SU1099188A1 - Method of incinerating carbon black production waste gases - Google Patents

Abstract

1. METHOD OF COMBUSTION OF FLUID GASES OF SEDGE PRODUCTION, including burning an axial stream of auxiliary fuel with receiving high-temperature gases, supplying a mixture of flue gases and an oxidant with a tangential stream, mixing these streams to produce a reaction mixture that combines the efficiency of burning gases with the efficiency of burning, with the aim of combining these streams with the efficiency of burning, with the aim of combining these streams with the efficiency of burning, with the aim of combining these flows with the efficiency of burning, with the aim of combining these streams with the efficiency of burning, with the aim of combining these flows with the efficiency of burning, with the goal of combining these streams with the goal of combining the effluent of burning gases and oxidizing gases. , the reaction mixture is kept at 900-1300 C for 0.05 - 0.4 s, after which an additional oxidizing agent is fed into it in the form of one or several streams. 2. The method according to claim 1, wherein the flow of the mixture of flue gases and the oxidizer is supplied to §, a centripetal acceleration of 1000 L 1500 m / s, prior to the supply of an additional oxidant.

Description

;ABOUT

00

oo i The invention relates to methods of generating waste gas from a carbon black production. containing soot particles. The heat carrier formed as a result of burning can be used for wetting of humid soot B sushi. Drum S; heating of raw tachological air, water S of the soot production process, to obtain technical steam in the boiler plant. A known method of burning waste gases includes the supply of fuel to the furnace and the air required for its burners. supply of flue gases and lj required for their afterburning. The disadvantage of this method is the insufficient burnout of soot particles in gases. The closest to the technical essence and the effect achieved is the method of burning exhaust gas from the production line including burning axial fuel. axial flow of air5 tangential flow of waste mixture ha ::; ОЕ К air, reduction of axial .1. {о-7С; and the combustion products of auxiliary, spruce fuel to tangential depletion of mixtures of garbage gas and air inlets, fuel change and burning are the components of the waste gases. The inconsistency of a known method is the insufficient fullness of the burnout of the research institute of soot particles contained in:; . gases. The aim of the invention is to improve the combustion efficiency of the csjSK particles contained in the waste gas from waste production. The goal is achieved by the fact that according to the combustion method; waste of gases produced in sake production, including the burning of the auxiliary flow of auxiliary fuel with obtaining high flow rasoBj and a ngdia.l: n.5 flow of mixture of gases and an oxidizing agent J. mixing of these flows with obtaining the reaction mixture5 the reaction mixture is kept at 900 1300 ° C for 0.05 - O ,, 4 Ca after which it is additionally fed with an oxidizer as one stream of several streams. Waste mixture of gases and an oxidizer is given to the flow of the mixture until an additional 882 oxidant is given a centripetal acceleration 1000 - 1500 m / s. When tangential supply of the mixture of exhaust gases of soot production, containing soot particles, there is an increase in the concentration of soot particles in the near-wall layer, depending on the magnitude of the centripetal acceleration compared to the central area of the furnace device. When a mixture of soot production and oxidant is fed in one tangential flow, required for complete combustion of combustible gas components of exhaust gases and particles cajKHj, uniform distribution of the oxidizing agent in the reaction gas is achieved. B of the furnace section. In the central area of the furnace, combustible gas components. Burn with some excess oxidant. In the near-wall layer, which has a significant content of soot particles, the oxidant is sufficient only to completely or almost completely burn the combustible gas components of the exhaust gases, and for burning soot particles that have less shs4n burning speed, the oxidizer is not enough, the transition of the oxidizer from the central zone of the furnace spaceJ when a single stream of a mixture of exhaust gases of soot production and oxidant j is difficult in the near-wall region, therefore an additional oxidizing agent is introduced into the reaction mixture for organizing efficient burning of soot particles concentrating in the near-wall zone. The invention is intended for burning of exhaust gases from soot production with a calorific value of 350 550 kcal / nm. Gases of this calorific value are stably hot at a temperature of at least 900 ° C, while their theoretical burning temperature is not 1300 C. For energy reasons, it is advisable to burn the exhaust gases in this temperature range, since already with a minimum supply of auxiliary fuel in the exhaust gases, the flammable components are fully combusted. It was experimentally established that, in the temperature range of 900 - 1300 ° C, the soot particles stayed in the air, containing & g B of the waste gas, until the moment of additional oxidizing agent must be 0.05 - 0.4 s. During this period of time, the complete combustion of the combustion products with the exhaust gases and the oxidizing agent occurs and, with the supply of an additional oxidizing agent, ignition and intense burning of the particles occur. With a decrease in the mixing time and induction period of less than 0.05 s, even at 1300 ° C in the furnace space, soot particles do not have time to go through the induction period, and when additional oxidizer is supplied, additional time is required for their ignition. In addition, during cyclone movement in the furnace space, oxidizer molecules penetrate through the layer of soot into the products of complete combustion of the exhaust gases and re-create a situation in which the oxidant for the mountain does not contain soot particles, while in the combustion products in the central the area of the furnace space will be an excess of oxidizing agent. Thus, the premature supply of oxidant leads to undesirable cooling of soot particles, a decrease in their reactivity, undesirable dilution of the combustion products with an oxidizing agent and, as a result, to the subsidence of soot particles. An increase in the residence time of soot particles in gas products having a temperature of 900 - more than 0.4 s before the introduction of an additional oxidizing agent only leads to an irrational increase in the combustion space In addition, the soot particles are long ago. ready for the combustion process with the introduction of the oxidant, with an increase in the time of the Dv of the fermentation in the cyclone furnace, there is a decrease and then complete destruction, with a sufficiently long length of the combustion zone, of the twisting component of the flow of the mixture of exhaust gases and oxidants or their combustion products, which in turn, leads to a gradual dispersion and, ultimately, to a uniform distribution of soot particles in the gas stream, which significantly improves the condition of burnout of soot particles. When tangentially supplying a mixture of soot produced flue gases containing soot particles and oxide bodies, soot particles are separated in the near-wall region. The combustible gas components of the waste gases are burned with the generation of heat, and some of the heat is generated by burning high-energy auxiliary fuel. The particles of haze are affected by radiation heat fluxes from high-temperature gases and hot lining, by convection from combustion products and by direct heat transfer due to a collision with the lining. The soot particles are heated by the action of these heat fluxes at 900–1300 ° C for 0.05–0.4 s, after which an additional oxidizer is supplied. When moving and interacting with a hot refractory lining, ignition and burning of soot particles is much more intense than just when moving in a gas stream. However, the active influence of the refractory lining on the process of burnout of soot particles appears under certain conditions. One of the main conditions is the centripetal acceleration with which soot particles move. It should be 10001500 m / s. With such a value of centripetal acceleration, the furnace lining actively influences the process of burning particles, without requiring significant energy costs. This centripetal acceleration of 1000 - 1500 m / s acts on soot particles in such a way that they separate and move along the hot surface of the lining, being located at a certain distance from each other, and when one of the particles burns, the heat from the combustion is intensely transferred to the adjacent particles. The burning of a layer of soot particles in the proposed method is carried out mainly according to the following principle. The soot particles close to the hot refractory lining by radiation and convective heat exchange with combustion products, as well as radiation heat exchange with the lining and by direct interaction with it rather quickly receive enough heat to ignite them and with the supply of additional oxidizing agent ignite. The resulting products of complete combustion from burning of these particles of soot and soot, located closer to the center of the furnace space, move towards each other. Under the influence of centripetal acceleration, the soot particles with a large mass displace the products of complete combustion from the near-wall layer into the central region of the furnace space, with active heat exchange taking place between them. Particles previously located closer to the center of the furnace space move to the lining and the process resumes. From experiments it was found that when

