CN110763018A - A kind of decomposition furnace with local directional combustion support - Google Patents

Abstract

The invention discloses a decomposing furnace with local directional combustion supporting, wherein the decomposing furnace 1 is divided into sections, necking is arranged between the sections, the upper necking part of each section of the decomposing furnace 1 is downwards arranged at a certain distance, a certain number of local directional combustion supporting nozzles 3 are uniformly arranged in the circumferential direction, the nozzles 3 are horizontally and downwards inserted into the furnace from the furnace wall along the tangential direction, the local directional combustion supporting is carried out on solid-gas mixed airflow in a backflow zone, high-temperature resistant temperature detectors 4 are respectively arranged in the central area and the circumferential area of each section of the decomposing furnace 1, and the temperature of the central area and the circumferential area of each section of the decomposing furnace is measured on line. The invention has the advantages that: through the combustion-supporting of original combustion-supporting air reposition of redundant personnel subregion with increase and carry out the accurate combustion-supporting device of local orientation to the solid gas mixture air current of backward flow, solve the unbalanced problem of decomposing furnace burning.

Description

A kind of decomposition furnace with local directional combustion support

technical field

The present invention relates to the technical field of calcining furnace type combustion equipment, in particular to a calcining furnace with local directional combustion support.

Background technique

There are many types of industrial furnaces in the industrial field. The decomposition furnace is a new type of thermal equipment in which fuel combustion, heat exchange and decomposition reaction are carried out at the same time. The calciner is arranged vertically, with one or more sections. The upper part of each section has a constriction (the diameter is obviously reduced), and the ground fuel and materials are injected into the furnace from the lower part of the calciner in the lowermost section, and the combustion-supporting air is also The fuel, material and combustion-supporting air (hereinafter referred to as "solid-gas mixture airflow") are fully mixed and ignited, and then sucked by the negative pressure at the outlet of the decomposition furnace in the uppermost section, and the solid-gas mixture airflow goes upwards. Flameless combustion, while decomposing and ascending, when encountering the upper constriction of each stage of the precalciner, a part of the solid-gas mixture flow enters the previous stage of the precalciner through the constriction, and a part of the solid-gas mixture is blocked by the constriction and variable diameter slope. Backflow is reversed along the inner wall of the circumference to form a reflux solid-gas mixed air flow. In the middle and lower part of the calcining furnace, the central solid-gas mixed air flow is again mixed into the central solid-gas mixed air flow due to the attraction of the central negative pressure, thereby forming a continuously upward flameless combustion state.

The combustion state, combustion speed, burnout rate and residence time of fuel and materials in the calciner fully mixed with combustion air have important influence on the decomposition of materials and the coal consumption of the calciner.

The current structure and form of the calcining furnace are mainly improved by expanding the volume of the calcining furnace and prolonging the residence time of the solid-gas mixture in the furnace, while ignoring the problems caused by the uneven matching of the combustion-supporting air in different areas of the furnace. The problem of unbalanced and insufficient combustion leads to incomplete combustion of fuel, low decomposition rate, high coal consumption of decomposition rate, and safety and quality risks to the operation of the next-level process system.

In fact, in the above combustion state, the rising solid-gas mixed gas flow encounters each section of the decomposition rate constriction, and is blocked in the reverse flow of the solid-gas mixed gas flow downward along the inner wall of the circumference, because of the inertia and centrifugal force of the solid and gas. Differently, the problem of insufficient combustion-supporting air inevitably exists in the backflow solid-gas mixture, which leads to insufficient combustion of the fuel in this area due to insufficient combustion-supporting air, which affects combustion and decomposition, resulting in the above-mentioned series of problems.

How to carry out local directional and precise combustion support for the reflux solid-gas mixture in the precalciner can solve the problem of insufficient fuel combustion in this area, realize the combustion balance in the furnace, improve the decomposition rate, reduce coal consumption, and reduce the safety and quality risks of the subsequent process system operation. significant.

