CN215757076U

CN215757076U - Two-step method reburning dolomite production system

Info

Publication number: CN215757076U
Application number: CN202121574742.7U
Authority: CN
Inventors: 杨晓东; 许文斌; 徐铭威; 王晶; 郭栋
Original assignee: Henan Zhengzhou Mining Machinery Co ltd
Current assignee: Henan Zhengzhou Mining Machinery Co ltd
Priority date: 2021-07-12
Filing date: 2021-07-12
Publication date: 2022-02-08
Anticipated expiration: 2031-07-12

Abstract

The utility model relates to a two-step method re-burning dolomite production system, which comprises a light burning section and a re-burning section, wherein the light burning section comprises a raw material bin and three furnace bodies, and the re-burning section comprises a mixer, a ball press machine and a rotary kiln; a cyclone separator is connected between two adjacent furnace bodies, the air inlet of the cyclone separator is connected with the upper part of the downstream furnace body, and the air outlet of the cyclone separator is connected with the lower end of the upstream furnace body; the secondary suspension calcining furnace is provided with a gas inlet, and the tertiary suspension cooling furnace is connected with a cooling fan; an auxiliary heat conveying pipeline is connected between the rotary kiln and the secondary suspension calcining furnace, and a dust remover is connected on the auxiliary heat conveying pipeline; the production system also comprises a controller connected with the temperature sensor for sampling, and the controller is connected with the control of the on-off valve. So as to increase part of heat source, thus saving part of fuel and improving the utilization rate of heat.

Description

Two-step method reburning dolomite production system

Technical Field

The utility model relates to a two-step method reburning dolomite production system.

Background

Dolomite is a carbonate mineral, the main components of the dolomite are calcium carbonate and magnesium carbonate, the dolomite deposit resources in China are rich, the ascertained reserves can meet the needs of economic construction, all deposits are developed and utilized, and the producing areas are all over each province; the dolomite can be used in the fields of building materials, ceramics, glass, refractory materials, chemical industry, agriculture, environmental protection, energy conservation and the like. Mainly used as alkaline refractory materials and fluxes for blast furnace ironmaking; producing calcium magnesium phosphate fertilizer and preparing magnesium sulfate; and to the batch for the production of glass and ceramics. Therefore, it is necessary to study the calcination process differently according to the use of the dolomite calcination product. The utility model provides a two-step method is white marble sand production system of burning again, the white marble sand that makes can be used as the raw materials of dolomite refractory material, and the product heat consumption is lower to can improve the compactedness of product, have certain economic benefits.

The existing dolomite calcination means is different according to different purposes, the used means is different, the process route is complex, the control of process parameters is difficult, the cost is higher, and the quality of calcined finished products is unstable. Dolomite is generally crushed and then mixed with corresponding components, and then calcined at a set temperature to prepare dolomite powder which is used as a main raw material of cement. However, the feasibility of the process is not high, the process control is difficult, the quality of the calcined finished product is unstable, and the capacity generated in the process cannot be effectively utilized, so that the relatively high energy consumption is caused.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a two-step method re-burning dolomite production system to solve the problems of unstable quality and large energy consumption of a finished dolomite calcination process product in the prior art.

In order to solve the problems, the two-step method re-burning dolomite production system adopts the following technical scheme:

the two-step method reburning dolomite production system comprises a light burning section and a reburning section, wherein the light burning section comprises a raw material bin and three furnace bodies which are sequentially connected along the conveying and processing sequence of dolomite, the three furnace bodies are respectively a primary suspension preheating furnace, a secondary suspension calcining furnace and a tertiary suspension cooling furnace, and the reburning section comprises a mixer, a ball press machine and a rotary kiln; a cyclone separator is connected between two adjacent furnace bodies, the air inlet of the cyclone separator is connected with the upper part of the downstream furnace body, the air outlet of the cyclone separator is connected with the lower end of the upstream furnace body, and the discharge outlet of the cyclone separator is connected with the lower part of the downstream furnace body; the secondary suspension calcining furnace is provided with a fuel gas inlet, and the tertiary suspension cooling furnace is connected with a cooling fan; an auxiliary heat conveying pipeline is connected between the rotary kiln and the secondary suspension calcining furnace, and a dust remover is connected on the auxiliary heat conveying pipeline; the production system also comprises a controller connected with the temperature sensor in a sampling way, and the controller is connected with the opening and closing valve in a control way.

