CN218646064U

CN218646064U - Preheating one-section stepped air supply system of chain grate machine

Info

Publication number: CN218646064U
Application number: CN202223137317.9U
Authority: CN
Inventors: 郑绥旭; 邢守正; 吴增福; 郑丹阳; 刘月星
Original assignee: Northern Engineering and Technology Corp MCC
Current assignee: Northern Engineering and Technology Corp MCC
Priority date: 2022-11-25
Filing date: 2022-11-25
Publication date: 2023-03-17
Anticipated expiration: 2032-11-25

Abstract

The utility model relates to a chain grate machine preheats one section step air feed system, including the chain grate machine, the chain grate machine divide into drum dry section, preheat one section and preheat the two-section, its characterized in that along the material flow direction in proper order: the chain grate machine is characterized by further comprising two cold-section waste gas pipelines, a combustion chamber and an adjusting valve, wherein the two cold-section waste gas main pipe is connected with the chain grate machine preheating section upper cover through a waste gas branch pipe, the adjusting valve is arranged on the waste gas branch pipe I, the combustion chamber I is arranged on the waste gas branch pipe II, the combustion chamber II is arranged on the waste gas branch pipe III, the combustion chamber III is arranged on the waste gas branch pipe IV, and a temperature detection device I, a temperature detection device II, a temperature detection device III and a temperature detection device IV are arranged on the side surface of the chain grate machine preheating section upper cover. The airflow temperature change gradient in the pellet temperature rise process can be controlled according to the actual production requirements, and a proper temperature field is established in the upper cover of the preheating section, so that green pellets can be prevented from bursting, and the raw material condition change can be adapted.

Description

Preheating one-section step air supply system of chain grate machine

Technical Field

The utility model belongs to the technical field of the iron and steel metallurgical industry pellet production, concretely relates to chain grate machine is in advance

A hot first-stage cascade air supply system.

Background

At present, a grate-rotary kiln-circular cooler process is one of the main production processes for producing iron ore pellets.

The green pellets are subjected to heat treatment on a chain grate machine, and the drying and preheating processes of the green pellets are completed by carrying out cross flow heat exchange between hot air flow and a material layer. According to the traditional hot air flow, the grate is divided into four sections according to the temperature of hot air flow and a mode of penetrating through a material layer, a blowing drying section, an exhausting drying section, a preheating section and a preheating section are sequentially arranged along the advancing direction of materials, and the temperature of the hot air flow required by each section of the grate is determined according to a pellet test result.

The forced air drying is the first process of treating green pellets on a chain grate, the heat source for forced air drying is cooling waste gas (hereinafter referred to as 'three-cold-section waste gas') from the upper cover of the three cold sections of the circular cooler, and hot air flow from bottom to top passes through a green pellet material layer to primarily remove moisture of the green pellets. In order to meet the requirement of emission standard, the moisture-containing waste gas passing through the material layer is discharged after being dedusted by the furnace cover deduster.

The air draft drying is the second procedure for processing the green pellets on a chain grate, the heat source for air draft drying is hot flue gas (called regenerative air for short hereinafter, the temperature is generally 350-450 ℃) from a regenerative fan of the chain grate, and the hot air from top to bottom passes through a green pellet material layer to remove the moisture of the green pellets.

The preheating section is a transition link on a chain grate machine, the heat source of the preheating section is hot waste gas (hereinafter referred to as 'waste gas of a second cooling section', the temperature is generally 600-800 ℃) from an upper cover of the second cooling section of the circular cooler, the waste gas of the second cooling section enters the cover from the top of the upper cover of the preheating section, hot gas flow from top to bottom passes through a green ball material layer, residual moisture of the green balls is completely removed, and the dry balls are heated to be heated as required.

And the flue gas of the air draft drying section and the preheating section of the air box is collected and then is treated by a main electric dust collector, a main exhaust fan and a desulfurization and denitrification device and then is discharged.

The preheating section is the last link for treating the green pellets on a chain grate, hot flue gas from a rotary kiln penetrates through a material layer from top to bottom, dry pellets are preheated for a certain time at a proper temperature, the strength of the dry pellets meets the requirement of entering the kiln, the flue gas penetrating through the material layer is used as 'hot return air', and the hot return air is sent to an upper cover of the air draft drying section by a heat return fan to be used as a heat source.

After the drying and preheating processes, the green pellets are dehydrated and heated, the pellets with certain strength enter the rotary kiln, the pellet roasting process is completed in the kiln, the roasted high-temperature pellets are discharged into the circular cooler from the rotary kiln, and the pellet cooling process is completed on the circular cooler.