SUMMARY OF THE INVENTION

The invention mainly relates to a calcining furnace with local directional combustion-supporting. , Oppositely connected to the calciner to form a vortex combustion-supporting air, which is mixed with the "coal, material, wind" solid-gas mixed airflow (mixed by pulverized coal, raw meal and high temperature flue gas in the kiln tail smoke chamber) rising from the cone of the calciner furnace. It is fully mixed by the negative pressure formed by the high temperature fan in the decomposition furnace.

In order to achieve the above purpose, the following technical solutions are adopted: a kind of calciner with local directional combustion support, the calciner is segmented, and the sections are constrictions, and a certain distance is downward at the upper constriction of each section of the calciner, and in the circumferential direction A certain number of local directional combustion-supporting nozzles are evenly arranged. The nozzles are inserted into the furnace along the tangential, horizontal or downward direction from the furnace wall to perform local directional combustion-supporting for the solid-gas mixture in the recirculation zone. Install high temperature resistant temperature detectors respectively to measure the temperature in the central area and the circumferential area of each section of decomposition online. The lower end of the decomposition furnace is connected with a tertiary air duct. Ordinary air or oxygen-enriched air is fed, and then sent to the nozzles of each section of the decomposition furnace through the combustion-supporting air duct. The nozzles used for supporting combustion of the solid-gas mixture in the recirculation zone can be provided with multiple groups of nozzles in layers from top to bottom in each section of the calcining furnace according to the structure of the calcining furnace and the needs for supporting combustion.

The combustion-supporting air duct is provided with an electric regulating valve and a pressure sensor, and the pressure and flow of the local directional combustion-supporting air or oxygen-enriched air of each nozzle can be adjusted by the valve provided on the combustion-supporting air duct.

The air used for local directional combustion-supporting is ordinary air or oxygen-enriched air. The oxygen-enriched air can be produced by an external oxygen-enriched production device, and then sent into the furnace to support combustion through a nozzle.

A temperature sensor is installed on the air outlet of the preheating air duct to measure the temperature of the gas connected to the combustion-supporting air duct.

One end of the high temperature-resistant temperature detector is fixed on the outer wall of the combustion-supporting air duct, and the other end is inserted into the central area and the circumferential area of the calcining furnace to detect the temperature of different areas in the calcining furnace. Principle of use: Local directional combustion-supporting air (oxygen-enriched air or ordinary air) is heated to a suitable temperature through a heat exchanger placed in the main pipe of the tertiary air duct. Under the control of an automatic control system such as PLC, the amount of combustion-supporting air or coal injection of the corresponding directional combustion-supporting nozzles is adjusted, so that the temperature in the central area and the circumferential area of each segment tends to be balanced.

The invention has the advantages that the original combustion-supporting air is divided into sub-divisions to support combustion, and the local directional and precise combustion-supporting device is added for the return solid-gas mixed air flow, so as to solve the problem of unbalanced combustion in the precalciner, thereby improving the decomposition rate of the precalciner and reducing the coal consumption of the precalciner. .

Description of drawings

FIG. 1 is a schematic view of the front structure of the present invention.

FIG. 2 is a schematic view of the side structure of the present invention.

FIG. 3 is a schematic diagram of the nozzle of the present invention.

FIG. 4 is a schematic diagram of the structure of the thermal bath pipe of the present invention.

Description of reference numerals: 1. Decomposition furnace, 2. Combustion-supporting air duct, 3. Nozzle, 4. High temperature resistant temperature detector, 5. Electric regulating valve, 6. Bath heat pipe, 7. Temperature sensor, 8. Tertiary air duct , 9. Pressure sensor, 10. Feeding tube.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the protection scope of the present invention can be more clearly defined.

