CN220708043U - Roller kiln structure for realizing low nitrogen oxide emission - Google Patents

Abstract

The utility model relates to the technical field of building ceramic production equipment, in particular to a roller kiln structure for realizing low nitrogen oxide emission, which comprises a roller kiln, a burner and a combustion air system; the roller kiln sequentially comprises a preheating zone, a firing zone, a quenching zone, a slow cooling zone and a fast cooling zone which are communicated with each other from the kiln head to the kiln tail, and a plurality of burners are arranged in the firing zone; the combustion-supporting air system comprises a waste heat exhaust pipe, a heating box, an induced draft fan and a combustion-supporting air component which are sequentially connected through pipelines; the combustion-supporting air assemblies are provided with a plurality of groups, and the outlet of each group of combustion-supporting air assemblies is connected with the combustion-supporting air inlets of the plurality of burners; the interval between the burners at the heating front section is uniform, and the interval between the adjacent burners is 0.5-0.6 m. The roller kiln structure for realizing low nitrogen oxide emission is beneficial to reducing the nitrogen oxide content in the flue gas, and can realize direct emission of the flue gas on the premise of not using a flue gas denitrification device.

Description

Roller kiln structure for realizing low nitrogen oxide emission

Technical Field

The utility model relates to the technical field of building ceramic production equipment, in particular to a roller kiln structure for realizing low nitrogen oxide emission.

Background

Roller kiln is a main device for realizing batch production of building ceramic products, and has the characteristics of large yield and high energy utilization efficiency, thus being widely applied to ceramic industries and the like. The firing temperature of ceramic products is generally up to 1000 ℃, and a large amount of excess oxygen exists in a high-temperature area due to the large excess air coefficient of a combustion system, so that a large amount of thermal nitrogen oxides can be generated in normal operation. With the increasing of the governments of the state and the local government on the treatment of atmospheric pollutants, the atmospheric pollutant emission standard of the ceramic industry will be more and more strict, and the emission control of nitrogen oxides has become one of the important problems to be solved in the industry.

At present, an emission reduction technology such as a flue gas denitrification device is generally adopted by an industrial kiln to reduce the content of nitrogen oxides in flue gas generated by the kiln so as to realize standard emission of the flue gas. However, the above means requires additional equipment to perform secondary treatment on the flue gas generated by the kiln, which not only increases the production cost and time of ceramic products, but also causes energy waste if the flue gas discharged from the kiln contains a large amount of heat, and the flue gas is directly discharged into the air after denitrification.

Disclosure of Invention

The utility model aims to provide a roller kiln structure for realizing low nitrogen oxide emission, which is favorable for reducing the nitrogen oxide content in flue gas, and can realize direct emission of the flue gas on the premise of not using a flue gas denitrification device so as to overcome the defects in the prior art.

To achieve the purpose, the utility model adopts the following technical scheme:

a roller kiln structure for realizing low nitrogen oxide emission comprises a roller kiln, a burner and a combustion air system; the roller kiln sequentially comprises a preheating zone, a firing zone, a quenching zone, a slow cooling zone and a fast cooling zone which are communicated with one another from the kiln head to the kiln tail; the burners are arranged in a plurality, and the burners are arranged in the sintering zone;

the combustion-supporting air system comprises a waste heat exhaust pipe, a heating box, an induced draft fan and a combustion-supporting air component which are sequentially connected through pipelines; the inlet of the waste heat exhaust pipe is positioned at the upper part of the roller rod of the slow cooling belt, the waste heat exhaust pipe is used for sucking waste heat flue gas of the slow cooling belt into the combustion air system, and the heating box is used for heating the waste heat flue gas; the combustion-supporting air assemblies are provided with a plurality of groups, and the outlet of each group of the combustion-supporting air assemblies is connected with the combustion-supporting air inlets of a plurality of burners;

the firing zone comprises a heating front section and a heating middle and rear section which are communicated with each other;

the combustion-supporting air assemblies are at least provided with two groups, the outlets of one group of the combustion-supporting air assemblies are connected with the combustion-supporting air inlets of the plurality of burners positioned at the front heating section, and the outlets of the other group of the combustion-supporting air assemblies are connected with the combustion-supporting air inlets of the plurality of burners positioned at the middle and rear heating section;

the interval between the burners at the heating front section is uniform, and the interval between two adjacent burners is 0.5-0.6 m.

