CN215062187U

CN215062187U - A anti structure that explodes for protecting coal injection pipe

Info

Publication number: CN215062187U
Application number: CN202023144253.6U
Authority: CN
Inventors: 刘礼龙
Original assignee: Tianjin Nanji Star Insulating Material Co ltd
Current assignee: Tianjin Nanji Star Insulating Material Co ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-12-07
Anticipated expiration: 2030-12-24

Abstract

The utility model relates to an anti structure of splitting that explodes for protecting coal injection pipe, including ceramic pipe, pouring material, at the hot junction suit ceramic pipe of coal injection pipe, pack the pouring material between ceramic pipe and coal injection pipe. The cold end of the ceramic tube is made into a flange structure with a closed end. The hot end of the ceramic tube is closed up and extends axially to form a rectifying tube, and the inner diameter of the rectifying tube is close to the outer diameter of the coal injection tube. The utility model discloses ceramic pipe adopts high temperature resistant carborundum material, has fine coefficient of heat transfer for the material has the impact of fine anti rapid cooling and rapid heating, and the internal stress that can not produce is exploded.

Description

A anti structure that explodes for protecting coal injection pipe

Technical Field

The utility model belongs to the burner field relates to the protection technology of coal injection pipe, especially an anti structure of splitting that explodes for protecting coal injection pipe.

Background

A coal injection pipe of a combustion device of a rotary kiln is generally protected by adopting a refractory castable outside a heat-resistant metal coal injection pipe, the service life of the castable at the hot end of the coal injection pipe is very short due to severe thermal shock, and a layer of castable needs to be solidified again in 3-6 months generally so as to maintain the normal work of the metal coal injection pipe. In order to solve the cracking problem, the anti-cracking refractory castable is also adopted in the industry, but the effect is not ideal, and the purpose of not cracking after long-term use is difficult to achieve.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's weak point, provide an anti structure of bursting for protecting coal injection pipe, the coking condition of elimination tradition castable tip that can be by a maximum margin takes place.

The utility model provides a technical scheme that technical problem adopted is:

an anti-cracking structure for protecting a coal injection pipe comprises a ceramic pipe and a casting material, wherein the ceramic pipe is sleeved at the hot end of the coal injection pipe, and the casting material is filled between the ceramic pipe and the coal injection pipe.

And the cold end of the ceramic tube is made into a closed flange structure.

And the hot end of the ceramic tube is closed, and the caliber of the ceramic tube is close to the inner diameter of the coal injection tube.

And the hot end of the ceramic tube is closed and extends axially to form a rectifying tube, and the inner diameter of the rectifying tube is close to the outer diameter of the coal injection tube.

And a layer of ceramic fiber blanket or nanometer heat insulation felt with the thickness of 5-15 mm is wound between the anchoring pieces of the tension-fixing castable and on the surface of the coal injection pipe.

And a layer of high-temperature-resistant ceramic fiber paper or high-temperature-resistant nano heat-insulating felt with the thickness of 3-5 mm is adhered between the casting material and the inner wall of the ceramic tube.

The ceramic tube is made of sintered silicon carbide or pressureless sintered silicon carbide or hot-pressed sintered silicon carbide or isostatic pressed sintered silicon carbide or silicon carbide fiber reinforced silicon carbide, and the density of the ceramic tube is 3.0-3.1 g/cm³Coefficient of thermal expansion of 3X 10^-6K^-1Left and right.

Moreover, the castable is made of high-alumina or mullite or silicon carbide or zirconium silicate refractory castable, and the density of the castable is 2.4-2.6 g/cm³A thermal expansion coefficient of 6X 10 at 1200 DEG C^-6K^-1。

The utility model provides an anti-burst structure for protecting coal injection pipe, includes the rectifier tube, and length 50 ~ 500 millimeters, wall thickness 10 ~ 25 millimeters, the cross-section is circular or wave form, and the internal diameter is the same with the external diameter of coal injection pipe, and the cold junction of rectifier tube passes through the flange and is connected with the end of coal injection pipe, the rectifier tube adopts sintered silicon carbide or pressureless sintered silicon carbide or hot pressing sintered silicon carbide or isostatic pressing sintered silicon carbide or silicon carbide fibre reinforced silicon carbide material to make.

And the ceramic pipe is sleeved on the coal injection pipe, and pouring materials are filled between the ceramic pipe and the coal injection pipe.

The utility model has the advantages that:

1. the utility model discloses ceramic pipe adopts high temperature resistant carborundum material, has fine coefficient of heat transfer (45 ~ 75W/mk) for the material has the impact of fine anti rapid cooling sharp heat, and the internal stress that can not produce is exploded.