Furthermore, the secondary suspension calcining furnace is connected with a combustion fan, and the tertiary suspension cooling furnace is connected with an auxiliary air cooler.

Furthermore, an air distribution plate is arranged in the furnace body, a plurality of air caps are arranged on the air distribution plate, and the air caps are communicated with the bottom of the furnace body to heat materials above the air distribution plate by introducing flue gas in a downstream cyclone separator.

Further, a bag type conveyor is arranged at the discharge end of the three-stage suspension cooling furnace, and a limestone powder feed opening is arranged on the bag type conveyor.

The utility model has the following beneficial effects: compared with the prior art, the two-step method reburning dolomite production system related by the utility model has the advantages that in the actual production process, dolomite is introduced into the furnace body through the raw material bin, and is preheated, calcined and cooled through the three furnace bodies to prepare a light-burnt finished product, and then the light-burnt finished product is mixed with other raw materials and enters the rotary kiln through the pressed balls for reburning, so that the harsh requirements of a driven primary reburning dolomite process on the raw materials are met, different auxiliary raw materials can be added according to the production purpose to improve the product quality of the reburning product, and the universality and the applicability of the raw materials are improved; in the calcination time period in the light burning process, the contact area of gas and solid phases is large in the suspension state, the heat exchange is fast, the energy is saved, the characteristics of different dolomite raw materials can be met, the quality of a heavy-burned finished product is uniform and stable, and the heavy-burned finished product can be used as a high-quality refractory material; in addition, the high-temperature flue gas generated in the reburning section is introduced into the secondary suspension calciner after being dedusted by the cyclone separator, so that the amount of the fuel gas entering the secondary suspension calciner and the amount of the flue gas introduced into the auxiliary heating pipeline can be reasonably controlled according to the temperature in the secondary suspension calciner, and the temperature in the kiln body can be effectively controlled. So as to increase part of heat source, thus saving part of fuel and improving the utilization rate of heat.

Drawings

In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings needed to be used in the embodiment will be briefly described as follows:

FIG. 1 is a schematic structural diagram of a two-step process for reburning dolomite production system according to the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is an enlarged view of a portion of FIG. 1 at B;

FIG. 4 is an enlarged view of a portion of FIG. 1 at C;

FIG. 5 is a logic diagram of temperature control of the secondary suspension calciner of FIG. 1.

Description of reference numerals: 1-a first scale; 2-a raw material bin; 3-a second scale; 4-first-stage suspension preheating furnace; 5-a first cyclone separator; 6-bag type dust collector; 7-a draught fan; 8-a chimney; 9-a discharge pipe; 10-electric valve; 11-a second cyclone separator; 12-a secondary suspension calciner; 13-a gas inlet; 14-an opening and closing valve; 15-a third cyclone; 16-three-stage suspension cooling furnace; 17-a cooling fan; 18-an auxiliary air cooler; 19-a combustion fan; 20-a discharge chamber; 21-closed screw conveyor; 22-a belt conveyor; 23-a mixer; 24-ball press machine; 25-rotary kiln; 26-auxiliary heat transfer lines; 27-a cyclone dust collector; 28-a temperature sensor; 29-air distribution plate; 30-blast cap.

Detailed Description

In order to make the technical purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention are further described below with reference to the accompanying drawings and specific embodiments.

