CN1281912C - Blaze insulating fluidized forge furnace - Google Patents

Abstract

A flame insulating fluidized calcining furnace of the present invention relates to the technical field of calcining devices. The present invention indirectly heats a calcining furnace of a fluidized bed by using high-temperature flame in combustion, flame is prevented from being directly contacted with material, and the phenomenon that calcinated material in the furnace is over-calcinated is effectively overcome; simultaneously, high-temperature flue gas from a flue is used as fluidized gas to enter a furnace chamber from a passage at the bottom of the furnace chamber from top to bottom to make the furnace chamber of the fluidized calcining furnace heated inside and outside, and the heating time is increased by one time; compared with a fluidized calcining furnace which is provided with a combustion chamber at the bottom and directly burns to heat material, the present invention has the advantage of greatly improvement of heat efficiency. The average residence time of material in the flame insulating fluidized calcining furnace of the present invention can be adjusted from several seconds to numbers of hours, the furnace temperature can be adjusted from 500 DEG C to 1300 DEG C, and the temperature difference of the furnace chamber is between minus 5 and plus 5 DEG C. The flame insulating fluidized calcining furnace of the present invention has the advantages of high heat transferring and mass transferring speed, uniform temperature in the furnace and low energy consumption.

Description

Flame fluidized calciner and its use

technical field

The invention relates to a flame-insulated fluidized calciner and a use method thereof, which relate to the technical field of calcining equipment.

Background technique

At present, calcining equipment includes fluidized bed calcining furnace, rotary kiln, multi-layer furnace, tunnel kiln and so on. For the calcination of powder materials, the fluidized bed calciner has fast material heat transfer and mass transfer, low energy consumption, and large production capacity of a single equipment, but the existing fluidized bed calciner heating method is directly heated inside the furnace or a combustion chamber is set outside. , which leads to the following problems: First, the fuel burns in the furnace, the flame is in direct contact with the material, the flame stability is poor in the dense phase, and the local temperature in the furnace is too high, which makes the surrounding material heated to a high temperature, resulting in overburning of the material; in addition, When the fuel is burned in the external combustion chamber, the heat released is large to the outside, and the effective utilization rate of the heat is reduced.

Contents of the invention

The purpose of the present invention is to overcome the defects of the existing fluidized bed calciner and provide a flame-chambered fluidized calciner, which not only has the characteristics of fast heat and mass transfer, uniform temperature in the furnace, and low energy consumption; but also effectively avoids The material is overburned, and the heat released by the combustion chamber is effectively used.

In order to achieve the above object, the technical solution of the present invention is to provide a flame-trap fluidized calciner, including a furnace roof, a burner burner, a secondary combustion air duct, a combustion chamber, an outer wall of the furnace, a furnace wall, a flue , furnace, feed pipe, channel, furnace bottom cover, outlet connecting pipe, gas-solid separator and cooling unloader; of which:

The outer wall of the furnace is a hollow body, and a plurality of burner nozzles and feed pipes are arranged on the side surface; The inner end communicates with the combustion chamber, and the two correspond to each other, and the side of each burner nozzle is provided with a secondary combustion air duct;

The combustion chamber is bell-shaped and is located on the inner wall of the outer wall of the furnace;

The furnace roof and furnace bottom cover are fixed up and down on the upper and lower ends of the outer wall of the furnace; the center of the furnace roof is provided with an outlet connecting pipe upward, and the outer end of the outlet connecting pipe is the outlet of the gas-solid mixture of the calciner, which is connected to the high-temperature gas-solid The separator is connected, and the cooling unloader is below the separator; the inner end of the outlet connecting pipe is connected with the hearth of the fluidized calciner. The hearth is in the middle of the outer wall of the furnace, surrounded by the hearth wall to form a cylindrical shape, and shares a central axis with the outer wall of the furnace. There is a gap between the outer peripheral surface of the furnace wall and the inner peripheral surface of the outer wall of the furnace, and the gap is a flue; the bottom of the furnace is provided with a channel connecting the flue and the furnace on the furnace wall;

The feeding pipe is arranged obliquely downward at the lower part of the outer wall of the furnace, and the pipe of the feeding pipe passes through the flue and communicates with the furnace;

The flame partition wall is arranged longitudinally in the gap between the outer peripheral surface of the furnace wall and the inner peripheral surface of the furnace outer wall, and the longitudinal passage separated by the flame partition wall is a flue;

The ash cleaning hole is located on the bottom cover of the furnace, at the bottom of the flue.