Preferably, the interval between the plurality of burners located at the middle and rear stage of the heating is uniform, and the interval between two adjacent burners is 1.0-1.2 m.

Preferably, a plurality of the burners are distributed at the upper and lower parts of the roller rod of the firing belt;

the combustion-supporting air assembly comprises a drainage fan, a shunt tube, an upper output main pipe and a lower output main pipe, and an outlet of the induced draft fan, the drainage fan and an inlet of the shunt tube are sequentially connected; the shunt tubes include first delivery outlet and second delivery outlet, first delivery outlet the last delivery manifold is located the combustion-supporting wind entry of the combustor of the roller stick upper portion in burning zone communicates in proper order, the second delivery outlet the lower delivery manifold is located the combustion-supporting wind entry of the combustor of the roller stick lower part in burning zone communicates in proper order.

Preferably, the drainage fan further comprises a cold air inlet, and the cold air inlet is communicated with the atmosphere.

Preferably, the preheating furnace further comprises a flue gas exhaust system, wherein the flue gas exhaust system is arranged in the preheating zone;

the flue gas exhaust system comprises a flue gas exhaust pipe and a flue gas exhaust machine, wherein an inlet of the flue gas exhaust pipe is positioned on the upper part of a roller rod of the preheating zone, an inlet of the flue gas exhaust machine is connected with an outlet of the flue gas exhaust pipe, and the flue gas exhaust machine is used for exhausting flue gas in the roller kiln through the flue gas exhaust pipe.

Preferably, the outlet of the smoke extractor is interconnected with the atmosphere.

The technical scheme provided by the embodiment of the utility model can have the following beneficial effects:

the waste heat exhaust pipe is used for pumping waste heat flue gas of the slow cooling zone into the combustion-supporting air system, and then the waste heat flue gas is secondarily heated by the heating box to serve as combustion-supporting air of the burner, so that on one hand, the recycling of waste heat can be realized, the loss and consumption of energy sources are reduced, on the other hand, the nozzle temperature of the burner can be increased to 120-300 ℃ from the existing 50-100 ℃, the air excess coefficient in the kiln can be reduced to a certain extent through the high-temperature heated combustion-supporting air, the kinetic energy generated by the combustion of the burner is increased, and therefore the high-speed flue gas can quickly enter the kiln, and the nitrogen can be effectively prevented from generating nitrogen oxides due to the fact that the residence time of the nitrogen in the burner area is shorter.

The roller kiln is additionally provided with a plurality of groups of combustion-supporting air assemblies, and the outlet of each group of combustion-supporting air assemblies is connected with the combustion-supporting air inlets of a plurality of burners, so that the combustion-supporting air inlets of all the burners in the firing zone are connected with the outlet of the combustion-supporting air assemblies, the full combustion of the burners is ensured, and meanwhile, the excessive air in the kiln can be reduced, and the generation of nitrogen oxides is reduced.

Drawings

Fig. 1 is a schematic structural view of a roller kiln structure for realizing low nitrogen oxide emission according to the utility model.

Fig. 2 is an enlarged view at a in fig. 1.

Wherein: roller kiln 1, preheating zone 11, firing zone 12, heating front section 121, heating middle and rear section 122, quenching zone 13, slow cooling zone 14, burner 2, combustion air system 3, waste heat exhaust pipe 31, heating box 32, induced draft fan 33, combustion air assembly 34, drainage fan 341, shunt tubes 342, upper output header 343, lower output header 344, cold air inlet 345, flue gas exhaust system 4, flue gas exhaust pipe 41, and smoke extractor 42.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

The technical scheme provides a roller kiln structure for realizing low nitrogen oxide emission, which comprises a roller kiln 1, a burner 2 and a combustion air system 3; the roller kiln 1 sequentially comprises a preheating zone 11, a firing zone 12, a quenching zone 13, a slow cooling zone 14 and a fast cooling zone (not shown in the figure) which are communicated with each other from the kiln head to the kiln tail; a plurality of the burners 2 are provided, and the plurality of the burners 2 are installed inside the firing zone 12;

