduce the service life of the bag. After the bag is blocked by tar, it is not easy to clean the dust and regenerate. The filter bag must be replaced regularly, thus increasing the operating cost.

e. Inflammable, poisonous and harmful gases such as carbon monoxide are discharged into the atmosphere, causing air pollution and threatening the living environment of nearby residents.

Therefore, how to solve the pollution-free production of charcoal kilns and improve the living environment of residents, reduce equipment operating costs and the frequency of replacement of consumable materials are the primary principles of the transformation plan.

Utility model content

In order to solve the technical problem that the flue gas produced by the charcoal kiln is difficult to handle and pollute the environment in the prior art, the utility model has invented a charcoal kiln flue gas treatment system, which has the advantages of simple operation, low energy consumption, environmental protection, and can thoroughly purify the flue gas. The characteristics of gas, the technical scheme that the utility model adopts for realizing its purpose is:

A charcoal kiln flue gas treatment system, including a graded dust removal device connected to the exhaust port of the charcoal kiln, a flue gas discharge chimney, and a power distribution cabinet. The structure of the graded dust removal device includes a condensation treatment device, an electrostatic adsorption device, and a The burner at the exit of the chimney, the gas inlet and outlet of the condensation treatment device are respectively connected to the exhaust port of the charcoal kiln and the gas inlet of the electrostatic adsorption device, and the gas outlet of the electrostatic adsorption device is connected to the air inlet of the chimney by means of an induced fan and a pipeline.

The electrostatic adsorption device is a tube-type electrostatic precipitator. The structure of the tubular electrostatic precipitator includes a cylinder body, a gas inlet and a gas outlet opened on the cylinder body, a discharge electrode and a dust collection electrode arranged in the cylinder body, and a set The dust collecting hopper below the dust collecting pole, the dust collecting pole is a group of steel pipes connected to the positive pole of the power distribution cabinet, and the discharge pole is a steel wire suspended in the center of the steel pipe and connected to the negative pole of the power distribution cabinet.

The condensation treatment device includes a box body, a series of tubes fixed inside the box body, an air inlet and an air outlet arranged at both ends of the box body and communicated with the gas outlet by means of the series tubes, and a waste liquid outlet at the bottom of the box body. An air cooling device and a water cooling device are also fixed above the column tubes.

There are two waste discharge ports, which are respectively arranged at the air inlet end and the air outlet end.

The air cooling device is composed of 3 cooling fans, and the 3 cooling fans are evenly distributed above the cabinet of the condensation treatment device.

The water cooling device is arranged above the tubes and below the air cooling device, and includes a nozzle, a pipeline, a water pump and a water tank. One end of the pipeline is connected to the nozzle, the other end is connected to the water pump, and the water pump is connected to the water tank. The water tank is provided with the bottom of the casing.

The beneficial effects of the utility model are: the electrostatic charcoal kiln flue gas treatment system of the utility model, the key lies in the coordinated use of the three processes and the strict control of the sequence, using a condensing device as the first process to condense the flue gas The liquid products of high-temperature gasification such as wood tar, wood vinegar, and water vapor are condensed and recovered by condensation; the electrostatic adsorption device is used as the second process to remove the tiny mist and dust of the liquid products in the condensed flue gas, Electrostatic adsorption is carried out by means of electric capture; then combined with the combustion device at the chimney as the last process of flue gas treatment, combustion is carried out when the carbon monoxide gas reaches the combustion concentration, so as to achieve the effect of thorough purification of charcoal kiln flue gas.

The key of the electrostatic adsorption device in the utility model equipment lies in the distribution of the adsorption electric field. It is composed of a dust collecting electrode composed of positively charged steel pipes arranged vertically and a discharge electrode composed of negatively charged steel wires in the center of the steel pipe. In the uneven electric field formed by the dust collector, the discharge pole is the negative pole, the dust collection pole is the positive pole, and it is charged with a 72 kV high-voltage DC power supply. When the intensity of this electric field increases to a certain value, a negative charge is formed around the discharge electrode. Halo, the ionization of gas molecules is strengthened, resulting in a large number of positive and negative ions, the positive and negative ions are neutralized by the discharge electrode, and the negative ions and free ions are transferred to the dust collecting electrode. When the gas with dust passes through, these negatively charged particles It will constantly encounter and be adsorbed on the dust particles during the movement, so that the dust powder and tiny mist droplets will be charged. The gas is purified on the pipe. When the fine mist accumulates and cannot bear its own weight, it will slide down along the wall of the dust collection pipe under the action of gravity, so as to achieve the purpose of dust removal and regeneration.

The utility model electrostatic charcoal kiln flue gas treatment equipment also has the following advantages:

1. Avoid the pollution caused by harmful gases to workers and nearby residents, and play an important role in protecting the physical and mental health of workers and reducing the investment in environmental protection projects.