The specific embodiment of the two-step heavy-burned dolomite production system related to the utility model is shown in fig. 1 to 5, and the production system comprises a light burning section and a heavy burning section, wherein the light burning section comprises a raw material bin 2 and three furnace bodies which are sequentially connected along the conveying and processing sequence of dolomite, and the three furnace bodies are a primary suspension preheating furnace 4, a secondary suspension calcining furnace 12 and a tertiary suspension cooling furnace 16 respectively.

The entrance of raw materials storehouse 2 is connected with first weigher 1 for in inputing dolomite dust to raw materials storehouse 2, the lower part exit of raw materials storehouse 2 is provided with the push-pull valve, second weigher 3 has been arranged to the below of export, the output of second weigher 3 is connected to one-level suspension preheater 4, and the end of giving vent to anger of suspension preheater is connected with first cyclone 5, the lower part of this first cyclone 5 is returned and is linked to one-level suspension preheater 4, return the solid powder of separation department to in one-level suspension preheater 4, the upper end gas outlet of first cyclone 5 is connected with bag collector 6, bag collector 6 is connected to draught fan 7, and through draught fan 7 with gas suction to in the chimney 8.

The discharge end of the primary suspension preheating furnace 4 is connected with a discharge pipe 9, an electric valve 10 is arranged on the discharge pipe 9, the tail end of the discharge pipe 9 is connected with a second cyclone separator 11, the bottom of the second cyclone separator 11 is connected with a secondary suspension calcining furnace 12, smoke generated in the secondary suspension calcining furnace 12 is connected to the air inlet of the second cyclone separator 11, and the air outlet of the second cyclone separator 11 is connected to the bottom of the primary suspension preheating furnace 4. And a gas inlet 13 is arranged on the secondary suspension calcining furnace 12 and is used for introducing gas into the furnace body for combustion. One side of the secondary suspension calciner 12 is connected with a combustion fan 19.

The discharge end of the secondary suspension calciner 12 is connected with a discharge pipe 9, an electric valve 10 is arranged on the discharge pipe 9, the tail end of the discharge pipe 9 is connected with a third cyclone separator 15, the bottom of the third cyclone separator 15 is connected with a tertiary suspension cooling furnace 16, smoke generated in the tertiary suspension cooling furnace 16 is connected to the air inlet of the third cyclone separator 15, and the air outlet of the third cyclone separator 15 is connected to the bottom of the secondary suspension calciner 12. The bottom of the three-stage suspension cooling furnace 16 is connected with a cooling fan 17, and one side of the cooling furnace is connected with an air assisting fan 18.

After the flue gas in the downstream furnace body is separated by the corresponding cyclone separator, the solid is returned downwards into the furnace body, and the gas is introduced into the upstream furnace body through the upper end gas outlet to perform ventilation and heat supply.

The reburning section comprises a mixer 23, a ball press 24 and a rotary kiln 25, specifically, the discharge end of the three-stage suspension cold zone furnace is connected with a discharge pipe 9, the discharge pipe 9 is connected with a discharge chamber 20, the discharge chamber 20 is connected with a closed screw conveyor 21, a belt conveyor 22 is arranged at the discharge end of the closed screw conveyor 21, a limestone powder feed opening is arranged above the belt conveyor 22, the light-burnt product of dolomite powder is premixed with limestone powder in the place, the output end of the belt conveyor 22 is connected with the mixer 23, the mixer 23 is connected with the ball press 24 through the belt conveyor 22, the tail end of the ball press 24 is connected with the rotary kiln 25, the rotary kiln 25 is a long kiln, and the reburning finished product is made of dolomite powder after the rotary kiln 25.

In addition, an auxiliary heat conveying pipeline 26 is connected between the rotary kiln 25 and the secondary suspension calcining furnace 12, and a dust remover is connected to the auxiliary heat conveying pipeline 26; the gas inlet 13 and the auxiliary heat conveying pipeline 26 of the secondary suspension calcining furnace 12 are provided with an opening and closing valve 14 door, the secondary suspension calcining furnace 12 is internally provided with a temperature sensor 28, the production system further comprises a controller connected with the temperature sensor 28 in a sampling mode, and the controller is connected with the opening and closing valve 14 door in a control mode.