the combustion-supporting air system 3 comprises a waste heat exhaust pipe 31, a heating box 32, an induced draft fan 33 and a combustion-supporting air component 34 which are sequentially connected through pipelines; the inlet of the waste heat exhaust pipe 31 is positioned at the upper part of the roller rod of the slow cooling belt 14, the waste heat exhaust pipe 31 is used for pumping waste heat flue gas of the slow cooling belt 14 into the combustion air system 3, and the heating box 32 is used for heating the waste heat flue gas; the combustion-supporting air assemblies 34 are provided with a plurality of groups, and the outlet of each group of the combustion-supporting air assemblies 34 is connected with the combustion-supporting air inlets of a plurality of the burners 2, so that the combustion-supporting air inlets of all the burners 2 in the firing zone 12 are connected with the outlet of the combustion-supporting air assemblies 34;

the firing belt 12 includes a heating front section 121 and a heating middle rear section 122 which are communicated with each other;

the combustion-supporting air assemblies 34 are provided with at least two groups, wherein the outlets of one group of the combustion-supporting air assemblies 34 are connected with the combustion-supporting air inlets of the plurality of burners 2 positioned at the heating front section 121, and the outlets of the other group of the combustion-supporting air assemblies 34 are connected with the combustion-supporting air inlets of the plurality of burners 2 positioned at the heating middle and rear sections 122;

the plurality of burners 2 positioned in the heating front section 121 are uniformly spaced, and the interval between two adjacent burners 2 is 0.5-0.6 m.

In order to reduce the content of nitrogen oxides in the flue gas, the technical scheme provides a roller kiln structure for realizing low nitrogen oxide emission, which is shown in figures 1-2 and comprises a roller kiln 1, a combustor 2 and a combustion air system 3. In the existing ceramic firing process, most of combustion-supporting air used by the kiln is natural air, and when the air at normal temperature is sent into the kiln, a considerable part of heat is absorbed, so that heat loss in the kiln can be caused, and the energy consumption is increased; meanwhile, in the conventional roller kiln, the waste heat flue gas of the ceramic product positioned in the slow cooling zone 14 is generally discharged out of the kiln directly through a fan, but because the waste heat flue gas contains a large amount of heat, if the waste heat flue gas is directly discharged into the air, the waste of energy sources can be caused, and if the heat in the flue gas is used for preheating combustion air, the heat loss in the kiln can be reduced, and the consumption of energy sources can be reduced.

Therefore, in order to solve the above problems, the solution firstly uses the waste heat exhaust pipe 31 to pump the waste heat flue gas of the slow cooling belt 14 into the combustion air system 3, and then uses the waste heat flue gas as the combustion air of the burner 2 after being secondarily heated by the heating box 32, on one hand, the recycling of the waste heat can be realized, the loss and consumption of energy can be reduced, on the other hand, the nozzle temperature of the burner 2 can be increased from the existing 50-100 ℃ to 120-300 ℃, the air excess coefficient in the kiln can be reduced to a certain extent by the high-temperature heated combustion air, the kinetic energy generated by the combustion of the burner 2 can be increased, so that the high-speed flue gas can quickly enter the kiln, and the nitrogen oxides can be effectively prevented from being generated because the residence time of the nitrogen in the burner 2 area is shorter.

Furthermore, the conventional roller kiln combustion air system is generally only provided with one set, namely a combustion air blower and a main combustion air duct, and the main combustion air duct extends from the tail section to the beginning section of the sintering belt 12, so that the structure has serious design defects, and the wind pressure of the combustion air is large at the tail section of the sintering belt 12, but insufficient wind pressure of the combustion air can occur at the beginning section of the sintering belt 12. If the air outlet pressure of the combustion-supporting air system is increased, when the combustion-supporting pressure of the beginning section of the burning zone 12 is ensured, the combustion-supporting air pressure of the end section of the burning zone 12 is higher, so that excessive oxygen in the end section enters the kiln, the flue gas amount is increased, the fuel consumption is higher, and finally more nitrogen oxides are generated.

Therefore, in order to more flexibly configure the combustion air pressure of the burners 2 in each area in the firing zone 12, the scheme adds a plurality of groups of combustion air assemblies 34 in the roller kiln 1, and the outlet of each group of combustion air assemblies 34 is connected with the combustion air inlets of a plurality of burners 2, so that the combustion air inlets of all the burners 2 in the firing zone 12 are connected with the outlets of the combustion air assemblies 34, thereby ensuring the full combustion of the burners, reducing the excessive air in the kiln and reducing the generation of nitrogen oxides.

