CN112479607B

CN112479607B - Hanging cylinder type parallel-flow heat storage double-hearth kiln with cooling structure

Info

Publication number: CN112479607B
Application number: CN202011381623.XA
Authority: CN
Inventors: 贾会平
Original assignee: Shijiazhuang Xinhua Energy Environmental Protection Technology Co Ltd
Current assignee: Shijiazhuang Xinhua Energy Environmental Protection Technology Co Ltd
Priority date: 2020-12-01
Filing date: 2020-12-01
Publication date: 2022-05-20
Anticipated expiration: 2040-12-01
Also published as: CN112479607A

Abstract

The invention relates to a suspended cylinder type parallel-flow heat storage double-hearth kiln with a cooling structure. The double-hearth kiln body consists of an inner furnace wall and an outer furnace wall, and the inner furnace wall is hung on the outer furnace wall. The lower part of the inner furnace wall is provided with an annular suspended cylinder type furnace wall, the lower part of the annular suspended cylinder type furnace wall is provided with 6-12 supporting walls, and the supporting walls are uniformly distributed along the circumference and independently supported. The annular suspension cylinder type furnace wall is composed of a steel structure jacket and refractory bricks, a heat conduction oil circulation cavity is arranged inside the steel structure jacket, and the heat conduction oil circulation cavity is connected with a heat conduction oil circulation system through a heat conduction oil inlet and a heat conduction oil outlet. According to the invention, the annular suspended cylinder type furnace wall composed of the steel structure jacket and the refractory bricks is adopted, and the suspended cylinder body is cooled by circulating heat conduction oil, so that the cooling effect of the suspended cylinder and the production safety are improved, and the production period and the service life of equipment are prolonged.

Description

Hanging cylinder type parallel-flow heat storage double-hearth kiln with cooling structure

Technical Field

The invention belongs to the technical field of chemical building material production equipment, relates to an industrial furnace, and particularly relates to a suspended cylinder type parallel-flow double-hearth kiln with a cooling structure.

Background

The double-hearth kiln is also called a double-hearth parallel flow heat accumulating type lime kiln, and fuel enters from the upper end of a calcining zone and is in parallel flow with raw materials. Since the fuel is injected from the upper part of the calcining zone, the raw material can absorb most of the heat released by the fuel, and the temperature of the calcining zone is 950 ℃ on average. Another important feature of the double-hearth kiln is heat accumulation, and a part of combustion air is preheated by using the heat accumulation. The thermal characteristics of cocurrent calcination and countercurrent heat storage determine that the double-hearth kiln has high thermal efficiency, the heat energy consumption is the lowest in all types of lime kilns such as rotary kilns and sleeve kilns, and the total heat consumption for producing lime is lower than 3.8 GJ/ton lime. The double-hearth kiln is beneficial to calcining limestone materials with small grain sizes, and the produced lime has good quality.

The suspension cylinder system is a key core device of the cocurrent flow double-chamber kiln, the cylinder body is arranged in the kiln chamber, and in order to prevent the cylinder body from being damaged by heat, the inside of the cylinder body is cooled by using circulating air. Because the internal structure of the suspension cylinder belongs to a hollow structure formed by heat-resistant stainless steel and is positioned at the calcining part of the kiln, in order to avoid the deformation of the structure under high temperature, at least 2 fans are needed to respectively carry out uninterrupted cooling and air supply protection on two suspension cylinder bodies of the kiln. The Roots blower pressurizes air, the air is blown into the suspension cylinder, the air cools the suspension cylinder, and cooled hot air is led out through a pipeline and is emptied or pumped into a combustion air pipeline for secondary utilization. The structure has the defects that the system pipeline is too long, so that the system pressure drop is too high, the cooling air pressure of the suspension cylinder is the highest point in a kiln pressure system, and the energy consumption is increased; the initial temperature of the cooling air of the suspension cylinder is too high, and can reach more than 80 degrees in summer and more than 60 degrees in winter, thereby influencing the cooling effect. Based on the defects, the cooling effect of the suspension cylinder cannot meet all production requirements, and the lime kiln is forced to be lowered.