The first weighing scale 1 and the second weighing scale 3 are both closed spiral weighing scales.

The furnace body is internally provided with an air distribution plate 29, a plurality of air caps 30 are arranged on the air distribution plate 29, and the air caps 30 are communicated with the bottom of the furnace body so as to heat materials above the air distribution plate 29 by introducing flue gas in a downstream cyclone separator.

The production principle of the production system in actual operation involves the following processes:

and (3) light burning:

a preheating section: the dolomite powder crushed and ground to a certain fineness (200-300 meshes) enters a raw material bin 2 through a first metering scale 1, and is quantitatively fed into a primary suspension preheating furnace 4 through a gate valve by a second metering scale 3; wherein, the hood 30 on the air distribution plate 29 at the bottom of the primary suspension preheating furnace 4 is provided with an air outlet, the opening position of the air outlet is upward, the included angle between the air outlet and the horizontal plane can be set to be 30-60 degrees, so that the blown dolomite dust is in a suspension state conveniently; the dolomite dust falls on the air distribution plate 29, is blown upwards from the bottom by the hot air flow generated by the secondary suspension calcining furnace 12, is in suspension fluidization, and fully exchanges heat in a short time to finish the preheating process. The airflow mixed with dolomite dust enters a first cyclone separator 5 from a hearth outlet and is subjected to gas-solid separation, the dolomite dust returns to a bed layer, and the airflow sequentially passes through a bag type dust collector 6 and an induced draft fan 7 and enters a chimney 8 to be discharged. The preheating time of the dolomite dust is controlled to be 10-20 min, and the air speed of the combustion-supporting fan 19 is controlled to enable the air speed entering the bottom of the preheating furnace through the blast cap 30 to be about 3-5 m/s.

A calcination section: the preheated dolomite powder enters a secondary suspension calcining furnace 12 through a discharge pipe 9 and a second cyclone separator 11; wherein, install motorised valve 10 in discharging pipe 9 to realize timing and quantitative feeding, discharging pipe 9 is connected with second cyclone 11 lower part. Similarly, the preheated dolomite powder is in suspension fluidization in a two-stage suspension calcining furnace, and the calcining process of the material is completed in a short time. The middle lower part of the secondary suspension calciner 12 is provided with a combustion fan 19 to supplement a part of required air quantity, and the middle upper part is provided with a fuel inlet, wherein the fuel can be natural gas, coal powder and the like. Meanwhile, the high-temperature flue gas generated in the reheating section is introduced into the secondary suspension calciner 12 after being dedusted by the cyclone dust collector 27 to increase part of heat sources, when the temperature in the calciner is within the range of 900-1100 ℃, the temperature sensor 28 feeds back signals to the controller, the controller sends instructions to the on-off valve 14 of the fuel gas inlet and the on-off valve 14 on the auxiliary heat conveying pipeline 26, the on-off valve 14 on the auxiliary heat conveying pipeline 26 is started, and the on-off valve 14 of the fuel gas inlet is closed; when the temperature in the furnace is less than 900 ℃, the temperature sensor 28 similarly feeds back a signal to the controller, the controller gives an instruction to the on-off valve 14 for gas intake and the on-off valve 14 on the auxiliary heat transfer pipeline 26, and the two on-off valves 14 are started to maintain the temperature in the furnace to 900 to 1100 ℃. And controlling the temperature in the second-stage suspension calcining furnace to be 900-1100 ℃. The calcination time of the dolomite powder is controlled to be 15-25 min, and the air speed of the auxiliary air cooler is controlled to enable the air speed entering the bottom of the secondary suspension calciner 12 to be about 5-8 m/s.