In the described muffled fluidized calciner, the geometric structure of the outer wall of the furnace, the wall of the furnace, the flue, and the furnace is cylindrical, square column or special-shaped.

A kind of method using described muffled flame fluidized calciner, its work process is as follows:

The fuel passes through the burner and the combustion-supporting air of the secondary air pipe is mixed and burned in the combustion chamber. The high-temperature flame and high-temperature flue gas pass through the combustion chamber and the flue, indirectly heating the furnace of the fluidized bed calciner; under the action of the fan power, The high-temperature flue gas in the flue enters the furnace from the channel at the bottom of the furnace as fluidizing gas; the material entering the furnace from the feed pipe and the high-temperature fluidizing gas form a fluidized mixture in the furnace, which makes the high-temperature gas and material produce efficient heat transfer , mass transfer; the calcined material rises upwards, and is sent to the high-temperature gas-solid separator through the outlet connecting pipe for gas-solid separation. The hot gas is used for material preheating, and the hot material falls into the cooling unloader, and then enters the cooling unloader after passing through the cooling unloader. storage bin.

In the method described above, the burner is automatically controlled, the temperature in the furnace can be adjusted arbitrarily within the range of 500°C-1300°C, and the furnace temperature difference is within ±5°C; this high-temperature flue gas heats the inside and outside of the fluidized calciner, and the heating time The increase is doubled, the heat released by the fuel is fully and effectively used, the thermal efficiency is high, and the temperature in the furnace of the fluidized bed calciner is uniform and stable.

In the method, the velocity of the fluidizing gas is in the range of 0.1-6.0 m/s.

In the method, the fuel is gas, fuel oil or pulverized coal

In the method, the average particle size of the materials is in the range of 0-5000 microns.

The flame-insulated fluidized calciner of the present invention not only has the characteristics of fast heat transfer and mass transfer, uniform temperature in the furnace, and low energy consumption; but also effectively avoids over-burning of materials, which is suitable for high-performance powders with narrow calcining temperature range and high activity requirements. Calcination preparation is very important and makes efficient use of the heat released from the combustion chamber.

The present invention is a flame-insulated fluidized calciner, which utilizes the high-temperature combustion flame to indirectly heat the fluidized bed calciner, avoids direct contact between the flame and the material, and has a stable combustion flame, which effectively overcomes the over-burning phenomenon of the calcined material in the furnace. At the same time, the high-temperature flue gas passes through the flue from top to bottom, passes through the channel leading to the fluidized bed calciner from the bottom, and enters the hearth of the fluidized bed calciner, so that the high temperature flue gas heats the inside and outside of the fluidized calciner, making the fluid state The heating time of the calcination furnace is doubled, which greatly improves the heat utilization rate compared with the direct combustion heating fluidized calcination furnace with a combustion chamber at the bottom; and the temperature in the calcination furnace is more uniform. The high-temperature flue gas is fully mixed with the fluidized material in the flame fluidized calciner, which greatly improves the heat transfer and mass transfer rate between the high-temperature flue gas and the material, and the temperature in the furnace is uniform, and the temperature difference is less than ±5°C.

This flame-chambered fluidized calciner is suitable for calcining materials such as decarburization, organic matter, hydroxyl water, crystal water, CO2, etc., especially for powder materials with a narrow calcining temperature range and high activity requirements, such as kaolin, magnesite, Activation and calcination of talc, limestone, aluminum hydroxide and other materials to prepare high-performance powders.

