Mixer for coal injection

Abstract

The utility model discloses a mixer for coal injection, which comprises an outer gas pipe and an inner coal pipe, the pipe wall of the outer gas pipe is provided with a gas inlet, the powder injection end of the inner coal pipe coaxially extends into the outer gas pipe, and a gas equalizing ring is coaxially arranged between the outer gas pipe and the inner coal pipe. The gas equalizing ring is located between the gas inlet and the powder spraying end of the inner coal pipe, and a plurality of through holes are formed in the gas equalizing ring. According to the mixer for coal injection, pulverized coal flow conveyed in the inner coal pipe is inside, gas flow conveyed in the outer gas pipe is outside, in order to adsorb gas inwards to achieve mixing, the amount of the pulverized coal conveyed in the inner coal pipe needs to be large, the conveying concentration of the pulverized coal is greatly improved, under the condition that the unit amount of the pulverized coal is large, the amount of the conveyed gas is relatively small, and the coal injection efficiency is improved. And the gas consumption is greatly saved. And due to the arrangement of the gas equalizing ring, gas flow output through the through holes in a pressure equalizing manner can be uniformly conveyed in the circumferential direction, the uniformity of coal and gas mixing is better, and the combustion efficiency is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of pulverized coal injection equipment, in particular to a mixer for pulverized coal injection. Background Art

[0002] Existing mixers for pulverized coal injection, as disclosed in the patent document with Chinese patent application number 201220205922.2, generally include a coal cylinder and an air pipe, and one end of the air pipe extends into the coal cylinder. During operation, pulverized coal is introduced into the coal cylinder, and gas is input into the air pipe. After the gas is output from the air pipe, it expands instantaneously, the pressure drops suddenly, forming a vacuum negative pressure. The gas with the vacuum negative pressure adsorbs the pulverized coal in the coal cylinder inward, mixes the pulverized coal with it, and conducts gas-phase transportation of the pulverized coal. For this kind of mixer for pulverized coal injection, since the air pipe is located inside the coal cylinder, during the working process, internal gas needs to be output to form a vacuum negative pressure, and the gas provides energy (kinetic energy) to adsorb the external pulverized coal inward for mixing. To provide the energy (kinetic energy) for adsorbing the pulverized coal, a large amount of gas is required. That is to say, for the existing mixer for pulverized coal injection with the air pipe extending into the coal cylinder, the gas consumption is large. And under the structure of the existing mixer for pulverized coal injection, although the internal air pipe can supply gas evenly, the pulverized coal input from the upper part into the external coal cylinder is mainly concentrated in the lower part of the coal cylinder, and the transportation of the pulverized coal in the coal cylinder is uneven. Even if the unevenly transported pulverized coal is mixed with the evenly transported gas, it is difficult to mix evenly. Therefore, the existing mixer for pulverized coal injection also has the problem of uneven mixing of coal and gas, resulting in low combustion efficiency in the blast furnace. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a mixer for pulverized coal injection.

[0004] The technical solution for realizing the purpose of the utility model is: a mixer for pulverized coal injection, including an outer air pipe and an inner coal pipe. An air inlet is provided on the pipe wall of the outer air pipe. The powder spraying end of the inner coal pipe coaxially extends into the outer air pipe. A gas equalizing ring is coaxially installed between the outer air pipe and the inner coal pipe. The gas equalizing ring is located between the air inlet and the powder spraying end of the inner coal pipe. A plurality of through holes are opened on the gas equalizing ring, and the plurality of through holes are arranged and distributed along the circumferential direction of the gas equalizing ring.

[0005] Further, the powder spraying end of the inner coal pipe is a reduced-diameter end with an inner diameter gradually decreasing along the conveying direction. The diameter of the outer air pipe is larger than that of the inner coal pipe. After the pulverized coal in the inner coal pipe is output and enters the outer air pipe, it expands suddenly to form a vacuum negative pressure. Under the action of this vacuum negative pressure, the gas sprayed into the outer air pipe is adsorbed inward, so that coal and gas are mixed. The setting of the reduced-diameter end can make the pressure of the pulverized coal in the inner coal pipe increase and the flow rate become faster after passing through the reduced diameter, playing the role of a Venturi tube. When the pulverized coal with increased pressure and faster flow rate is output from the powder spraying end to the outer air pipe with a larger diameter, the effect of forming a vacuum negative pressure is better, and the effect of mixing coal and gas is also better.