By reducing centripetal acceleration less than 1000 m / s, some soot particles from the central region of the furnace space do not fall into the peripheral region of the most intense combustion, since it is difficult for them to overcome the resistance of the near-wall layer and therefore do not burn completely.

The increase in centripetal acceleration of more than 1500 m / s is uneconomical, since the degree of growth of energy costs exceeds the degree of growth of particle burnout.

One of the important parameters affecting the efficiency of the combustion process of the flue gas produced with soot particles is the completeness of combustion of auxiliary fuel.

The energy indicators of the combustion process of waste gases from soot production are greatly influenced by the twisting of the mixture of these gases and the oxidizer. By the degree of twist in the present invention is meant the ratio of the tangential component of the mixture velocity to the translational component. The degree of twist for this process should be equal to 1-5. With a decrease in this degree of swirling, the above mentioned effects disappear, contributing to the complete combustion of soot particles in gaseous media containing them. The increase in the degree of twist more than 5 leads to an increase in energy costs.

The method is carried out as follows.

High-temperature products of complete combustion, resulting from the combustion of high-calorie fuel, are fed into the combustion chamber of the furnace space by an axial stream. After preheating the combustion chamber, a mixture of soot containing particles and air is fed into it tangentially. After a certain time in

An additional oxidant in the form of one or several streams is supplied by the tangential flow to the combustion chamber. The products of complete combustion are removed from the combustion device.