Description of drawings

Fig. 1 is the structural diagram of flame-chambered fluidized calciner of the present invention;

Fig. 2 is A-A sectional view of the structure of the present invention's muffled fluidized calciner;

Fig. 3 is the structure B-B sectional view of flame-trap fluidized calciner of the present invention;

Detailed ways

As shown in Fig. 1, Fig. 2 and Fig. 3, it is a structure diagram of a flame-chambered fluidized calciner of the present invention. Flame fluidized calciner includes furnace roof 1, burner burner 2, secondary combustion air pipe 3, combustion chamber 4, furnace outer wall 5, furnace wall 6, flue 7, furnace 8, feed pipe 9, Channel 10, soot cleaning hole 11, furnace bottom cover 12, flame partition wall 13, outlet connecting pipe 14, high temperature gas-solid separator 15, cooling unloader 16.

Wherein, the outer wall 5 of the furnace is a hollow cylinder, and a plurality of burner burners 2 and feeding pipes 9 are arranged on the side peripheral surface thereof. The burner burners 2 are evenly arranged on a plurality of equal-height circles that are vertically evenly distributed. The inner end of the burner 2 of each burner communicates with the combustion chamber 4, and the two correspond one by one. Referring to the sectional view A-A in FIG. The combustion chamber 4 is in the shape of a bell mouth, see the sectional view A-A in Fig. 2, and is arranged on the inner wall surface of the outer wall 5 of the furnace, and its expansion angle α is determined by the combustion state of the burner.

The furnace top cover 1 and the furnace bottom cover 12 are fixedly connected to the upper and lower ends of the furnace outer wall 5 up and down. The center part of the furnace roof 1 is provided with an outlet connecting pipe 14 upwards, and the outer end of the outlet connecting pipe 14 is the outlet of the gas-solid mixture of the calciner. . The inner end of the outlet connecting pipe 14 communicates with the hearth 8 of the fluidized calciner, and the hearth 8 of the fluidized calciner is in the middle of the outer wall 5 of the furnace, surrounded by the hearth wall 6 to form a cylindrical shape, and shares a central axis with the outer wall 5 of the furnace; The gap between the outer peripheral surface of the furnace wall 6 and the inner peripheral surface of the furnace outer wall 5 forms a ring-shaped gap, and a flame partition wall 13 is longitudinally arranged in the ring-shaped gap, and the longitudinal passage separated by the flame partition wall 13 is a flue 7, see Fig. 2 A-A sectional view, B-B sectional view in Fig. 3 . At the bottom of the furnace 8, a channel 10 connecting the flue 7 to the fluidized calcination furnace 8 is provided on the furnace wall 6, see the B-B sectional view in FIG. 3 .

The feed pipe 9 is arranged obliquely downward on the lower part of the furnace outer wall 5 , and the pipeline of the feed pipe 9 passes through the flue 7 and communicates with the furnace 8 .

Bottom cover 12 is provided with soot cleaning hole 11, and soot cleaning hole 11 is positioned at the bottom of flue 7.

The flame partition 13 plays the role of separating the flame and supporting and strengthening the hearth 8 of the calciner, and its thickness is determined by the material and the calcining temperature. The internal and external geometry of the flame-chambered fluidized calciner (including combustion chamber 4, flue 7 and other channels) can be determined by the size of the calciner, heat transfer area and mechanical stability, such as cylindrical, square column, special-shaped, etc.

The setting positions of the burner 2 and the combustion chamber 4 of the flame fluidized calciner are determined according to the height of the flame fluidized calciner and the size of the cross section, and are determined by the height of the calciner in the longitudinal direction. There are 1 to dozens of burners at the bottom; the setting of burners on the cross section is determined by the size of the cross section of the calciner, which can be from 1 to dozens. The burners 2 are arranged in a top-to-top type and a staggered type. The installed quantity and size of the burners 2 are determined by the properties and quantities of the calcined materials and the calcined temperature; the installation angle of the burners 2 is determined by the combustion conditions of the burners and the combustion chamber 4.