2. The structure of the equipment is simple and easy to operate, the maintenance cost is low, there is no need to replace wearing parts, no secondary pollution, and the waste of water resources is reduced.

3. Low energy consumption. The fan adopts frequency conversion control to effectively reduce energy consumption. The high-voltage power supply uses ordinary 380V/220V civilian electricity to convert it from a high-voltage package. The voltage is high and the current is low, and the energy consumption is low (about several hundred watts).

4. The collected liquid products such as wood tar and wood vinegar can be recycled and reused.

(1) Wood tar --- is an organic compound containing hydrocarbons, acids, and phenols. It is mainly used as a disinfectant and preservative. After processing, creosote, antipolymerization agent, and flotation agent can be obtained Foaming agent, wood asphalt and other products; it can also be used in medicine, synthetic rubber and metallurgy and other departments. It is a chemical raw material with very high economic value.

(2) Wood vinegar--an acidic liquid with a pH of about 3 with acetic acid as the main component, which is very similar in composition and color to table vinegar, and is refined into wood acetic acid by different methods. Simply put, it is obtained by liquefying the smoke emitted during the process of making wood into charcoal. Therefore, wood vinegar is obtained by carbonizing trees and condensing the energy in wood into gas. It contains K, Ca, Mg, Zn , Ge, Mn, Fe and other minerals, in addition to vitamin B1 and B2, general wood vinegar: agricultural, feed, industrial. Initial distillation of wood vinegar: for skin management (atopic skin, beriberi, etc.), second distillation of wood vinegar: as food additives, beverages, etc., agricultural use can restore soil fertility, improve cultivation, and save chemical pesticides , chemical fertilizers, restore moisture and other effects.

Description of drawings

Fig. 1 is a structural schematic diagram of a charcoal kiln flue gas treatment system of the present invention.

Fig. 2 is an enlarged view of part A in Fig. 1 .

In the drawings, 1 represents the condensation treatment device, 1-1 represents the box body, 1-2 represents the tube array, 1-3 represents the air inlet, 1-4 represents the gas outlet, 1-5 represents the waste liquid outlet, 1- 6 represents air cooling device, 1-7 represents water cooling device, 1-8 represents water tank, 2 represents electrostatic adsorption device, 2-1 represents cylinder, 2-2 represents gas inlet, 2-3 represents gas outlet, 2-4 represents Discharge electrodes, 2-5 represent dust collectors, 3 represent chimneys, 4 represent burners, 5 represent induced draft fans, and 6 represent pipes.

Detailed ways

In order to solve the technical problem that the flue gas produced by the charcoal kiln is difficult to handle and pollute the environment in the prior art, the utility model has invented a charcoal kiln flue gas treatment system, which has the advantages of simple operation, low energy consumption, environmental protection, and can thoroughly purify the flue gas. The characteristics of gas, the utility model will be further described below in conjunction with specific embodiments.

In the utility model, the power supply of the charcoal kiln flue gas treatment system is provided by the power distribution cabinet, and the power distribution cabinet is composed of the power distribution box and the start and stop buttons installed on the control panel of the power distribution box and the high-voltage direct current installed in the power distribution box. It is composed of power supply, oxygen sensor controller, air cooling device contactor, water cooling device contactor and oxygen sensor installed on the pipeline at the flue gas inlet. Among them, the start and stop buttons on the control panel of the distribution box are connected with the action contacts of the air-cooling device contactor and the water-cooling device contactor inside the distribution box through the control cable, and the contactors of the air-cooling device contactor and the water-cooling device contactor are The output ends of the three-phase power supply are respectively connected to three axial flow fans of the air-cooling device and one water pump of the water-cooling device on the tubular condenser through three-phase cables. The positive and negative poles of the high-voltage DC power supply inside the distribution box pass through the cable and the steel pipe (dust collector) with positive "+" charge vertically arranged in the tubular electrostatic precipitator and the steel wire with negative "-" charge in the center of the steel pipe ( discharge electrodes) are connected separately.

The specific process is as follows: see Figure 1, the direction of the arrow indicates the flow direction of the flue gas, the flue gas outlet on the charcoal kiln is controlled by a sealed butterfly valve to prevent air from entering, when the temperature in the kiln reaches the thermal decomposition reaction conditions, open the control butterfly valve when flue gas is generated , press the start button on the power distribution cabinet to connect the whole system to the power supply and start working. The flue gas is driven by the induced draft fan, and a negative pressure is generated at the air inlet of the induced draft fan, forcing the flue gas in the charcoal kiln to pass through the condensation treatment device from the charcoal kiln outlet. The air inlet 1-3 of 1 enters the column tube 1-2. When the flue gas passes through the column tube 1-2 of the condensation treatment device, because the column tube 1-2 has a large cross-sectional area of the flue gas, the flue gas passes through the condensation treatment device. The air inlet 1-3 of the device 1 flows slowly toward the air outlet 1-4, and under the forced cooling of the air cooling device 1-6 and the water cooling device 1-7 above the outside of the tube wall, the air in the tube 1-2 The high-temperature flue gas continuously exchanges heat with the tube wall. When the tiny liquid product in the flue gas reaches the condensation temperature, it drops into the tube 1-2 and passes through the lower part of the air inlet 1-3 and the gas outlet 1- The waste liquid port 1-5 below 4 flows out and collects.