2. The utility model discloses carborundum ceramic tube can improve the combustion efficiency of nozzle, improves the furnace temperature and reduces the effect of energy consumption.

3. The utility model discloses the temperature of end department can be increased substantially in carborundum ceramic tube high temperature radiation effect, reasonable flame combustion shape can be controlled simultaneously, carries out the plastic to the flame shape of coal injection pipe export promptly for buggy and tar can not combine and form the coking material with the grog dust in the overgrate air, and the coking condition of elimination tradition pouring material tip that can be by a maximum margin takes place.

4. The utility model discloses the structure can also improve the shell temperature of coal-injection pipe except preventing exploding, increases hot radiant efficiency. Meanwhile, the smooth outer wall of the tube which resists acid and alkali corrosion can not adhere to any attachments.

5. The utility model discloses the rectifier tube makes metal coal injection pipe spun buggy, volatile matter and combustion-supporting wind intensive mixing, forms the stream shape of the required ideal of stable burning, reaches the temperature burning of ideal, can reduce local high temperature by a wide margin, reduces high temperature nitrogen oxide's production.

Drawings

FIG. 1 is an axial sectional view of a ceramic tube of example 1;

FIG. 2 is a view showing an installation structure of a ceramic tube according to example 1;

FIG. 3 is a schematic axial cross-sectional view of a ceramic tube (with a rectifying tube) according to example 2;

FIG. 4 is a schematic view showing an installation structure of a ceramic tube (with a rectifying tube) according to example 2;

FIG. 5 is a schematic view of the mounting structure of embodiment 3;

FIG. 6 is a schematic view of the mounting structure of embodiment 4;

Detailed Description

The present invention will be described in further detail with reference to specific examples, which are provided for illustrative purposes only, and are not intended to be limiting, and the scope of the present invention should not be limited thereby.

Example 1

A ceramic tube 1 is arranged at the hot end of a traditional coal injection tube, a flange plate is manufactured at the cold end of the ceramic tube and used for clamping internal castable, and the hot end of the ceramic tube is closed, and the caliber of the ceramic tube is close to the inner diameter of the coal injection tube. A refractory castable 4 is filled in a space between the ceramic pipe and the metal coal injection pipe shell, a layer of ceramic fiber blanket or nanometer heat insulation felt 5 with the thickness of 5-15 mm is wound on the surface of the metal coal injection pipe between anchoring pieces for pulling and fixing the castable, and a layer of high-temperature ceramic fiber paper or high-temperature nanometer heat insulation felt 3 with the thickness of 3-5 mm is adhered on the inner wall of the castable, which is in contact with the ceramic pipe, as shown in figure 2.

Example 2

The difference from example 1 is that: the hot end of the ceramic tube closes up and extends axially to form a rectifying tube 2, the inner diameter of the rectifying tube is close to the outer diameter of the coal injection tube, and the cross section of the rectifying tube is circular or wave-shaped.

Example 3

The difference from example 2 is that: the ceramic tube and the rectifying tube are independent and are manufactured in a non-integrated manner. One end of the cold end of the rectifier tube is fixedly mounted on an end flange of the metal coal injection tube in a flange structure clamping mode, the shape of the outlet end is arc-shaped or wavy or folded, the length of the outlet end is 50-500 mm, and the wall thickness of the outlet end is 10-25 mm.

Example 4

The difference from example 3 is that: only a rectifier tube is used, and a ceramic tube is not used.

The ceramic tube has an inner diameter of 350-850 mm, a length of 500-800 mm and a wall thickness of 5-25 mm. The length range of the rectifying tube is 50-500 mm, the inner diameter is 250-650 mm, and the wall thickness is 5-25 mm.

The ceramic tube is made of high-performance high-temperature-resistant refractory ceramic materials with good thermal shock resistance and scouring resistance at high temperature, such as sintered silicon carbide, pressureless sintered silicon carbide, hot-pressed sintered silicon carbide, isostatic pressed sintered silicon carbide, silicon carbide fiber reinforced silicon carbide materials and the like, the density of the high-performance high-temperature-resistant refractory ceramic materials is 3.0-3.1 g/cm3, and the thermal expansion coefficient of the high-temperature-resistant refractory ceramic materials is about 3 multiplied by 10 < -6 > K < -1 >.

The castable is made of high-alumina, mullite, silicon carbide and zirconium silicate refractory castable, the density of the castable is 2.4-2.6 g/cm3, and the thermal expansion coefficient at 1200 ℃ is 6 multiplied by 10 < -6 > K < -1 >.