Disclosure of Invention

The invention aims to provide a hanging cylinder type parallel-flow double-hearth kiln with a cooling structure.

The technical scheme of the invention is as follows: a suspended cylinder type parallel-flow heat storage double-chamber kiln with a cooling structure comprises a double-chamber kiln body, a feeding device, a discharging device, an air supply system and a waste gas discharge system. The double-hearth kiln body consists of an upper inner furnace wall and a lower outer furnace wall, and the inner furnace wall is hung on the outer furnace wall. The double-hearth kiln body is internally provided with a preheating zone, a calcining zone and a cooling zone. The double-chamber kiln body comprises a kiln chamber A and a kiln chamber B, wherein the upper parts of the two kiln bodies are provided with air inlet and outlet ports which are connected with an air blower and a waste gas discharge system through a three-way valve. The calcining zone is provided with a burner, the cooling zone is provided with a cooling air inlet, and the cooling air inlet is connected with a cooling fan through a three-way valve. The lower part of the inner furnace wall is provided with an annular suspension cylinder type furnace wall, the lower part of the annular suspension cylinder type furnace wall is provided with 6-12 support walls, the support walls are uniformly arranged along the circumference and independently support the suspension cylinder type furnace wall, and the lower part of each support wall is connected with the outer furnace wall. The annular suspension cylinder type furnace wall is composed of a steel structure jacket and an external masonry refractory brick, a heat conduction oil circulation cavity is formed in the steel structure jacket, a heat conduction oil inlet is connected with a heat conduction oil circulation system through an oil supply pipe, a heat conduction oil outlet is connected with the heat conduction oil circulation system through an oil return pipe, and the oil return pipe of the oil supply pipe is located inside the supporting wall.

The connection part of the annular suspension cylinder type furnace wall and the inner furnace wall is provided with refractory fiber. The lower part of the annular suspension cylinder type furnace wall is connected with a support wall through a pouring layer, a steel structure jacket is provided with a support structure, the support structure is provided with an anchoring piece, and the anchoring piece is embedded into the pouring layer. An annular channel is arranged between the annular suspension cylinder type furnace wall and the outer furnace wall, and the double-hearth kiln is provided with an air cannon which is connected to the annular channel through a pipeline and used for blowing soot by the annular channel.

The heat conducting oil circulating system is provided with a circulating pump, a heat conducting oil heat exchanger and a cooler, and the heat conducting oil outlet is connected to the heat conducting oil inlet through the circulating pump, the heat conducting oil heat exchanger and the cooler. The steel structure jacket in the annular suspension cylinder type furnace wall is of a segmented structure, and each segment of steel structure jacket is provided with a heat conduction oil inlet and a heat conduction oil outlet. The support wall is formed by laying refractory bricks or pouring concrete. The burner is an inserted burner, a combustion beam or a peripheral burner; the inserted burner is a gas fuel burner, a liquid fuel burner or a solid fuel burner.

The hanging cylinder type parallel-flow heat storage double-hearth kiln with the cooling structure has the advantages that the annular hanging cylinder type furnace wall formed by the steel structure jacket and the refractory bricks is arranged at the joint part of the inner furnace wall and the outer furnace wall, and the hanging cylinder body is cooled by utilizing the heat conduction oil in a circulating manner, so that the cooling effect of the hanging cylinder is improved. Bear through the knee wall and hang cylinder type furnace wall, and the interior furnace wall in upper portion is direct to be supported by the outer furnace wall of lower part, makes double-chamber kiln overall structure more firm, utilizes the air cannon to blow the ash, has reduced the deposition, and the flue gas passageway is not fragile, has improved double-chamber kiln's operational safety nature, is favorable to prolonging the life of production cycle and equipment. The heat conducting oil cooling areas of the steel structure jacket of the suspended cylinder type furnace wall are divided into a plurality of groups, so that the cooling effect can be improved, and the safe operation of the double-hearth kiln is facilitated. The waste heat of the heat conducting oil after cooling the suspended cylinder body preheats combustion air, so that the heat consumption can be reduced, and the energy is saved.