When the flue gas that condenses and removes the liquid product enters the electrostatic adsorption device 2 through the gas outlet 1-4 of the condensation treatment device 1 and the pipeline, due to the large cross section of the cylinder body 2-1 of the electrostatic adsorption device 2, the flue gas slowly enters the adsorption electric field , the discharge electrode 2-4 and the dust collection electrode 2-5 of the electric field are driven by the positive and negative electrodes of the high-voltage power supply, the air in the electric field is ionized, a negative corona is formed around the discharge electrode 2-4, and the particle molecules in the air are ionized The effect is strengthened, and a large number of positive and negative ions are produced. The positive and negative ions are neutralized by the discharge electrode, and the negative ions and free ions are transferred to the dust collecting electrode 2-5. When the flue gas with dust and residual liquid droplets passes through, these negatively charged The particles will constantly encounter and be adsorbed on the dust particles during the movement, so that the dust powder will be charged. The gas is purified on the dust plate. When there are more and more dust and liquid droplets on the dust collecting plate, due to the gravity of the liquid droplets and the dust, they drop into the sedimentation tank below the electrostatic adsorption device 2, and finally the liquid in the sedimentation tank passes through The pipes connecting the bottom of the sedimentation tank to the outside flow out for collection.

The flue gas purified by the electrostatic adsorption device 2 passes through the induced draft fan 5 and enters the chimney 3 connected to the outlet of the induced draft fan 5, and finally the combustible gas containing CO is ignited and burned by the burner 4 installed at the exit of the chimney 3, so as to reach the smoke. The purpose of thoroughly purifying the air.

Claims (6)

1. a charcoal kiln flue gas governing system, comprise the classification cleaner be connected with charcoal kiln exhaust outlet, fume emission chimney (3) and power distribution cabinet, it is characterized in that: described classification cleaner structure comprises condensation process device (1), electrostatic adsorption device (2) and be arranged at the burner (4) in chimney (3) exit, entering of condensation process device (1), gas outlet respectively with charcoal kiln exhaust outlet, the gas access of electrostatic adsorption device (2) connects, the gas vent of electrostatic adsorption device (2) is connected with chimney (3) air inlet with pipeline (6) by air-introduced machine (5).

2. a kind of charcoal kiln flue gas governing system according to claim 1, it is characterized in that: described electrostatic adsorption device (2) is tubular electrostatic precipitator, this tubular electrostatic precipitator structure comprises cylindrical shell (2-1), the gas access (2-2) that cylindrical shell (2-1) is offered and gas vent (2-3), be arranged at the discharge electrode (2-4) in cylindrical shell (2-1) and dust collecting electrode (2-5), be arranged at the dust hopper of dust collecting electrode (2-5) below, dust collecting electrode (2-5) is the one group of steel pipe be connected with power distribution cabinet positive pole, discharge electrode (2-4) is for being suspended to steel pipe center and the steel wire be connected with power distribution cabinet negative pole.

3. according to claim a kind of charcoal kiln flue gas governing system, it is characterized in that: described condensation process device (1) comprises casing (1-1), be fixed on the inner tubulation (1-2) of casing (1-1), be arranged at casing (1-1) two ends and the air inlet (1-3) be communicated with by tubulation (1-2) and gas outlet (1-4) and the removal waste fluid mouth (1-5) being positioned at casing (1-1) bottom, is also fixed with air cooling equipment (1-6) and water cooling plant (1-7) in tubulation (1-2) top.

4. a kind of charcoal kiln flue gas governing system according to claim 3, is characterized in that: described removal waste fluid mouth (1-5) is provided with 2, is arranged at air inlet end and gas outlet end respectively.

5. a kind of charcoal kiln flue gas governing system according to claim 3, is characterized in that: described air cooling equipment (1-6) is made up of 3 cooling fans, and 3 cooling fans are evenly distributed on the top of condensation process device box.

6. a kind of charcoal kiln flue gas governing system according to claim 3, it is characterized in that: described water cooling plant (1-7) is arranged at tubulation (1-2) top, air cooling equipment (1-6) below, comprise shower nozzle, pipeline, water pump and water tank, described pipeline one end is connected with shower nozzle, the other end is connected with water pump, described water pump is connected with water tank (1-8), and described water tank (1-8) arranges casing (1-1) bottom.