A process nozzle with a screw mechanism

Abstract

The present application provides a process nozzle with a spiral mechanism, which comprises, from outside to inside, an outer oxygen pipe, a coal water slurry pipe and a center oxygen pipe arranged concentrically, a detachable spiral mechanism is arranged between the coal water slurry pipe and the center oxygen pipe, so that the coal water slurry is spirally transported around the center oxygen pipe, and the spiral mechanism can slide along the axis of the center oxygen pipe. The present application has the advantages that the deposition degree of the flat spraying type coal water slurry solid particles under the action of gravity in the horizontal pipe is improved, the distribution of the solid particles of the coal water slurry in the pipe is more uniform, the wear degree of the coal slurry particles in the lower part of the inner wall of the horizontal pipe of the nozzle is reduced, the service life of the process nozzle is improved, the atomization effect of the coal water slurry nozzle is improved, the chemical reaction in the gasification furnace is effectively promoted, the content of the coarse slag residual carbon is reduced to save resources, the generation of effective gas is increased, the temperature of the dome and the periphery of the nozzle in the furnace is reduced, and the service life of the refractory bricks in the furnace is further prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal chemical industry, in particular to a structure improvement of a process nozzle suitable for a flat spray opposed water coal slurry gasifier, namely a process nozzle with a spiral mechanism. BACKGROUND

[0002] At present, there are two structures of water coal slurry process nozzles used in the gasifier of domestic coal chemical plants: one is a single nozzle device vertically installed on the top of the gasifier, and a representative is the Lurgi water coal slurry top-mounted single process nozzle pressurized gasification technology (GE) introduced since the 1980s, and currently there are more than 180 gasifiers in operation in China; due to the continuous rapid development of domestic coal gasification technology, the introduced Lurgi technology has been gradually replaced by another new technology developed in China, namely a four-nozzle flat spray opposed nozzle water coal slurry gasifier, which has become the mainstream in the industry, and currently there are more than 200 in construction and operation in China.

[0003] However, the main defect of the four-nozzle flat spray opposed nozzle form of the water coal slurry gasifier is that the nozzle is horizontally arranged in the gasifier, which will cause the following problems:

[0004] (1) Under the action of gravity, water coal slurry solid particles will be deposited to different degrees in the horizontal pipe during transportation, and the lower part of the nozzle coal slurry pipe will be more severely worn than the upper part, and the nozzle will appear problems of poor coal slurry atomization effect and local overheating caused by the misalignment of the three rings during the later operation.

[0005] (2) The gravity direction of the flat spray method is perpendicular to the spray direction, which has a certain influence on the uniformity of the nozzle spray and the impingement flow; and the jet direction is different from the overall axial flow direction of the gasifier, which also increases the complexity of the problem, and may cause short circuit of the original good single nozzle flow field due to oblique spray or asymmetric flow, resulting in poor overall flow field atomization effect. The actual situation may be the generation of asymmetric flow field along the axial direction of the gasifier, which may cause severe erosion and damage to the refractory bricks.

[0006] In summary, the nozzle of the flat spray method is prone to cause uneven dispersion of the water coal slurry impingement flow area, thereby causing the temperature rise of the dome and the nozzle periphery in the furnace, weakening the anti-erosion capacity of the refractory bricks, leading to the temperature rise of the end of the process nozzle, the stress deformation intensifies, the opportunities of carburization and sulfur increase, causing the end face of the nozzle to crack and even damage. SUMMARY

[0007] The present application mainly applies to the structure improvement of the process nozzle of the flat spray opposed water coal slurry gasifier, does not change the size and structure of the original process nozzle, installs a spiral mechanism, namely the fixed device with spiral reverse vane, on the outer wall of the central oxygen pipe, thereby improving the deposition degree of the flat spray water coal slurry solid particles in the horizontal pipe caused by the gravity, making the distribution of the water coal slurry solid particles in the pipe more uniform, reducing the wear degree of the coal slurry particles in the lower part of the inner wall of the nozzle horizontal pipe, thereby improving the service life of the process nozzle, improving the atomization effect of the water coal slurry nozzle, effectively promoting the chemical reaction in the gasifier, reducing the residual carbon content of the coarse slag to save resources, increasing the generation of effective gas and reducing the dome and nozzle peripheral temperature in the furnace, further prolonging the service life of the refractory bricks in the furnace.

[0008] In order to achieve the above-mentioned purpose, the present application realizes the technical scheme as follows:

[0009] A process nozzle with a spiral mechanism, which comprises, from outside to inside, an outer oxygen pipe, a water coal slurry pipe and a central oxygen pipe arranged concentrically, and a detachable spiral mechanism is arranged between the water coal slurry pipe and the central oxygen pipe, so that the water coal slurry is spirally transported around the central oxygen pipe, and the spiral mechanism can slide along the axis of the central oxygen pipe.