[0006] Furthermore, the inner wall of the gas equalizing ring is sleeved on the inner coal pipe. The gas equalizing ring is directly sleeved on the inner coal pipe, which simplifies the installation of the gas equalizing ring and ensures the sealing performance between the gas equalizing ring and the inner coal pipe. In this way, the gas in the outer gas pipe can only pass through the through holes of the gas equalizing ring. On the one hand, the gas equalizing ring has a better blocking effect on the gas transportation in the outer gas pipe, and the control effect on the small amount of gas transportation in the outer gas pipe is better; on the other hand, the gas that can only pass through the through holes of the gas equalizing ring can be distributed more evenly, and the uniformity of the coal-gas mixture is also better.

[0007] Furthermore, the outer wall of the gas equalizing ring is fixed to the inner wall of the outer gas pipe. The gas equalizing ring is directly sleeved on the inner wall of the outer gas pipe, which simplifies the installation of the gas equalizing ring and ensures the sealing performance between the gas equalizing ring and the outer gas pipe. In this way, the gas in the outer gas pipe can only pass through the through holes of the gas equalizing ring. On the one hand, the gas equalizing ring has a better blocking effect on the gas transportation in the outer gas pipe, and the control effect on the small amount of gas transportation in the outer gas pipe is better; on the other hand, the gas that can only pass through the through holes of the gas equalizing ring can be distributed more evenly, and the uniformity of the coal-gas mixture is also better.

[0008] Furthermore, several of the through holes are evenly distributed along the circumferential direction of the gas equalizing ring. The uniform distribution of the through holes can improve the uniformity of the gas in the outer gas pipe.

[0009] Furthermore, the air inlet is close to the powder feeding end of the inner coal pipe and far from the powder spraying end of the inner coal pipe. This setting can ensure that the gas entering the outer gas pipe from the air inlet has a longer transportation distance, and this longer transportation distance is conducive to the uniform transportation of the gas.

[0010] For the coal powder mixer for coal injection of the present utility model, the inner coal pipe extends into the outer gas pipe. The coal powder flow conveyed in the inner coal pipe is inside, and the gas flow conveyed in the outer gas pipe is outside. When the coal powder flow is output from the inner coal pipe and input into the outer gas pipe, a negative pressure is formed in the inner coal powder flow, which sucks the outer gas flow inward. In the working mode where the coal powder flow forms a negative pressure to suck the gas flow, the adsorption process is provided with energy (kinetic energy) by the coal powder flow. That is to say, in order to suck the gas inward, a relatively large amount of coal powder needs to be conveyed in the inner coal pipe. Under the mixed transportation of a relatively large amount of coal powder, the transportation concentration of the coal powder is greatly improved, and the dense-phase transportation is truly realized, improving the transportation efficiency of the coal powder. Moreover, precisely because the transportation concentration of the coal powder is improved, under the condition of a unit amount of coal powder, the consumption of the conveyed gas is relatively small, greatly saving the gas consumption.

[0011] The mixer for pulverized coal injection of the present utility model coaxially installs the gas equalizing ring between the outer gas pipe and the inner coal pipe. Although the installed gas equalizing ring will hinder the gas transportation, due to its small gas consumption, the hindrance of the gas equalizing ring will not affect the gas supply. Moreover, the setting of the gas equalizing ring instead provides a control structure for the small amount of gas supply. In the mixer for pulverized coal injection of the present utility model, after the gas equalizing ring is arranged between the outer gas pipe and the inner coal pipe, under the hindrance of the gas equalizing ring, the concentrated gas flow is evenly pressured and output through each through hole, and the gas flow evenly pressured and output through the through hole realizes the circumferential uniform transportation. The gas in the outer gas pipe is evenly transported, the coal gas in the inner coal pipe is evenly transported, the evenly transported coal gas adsorbs the evenly transported gas inward, and the uniformity of the coal-gas mixture is better and the combustion efficiency is higher.

[0012] In addition, the gas equalizing ring located between the outer gas pipe and the inner coal pipe can also support the outer gas pipe and the inner coal pipe, making the installation of the outer gas pipe and the inner coal pipe more firm and stable. Brief Description of the Drawings

[0013] Figure 1 is a schematic structural diagram of the mixer for pulverized coal injection of the present utility model;

[0014] Figure 2 is a schematic structural diagram of the gas equalizing ring of the mixer for pulverized coal injection of the present utility model. Detailed Description of the Preferred Embodiment

[0015] The following describes in detail the preferred embodiment of the mixer for pulverized coal injection of the present utility model in conjunction with the drawings:

[0016] As Figure 1 and Figure 2 shown, a mixer for pulverized coal injection includes an outer gas pipe 1 and an inner coal pipe 2. An air inlet 11 is provided on the pipe wall of the outer gas pipe 1. The powder spraying end 21 of the inner coal pipe 2 coaxially extends into the outer gas pipe 1. A gas equalizing ring 3 is coaxially installed between the outer gas pipe 1 and the inner coal pipe 2. The gas equalizing ring 3 is located between the air inlet 11 and the powder spraying end 21 of the inner coal pipe 2. A plurality of through holes 31 are formed on the gas equalizing ring 3, and the plurality of through holes 31 are arranged and distributed along the circumferential direction of the gas equalizing ring 3.

