WO2016150100A1

WO2016150100A1 - Heat-accumulating lime rotary kiln

Info

Publication number: WO2016150100A1
Application number: PCT/CN2015/088329
Authority: WO
Inventors: 贾会平
Original assignee: 石家庄新华能源环保科技股份有限公司
Priority date: 2015-03-24
Filing date: 2015-08-28
Publication date: 2016-09-29
Also published as: CN104803615A

Abstract

A heat-accumulating lime rotary kiln comprises two rotary kilns (13), a cooler (16), one or two heat accumulators (4), an air blower (11), a cooling fan (17) and an exhaust emission system. The two rotary kilns (13) are connected via a kiln tail hood (14) and the cooler (16). An upper air port of the heat accumulator (4) is connected to, via a three-way valve (1), the air blower (11) and the exhaust emission system respectively. The heat accumulator (4) has a sleeve structure, and an inner sleeve (20) and an outer sleeve are concentrically provided. The inner sleeve (20) and the outer sleeve form an annular space (21) therebetween. A lower portion of the annular space (21) is in communication with the rotary kiln (13) via a kiln head (22). A lime kiln is provided with a burner (7) and an auxiliary burner (15). The burner (7) is mounted at the kiln head (22), and the auxiliary burner (15) is mounted at the kiln tail hood (14). The heat accumulator (4) employs a sleeve parallel-flow structure, has a good heat transfer effect, and enables a machined material to be uniformly preheated. The two rotary kilns (13) are combined with the heat accumulator (4) via the kiln tail hood (14), and the burnt raw material and combustion air are preheated, thus facilitating continuity and stability of lime production, and improving a production capacity.

Description

Regenerative lime rotary kiln

Technical field

The invention belongs to the technical field of industrial furnaces and relates to a rotary kiln, in particular to a regenerative lime rotary kiln.

Background technique

Rotary kiln refers to rotary calcining kiln. Lime rotary kiln is a kiln that uses a wide range of calcined small particles. It is suitable for steel, calcium carbide chemical, non-ferrous metals and other production enterprises. The lime rotary kiln can directly calcine 10~40mm fine-grained raw material limestone or light burnt dolomite, which has the characteristics of good raw material adaptability, large output, uniform product, high activity and stable production operation. The lime rotary kiln has a simple structure, the airflow is smooth, the sulfur-containing flue gas can be discharged in time, and the sulfur in the fuel is not easy to adhere. Therefore, the calcined product has low sulfur content, high purity, and meets the quality requirements of the finished product; at the same time, the material rolls in the circumferential direction. It moves along the axial direction and is evenly heated. The temperature of the combustion device is easy to control, the calcination quality is good, and the product activity can reach 360mlL or more.

However, due to the large energy consumption of the lime rotary kiln, the promotion and development of the lime rotary kiln is seriously restricted. The Chinese utility model patent with the application number 200920227150.0 discloses an "energy-saving rotary kiln calcination system", in which the "rotary kiln calcination system includes a rotary kiln, the fuel gas is fed from the low end of the rotary kiln, from the high end of the rotary kiln; The high-end of the rotary kiln is taken from the lower end of the rotary kiln. The high-end rotary kiln is connected to a heat recovery chamber. The heat recovery chamber is provided with a feed preheating pipe connected to the rotary kiln, and the raw material is preheated by feeding. After the tube is preheated, it enters the rotary kiln. In this way, the raw material is dried and heated before entering the rotary kiln.". However, in this patent, the preheating pipe has limited energy recovery by preheating raw materials, and there is sufficient space for energy saving. In addition, the patented rotary kiln is a single rotary kiln, which is not conducive to expanding production capacity.

Summary of the invention

The object of the invention is to provide a regenerative lime rotary kiln, which utilizes two rotary kiln and a heat accumulator to fully utilize the waste heat of the flue gas to preheat the raw materials and air, thereby reducing energy consumption and expanding lime production capacity.