[0010] Further, the distance of the spiral mechanism from the outer oxygen end face ranges from 300 to 1500 mm.

[0011] Further, the spiral mechanism comprises a spiral vane group, an annular seat, a pipe clamp and a fastening screw, the annular seat is provided at the front and rear ends of the spiral vane group and is fixed to the central oxygen pipe by the fastening screw, the boss on the annular seat is inserted into the positioning gap on the spiral vane group, and the pipe clamp is clamped at the head and tail of the spiral vane group.

[0012] Further, the spiral vane group is composed of three identical single spiral vanes, and the three single spiral vanes are uniformly distributed at an angle of 120 degrees; the annular seat can be equally divided into three arc-shaped seats, and the three arc-shaped seats are uniformly distributed at an angle of 120 degrees.

[0013] Further, the spiral mechanism further comprises a pipe clamp, and the pipe clamp is clamped on the annular seat.

[0014] Further, the height of the spiral vane group is 2 / 3 of the distance between the inner diameter of the water coal slurry pipe and the outer diameter of the central oxygen pipe.

[0015] Further, the spiral vane group is integrally formed by high-temperature wear-resistant material, the length of the single spiral vane ranges from 500 to 1500 mm, and the spiral angle of the single spiral vane ranges from 60 to 85 degrees.

[0016] Further, the inner diameter of the annular seat has an inclination angle of 1.5-2 from outside to inside.

[0017] Compared with the prior art, the present application has the following advantages:

[0018] The process nozzle with a spiral mechanism improves the deposition degree of the horizontally placed water-coal slurry solid particles under the action of gravity in the horizontal pipe, makes the distribution of the water-coal slurry solid particles in the pipe more uniform, reduces the wear degree of the coal slurry particles in the lower part of the inner wall of the horizontal pipe of the nozzle, further improves the service life of the process nozzle, improves the atomization effect of the water-coal slurry nozzle, effectively promotes the chemical reaction in the gasifier, reduces the content of the coarse slag residual carbon to save resources, increases the generation of effective gas, and reduces the temperature of the dome and the periphery of the nozzle in the furnace, further prolongs the service life of the refractory bricks in the furnace. Specifically as follows:

[0019] (1) Because the water-coal slurry generates a certain amount of rotational potential energy through the spiral blade, the water-coal slurry is transported in the gap between the center oxygen pipe and the coal slurry pipe in the rotational direction, and the coal slurry raw liquid will not be deflected due to the self-weight of the horizontally placed process nozzle.

[0020] (2) Because the rotating coal slurry raw liquid has a spiral diffusion kinetic energy trend after being sprayed, the collision opportunities of the solid particles in the coal slurry raw liquid sprayed by the four process nozzles are increased, and the suspension time of the solid particles in the coal slurry raw liquid is also increased, which is more conducive to the chemical reaction in the gasifier.

[0021] (3) Because the rotating coal slurry raw liquid has a spiral diffusion kinetic energy trend after being sprayed, the wear of the solid particles in the coal slurry raw liquid to the pipe wall changes from axial stretching to rotational axial wear, so that the particles are sprayed from the tangent direction when the coal slurry particles are sprayed, thereby avoiding the direct wear of the solid particles in the coal slurry raw liquid to the outer oxygen port.

[0022] (4) Because the rotating coal slurry raw liquid has a spiral diffusion kinetic energy trend after being sprayed, the centrifugal force generated in the rotational transportation of the coal slurry raw liquid makes the water in the coal slurry raw liquid more adhere to the inner wall of the coal slurry pipe, and the head of the coal slurry is taken away by the heat radiation in the furnace body during spraying.

[0023] (5) Because the installation of the spiral mechanism can effectively reduce the vibration generated by the high-speed gas through the center oxygen pipe. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the process nozzle with a spiral mechanism.

[0025] Figure 2 It is a schematic diagram of the installation position of the spiral mechanism of the present application.

[0026] Figure 3It is the detailed structure schematic view of the spiral mechanism of the present application (I).

[0027] Figure 4 It is the detailed structure schematic view of the spiral mechanism of the present application (II).

[0028] Figure 5 It is the structure schematic view of the spiral blade group of the present application.

[0029] Figure 6 It is the structure schematic view of the single spiral blade of the present application.

[0030] Figure 7 It is the side sectional structure schematic view of the annular seat of the present application.

[0031] Figure 8 It is the longitudinal sectional structure schematic view of the annular seat of the present application.