Drawings

FIG. 1 is a schematic structural diagram of a suspended cylinder type parallel-flow heat accumulation double-chamber kiln with a cooling structure;

FIG. 2 is detail D of FIG. 1;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 1;

fig. 4 is a cross-sectional expanded view of the steel-structured jacket.

Wherein: 1-feeding inlet, 2-blower, 3-heat conducting oil heat exchanger, 4-air inlet and outlet, 5-inner furnace wall, 6-annular channel, 7-outer furnace wall, 8-supporting wall, 9-cooling air inlet, 10-discharging outlet, 11-annular suspended cylinder type furnace wall, 12-three-way valve, 13-burner, 14-flue gas channel, 15-air cannon, 16-cooling zone, 17-cooling fan, 18-waste gas discharge system, 19-preheating zone, 20-calcining zone, 21-refractory fiber, 22-refractory brick, 23-steel structure jacket, 24-anchoring piece, 25-supporting structure, 26-heat conducting oil inlet, 27-heat conducting oil outlet, 28-heat conducting oil circulation cavity and 29-pouring layer.

Detailed Description

The present invention will be described in detail with reference to the following examples and drawings. The scope of protection of the invention is not limited to the embodiments, and any modifications made by those skilled in the art within the scope defined by the claims also belong to the scope of protection of the invention.

The invention relates to a suspended cylinder type parallel-flow heat storage double-chamber kiln with a cooling structure, which comprises double-chamber kiln bodies, a feeding device, a discharging device, an air supply system, a heat-conducting oil circulating system and a waste gas discharging system 18 as shown in figure 1, wherein a flue gas channel 14 is arranged between the two kiln bodies. The double-hearth kiln body consists of an upper inner furnace wall 5 and a lower outer furnace wall 7, the inner furnace wall is hung on the outer furnace wall, and a preheating zone 19, a calcining zone 20 and a cooling zone 16 are arranged in the double-hearth kiln body. The double-chamber kiln body comprises a kiln chamber A and a kiln chamber B, wherein the upper parts of the two kiln bodies are provided with an air inlet and outlet 4, the lower parts of the two kiln bodies are provided with a discharge hole 10, the air inlet and outlet is connected with an air blower 2 and a waste gas discharge system 18 through a three-way valve 12, and the discharge hole is connected with a discharge device. The calcining zone is provided with a burner 13 which is an insert burner which is a gas fuel burner. The cooling zone is provided with a cooling air inlet 9 which is connected with a cooling fan 17 through a three-way valve. The waste gas discharge system comprises a dust remover, an induced draft fan and a chimney. The lower part of the inner furnace wall 5 is provided with an annular hanging cylinder type furnace wall 11, as shown in figure 3, the lower part of the annular hanging cylinder type furnace wall is provided with 6 support walls 8, and the support walls 8 are uniformly arranged along the circumference of the kiln chamber and independently support the hanging cylinder type furnace wall. The support wall 8 is constructed by refractory bricks, and the lower part of the support wall is connected with the outer furnace wall. As shown in fig. 2, the annular suspended cylinder type furnace wall 11 is composed of a steel structure jacket 23 and refractory bricks 22 built outside the steel structure jacket, a heat conduction oil circulation cavity 28 is arranged inside the steel structure jacket, and the heat conduction oil circulation cavity is provided with a heat conduction oil inlet 26 and a heat conduction oil outlet 27. The heat conducting oil inlet 26 is connected with the heat conducting oil circulating system through an oil supply pipe, the heat conducting oil outlet 27 is connected with the heat conducting oil circulating system through an oil return pipe, and the oil return pipe of the oil supply pipe is positioned inside the support wall 8. The connection part of the annular suspension cylinder type furnace wall 11 and the inner furnace wall 5 is provided with refractory fiber 21. The lower part of the ring-shaped suspension cylinder type furnace wall 11 is connected with the supporting wall 8 through a casting layer 29, and the steel structure jacket 23 is provided with a supporting structure 25 which is provided with an anchoring piece 24, and the anchoring piece is embedded into the casting layer 29. An annular channel 6 is arranged between the annular suspension cylinder type furnace wall 11 and the outer furnace wall 7, the double-chamber kiln is provided with an air cannon 15, the air cannon is connected to the annular channel 6 through a pipeline, and the annular channel is provided with an outlet of the air cannon and used for spraying air to blow out dust in the annular channel 6.