[0017] The mixer for pulverized coal injection of the present utility model. The outer gas pipe 1 is used for transporting gas. The air inlet 11 is arranged on the pipe wall of the outer gas pipe 1. The port 12 of the outer gas pipe 1 away from the inner coal pipe 2 is the coal and gas output port. The inner coal pipe 2 is used for transporting pulverized coal. The powder spraying end 21 of the inner coal pipe 2 coaxially extends into the outer gas pipe 1 and is the pulverized coal output port. The powder feeding end 22 of the inner coal pipe 2 is located outside the outer gas pipe 1. The air equalizing ring 3 is coaxially installed between the outer gas pipe 1 and the inner coal pipe 2. The air equalizing ring 3 blocks the gas. While playing a throttling role, it can also make the gas spray evenly, playing the role of equalizing the gas.

[0018] For the mixer for pulverized coal injection of the present utility model, during operation, gas is sent into the outer gas pipe 1 from the air inlet 11. After the gas in the outer gas pipe 1 is transported to the air equalizing ring 3, it continues to be transported to the powder spraying end 21 of the inner coal pipe 2 through each through hole 31 of the air equalizing ring 3. Pulverized coal is sent into the inner coal pipe 2. The pulverized coal in the inner coal pipe 2 is output from the powder spraying end 21 of the inner coal pipe 2, enters the outer gas pipe 1. After entering the outer gas pipe 1, the sudden expansion of the pipe diameter causes the pressure of the pulverized coal flow to drop suddenly, forming a vacuum negative pressure. The pulverized coal flow with the vacuum negative pressure adsorbs the gas in the outer gas pipe 1 inward, mixes the gas with it, and conducts gas-phase transportation of the pulverized coal.

[0019] For the mixer for pulverized coal injection of the present utility model, the inner coal pipe 2 extends into the outer gas pipe 1. The pulverized coal flow transported in the inner coal pipe 2 is inside, and the gas flow transported in the outer gas pipe 1 is outside. When the pulverized coal flow is output from the inner coal pipe 2 and input into the outer gas pipe 1, a negative pressure is formed in the inner pulverized coal flow, adsorbing the outer gas flow inward. In the working mode where the pulverized coal flow forms a negative pressure to adsorb the gas flow, the adsorption process is powered by the pulverized coal flow. That is to say, in order to adsorb the gas inward, a relatively large amount of pulverized coal needs to be transported in the inner coal pipe 2. Under the mixed transportation with a relatively large amount of pulverized coal, the transportation concentration of the pulverized coal is greatly improved, truly realizing dense-phase transportation and improving the transportation efficiency of the pulverized coal. Moreover, precisely because the transportation concentration of the pulverized coal is improved, in the case of a unit amount of pulverized coal, the consumption of the transported gas is relatively less, greatly saving the gas consumption.

[0020] The mixer for pulverized coal injection of the present utility model coaxially installs the gas equalizing ring 3 between the outer gas pipe 1 and the inner coal pipe 2. Although the installed gas equalizing ring 3 will hinder the gas transportation, since its gas consumption is small, the hindrance of the gas equalizing ring 3 will not affect the gas supply. Moreover, the setting of the gas equalizing ring 3 instead provides a control structure for the small amount of gas supply. For the mixer for pulverized coal injection of the present utility model, after the gas equalizing ring 3 is arranged between the outer gas pipe 1 and the inner coal pipe 2, under the hindrance of the gas equalizing ring 3, the concentrated gas flow is evenly pressurized and output through each through hole 31, and the gas flow evenly pressurized and output through the through hole 31 realizes uniform transportation in the circumferential direction. The gas in the outer gas pipe 1 is evenly transported, the coal gas in the inner coal pipe 2 is evenly transported, and the evenly transported coal gas adsorbs the evenly transported gas inward, so that the mixing uniformity of coal and gas is better and the combustion efficiency is higher.

[0021] In addition, the gas equalizing ring 3 located between the outer gas pipe 1 and the inner coal pipe 2 can also support the outer gas pipe 1 and the inner coal pipe 2, making the installation of the outer gas pipe 1 and the inner coal pipe 2 more firm and stable.