The technical solution of the invention is a regenerative lime rotary kiln comprising two rotary kiln, a cooler, one or two regenerators, a loading system, a discharging system, a blower, a cooling fan and an exhaust gas discharge system. The rotary kiln is provided with a kiln head, and the two rotary kiln are connected to the cooler through a kiln tail cover, and the cooler is connected to the discharge system. The upper port of the regenerator is connected to the loading system via a feed valve. The upper port of the regenerator is connected to the blower and the exhaust system through a three-way valve, and the cooling fan is connected to the cooler. The heat accumulator is of a sleeve type structure, comprising an outer cylinder and an inner cylinder, an annular space between the outer cylinder and the inner cylinder, and a lower part of the annular space is connected with the rotary kiln through the kiln head. The regenerator has 2 to 10 pushers, and the pusher has a pusher plate. The lime kiln is provided with a burner and an auxiliary burner, the burner is installed in the kiln head, and the auxiliary burner is installed in the kiln tail cover.

The upper part of the inner cylinder has a tapered structure, and the middle section has a circular structure. The two rotary kiln are symmetrically arranged or asymmetrically arranged on both sides of the kiln tail cover. The heat accumulator is provided with a partition which divides the heat accumulator into two parts. One of the two rotary kiln is connected to the cooler through the kiln tail cover and the other end is connected to the heat accumulator through the kiln head. Exhaust system includes dust collector and induced draft fan And the chimney. The three-way valve is connected to the exhaust gas discharge system through the waste heat power generation equipment. Waste heat power generation equipment includes waste heat boilers, steam turbines and generators. The waste heat boiler is provided with a steam coil, the steam coil is connected with the steam turbine, and the steam turbine is coaxially connected with the generator set. The burner and the auxiliary burner are gas fuel burners, liquid fuel burners or solid fuel burners. The loading system includes a loading machine, a loading trolley and a hopper. The rotary kiln is equipped with temperature measuring equipment, and the temperature measuring equipment is a wireless signal temperature measuring device.

The regenerative lime rotary kiln of the invention preheats the processed material by adding the regenerator, utilizing the flue gas generated by the calcination process and the decomposition gas generated by the decomposition of the material, and preheating the air by using the preheated heated material to improve the air. The combustion temperature of the fuel makes full use of the waste heat and reduces energy consumption. The heat accumulator adopts a sleeve parallel flow structure, and the heat transfer effect is good, which is favorable for uniform preheating of the material to be processed. Through the combination of two rotary kiln and heat accumulator in the kiln tail cover, preheating the calcined raw material and combustion air is realized, which is beneficial to the continuity and stability of lime production and expands production capacity. The burner is placed at the junction of the regenerator and the kiln head or at the kiln head, increasing the selectivity of the production operation.

DRAWINGS

1 is a schematic structural view of a regenerative lime rotary kiln according to the present invention;

2 is a schematic structural view of another embodiment of the present invention;

Figure 3 is a cross-sectional view of the heat accumulator;

Figure 4 is a cross-sectional view of another embodiment of the heat accumulator;

among them:

1-3-way valve, 2-feed valve, 3-feed system, 4-heat accumulator, 5-propeller, 6-propeller plate, 7-burner, 8-flue pipe, 9- Valve, 10-waste heat power generation equipment, 11-blower, 12-temperature measuring equipment, 13-rotary kiln, 14-kiln tail cover, 15-auxiliary burner, 16-cooler, 17-cooling fan, 18-discharge system 19-separator, 20-inner cylinder, 21-annular space, 22-kiln head.

detailed description

The invention will now be described in detail in conjunction with the embodiments and the drawings. The scope of the present invention is not limited to the embodiments, and any modifications made by those skilled in the art within the scope of the claims are also within the scope of the present invention.

