CN209840102U

CN209840102U - Low-nitrogen kiln burner

Info

Publication number: CN209840102U
Application number: CN201920683654.7U
Authority: CN
Inventors: 丁光学
Original assignee: Foshan Azure Environmental Protection Equipment Co Ltd
Current assignee: Foshan Azure Environmental Protection Equipment Co Ltd
Priority date: 2019-05-13
Filing date: 2019-05-13
Publication date: 2019-12-24
Anticipated expiration: 2029-05-13

Abstract

The utility model discloses a low nitrogen kiln nozzle, the initial section of a spout section of thick bamboo of this nozzle has radially falls into in the interior outer three-layer chamber way, wherein outer chamber says the combustion-supporting wind of intercommunication, central chamber says the combustion-supporting wind of intercommunication secondary, the intercommunication gas is said to the middle level chamber, the end that the middle level chamber was said is equipped with the flame projecting lid that keeps off the outer chamber of lid and the middle level chamber is said, flame projecting is covered and is laid the gas orifice that once combustion-supporting wind orifice and radially link up, central chamber says that keep away from flame projecting lid and extend one section, and the end establishes the combustion-supporting wind shower nozzle of secondary, outer chamber is said and is installed the some firearm that the ignition utmost point stretched out the flame projecting lid. The utility model discloses low nitrogen kiln nozzle sets up twiceAnd (3) supporting combustion, namely firstly enabling the primary combustion to be combusted in a reducing atmosphere with 80% of theoretical air amount to generate a reduction reaction without generating nitrogen oxides basically, and then carrying out secondary combustion in an oxidizing atmosphere to enable the fuel gas to be completely combusted. Practice shows that the nitrogen oxide content of the kiln of the utility model is less than 50mg/Nm³。

Description

Low-nitrogen kiln burner

Technical Field

The utility model belongs to the technical field of the kiln nozzle technique and specifically relates to indicate to realize low nitrogen burning kiln nozzle.

Background

Through the development and opening of forty years, China has become the largest manufacturing industry big country all over the world, and the global share of the manufacturing industry of China is more than five percent in the near futureAnd ten. While the manufacturing industry is developing vigorously, people pay more and more attention to the problem of environmental pollution, and a series of laws and regulations are timely issued to the environment management in the party and the country. As a branch of the manufacturing industry, the ceramic industry also carries out vigorous treatment on environmental pollution, wherein sulfur dioxide and pollutants thereof are effectively treated, and a plurality of enterprises can even reduce the emission of the sulfur dioxide to 10mg/Nm³The following; the discharge amount of nitrogen oxides is not well controlled, and the common practice of various industries at present is not more than four types: the denitration efficiency of the SNCR method of spraying ammonia water (or urea solution) at high temperature in the furnace is lower than 50 percent; the denitration efficiency is lower than 80 percent by an SCR method of spraying ammonia water (or urea solution) at low temperature under the action of a catalyst; the denitration efficiency of the ozone oxidation method is about 90 percent; the denitration efficiency is about 90 percent by a sodium hypochlorite oxidation method; however, the four methods have respective obvious defects, the SNCR method has low denitration efficiency, the SCR method has strict requirements on flue gas temperature, a catalyst is easy to lose efficacy due to blockage, the ozone method has high cost, ozone is easy to escape to cause secondary pollution, and the sodium hypochlorite method has high cost, and reaction products of nitrate, nitrite, hydrochloride and even sulfate are substances which are not easy to treat. In a strict sense, no stable and good method with low running cost exists for removing the nitrogen oxide, so that people want to solve the problem of the nitrogen oxide fundamentally by thinking on the source of generating the nitrogen oxide, namely combustion.

Specifically, in the ceramic industry, different strict requirements are imposed on temperature and atmosphere at different stages in the firing process of ceramic products, which is shown in that the temperature and atmosphere in the kiln are different in the length direction of the kiln, and the difference between the temperature and the atmosphere is completely achieved by adjusting a burner. Especially ceramic products require a strong oxidizing atmosphere inside the kiln, which significantly increases the nitrogen oxide production. In order to save energy consumption, the kilns develop towards the direction of increasing length and increasing width, two hundred to five hundred burners used by each kiln are different, gas (natural gas or generator gas) of the hundreds of burners is controlled in groups (most of the burners are arranged in one group every eight burners), and the consumption of the gas (the opening degree of a valve) is distributed between five percent and eighty percent; the amount of air (combustion air) for combustion is controlled by fans (basically two combustion fans per kiln). This results in the use of the same amount of air (combustion air) for burners of different opening degrees, which is a common phenomenon, and objectively results in the combustion of gas in an oxidizing atmosphere, and the production of nitrogen oxides is inevitably high.