As shown in FIG. 4, the steel structure jacket 23 in the annular suspended cylinder type furnace wall 11 is a segmented structure, and each segment of the steel structure jacket 23 is provided with a heat conduction oil inlet 26 and a heat conduction oil outlet 27. The steel jacket 23 is divided into 6 sections. The heat conducting oil circulating system is provided with a circulating pump, a heat conducting oil heat exchanger 3 and a cooler, and a heat conducting oil outlet 27 of each section is connected to a heat conducting oil inlet 26 through the circulating pump, the heat conducting oil heat exchanger 3 and the cooler.

The operation process of the suspended cylinder type parallel-flow heat storage double-hearth kiln with the cooling structure comprises the following steps: when the left kiln chamber A is calcined, fuel gas sprays fuel through an inserted burner 13 of the kiln chamber A, combustion-supporting air blown by the air blower 2 exchanges heat with the heat-conducting oil heat exchanger 3 and then enters the kiln chamber A from the air inlet and outlet 4 through the three-way valve 12 to be combusted in a combustion-supporting mode, and limestone materials in the left kiln chamber A are calcined. The flue gas generated by calcination is delivered to the right kiln chamber B through the flue gas channel 14 to preheat the materials in the kiln chamber, and then is delivered to the waste gas discharge system 18 through the gas inlet and outlet 4 and the three-way valve of the right kiln chamber B to be discharged. When in calcination, the fuel is uniformly distributed on the cross section of the whole kiln chamber, and the temperature fields on the cross sections of the calcination zone are uniform, which is favorable for uniform calcination of limestone. And reversing after 12 minutes of operation, calcining the kiln chamber B on the right side after reversing, storing heat in the kiln chamber A on the left side, alternately performing cocurrent calcination and countercurrent heat storage in the kiln chambers on the two sides, and realizing automatic reversing operation through the actions of a three-way valve and a feeding valve. And the calcined lime enters a cooling zone 16, exchanges heat with cooling air entering from a cooling air inlet 9 to reduce the temperature of the lime to 60-80 ℃, and then is discharged from the kiln through a discharge hole 10. The temperature of the cooling air after lime cooling rises, and the cooling air rises to the flue gas channel 14 to be mixed with the combustion flue gas and enter the kiln chamber which is storing heat. The mixed gas and limestone directly carry out heat exchange, and the temperature is reduced to about 160-180 ℃ after heat energy is transferred to the limestone and then the limestone is discharged by a waste gas discharge system. An annular channel 6 is formed between the inner furnace wall 5 and the outer furnace wall on the upper part of the supporting wall 8, so that flue gas generated by combustion in one period can uniformly enter the annular channel 6 and uniformly enter the other kiln chamber through a flue gas channel 14 connecting the two kiln chambers.

The heat conducting oil circulation process is that heat conducting oil enters the steel structure jacket 23 of the annular hanging cylinder type furnace wall 11 through the heat conducting oil inlet 26 in a subsection mode to cool the hanging cylinder, passes through the heat conducting oil outlet 27, enters the heat conducting oil heat exchanger 3 through the circulating pump to preheat combustion-supporting air, is cooled by the cooler (air cooling), and then returns to the steel structure jacket 23 through the heat conducting oil inlet 26 to be continuously cooled. The air cannon 15 regularly sweeps the accumulated dust on the top of the supporting wall 8 to prevent the accumulated dust.