The length of the hot end rectifying tube of the ceramic tube is 50-500 mm, the cross section of the hot end rectifying tube can be circular, corrugated and folded, the shapes are used for rectifying the flame shape of the coal injection tube, and the thickness of the corrugated and folded shapes is 20-100 mm.

The cold end of the ceramic tube is in the shape of a closed circular flange disc and used for clamping the casting material inside, the width of the flange-shaped closed is 25-50 mm, and the wall thickness is 5-25 mm.

Winding a 1260 type ceramic fiber blanket (the highest using temperature is 1260 ℃, the density is 130Kg/m3, and the thermal conductivity coefficient is 0.31W/mK) or 1100 type nanometer heat insulation felt (the highest using temperature is 1100 ℃, the density is 400Kg/m3, and the thermal conductivity coefficient is 0.035W/mK) with the thickness of 5-15 mm on the surface of the metal coal injection pipe, wherein the contact surface of the ceramic radiation pipe and the filled refractory castable material adopts high-temperature resistant ceramic fiber paper or high-temperature nanometer heat insulation felt, the thickness is 3-5 mm, and the highest using temperature is 1430-1650 ℃ ceramic fiber paper or high-temperature nanometer heat insulation felt.

The ceramic tube is made of high-temperature-resistant silicon carbide and has a good heat transfer coefficient (45-75W/mk), so that the material has good shock resistance to rapid cooling and rapid heating, and cannot explode due to generated internal stress.

The silicon carbide ceramic tube can improve the combustion efficiency of the burner, improve the temperature of the hearth and reduce the energy consumption. The utility model discloses a radiant tube is made to the carborundum pottery of high radiance, the carborundum pipe (50 ~ 500 millimeters) that the radiation rectifier tube adopted one section to stretch out, the infrared radiation coefficient of the high temperature of this kind of material is very big, reach more than 0.9, just so can be so that the exterior temperature of carborundum radiant tube, improve more than 1350 ℃ by ordinary 1250 ℃, heat radiation heat transfer efficiency under the high temperature is the cubic of temperature, the radiation heat transfer capacity increases more than 25%, same fuel use amount so, can improve 25% heat, just reached and increased substantially combustion efficiency and burning strength, can obviously improve the quality and the reduction energy consumption of calcining the grog.

The end of the metal coal injection pipe is often subjected to low-temperature condensation to form coking, and the normal combustion of the coal injection pipe is affected under severe conditions. The high-temperature radiation effect of the silicon carbide pipe can greatly improve the temperature at the end, and simultaneously can control the reasonable flame combustion shape, namely, the flame shape at the outlet of the coal injection pipe is shaped, so that the coal powder and the tar can not be combined with clinker dust in secondary air to form a coking substance, and the coking condition at the end part of the traditional casting material can be eliminated to the greatest extent.

The utility model discloses a high temperature's carborundum ceramic tube has high temperature resistance 1750 ℃, and thermal shock resistance (not ftractureing more than 1100 ℃ water-cooling 50 times), corrosion-resistant, high temperature are resistant to the scouring performance and are good, and density 3.0 ~ 3.2g/m3, coefficient of thermal expansion are 3 x 10-6K-1 to ensure that high temperature ceramics explosion-proof flame radiation rectifier tube uses for a long time under the high temperature and can not explode and split. A layer of ceramic fiber blanket with the thickness of 5-15 mm or 1100 type nanometer heat insulation felt is adopted on the contact surface of the metal coal injection pipe and the refractory castable, so that the huge high-temperature expansion amount of the metal coal injection pipe is absorbed, and the refractory castable is prevented from being damaged by the radial expansion of metal. The contact surface of the ceramic radiation tube and the refractory castable material adopts a layer of 3-5 mm refractory high-temperature ceramic fiber paper or a nanometer heat insulation felt, because the expansion coefficient of the refractory castable material is larger (the temperature of 1200 ℃ is 6 multiplied by 10 < -6 > K < -1 >), and the expansion coefficient of the silicon carbide ceramic radiation tube is smaller (the temperature of 3 multiplied by 10 < -6 > K < -1 >), the 1200 ℃ expansion amount of the castable material reaches more than 1.1 mm (the radial thickness of the castable material is 150 mm), and the ceramic radiation tube is easily burst from the inside due to huge expansion stress generated. The high-temperature ceramic fiber paper with the thickness of 3-5 mm has certain elasticity, so that the expansion of the refractory castable at high temperature can be absorbed, and the damage to the ceramic radiation tube caused by the expansion of the castable can be eliminated. In the same way, the 1100 type high-temperature nanometer heat insulation felt with the thickness of 3-5 mm is used instead of the fiber blanket paper, so that on one hand, the expansion of the refractory castable is absorbed, on the other hand, the heat insulation effect of the position can be enhanced, the temperature of the internal castable and the temperature of the metal coal injection pipe are reduced, and the high-temperature expansion amount of the castable and the metal coal injection pipe is greatly reduced.