About r and meer. An axial flow stream into the combustion chamber is injected with a stream of products of complete combustion of fuel, formed by burning 200 kg / h of diesel fuel. The amount of air used to burn this amount of diesel fuel is 2800 nm / h. Simultaneously with the supply of an axial flow of products of complete combustion of diesel fuel, a mixture of 14,000 nm / h of exhaust gas of the soot-made and 7000 nm / h of air is introduced into the combustion chamber with a tangential flow of 30 m / s. Waste gas temperature

I o / “. - OrV t;

200 C, air - 20 C, pressure

the mixture is 200 kg / m. The calorific value of the waste gases for this case is 400 kcal / nm, the amount of soot in them is 10 g / nm.

In a combustion chamber having a temperature of 1100 ° C, the reacting products move at an average translational velocity of 10.5 m / s over the cross section of the chamber and a centripetal acceleration of 900-1500 n / s.

In tab. Table 1 presents comparative data on the effect of dividing the amount of air required for burning exhaust gases containing soot particles into several streams per degree of soot burnout.

From tab. 1 shows that, all other conditions equal to the prototype of the proposed method, the separation of the total amount of air and the supply of a separate flow through 0.05 s (the minimum possible time) 1500 nm / h of air leads to an increase in soot removal from 57% to 60 % In tab. Fig. 1 also presents data on the effect of the time of introduction of an additional stream on the degree of soot burnout.

In tab. Figure 2 shows the effect of centripetal acceleration on the degree of burnout of soot particles (quantitative values of flue gas consumption, calorific value of flue gases, initial concentration of soot particles in the flue gases, consumption of auxiliary fuel and air on its combustion temperature in the firebox are the same and in Table 1

From tab. As can be seen in Figure 2, with increasing centripetal acceleration compared with the prototype, in the case of supplying all the air without splitting into streams, there is a slight increase in the degree of soot burnout.

In tabl; Figure 3 shows the effect of centripetal acceleration upon a separate supply of oxidant on the degree of burnout of soot particles while maintaining the remaining quantitative values from Table. one.

From tab. 2 that when the additional oxidizing time is supplied 0.2 s after the introduction of exhaust gases and the oxidizing agent, and giving this mixture a centripetal acceleration of 1200 m / s, the best result is achieved - soot particles burn out up to 97% at relatively low energy costs.

The use of the invention in industry will allow reducing emissions of pollutants into the atmosphere, reducing soot deposits on heat transfer surfaces, for example, in boilers, and thereby increasing the efficiency of boiler plants. -

Table 1

Exhaust gas consumption

Air consumption for mixing with waste gases, them / h

Calorie content

waste

gases,

cap / nm

The initial concentration of soot particles in the exhaust gases, g / nm

Additional air flow, nm / h

Consumption of auxiliary fuel (diesel fuel), kg / h

Air consumption for burning auxiliary fuel, nm / h

14,000

14,000

14,000

7,000

7,000

7,000

400

400

ten

ten

1500

1500

1500

200

200

2800

2800

2800

at

1150

1150

Centripetal acceleration m / s

The residence time of the additional oxidant input), with

The burnout rate of combustible gaseous fluids is 5%.

The degree of burnout of soot particles,%

Air flow rate for mixing with waste W –N and gases, nm / h

Centripetal acceleration, m / s

900

The degree of burnout of combustible gas components of S%

The degree of burnout particles SA57, LI 5%

Relative energy

100 saTpaTbij%

Continued table. one

1150

1150

8500

8500

8500

1000

1500

1200

100 100

100

63

70

62

140

103

115

eleven

Air consumption for mixing with waste gases,

Additional air flow, nm / hCentric acceleration,

The residence time before the introduction of additional oxidant, with

The degree of burnout of combustible gas components,%

The degree of burnout of soot particles,%

Relative

energetic

expenses, %

12

1099188

Table 3

7,000

7,000

7,000

1500

1500

1500

1200

1000

1500

0.2

0.2

100

100 95

97

90

110

Claims (2)

1. METHOD FOR COMBUSING EXHAUST GASES OF SOOT PRODUCTION, including burning an axial stream of auxiliary fuel to produce high-temperature gases, supplying a tangential stream of a mixture of exhaust gases and an oxidizing agent, mixing these streams to obtain a reaction mixture, characterized in that, in order to increase the efficiency of particle particle combustion carbon black, the reaction mixture is kept at 900-1300 ° C for 0.05 - 0.4 s, after which an additional oxidizing agent is fed into it in the form of one or more streams. 2. The method of pop. 1, characterized in that a centripetal acceleration of 10001500 m / s * is imparted to the flow of a mixture of exhaust gases and an oxidizing agent before an additional oxidizing agent is supplied. > 'i