In the production process of the traditional air flow, the temperature of waste gas in a secondary cooling section used as a preheating first-section heat source is usually lower, in order to meet production requirements, an auxiliary heating device is usually arranged for heat compensation, and the following problems can be caused by a common heat compensation method:

1) One method is to arrange an auxiliary heating device on the side wall of the preheating section of the upper cover of the chain grate machine, and has the defects that in the limited space of the upper cover, hot flue gas provided by the auxiliary heating device cannot be fully mixed with waste gas of the two cooling sections entering the upper cover from the top, and the material layer is difficult to be uniformly heated;

2) The other method is that an auxiliary heating device is arranged on a hot waste gas pipeline leading to a preheating section of upper cover of a chain grate machine to integrally heat gas in the pipeline, the method can lead the temperature of the hot waste gas entering the preheating section of upper cover to be consistent, and overcomes the problem of uneven material layer heating, but the method also has the problems that the temperature field in the preheating section of upper cover cannot be regulated and controlled according to requirements, the condition that the temperature rises steeply after pellets enter the preheating section cannot be avoided, green pellets with poor drying effect can crack or even burst when suddenly contacting high temperature, and the production and pellet ore quality are influenced.

In addition, when different raw materials are adopted, the proper thermal regulation of the pellet drying and preheating processes can have larger difference, in order to ensure that the pellet heating process is uniformly heated and can correspond to the different thermal regulation, the hot air supply mode of the chain grate machine for preheating the first section is optimized, the heating process of the pellet at the preheating section is controllable, green pellets are prevented from cracking, the drying and preheating effects of the pellets on the chain grate machine are ensured, and the adaptability of the chain grate machine to the raw materials is improved.

Disclosure of Invention

An object of the utility model is to provide a chain grate preheats one section step air feed system for the control gets into the air current temperature that the chain grate preheated one section upper shield, can improve the adaptability of chain grate to the raw materials, creates the condition for energy saving and emission reduction, high-efficient operation of chain grate-rotary kiln pelletizing production system.

The utility model aims at realizing through the following technical scheme:

the utility model discloses a chain grate machine preheats one section step air feed system, including the chain grate machine, the chain grate machine divide into drum dry section, the section of drying out in proper order along the material flow direction, preheats one section and preheats the two-section, its characterized in that: the chain grate machine is characterized by further comprising a secondary cooling section waste gas main pipeline, a combustion chamber and a regulating valve secondary cooling section waste gas main pipeline which are connected with a secondary cooling section upper cover of the ring cooler, the secondary cooling section waste gas main pipeline is connected with the top of a preheating section upper cover of the chain grate machine through a plurality of waste gas branch pipes, the regulating valve is arranged on the waste gas branch pipe I, the combustion chamber I is arranged on the waste gas branch pipe II, the combustion chamber II is arranged on the waste gas branch pipe III, the combustion chamber III is arranged on a waste gas branch pipe IV, and a temperature detection device I, a temperature detection device II, a temperature detection device III and a temperature detection device IV are arranged on the side surface of the preheating section upper cover of the chain grate machine.

Furthermore, temperature-detecting device I correspond to exhaust branch pipe I, temperature-detecting device II correspond to exhaust branch pipe II, temperature-detecting device III correspond to exhaust branch pipe III, temperature-detecting device IV correspond to exhaust branch pipe IV.

Furthermore, the chain grate machine preheating section of stepped air supply system further comprises a control system, wherein the control system is connected with the temperature detection device I, the temperature detection device II, the temperature detection device III and the temperature detection device IV and controls the regulating valve, the combustion chamber I, the combustion chamber II and the combustion chamber III.

Compared with the prior art, the utility model has the advantages that:

1) The heat supply intensity of the auxiliary heat supply device can be adjusted, so that the temperature of the airflow entering the chain grate machine preheating section upper cover reaches the required temperature, and the pellets in the width direction of the chain grate machine can be uniformly heated;

2) The heat supply intensity of each combustion chamber can be independently adjusted, the temperature of the airflow in the hot air branch pipes corresponding to different combustion chambers can be controlled, the airflow temperature change gradient in the pellet heating process can be controlled according to production requirements, and a proper temperature field is established in the upper cover of the preheating section, so that green pellets can be prevented from bursting, and the raw material condition can be adapted to the change;

3) The utility model discloses a chain grate machine preheats one section step air feed system simple structure, occupation space is little, the operation is more simple and convenient, usable original system transformation.

Drawings

Fig. 1 is a schematic view of a chain grate machine preheating one-section step air supply system of the utility model.

Detailed Description

The present invention will be further explained with reference to the drawings and examples.

As shown in fig. 1, the utility model discloses a chain grate preheats one section step air feed system, including chain grate 1, chain grate 1 divide into drum dry section, the section of drying in proper order along the material flow direction, preheats one section and preheats two-section, its characterized in that: the two-cold-section waste gas preheating device comprises a chain grate machine 1, and is characterized by further comprising a two-cold-section waste gas main pipeline 2 connected with an upper cover of a two-cold-section of the ring cooler, a combustion chamber and an adjusting valve 4, wherein the two-cold-section waste gas main pipeline 2 is connected with the top of the upper cover of a preheating section of the chain grate machine 1 through a plurality of waste gas branch pipes, the plurality of waste gas branch pipes are composed of a waste gas branch pipe I2-1, a waste gas branch pipe II 2-2, a waste gas branch pipe III 2-3 and a waste gas branch pipe IV 2-4, the adjusting valve 4 is arranged on the waste gas branch pipe I2-1, the combustion chamber I3-1 is arranged on the waste gas branch pipe II 2-2, the combustion chamber II 3-2 is arranged on the waste gas branch pipe III 2-3, the combustion chamber III 3-3 is arranged on the waste gas branch pipe IV 2-4, and a temperature detection device I5-1, a temperature detection device II 5-2, a temperature detection device III-3 and a temperature detection device IV 5-4 are arranged on the side surface of the preheating section of the upper cover of the chain grate machine 1.