Please refer to accompanying drawings 1-4, a kind of calcining furnace with partial directional combustion support, the calcining furnace 1 is divided into sections, and there is a constriction between the sections. A certain number of local directional combustion-supporting nozzles 3 are evenly arranged in the direction. The nozzles 3 are inserted into the furnace along the tangential, horizontal or downward direction from the furnace wall to carry out local directional combustion-supporting for the solid-gas mixture in the reflow area. High temperature resistant temperature detectors 4 are installed in the area and the peripheral area respectively, and the temperature in the central area and the peripheral area of each segment is measured online.

The nozzles 3 for supporting combustion of the solid-gas mixture in the recirculation zone can be provided with multiple groups of nozzles 3 in layers from top to bottom in each section of the precalciner 1 according to the structure of the precalciner 1 and the requirements for supporting combustion.

The air used for local directional combustion-supporting is ordinary air or oxygen-enriched air. The oxygen-enriched air can be produced by an external oxygen-enriched production device, and then sent to the furnace through the nozzle 3 to support combustion.

The pressure and flow of the locally directed combustion-supporting air or oxygen-enriched air of each nozzle 3 can be adjusted by the valve 5 provided on the combustion-supporting air duct 2 .

Locally directional combustion air, that is, oxygen-enriched air or ordinary air, is heated to a suitable temperature through a heat exchanger placed in the main pipe of the tertiary air duct.

Two of the high temperature-resistant temperature detectors 4 are provided in each section of the calcining furnace, one for detecting the temperature in the central region of the calcining furnace 1 , and the other for detecting the temperature in the peripheral region of the calcining furnace 1 . Principle of use: Locally directional combustion-supporting air, namely oxygen-enriched air or ordinary air, is heated to a suitable temperature through a heat exchanger placed in the main pipe of the tertiary air duct. Under the control of an automatic control system such as PLC, the amount of combustion-supporting air of the corresponding directional combustion-supporting nozzles 3 is adjusted, so that the temperature of the central area and the circumferential area of the decomposition sections tends to be balanced.

Not limited to this, any changes or substitutions that are not thought of through creative work should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined by the claims.

Claims (5)

1. a calcining furnace with local directional combustion-supporting, it is characterized in that, comprises calcining furnace (1), combustion-supporting air duct (2), nozzle (3); A certain number of local directional combustion-supporting nozzles (3) are evenly arranged on the combustion-supporting air duct (2) in the circumferential direction at a certain distance from the upper constriction of each stage of the calcining furnace (1). Insert it into the furnace horizontally and downward along the tangential direction, conduct local directional combustion support for the solid-gas mixture in the reflow zone, and install high temperature resistant temperature detectors (4) in the central area and the circumferential area of each section of the decomposition furnace (1) respectively, and measure it online. The temperature in the central area and the circumferential area of each section is decomposed. The lower end of the decomposition furnace (1) is connected with a tertiary air duct (8), and the U-shaped bottom in the middle of the bath heat pipe (6) extends into the tertiary air duct (8). The pipe (6) is connected to ordinary air or oxygen-enriched air, and then connected to the combustion-supporting air pipe (2), and the feeding pipe (10) is located at the lower part of the decomposition furnace (1). 2. The calcining furnace with local directional combustion support according to claim 1, characterized in that the nozzle (3) for supporting combustion of the solid-gas mixed gas flow in the recirculation zone is based on the structure of the calcining furnace (1) and the combustion support. If necessary, multiple groups of nozzles (3) are arranged in layers from top to bottom in each section of the calcining furnace (1). 3 . The precalciner with local directional combustion support according to claim 1 , wherein an electric regulating valve ( 5 ) and a pressure sensor ( 9 ) are arranged on the combustion air duct ( 2 ). 4 . 4. A kind of decomposition furnace with local directional combustion support according to claim 1, characterized in that, the air outlet of the bath heat pipe (6) is provided for measuring the gas temperature in the access combustion air pipe (2) temperature sensor (7). 5 . The calcining furnace with local directional combustion support according to claim 1 , wherein two high temperature-resistant temperature detectors ( 4 ) are provided in each section of the calcining furnace. 6 .

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