In fact, the generation amount of nitrogen oxides in the ceramic firing kiln is mostly 200-450 mg/Nm³In which the nitrogen oxides are less than 300mg/Nm³The burners of the kiln adopt more or less the combustion principle of the burners of the kiln from SCM italy, as shown in figure 1. The combustion-supporting air jet orifice is divided into a primary combustion-supporting air jet orifice 1 which is directly injected and a secondary combustion-supporting air jet orifice 2 which is obliquely injected in an inverted cone at a combustion part (a nozzle) of the burner, so that a small part of air participates in secondary combustion, and a large part of air participates in primary combustion. The method can properly reduce the generation amount of nitrogen oxides, but has the fatal defects that air participating in primary combustion and secondary combustion is conveyed by the same pipeline and cannot be separately adjusted, particularly, when the pressure of combustion-supporting air is low (about 500Pa is normal), the inverted cone injection effect is not ideal, the amount of air sent to the center of a combustion chamber is very small, the designed use working condition cannot be reached, particularly, complete combustion is often completed by one-time combustion in a ceramic kiln with strong oxidizing property (the combustion-supporting air quantity is generally overlarge), and therefore, the effect of reducing the content of the nitrogen oxides is not obvious.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a can improve combustion efficiency, reduce the energy consumption, can show the kiln nozzle that reduces nitrogen oxide content again.

The technical scheme adopted for solving the technical problems is as follows: the utility model provides a low nitrogen kiln nozzle, the initial section of the spout section of thick bamboo of this nozzle has radially to divide into three layers chamber way outside the interior, characterized in that: the outer layer cavity channel is communicated with primary combustion-supporting air, the central cavity channel is communicated with secondary combustion-supporting air, the middle layer cavity channel is communicated with fuel gas, the tail end of the middle layer cavity channel is provided with a flame spraying cover for blocking the outer layer cavity channel and the middle layer cavity channel, primary combustion-supporting air spray holes and radially communicated fuel gas spray holes are distributed in the flame spraying cover, the central cavity channel is far away from the flame spraying cover and extends for a section, the tail end of the central cavity channel is provided with a secondary combustion-supporting air spray head, and the outer layer cavity channel is provided with an igniter with an ignition electrode extending.

On the basis, the primary combustion-supporting air jet holes are set to be cyclone jet holes.

Adopt the utility model discloses the beneficial effect who brings: based on the theory of combustion, i.e., the combustion atmosphere goes from reducing to oxidizing, the combustion produces more and more nitrogen oxides and faster. The utility model discloses low nitrogen kiln nozzle sets up twice combustion-supporting, and the amount of wind of the twice combustion-supporting wind of accessible accurate control makes earlier a burning burn under theoretical air quantity 80%'s reducing atmosphere, takes place reduction reaction, does not produce nitrogen oxide basically, then carries out the postcombustion under the oxidizing atmosphere again, makes the gas burn completely. In contrast, the amount of air involved in the secondary combustion is much smaller than the amount of air involved in the primary combustion, and the total amount of nitrogen oxide produced is greatly reduced. Practice shows that the nitrogen oxide content of the kiln of the utility model is less than 50mg/Nm³。

Adopt the utility model discloses, the enterprise neither needs investment denitration equipment, does not have the denitration working costs, can also make future nitrogen oxide's national emission standard further reduction, can reduce greenhouse effect, effectively reduces the haze.

Drawings

FIG. 1 is a schematic diagram of a nozzle in a kiln burner of SCM corporation, Italy;

FIG. 2 is a schematic structural view of the low-nitrogen kiln burner of the present invention;

fig. 3 is a schematic structural view of the middle flame-spraying cover of the present invention.