The working process of the flame-trap fluidized calciner of the present invention is as follows:

The fuel passes through the burner 2 and the combustion-supporting air of the secondary air pipe 3 is mixed and burned in the combustion chamber 4, and the high-temperature flame and high-temperature flue gas during combustion pass through the combustion chamber 4 and the flue 7, indirectly heating the furnace 8 of the fluidized bed calciner; Under the action of fan power, the high-temperature flue gas in the flue 7 enters the fluidized bed calciner furnace 8 from the channel 10 at the bottom of the furnace 8 as fluidizing gas; the material entering the fluidized bed calciner furnace 8 from the feed pipe 9 is The high-temperature fluidized gas forms a fluidized mixture in the furnace 8, so that the high-temperature gas and materials can produce efficient heat transfer and mass transfer. The calcined material rises upward, and is sent to the high-temperature gas-solid separator 15 through the outlet connecting pipe 14 for gas-solid separation. The hot gas is used for material preheating, and the hot material falls into the cooling unloader 16, and then enters the cooling unloader 16. storage bin. The temperature in the furnace 8 is adjusted and controlled by the burner 4 fuel volume and air volume (closed-loop automatic control or manual control). When the set temperature is 930°C and the furnace 8 is heated to the set temperature, the temperature of the upper, middle, and lower parts of the furnace 8 is within 930±5°C. The material pipe 9 is put into the hearth 8 of the fluidized bed calciner, and the high-temperature fluidizing gas and the powder form a fluidized mixture in the hearth 8 of the fluidized bed calciner to perform rapid heat transfer and mass transfer; when the material balance is reached, the hearth 8 When the temperature is stable, the temperature in the upper, middle and lower parts of the furnace 8 is still within 930±5°C. At this time, sampling and analysis are shown in Table 1, and the powder has not undergone sintering and crystallization. The heat utilization rate of the flame fluidized calciner is about 10% higher than that of the external combustion chamber fluidized calciner.

Table 1. Situation of different calcining methods of hard kaolin powder Calcination method index Ignition loss/% Crystal structure BaiDu/% Flame fluidized calciner 15.32 amorphous state 90.72 Direct combustion heating fluidized calciner 15.33 Amorphous and Crystalline 90.73 Thermogravimetric Analysis 15.32 amorphous state ——

When the flame-insulated fluidized calciner of the present invention is in operation, the high-temperature flame burned in the combustion chamber 4 indirectly heats the fluidized bed calciner, avoiding direct contact between the high-temperature flame and the material, and overcoming the overheating of the material. At the same time, the high-temperature flue gas passes through the flue gas The channel 7 enters the furnace 8 of the fluidized bed calciner from top to bottom from the bottom channel 10 of the furnace 8 as fluidized gas, so that the high-temperature flue gas heats the inside and outside of the fluidized calciner, and the heating time is doubled, which fully and effectively utilizes the fuel released The heat is high, the thermal efficiency is high, and the temperature in the furnace of the fluidized bed calciner is uniform and stable.

The velocity of the fluidizing gas is determined by the properties of the calcined powder, the fluidized state, and the calcining time, and is in the range of 0.1-6.0 m/s; the average residence time of the material in the furnace is determined by the amount of material stored in the furnace 8. The height and cross-sectional area of the muffled fluidized calciner are determined by the material properties, calcination time, processing capacity and fluidization state.

The fuel used in the flame-chambered fluidized calciner can be gas, fuel oil or coal powder, depending on the requirements of the calcined material.

The temperature in the flame-chambered fluidized calciner can be adjusted arbitrarily by the automatic control of the burner within the range of 500-1300 °C, and the furnace temperature difference is within ±5 °C; the atmosphere in the furnace can be adjusted (oxidizing atmosphere, reducing atmosphere).

The average particle size of the calcined material in the flame fluidized calciner is in the range of 0-5000 microns.