The silicon carbide ceramic tube with the inner pouring material is used as a circular flange plate with a closing-in end near the cold end, and the function of the circular flange plate is to clamp the pouring material so as to fix the radiant tube. Because the coal injection pipe is used, due to the cantilever with the length of about 6 meters, and high-speed coal powder and wind flow conveying and high-frequency violent vibration generated by combustion simultaneously, the radiation rectifying pipe also needs reliable fixing action. The radiation ceramic tube is broken by excessive expansion formed by high-temperature expansion of the castable so as to prevent the radiation ceramic tube from being broken by certain expansion and extrusion of the castable in the radiation tube, and the interface of the radiation tube, which is in contact with the castable, is adhered with the thermal insulation felt which is expanded by the high-temperature absorption castable and is 3-5 mm.

The rectifying tube reasonably rectifies fuel and air flow of the coal injection tube. At the end faces of the traditional coal injection pipe and the castable, no flow guiding effect on flow and flame exists, vortex backflow alternation of high-temperature flame, high-temperature secondary air and cold air exists, tar evaporated from coal dust is adhered to the hot end face of the metal coal injection pipe, and secondary high-temperature air generated by mixed backflow of the tar wraps entrained clinker dust to form a mixture with strong high-temperature resistance and viscosity to be adhered to the hot end face of the metal coal injection pipe. Therefore, the adhesion substance is accumulated on the upper end of the castable of the end of the coal injection pipe to form candle-shaped accumulation, or the adhesion substance is adhered on the lower end of the castable of the end to form a beard-shaped suspension substance, when the condition is serious, the coal injection pipe needs to be withdrawn to stop burning, the special scraper of the coal injection pipe is used for specially cleaning the end, meanwhile, the candle-shaped accumulation substance on the upper end of the castable and the beard-shaped suspension substance on the lower end of the castable are manually removed by steel chisel, the working condition is severe and dangerous, the end of the coal injection pipe is easily damaged manually, the vortex backflow stability of the castable of the position is further influenced, the shape of flame is damaged, and the burning stability is damaged.

The rectifier tube is used for eliminating local high-temperature vortex backflow at the end face of the coal injection tube, so that backflow high-temperature dust materials cannot reach the end face of the coal injection tube, and pulverized coal sprayed by the metal coal injection tube and volatilized ash cannot form condensation and any adhesive cannot be formed. The high-speed jet coal powder and the air mixture can not be adhered in the rectifying pipe, the rectifying pipe enables the coal powder, the volatile matter and the combustion-supporting air sprayed by the metal coal spraying pipe to be fully mixed to form an ideal stream flow shape required by stable combustion, ideal temperature combustion is achieved, local high temperature can be greatly reduced, and the generation of high-temperature nitrogen oxides is reduced, which is another function of the rectifying pipe.

Application example 1

On the coal injection pipe of 5000 tons of cement kilns of producing on a certain day, will the utility model discloses a two sections holistic burst-proof ceramic flame radiation rectifier tube covers on metal coal injection pipe, fills the pouring material between metal coal injection pipe and ceramic rectifier tube, and the total length of ceramic rectifier tube is 800 millimeters, and shell diameter 860 millimeters, wherein extension segment length is 200 millimeters, and the shape of rectifier tube is smooth circular inner wall, and the wall thickness of radiant tube and extension rectifier tube is 15 millimeters.

The castable on the surface of the original coal injection pipe can fall off in a large area when used for 3-6 months, and the refractory castable has to be replaced. And adopt the utility model discloses after the ceramic flame radiation rectifier tube of preventing exploding, use coking that does not appear more than 12 months to influence the flame shape, ceramic rectifier tube section of thick bamboo wall body also does not have any crack to appear, and the ceramic rectifier tube of coal-injection pipe hot side is intact harmless.

The surface of the end of the original metal coal injection pipe can be coked every 5 to 7 days, the coal injection pipe needs to be pulled out for coke cleaning treatment, or a coke cleaning device carried by the coal injection pipe is used for coke cleaning and then is put into use, so that the smooth production is influenced. After the anti-cracking ceramic flame rectifying radiant tube is adopted, the coking phenomenon completely disappears.