Detailed Description

As shown in fig. 2 and 3, the burner of the low-nitrogen kiln comprises a starting section of a nozzle barrel 1 which is provided with three layers of cavity channels radially divided into an inner layer, a middle layer and an outer layer, wherein an outer layer cavity channel 2 is communicated with primary combustion-supporting air, a central cavity channel 3 is communicated with secondary combustion-supporting air, a middle layer cavity channel 4 is communicated with fuel gas, a flame cap 5 for blocking the outer layer cavity channel 2 and the middle layer cavity channel 4 is arranged at the tail end of the middle layer cavity channel 4, primary combustion-supporting air spray holes 5.1 and radially communicated fuel gas spray holes 5.2 are distributed on the flame cap 5, the central cavity channel 3 extends a section away from the flame cap 5, the tail end of the central cavity channel is provided with a secondary combustion-supporting air spray head 3.1, and an igniter 6 with an ignition electrode extending out of.

Specifically, the outer-layer cavity 2, the middle-layer cavity 4 and the central cavity 3 can be formed by separating three layers of sleeves, the outer-layer cavity sleeve is the spraying cylinder 1, the middle-layer cavity sleeve 7 is sleeved in the spraying cylinder 1, and the central cavity sleeve 8 is sleeved in the middle-layer cavity sleeve 7. The starting end of the spray tube 1 is sleeved with a sleeve seat 9 for fixing the burner, the extension end of the spray tube forms a flame spray opening 1.1 with a tapered closing-in, and the sleeve seat 9 is provided with a lateral interface 9.1 communicated with primary combustion-supporting air. The tail end of the middle-layer cavity sleeve 7 is sleeved with the flame-throwing cover 5, the starting end is sleeved with the gas distribution cover 10, and the gas distribution cover 10 is provided with a lateral connector 10.1 communicated with gas. The initial end of the central cavity sleeve 8 is communicated with secondary combustion-supporting air, and the tail end is connected with a section of spray pipe 11 with a spray head 3.1 to be used as an extension section. It is known that the spray head 3.1 is provided with densely distributed spray holes at the blind end of the spray pipe 11.

The gas enters from the side interface 10, enters the middle layer cavity channel 4 through the gas distributing cover 9, is radially sprayed out from the gas spraying hole 5.2 of the flame spraying cover 5, directly impacts on the inner wall of the spraying cylinder 1 and is rapidly dispersed. The primary combustion-supporting air enters the outer-layer cavity 2 from the lateral interface 9.1 of the sleeve seat 9, is directly sprayed out from the primary combustion-supporting air spray hole 5.1 of the flame spray cover 5, is fully mixed with dispersed fuel gas, and is ignited by the igniter 6 to perform primary combustion. The air quantity of the primary combustion-supporting air is accurately controlled through the air quantity control system, so that the primary combustion is performed in the reducing atmosphere with the theoretical air quantity of 80%. The secondary combustion-supporting air is sprayed out of the spray head 3.1 in the central cavity sleeve 8, collides with the inner wall of the spray cylinder 1, is dispersed, is fully mixed with the residual combustible gas in the primary combustion, ensures that the secondary combustion is carried out under the oxidizing atmosphere by controlling the air quantity of the secondary combustion-supporting air, and ensures complete combustion.

In order to further improve the combustion effect, the primary combustion-supporting air nozzle holes 5.1 are cyclone-type nozzle holes, that is, the nozzle holes are impeller-groove type, as shown in fig. 2, so that the combustion-supporting air is rotationally injected and is more fully mixed with the fuel gas, thereby further improving the combustion efficiency.

Claims

1. The utility model provides a low nitrogen kiln nozzle, the initial section of the spout section of thick bamboo of this nozzle has radially to divide into three layers chamber way outside the interior, characterized in that: the outer layer cavity channel is communicated with primary combustion-supporting air, the central cavity channel is communicated with secondary combustion-supporting air, the middle layer cavity channel is communicated with fuel gas, the tail end of the middle layer cavity channel is provided with a flame spraying cover for blocking the outer layer cavity channel and the middle layer cavity channel, primary combustion-supporting air spray holes and radially communicated fuel gas spray holes are distributed in the flame spraying cover, the central cavity channel is far away from the flame spraying cover and extends for a section, the tail end of the central cavity channel is provided with a secondary combustion-supporting air spray head, and the outer layer cavity channel is provided with an igniter with an ignition electrode extending.

2. The low nitrogen kiln burner of claim 1, wherein: the primary combustion-supporting air spray holes are set as cyclone spray holes.