In order to control the running cost of the roller kiln structure and reduce the generation of nitrogen oxides, at least two groups of combustion air assemblies 34 are arranged, and combustion air is respectively provided for the burner 2 positioned at the beginning section (namely the heating front section 121) of the firing zone 12 and the burner 2 positioned at the tail section (namely the heating middle and rear section 122) of the firing zone 12 so as to balance the air outlet pressure of the combustion air assemblies 34.

In addition, since the firing temperature of the heating front section 121 of the firing zone 12 is generally 700-1100 ℃, in order to further reduce the generation of nitrogen oxides in the kiln, the interval between two adjacent burners 2 in the area is shortened from 0.9-1.1 m to 0.5-0.6 m, which is beneficial to increasing the number of the burners 2 in the area, so that the fuel (such as natural gas) and combustion air in the burners 2 are more uniformly mixed, and the combustion of each burner 2 is more sufficient; in addition, on the premise of unchanged total fuel quantity, the number of the burners 2 is increased, and the temperature of a local area near the burners 2 can be reduced, so that the aim of reducing the generation of nitrogen oxides in the kiln is fulfilled.

Further, the interval between the plurality of burners 2 in the middle-rear stage 122 is uniform, and the interval between the adjacent two burners 2 is 1.0-1.2 m.

In addition, the present solution increases the spacing between adjacent two burners 2 in this region to 1.0-1.2 m to better configure the total amount of combustion air in the firing zone 12, considering that the amount of gas required for the middle and rear sections 122 of the firing zone 12 is small.

Further, a plurality of the burners 2 are distributed on the upper and lower portions of the roll bars of the burning zone 12;

the combustion-supporting air assembly 34 comprises a drainage fan 341, a shunt pipe 342, an upper output main pipe 343 and a lower output main pipe 344, wherein the outlet of the induced draft fan 33, the drainage fan 341 and the inlet of the shunt pipe 342 are sequentially connected; the shunt tubes 342 comprise a first output port and a second output port, the first output port, the upper output header 343 and the combustion air inlet of the burner 2 positioned at the upper part of the roller rod of the firing zone 12 are sequentially communicated, and the second output port, the lower output header 344 and the combustion air inlet of the burner 2 positioned at the lower part of the roller rod of the firing zone 12 are sequentially communicated.

In another preferred embodiment of the present solution, the burners 2 are arranged in two rows up and down in the firing belt 12, which is advantageous for further improving the combustion efficiency and making the combustion more complete.

Further, the drainage fan 341 further includes a cold air inlet 345, and the cold air inlet 345 communicates with the atmosphere.

Further, the cold air inlet 345 is further formed in the drainage fan 341 of the scheme, so that the combustion-supporting air system 3 can be flexibly adjusted according to actual combustion needs, heated waste heat flue gas can be used as combustion-supporting air, and mixed gas of the heated waste heat flue gas and air can be used as combustion-supporting air.

In the scheme, the working process of the roller kiln structure is as follows: waste heat flue gas generated by the roller kiln 1 is pumped into the combustion-supporting air system 3 by the waste heat exhaust pipe 31 in the slow cooling zone 14; in the combustion air system 3, the waste heat flue gas is secondarily heated by the heating box 32 to serve as combustion air of the burner 2, and is conveyed to the combustion air assembly 34 through the induced draft fan 33. In a preferred embodiment of the present embodiment, the flue gas with waste heat after the secondary heating can be directly used as the combustion air of the burner 2; in another preferred embodiment of this embodiment, the flue gas with waste heat after secondary heating can also be mixed with air and then used as combustion air for the burner 2.

Further describing, the device also comprises a flue gas draft system 4, wherein the flue gas draft system 4 is arranged in the preheating zone 11;

the flue gas exhaust system 4 comprises a flue gas exhaust pipe 41 and a flue gas exhaust machine 42, wherein an inlet of the flue gas exhaust pipe 41 is positioned on the upper portion of a roller rod of the preheating zone 11, an inlet of the flue gas exhaust machine 42 is connected with an outlet of the flue gas exhaust pipe 41, and the flue gas exhaust machine 42 is used for exhausting flue gas in the roller kiln 1 through the flue gas exhaust pipe 41.

The roller kiln structure of this scheme still includes flue gas exhaust system 4, can carry out the pump drainage through setting up in the flue gas exhaust column 41 and the smoke extractor 42 of preheating zone 11 with the flue gas in the kiln towards kiln head direction, more is favorable to ceramic product in the kiln to contact with high temperature air current, ensures the effect of sintering.