Example 1

The regenerative lime rotary kiln of the present invention, as shown in FIG. 1, comprises two rotary kiln 13, a cooler 16, two regenerators 4, a loading system 3, a discharging system 18, a blower 11, and a cooling fan 17, Waste heat power generation equipment 10 and an exhaust gas discharge system. The two rotary kiln are arranged symmetrically on the left and right sides, respectively, on both sides of the kiln tail cover. The rotary kiln is provided with a kiln head 22, and the two rotary kiln are connected to the cooler through the kiln tail cover 14, the cooler 16 is connected to the discharge system, and the cooling fan is connected to the cooler. The upper port of the heat accumulator 4 is connected to the loading system 3 via a feed valve 2. The two heat accumulators 4 are of a sleeve type structure. As shown in FIG. 3, the heat accumulator 4 includes an outer cylinder and an inner cylinder 20. The upper portion of the inner cylinder has a tapered structure, and the middle section has a circular structure. An annular space 21 is defined between the outer cylinder and the inner cylinder. The annular space is a space through which the raw material passes, and the flue gas or air exchanges heat with the raw material in the annular space, and the lower part of the annular space passes through The kiln head 22 is connected to the rotary kiln 13. The upper port of the heat accumulator 4 is connected to the blower 11 all the way through the three-way valve 1, and the other path is connected to the waste heat power generating device 10 through the pipe flue gas line 8, and the outlet of the waste heat power generating device is connected to the exhaust gas discharge system. The exhaust system includes a dust collector, an induced draft fan and a chimney. The waste heat power generation facility 10 includes a waste heat boiler, a steam turbine, and a generator. The waste heat boiler is provided with a steam coil, the steam coil is connected with the steam turbine, and the steam turbine is coaxially connected with the generator set. The lime kiln is provided with a burner 7 and an auxiliary burner 15, the burner and the auxiliary burner are gas fuel burners, the burner is mounted on the kiln head 22, and the auxiliary burner is mounted on the kiln tail cover 14. The heat accumulator 4 is provided with six pushers 5, and the pusher has a pusher plate 6, and the pusher plate 6 is evenly distributed in the lower portion of the heat accumulator. The rotary kiln is provided with a temperature measuring device 12, and the temperature measuring device is an infrared wireless signal temperature measuring device, which is installed on the kiln body of the rotary kiln on both sides, and is rotated with the kiln body to measure the temperature and wirelessly transmitted to the control room.

The operation process of the regenerative lime rotary kiln of the present invention is that the limestone raw material enters the heat accumulator 4 via the left loading system 3, and the cone passing through the upper portion of the inner cylinder 20 is evenly distributed in the annular space 21. The flue gas from the left rotary kiln 13 enters the annular space of the heat accumulator 4 through the kiln head 22, and preheats the raw materials in the heat accumulator. The preheated limestone raw material is pushed into the kiln head 22 by the pusher 5, and is calcined through the kiln head into the left rotary kiln 13. The calcined lime passes through the kiln tail cover 14 to the cooler 16, and the cooling air sent from the cooling fan 17 cools the high temperature lime in the cooler 16, and the cooled lime is discharged through the discharge port and the discharge system 18. The gas operation mode is that the air blasted by the right side blower 11 passes through the three-way valve 1 to the right side heat accumulator 4, and the heat released from the raw material preheated in the heat accumulator preheats the combustion air. The fuel gas enters the right burner 7 to eject the fuel, mixes with the air preheated by the regenerator, enters the right rotary kiln 13 through the kiln head 22 for combustion, and calcinates the limestone material in the right rotary kiln. The flue gas and the decomposition gas generated by the combustion are mixed together with the gas for cooling the lime through the kiln tail cover 14 and the cooler 16 to continue heating the limestone material to the left rotary kiln 13. Then, the mixed gas preheats the limestone material through the kiln head and the left side heat accumulator 4 and stores heat, and the flue gas after releasing the heat is generated by the three-way valve 1 and the flue gas pipeline 8 to the waste heat power generation device 10, and the waste after power generation The flue gas is discharged to the exhaust system, and the temperature of the flue gas is lower than 150 °C. According to the set temperature of the flue gas discharge, the rotary kiln 13 on both sides alternately performs calcination and preheating, and the regenerators 4 on both sides alternately store heat and release heat to preheat the air through the three-way valve 1, the valve 9 and the feed valve. The action of 2 is alternately operated, and the set temperature of the flue gas emission is 150 °C. When the preheating temperature is insufficient, the auxiliary burner 15 is selected to be used, and the fuel is burned to supplement the heat.