[0022] For the mixer for pulverized coal injection of the present utility model, preferably, the powder spraying end 21 of the inner coal pipe 2 is a reduced diameter end with an inner diameter gradually decreasing along the transportation direction. The diameter of the outer gas pipe 1 is larger than that of the inner coal pipe 2. After the pulverized coal in the inner coal pipe 2 is output and enters the outer gas pipe 1, it suddenly expands to form a vacuum negative pressure. Under the action of this vacuum negative pressure, the gas sprayed in the outer gas pipe 1 is adsorbed inward to mix coal and gas. The setting of the reduced diameter end can make the pressure of the pulverized coal in the inner coal pipe 2 increase and the flow rate become faster after passing through the reduced diameter, playing the role of a Venturi tube. When the pulverized coal with increased pressure and faster flow rate is output from the powder spraying end 21 to the outer gas pipe 1 with a larger diameter, the effect of forming a vacuum negative pressure is better, and the mixing effect of coal and gas is also better.

[0023] For the mixer for pulverized coal injection of the present utility model, preferably, the inner wall of the gas equalizing ring 3 is sleeved on the inner coal pipe 2. The gas equalizing ring 3 is directly sleeved on the inner coal pipe 2, which simplifies the installation of the gas equalizing ring 3 and can also ensure the sealing performance between the gas equalizing ring 3 and the inner coal pipe 2, so that the gas in the outer gas pipe 1 can only pass through the through holes 31 of the gas equalizing ring 3. In this way, on the one hand, the blocking effect of the gas equalizing ring 3 on the gas transportation in the outer gas pipe 1 is better, and the control effect on the small amount of gas transportation in the outer gas pipe 1 is better; on the other hand, the gas that can only pass through the through holes 31 of the gas equalizing ring 3 can be more evenly distributed, and the mixing uniformity of coal and gas is also better.

[0024] The mixer for pulverized coal injection of the present utility model. Preferably, the outer wall of the gas equalizing ring 3 is fixed to the inner wall of the outer gas pipe 1. The gas equalizing ring 3 is directly sleeved on the inner wall of the outer gas pipe 1. While simplifying the installation of the gas equalizing ring 3, it can also ensure the sealing performance between the gas equalizing ring 3 and the outer gas pipe 1, so that the gas in the outer gas pipe 1 can only pass through the through holes 31 of the gas equalizing ring 3. In this way, on the one hand, the gas equalizing ring 3 has better blocking effect on the gas transportation in the outer gas pipe 1 and better control effect on the small amount of gas transportation in the outer gas pipe 1; on the other hand, the gas passing through only the through holes 31 of the gas equalizing ring 3 can be more evenly distributed, and the uniformity of the coal-gas mixture is also better.

[0025] The mixer for pulverized coal injection of the present utility model. Preferably, several through holes 31 are evenly distributed along the circumferential direction of the gas equalizing ring 3. The uniform distribution of the through holes 31 can improve the uniformity of the gas in the outer gas pipe 1.

[0026] The mixer for pulverized coal injection of the present utility model. Preferably, the air inlet 11 is close to the powder inlet end 22 of the inner coal pipe 2 and far from the powder spraying end 21 of the inner coal pipe 2. This setting can ensure that the gas entering the outer gas pipe 1 from the air inlet 11 has a longer transportation stroke, and this longer transportation stroke is beneficial to the uniform transportation of the gas.

[0027] For those of ordinary skill in the technical field to which the present utility model pertains, without departing from the concept of the present utility model, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present utility model.

Claims

1. A mixer for pulverized coal injection, characterized in that: It includes an outer air pipe and an inner coal pipe. An air inlet is provided on the pipe wall of the outer air pipe. The powder spraying end of the inner coal pipe coaxially extends into the outer air pipe. A gas equalizing ring is coaxially installed between the outer air pipe and the inner coal pipe. The gas equalizing ring is located between the air inlet and the powder spraying end of the inner coal pipe. A number of through holes are formed in the gas equalizing ring, and the number of through holes are arranged and distributed along the circumferential direction of the gas equalizing ring.

2. The mixer for pulverized coal injection according to claim 1, characterized in that: The powder spraying end of the inner coal pipe is a reduced diameter end with an inner diameter gradually decreasing along the conveying direction.

3. The mixer for pulverized coal injection according to claim 1, wherein: The inner wall of the gas equalizing ring is sleeved on the inner coal pipe.

4. The mixer for pulverized coal injection according to claim 1, characterized in that: The outer wall of the gas equalizing ring is fixed to the inner wall of the outer air pipe.

5. The mixer for pulverized coal injection according to claim 1, characterized in that: A number of through holes are evenly distributed along the circumferential direction of the gas equalizing ring.

6. The mixer for pulverized coal injection according to claim 1, characterized in that: The air inlet is close to the powder inlet end of the inner coal pipe and far from the powder spraying end of the inner coal pipe.

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