Further described, the outlet of the extractor 42 is interconnected with the atmosphere.

After the roller kiln structure is designed according to the scheme, the content of nitrogen oxides in the flue gas generated in the kiln is greatly reduced, so that the flue gas generated in the kiln can be directly discharged, and the discharge cost of the flue gas is reduced.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present utility model unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In the description of the present utility model, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present utility model and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present utility model; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present utility model.

It should be noted that the terms "first," "second," and the like in the description and claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the present application described herein may be implemented in sequences other than those illustrated or described herein.

The technical principle of the present utility model is described above in connection with the specific embodiments. The description is made for the purpose of illustrating the general principles of the utility model and should not be taken in any way as limiting the scope of the utility model. Other embodiments of the utility model will be apparent to those skilled in the art from consideration of this specification without undue burden.

Claims (6)

1. The roller kiln structure for realizing low nitrogen oxide emission is characterized in that: comprises a roller kiln, a burner and a combustion-supporting air system; the roller kiln sequentially comprises a preheating zone, a firing zone, a quenching zone, a slow cooling zone and a fast cooling zone which are communicated with one another from the kiln head to the kiln tail; the burners are arranged in a plurality, and the burners are arranged in the sintering zone;

the combustion-supporting air system comprises a waste heat exhaust pipe, a heating box, an induced draft fan and a combustion-supporting air component which are sequentially connected through pipelines; the inlet of the waste heat exhaust pipe is positioned at the upper part of the roller rod of the slow cooling belt, the waste heat exhaust pipe is used for sucking waste heat flue gas of the slow cooling belt into the combustion air system, and the heating box is used for heating the waste heat flue gas; the combustion-supporting air assemblies are provided with a plurality of groups, and the outlet of each group of the combustion-supporting air assemblies is connected with the combustion-supporting air inlets of a plurality of burners;

the firing zone comprises a heating front section and a heating middle and rear section which are communicated with each other;

the combustion-supporting air assemblies are at least provided with two groups, the outlets of one group of the combustion-supporting air assemblies are connected with the combustion-supporting air inlets of the plurality of burners positioned at the front heating section, and the outlets of the other group of the combustion-supporting air assemblies are connected with the combustion-supporting air inlets of the plurality of burners positioned at the middle and rear heating section;

the interval between the burners at the heating front section is uniform, and the interval between two adjacent burners is 0.5-0.6 m.

2. A roller kiln structure for achieving low nitrogen oxide emissions according to claim 1, characterized in that: the interval between the burners at the middle and rear sections of the heating is uniform, and the interval between two adjacent burners is 1.0-1.2 m.

3. A roller kiln structure for achieving low nitrogen oxide emissions according to claim 1, characterized in that: the burners are distributed at the upper part and the lower part of the roller rod of the burning belt;

the combustion-supporting air assembly comprises a drainage fan, a shunt tube, an upper output main pipe and a lower output main pipe, and an outlet of the induced draft fan, the drainage fan and an inlet of the shunt tube are sequentially connected; the shunt tubes include first delivery outlet and second delivery outlet, first delivery outlet the last delivery manifold is located the combustion-supporting wind entry of the combustor of the roller stick upper portion in burning zone communicates in proper order, the second delivery outlet the lower delivery manifold is located the combustion-supporting wind entry of the combustor of the roller stick lower part in burning zone communicates in proper order.

4. A roller kiln structure for achieving low nitrogen oxide emissions according to claim 3, characterized in that: the drainage fan further comprises a cold air inlet, and the cold air inlet is communicated with the atmosphere.

5. A roller kiln structure for achieving low nitrogen oxide emissions according to claim 1, characterized in that: the preheating zone is provided with a preheating zone, and the preheating zone is provided with a preheating zone;

the flue gas exhaust system comprises a flue gas exhaust pipe and a flue gas exhaust machine, wherein an inlet of the flue gas exhaust pipe is positioned on the upper part of a roller rod of the preheating zone, an inlet of the flue gas exhaust machine is connected with an outlet of the flue gas exhaust pipe, and the flue gas exhaust machine is used for exhausting flue gas in the roller kiln through the flue gas exhaust pipe.

6. A roller kiln structure for achieving low nitrogen oxide emissions according to claim 5, characterized in that: the outlet of the smoke extractor is communicated with the atmosphere.