Temperature detect device I5-1 correspond with exhaust branch I2-1, temperature detect device II 5-2 correspond with exhaust branch II 2-2, temperature detect device III 5-3 correspond with exhaust branch III 2-3, temperature detect device IV 5-4 correspond with exhaust branch IV 2-4.

The utility model discloses chain grate machine preheats one section step air feed system still includes control system, control system and temperature-detecting device I5-1, temperature-detecting device II 5-2, temperature-detecting device III 5-3, temperature-detecting device IV 5-4 to control governing valve 4 and combustion chamber I3-1, combustion chamber II 3-2 and combustion chamber III 3-3.

Adopt the utility model discloses a chain grate machine preheats one section step air feed system's air feed method, including following step:

s1, setting a temperature value of a preheating section of upper cover of the chain grate machine, automatically controlling the opening of a small regulating valve 4 through a control system when a numerical value of a temperature detection device I5-1 is lower than a set value, and automatically controlling the opening of a large regulating valve 4 through the control system when the numerical value is higher than the set value, so that the temperature of a region, corresponding to an exhaust gas branch pipe I2-1, in the preheating section of upper cover of the chain grate machine reaches the set value;

s2, when the temperature detection device II 5-2, the temperature detection device III 5-3 and the temperature detection device IV 5-4 are lower than a set value, the control system automatically controls and increases the heating intensity of the combustion chamber on the corresponding branch pipe, so that the temperature of the area, corresponding to the exhaust gas branch pipe II 2-2, the exhaust gas branch pipe III 2-3 and the exhaust gas branch pipe IV 2-4, in the upper cover section preheated by the chain grate machine reaches the set value, and when the temperature detection device II 5-2, the temperature detection device III 5-3 and the temperature detection device IV 5-4 are higher than the set value, the control system automatically controls and decreases the heating intensity of the combustion chamber on the corresponding branch pipe, so that the temperature of the area, corresponding to the exhaust gas branch pipe II 2-2, the exhaust gas branch pipe III 2-3 and the exhaust gas branch pipe IV 2-4, in the upper cover section preheated by the chain grate machine reaches the set value.

Adopt the utility model discloses a chain grate machine preheats one section step air feed system, the heating intensity of each combustion chamber can be adjusted alone, can control the airflow temperature in the different combustion chambers correspond hot-blast spinal branch pipes, can be according to the actual production needs, and the airflow temperature gradient of control pelletizing intensification in-process sets up suitable temperature field in preheating one section upper shield, can prevent that the green ball from bursting, can adapt to the change of raw materials condition again.

The utility model discloses simple structure, occupation space are little, the operation is more simple and convenient, can be used to newly-built production line, also can utilize original system transformation.

Claims

1. The utility model provides a chain grate machine preheats one section step air feed system, includes the chain grate machine, and the chain grate machine divide into drum dry section, takes out dry section, preheats one section and preheats the two-section, its characterized in that along the material flow direction in proper order: the circular cooler is characterized by further comprising a secondary cooling section waste gas pipe main pipeline, a combustion chamber and a regulating valve secondary cooling section waste gas main pipeline which are connected with a secondary cooling section upper cover of the circular cooler through a plurality of waste gas branch pipes and are connected with the top of a primary preheating upper cover of the chain grate machine, a regulating valve is arranged on the waste gas branch pipe I, the combustion chamber I is arranged on the waste gas branch pipe II, the combustion chamber II is arranged on the waste gas branch pipe III, the combustion chamber III is arranged on a waste gas branch pipe IV, and a temperature detection device I, a temperature detection device II, a temperature detection device III and a temperature detection device IV are arranged on the side surface of the primary preheating upper cover of the chain grate machine.

2. The chain grate machine preheating section of stepped air supply system as recited in claim 1, wherein: the temperature detection device I corresponds to the exhaust branch pipe I, the temperature detection device II corresponds to the exhaust branch pipe II, the temperature detection device III corresponds to the exhaust branch pipe III, and the temperature detection device IV corresponds to the exhaust branch pipe IV.

3. The grate preheated one-stage air supply system of claim 1, wherein: the chain grate machine preheating section step air supply system further comprises a control system, wherein the control system is connected with the temperature detection device I, the temperature detection device II, the temperature detection device III and the temperature detection device IV and controls the regulating valve, the combustion chamber I, the combustion chamber II and the combustion chamber III.