Claims (7)

1, a kind of blaze insulating fluidized forge furnace comprises furnace top cover, combustor nozzle, the combustion-supporting airduct of secondary, combustion chamber, furnace outer wall, hearth wall, flue, burner hearth, feed pipe, passage, furnace bottom lid, outlet connecting pipe road, gas-solid separator and cooling discharger; It is characterized in that:

Furnace outer wall is a ducted body, and a plurality of combustor nozzles and feed pipe are set on its lateral circle surface; Combustor nozzle uniform setting on vertical uniform a plurality of contour Zhou Yuan, each combustor nozzle is inner to communicate with the combustion chamber, and both are corresponding one by one, and each combustor nozzle side is provided with the combustion-supporting airduct of secondary;

The combustion chamber is a bell mouth shape, is located at the internal face of furnace outer wall;

Furnace top cover and furnace bottom cover down the two ends up and down that are fixed in furnace outer wall; The furnace top cover central part is provided with the outlet connecting pipe road upward, and outer end, outlet connecting pipe road is the outlet of calciner gas solid mixture, and this outlet communicates with the High Temperature Gas solid separator, and the separator below is the cooling discharger; The outlet connecting pipe road is inner to communicate with the fluidized calcinator burner hearth, and burner hearth is in the middle part of furnace outer wall, is centered on by hearth wall to constitute tubular, with furnace outer wall totally one axis; Hearth wall outer peripheral face and furnace outer wall inner peripheral surface have a gap, and the gap is a flue; The burner hearth bottom position is provided with the passage that flue is connected with burner hearth on hearth wall;

Feed pipe is located at the furnace outer wall bottom to declivity, and the pipeline of feed pipe passes flue and communicates with burner hearth;

Flame partition wall vertically is provided with in the gap of hearth wall outer peripheral face and furnace outer wall inner peripheral surface, and the vertical passage that flame partition wall is separated out is a flue;

Ash removing opening is located at furnace bottom and is covered, and is positioned at the bottom of flue.

2, blaze insulating fluidized forge furnace as claimed in claim 1 is characterized in that: described furnace outer wall, and hearth wall, flue, the geometry of burner hearth is cylindrical, square column type or abnormity.

3, a kind of use method of blaze insulating fluidized forge furnace as claimed in claim 1 or 2, it is characterized in that: the course of work is as follows:

The combustion air of fuel by burner and secondary air channel be in combustion chamber mixed combustion, and thermal-flame during burning and high-temperature flue gas be by combustion chamber and flue, indirect fluidized bed calcination stove burner hearth; Under the blower fan dynamic action, the high-temperature flue gas in the flue enters burner hearth from the passage of burner hearth bottom as fluidizing gas; The material that enters burner hearth from feed pipe forms fluidization with high temperature fluidized gas in burner hearth mixes, and makes high-temperature gas and material produce heat transfer, mass transfer efficiently; The material that calcining the is good ascension that makes progress is sent into the High Temperature Gas solid separator through the outlet connecting pipe road and is carried out gas solid separation, and hot gas is used for the material preheating, and thermal material crashes into the cooling discharger, through the laggard warehouse of supercooling discharger.

4, method as claimed in claim 3 is characterized in that: burner is automation control, and temperature can be regulated arbitrarily in 500 ℃ of-1300 ℃ of scopes in the stove, in the burner hearth temperature difference ± 5 ℃; This high-temperature flue gas is heated inside and outside making fluidized calcinator, and double heat time heating time, has fully effectively utilized the fuel liberated heat, thermal efficiency height, and make that the interior temperature of fluidized bed calcination stove burner hearth is even, stable.

5, method as claimed in claim 3 is characterized in that: described fluidizing gas, its speed are 0.1---6.0 meter per second scopes.

6, method as claimed in claim 3 is characterized in that: described fuel is combustion gas, fuel oil or coal dust

7, method as claimed in claim 3 is characterized in that: described material, and particle mean size is 0---5000 micrometer ranges.

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