Due to the high-temperature radiation effect of the silicon carbide ceramic, the temperature of flame is greatly improved, the combustion efficiency of pulverized coal is also improved, the same combustion strength is maintained, and the coal-saving rate of the coal-injection pipe is 2-3 Kg/h higher than that of the original common castable structure.

Application example 2

Adopt the utility model discloses a two sections split type ceramic radiant tubes, fix the head at the metal coal injection pipe with the flange for little rectifier tube earlier, then sheathe the ceramic radiant tube of major diameter in, pour into the pouring material into the ceramic radiant tube of major diameter again, the advantage of the ceramic radiant tube that two sections are separated like this is that the cost of manufacture is low, the anti-explosion splits and radiation rectification effect be inferior to two sections ceramic tubes that are linked into whole, wherein little rectifier tube material adopts the carborundum material of carborundum fiber reinforcement, the pipe box of cold junction major diameter adopts ordinary sintered carborundum material.

Through practical application, the large-diameter sintered silicon carbide pipe sleeve achieves the anti-explosion effect, and the time for repeatedly maintaining the castable of the coal injection pipe is shortened. The silicon carbide fiber reinforced silicon carbide material adopted by the small rectifying tube is more resistant to high-temperature abrasion than the common silicon carbide material, can be used for the scouring action and abrasion of a high-temperature high-speed coal-air mixture for a long time, simultaneously avoids the coking phenomenon of a metal coal injection tube, can improve the combustion stability of flame, improves the efficient infrared radiation action of the rectifying tube, improves the temperature of the flame, the surface infrared temperature of refractory bricks and clinker, and finally obtains the good effect of saving coal by 2-3 Kg/h.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, many modifications and improvements can be made without departing from the spirit of the present invention, and these modifications and improvements are all within the protection scope of the present invention.

Claims

1. The utility model provides an anti-burst structure for protecting coal injection pipe which characterized in that: the ceramic tube is sleeved at the hot end of the coal injection tube, the casting material is filled between the ceramic tube and the coal injection tube, the hot end of the ceramic tube is closed, and the caliber of the ceramic tube is close to the inner diameter of the coal injection tube.

2. The blast-resistant structure for protecting a coal injection lance of claim 1, wherein: the cold end of the ceramic tube is made into a flange structure with a closed end.

3. The blast-resistant structure for protecting a coal injection lance of claim 1, wherein: the hot end of the ceramic tube is closed up and extends axially to form a rectifying tube, and the inner diameter of the rectifying tube is close to the outer diameter of the coal injection tube.

4. The blast-resistant structure for protecting a coal injection lance of claim 1, wherein: and winding a layer of ceramic fiber blanket or nano heat insulation felt with the thickness of 5-15 mm between the anchoring pieces of the tension-fixing castable and on the surface of the coal injection pipe.

5. The blast-resistant structure for protecting a coal injection lance of claim 1, wherein: and a layer of high-temperature-resistant ceramic fiber paper or high-temperature-resistant nano heat-insulating felt with the thickness of 3-5 mm is adhered between the casting material and the inner wall of the ceramic tube.

6. The blast-resistant structure for protecting a coal injection lance of claim 1, wherein: the ceramic tube is made of sintered silicon carbide or pressureless sintered silicon carbide or hot-pressed sintered silicon carbide or isostatic pressed sintered silicon carbide or silicon carbide fiber reinforced silicon carbide, and the density of the ceramic tube is 3.0-3.1 g/cm³Coefficient of thermal expansion of 3X 10^-6K^-1。

7. The blast-resistant structure for protecting a coal injection lance of claim 1, wherein: the castable is made of high-alumina or mullite or silicon carbide or zirconium silicate refractory castable, and the density of the castable is 2.4-2.6 g/cm³A thermal expansion coefficient of 6X 10 at 1200 DEG C^-6K^-1。

8. The utility model provides an anti-burst structure for protecting coal injection pipe which characterized in that: the rectifying tube is 50-500 mm in length, 10-25 mm in wall thickness, circular or wavy in cross section, and has inner diameter the same as that of coal spraying tube, cold end connected via flange to the end of the coal spraying tube, and sintered silicon carbide or pressureless sintered silicon carbide or hot pressed sintered silicon carbide or isostatic pressed sintered silicon carbide or silicon carbide fiber reinforced silicon carbide material.

9. The blast-resistant structure for protecting a coal lance as claimed in claim 8, wherein: the coal spraying device also comprises a ceramic tube, wherein the ceramic tube is sleeved on the coal spraying tube, and pouring materials are filled between the ceramic tube and the coal spraying tube.