Claims

1. A hanging cylinder type parallel-flow heat storage double-chamber kiln with a cooling structure comprises a double-chamber kiln body, a feeding device, a discharging device, an air supply system and a waste gas discharge system (18), wherein the double-chamber kiln body is composed of an upper inner furnace wall (5) and a lower outer furnace wall (7), the inner furnace wall is hung on the outer furnace wall, and a preheating zone (19), a calcining zone (20) and a cooling zone (16) are arranged in the double-chamber kiln body; the double-chamber kiln comprises a kiln chamber A and a kiln chamber B, the upper parts of the two kiln bodies are provided with air inlet and outlet ports (4), the air inlet and outlet ports are connected with an air blower (2) and a waste gas discharge system (18) through a three-way valve (12), and a discharge port is connected with a discharge device; the calcining zone is provided with a burner (13), the cooling zone is provided with a cooling air inlet (9), the lower part of the cooling zone is provided with a discharge hole (10), and the cooling air inlet is connected with a cooling fan (17) through a three-way valve; the method is characterized in that: the lower part of the inner furnace wall (5) is provided with an annular suspension cylinder type furnace wall (11), the lower part of the annular suspension cylinder type furnace wall (11) is provided with 6-12 support walls (8), the support walls (8) are uniformly arranged along the circumference and independently support the suspension cylinder type furnace wall, and the lower part of each support wall is connected with the outer furnace wall; the annular suspension cylinder type furnace wall (11) is composed of a steel structure jacket (23) and an external masonry refractory brick (22), the steel structure jacket is internally provided with a heat conduction oil circulation cavity (28), the heat conduction oil circulation cavity is provided with a heat conduction oil inlet (26) and a heat conduction oil outlet (27), the heat conduction oil inlet (26) is connected with a heat conduction oil circulating system through an oil supply pipe, the heat conduction oil outlet (27) is connected with the heat conduction oil circulating system through an oil return pipe, and the oil return pipe of the oil supply pipe is positioned inside a support wall (8).

2. The hanging cylinder type co-current flow regenerative dual-bore kiln with a cooling structure as set forth in claim 1, wherein: the connection part of the annular suspension cylinder type furnace wall (11) and the inner furnace wall (5) is provided with refractory fibers (21); the lower part of the annular suspension cylinder type furnace wall (11) is connected with a support wall (8) through a pouring layer (29), a steel structure jacket (23) is provided with a support structure (25), the support structure is provided with an anchoring piece (24), and the anchoring piece is embedded into the pouring layer (29).

3. The hanging cylinder type co-current flow regenerative dual-bore kiln with a cooling structure as set forth in claim 1, wherein: an annular channel (6) is arranged between the annular suspension cylinder type furnace wall (11) and the outer furnace wall (7), the double-hearth kiln is provided with an air cannon (15), and the air cannon is connected to the annular channel (6) through a pipeline and used for blowing soot by the annular channel (6).

4. The hanging cylinder co-current thermal storage dual-chamber kiln as claimed in claim 1, wherein: the heat conducting oil circulating system is provided with a circulating pump, a heat conducting oil heat exchanger (3) and a cooler, and the heat conducting oil outlet (27) is connected to the heat conducting oil inlet (26) through the circulating pump, the heat conducting oil heat exchanger (3) and the cooler.

5. The hanging cylinder type co-current flow regenerative dual-bore kiln with a cooling structure as set forth in claim 1, wherein: the steel structure jacket (23) in the annular suspension cylinder type furnace wall (11) is of a segmented structure, and each segment of steel structure jacket (23) is provided with a heat conduction oil inlet (26) and a heat conduction oil outlet (27); the steel structure jacket (23) is at least divided into 1 section.

6. The hanging cylinder type co-current flow regenerative dual-bore kiln with a cooling structure as set forth in claim 1, wherein: the support wall (8) is formed by building refractory bricks or pouring concrete.

7. The hanging cylinder type co-current flow regenerative dual-bore kiln with a cooling structure as set forth in claim 1, wherein: the burner (13) is an insertion burner, a combustion beam or a peripheral burner; the inserted burner is a gas fuel burner, a liquid fuel burner or a solid fuel burner.