Example 2

According to another embodiment of the present invention, as shown in FIGS. 2 and 4, the regenerative lime rotary kiln includes two rotary kiln 13 and one heat accumulator 4, and the heat accumulator 4 is provided with a partition 19, which will be stored. The heat exchanger 4 is divided into two parts, and the two parts have the same structure. One of the two rotary kiln 13 is connected to the cooler 16 through the kiln tail cover 14, and the other end is connected to the heat accumulator 4. The two rotary kiln 13 are alternately calcined and preheated, and the material spaces on both sides of the accumulator partition 19 alternately store heat and release heat to preheat the air, and are realized by the actions of the three-way valve 1, the valve 9 and the feed valve 3. Alternate operation, the set temperature of the flue gas emission is 160 °C. Other devices and connection states are the same as in the first embodiment. The advantage of this embodiment is that the device is compact and saves space.

Claims

A regenerative lime rotary kiln comprising two rotary kiln (13), a cooler (16), one or two regenerators (4), a feeding system (3), a discharging system (18), a blower (11), a cooling fan (17) and an exhaust gas discharge system, the rotary kiln is provided with a kiln head (22), and two rotary kiln are connected to the cooler through a kiln tail cover (14), and the cooler is connected to the discharge system The upper port of the regenerator is connected to the loading system through a feed valve; and the upper port of the regenerator (4) is connected to the blower and the exhaust system through a three-way valve (1), the cooling fan Connected to a cooler; the heat accumulator is of a sleeve type structure, comprising an outer cylinder and an inner cylinder (20), an annular space (21) between the outer cylinder and the inner cylinder, and a lower portion of the annular space passes through the kiln head The rotary kiln is connected; the regenerator is provided with 2 to 10 pushers, and the pusher is provided with a pusher plate; the lime kilns are provided with a burner (7) and an auxiliary burner (15), which are burned The mouth is installed in the kiln head, and the auxiliary burner is installed in the kiln tail cover.
The regenerative lime rotary kiln according to claim 1, wherein the upper portion of the inner cylinder (20) has a tapered structure and a circular cross section in the middle.
The regenerative lime rotary kiln according to claim 1, characterized in that the two rotary kiln (13) are arranged symmetrically or asymmetrically on both sides, respectively located on both sides of the kiln tail cover (14).
A regenerative lime rotary kiln according to claim 1, wherein said heat accumulator (4) is provided with a partition (19), the partition dividing the heat accumulator into two parts; and two rotary kiln (13) One end is connected to the cooler (16) through the kiln tail cover (14), and the other end is connected to the heat accumulator through the kiln head (22).
A regenerative lime rotary kiln according to claim 1 wherein said exhaust gas discharge system comprises a precipitator, an induced draft fan and a chimney.
A regenerative lime rotary kiln according to claim 1, characterized in that said three-way valve (1) is connected to the exhaust gas discharge system via a waste heat power generating device (10).
The regenerative lime rotary kiln according to claim 6, wherein the waste heat power generation device (10) comprises a waste heat boiler, a steam turbine and a generator; the waste heat boiler is provided with a steam coil, and the steam coil is connected to the steam turbine. The steam turbine is coaxially connected to the generator set.
A regenerative lime rotary kiln according to claim 1, wherein said burner (7) and auxiliary burner (15) are gas fuel burners, liquid fuel burners or solid fuel burners.
The regenerative lime rotary kiln according to claim 1, wherein the rotary kiln is provided with a temperature measuring device (12), and the temperature measuring device is a wireless signal temperature measuring device.