A cooling section: the calcined material enters a three-stage suspension cooling furnace 16 through a discharge pipe 9 and a third cyclone separator 15; wherein, install motorised valve 10 in discharging pipe 9 to realize timing and quantitative feeding, discharging pipe 9 is connected with third cyclone 15 lower part. The calcined material is fluidized in suspension in the three-stage suspension cooling furnace 16, and the cooling process of the material is completed in a short time. The cooling fan 17 blows air from the bottom of the three-stage suspension cooling furnace 16 to enter the furnace, so that the material is rapidly cooled while the material is in a suspension state, and meanwhile, an auxiliary air cooler at the middle lower part of the three-stage suspension cooling furnace 16 assists in cooling the material. The cooled material enters the discharging chamber 20 through the discharging pipe 9, and similarly, an electric valve 10 is arranged in the discharging pipe 9 to realize quantitative and timing feeding. And a closed screw conveyor 21 connected to the bottom of the discharging chamber 20 completes dust-free conveying of the materials. The cooling time of the dolomite dust is controlled to be 30-60 min (or the air speed of the cooling fan 17 is freely adjusted to accelerate the cooling speed of the dolomite dust, so that the cooling time is shortened) until the temperature is reduced to below 50 ℃. And controlling the air speed of the cooling fan 17 to enable the air speed entering the bottom of the secondary suspension calcining furnace 12 to be about 5-12 m/s.

A re-burning section:

after being matched with limestone powder, the lightly calcined dolomite finished product enters a mixer 23 through a belt conveyor 22 to be uniformly mixed, then is sent to a ball press 24 through the belt conveyor 22 to be pressed into oval spherical cores with the diameter of about 25mm, then enters a rotary kiln 25 through a kiln inlet chute through the belt conveyor 22 to be calcined, the calcining temperature is controlled to be 1600-1700 ℃, the calcining time is 8-10 hours, and finally the re-calcined finished product is obtained. The rotary kiln 25 is a long kiln.

Finally, it should be noted that: the above embodiments are merely illustrative and not restrictive of the technical solutions of the present invention, and any equivalent substitutions and modifications or partial substitutions made without departing from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. The two-step method reburning dolomite production system is characterized by comprising a light burning section and a reburning section, wherein the light burning section comprises a raw material bin and three furnace bodies which are sequentially connected along the conveying and processing sequence of dolomite, the three furnace bodies are respectively a primary suspension preheating furnace, a secondary suspension calcining furnace and a tertiary suspension cooling furnace, and the reburning section comprises a mixer, a ball press machine and a rotary kiln; a cyclone separator is connected between two adjacent furnace bodies, the air inlet of the cyclone separator is connected with the upper part of the downstream furnace body, the air outlet of the cyclone separator is connected with the lower end of the upstream furnace body, and the discharge outlet of the cyclone separator is connected with the lower part of the downstream furnace body; the secondary suspension calcining furnace is provided with a fuel gas inlet, and the tertiary suspension cooling furnace is connected with a cooling fan; an auxiliary heat conveying pipeline is connected between the rotary kiln and the secondary suspension calcining furnace, and a dust remover is connected on the auxiliary heat conveying pipeline; the production system also comprises a controller connected with the temperature sensor in a sampling way, and the controller is connected with the opening and closing valve in a control way.

2. The two-step process reburning dolomite production system according to claim 1, wherein the secondary suspension calciner is connected with a combustion fan, and the tertiary suspension cooling furnace is connected with a cooling fan.

3. The two-step reburning dolomite production system according to claim 1, wherein the furnace body is internally provided with an air distribution plate, a plurality of air caps are arranged on the air distribution plate, and the air caps are communicated with the bottom of the furnace body so that flue gas in a downstream cyclone separator can be introduced to heat materials above the air distribution plate.

4. A two-step method double-burned dolomite production system according to any one of claims 1 to 3, wherein a bag conveyor is arranged at the discharge end of the three-stage suspension cooling furnace, and a limestone powder feed opening is arranged on the bag conveyor.