[0032] Reference signs: 1, outer oxygen pipe; 2, coal water slurry pipe; 3, center oxygen pipe; 4, spiral mechanism; 41, spiral blade group; 411, single spiral blade; 412, spiral blade dividing line; 413, positioning notch; 42, annular seat; 421, arc-shaped seat; 422, boss; 423, annular seat dividing line; 424, mounting groove one; 425, mounting groove two; 426, threaded hole; 43, pipe clamp; 44, pipe clamp; 45, fastening screw. DETAILED DESCRIPTION

[0033] The embodiments of the present application are described in further detail below in combination with the drawings.

[0034] In order to solve the problem of nozzle service life of the flat spraying mode, the simulation of the computational fluid dynamics (CFD) model is made according to the actual coal quality data and the actual nozzle size. The simulation result shows that the coal slurry flow state in the nozzle of the flat spraying mode is indeed uneven under the action of gravity, which will cause the spraying three rings to be eccentric. Therefore, a spiral mechanism, i.e. a fixed device with spiral reverse blades, is added on the outer wall of the center oxygen pipe without changing the size and structure of the original process nozzle, so as to change the flow state of the coal slurry in the horizontal pipe.

[0035] The simulation result of the computational fluid dynamics (CFD) model of the nozzle with the added spiral reverse blades on the center oxygen pipe shows that the flow state of the coal slurry in the horizontal pipe is greatly improved compared with the nozzle without the added spiral reverse blades. The specific invention content is described as follows.

[0036] As Figure 1 , 2As shown in the figure, a process nozzle with a spiral mechanism includes, from outside to inside, an outer oxygen pipe 1, a coal water slurry pipe 2 and a center oxygen pipe 3 arranged concentrically, a detachable spiral mechanism 4 is additionally arranged between the coal water slurry pipe 2 and the center oxygen pipe 3, so that the coal water slurry is spirally transported around the center oxygen pipe 3, and the spiral mechanism 4 can slide along the axis of the center oxygen pipe 3. The above structure makes the flow state of the coal water slurry in the horizontal pipe more uniform at the outlet of the process nozzle, ensures good atomization effect of the nozzle, avoids the deflection problem of the flat nozzle, prolongs the service life of the nozzle, ensures the stability of the gasification furnace, reduces the carbon content of the coarse slag to save resources, is beneficial to the chemical reaction in the gasification furnace, and increases the generation of effective gas. Specifically, when the movement trajectory of the coal water slurry in the process nozzle is changed, the coal water slurry is spirally sprayed at the outlet of the process nozzle, and the spirally sprayed coal water slurry can also be effectively cut and atomized by the outer ring oxygen when subjected to pressure difference fluctuation in the gasification furnace. The spiral mechanism 4 has a detachable structure, the installation of the spiral mechanism 4 is a structure of adding an outer wall to the center oxygen pipe 3 without changing the center oxygen pipe 3, and the installed spiral mechanism 4 can slide along the axis of the center oxygen pipe 3. Due to the different coal types used by the process nozzle and the different gasification furnaces, the distance between the spiral mechanism 4 and the outer oxygen end face can also be changed according to the actual application parameters, and the specific control range is 300-1500 mm.

[0037] Further, as shown in Figure 3 、 4 , the spiral mechanism 4 includes a spiral blade group 41, an annular seat 42, a pipe clamp 43, a pipe clamp 44, and a fastening screw 45. The annular seat 42 is provided at the front and rear ends of the spiral blade group 41, and is fixed to the center oxygen pipe 3 by the fastening screw 45. As shown in Figure 5 、 6 , the spiral blade group 41 is a key component of the present application, which is composed of three identical single spiral blades 411. The three single spiral blades 411 are evenly distributed at an angle of 120°, and the single spiral blades 411 are divided by a spiral blade dividing line 412. The length of the single spiral blade 411 is 500-1500 mm, and the spiral angle a is 60°-85°, which are obtained through rigorous calculation and simulation operation. The both ends of the single spiral blade 411 are provided with positioning notches 413, which are evenly distributed at an angle of 120° after assembly, and correspond to the bosses 422 on the annular seat 42, which are also evenly distributed at an angle of 120° on the annular seat 42. The single spiral blade 411 is integrally formed by high-temperature wear-resistant material, and the spiral blade surface and the blade root are smoothly transitioned to reduce the friction resistance between the coal water slurry and the blade surface. As shown in Figure 7 、 8As shown, the annular seat 42 serves as a mounting seat for mounting and fixing the helical blade set 41, and functions to fix the helical blade set 41 to a set position on the central oxygen pipe 3; correspondingly, the annular seat 42 can be equally divided into three identical arc-shaped seats 421, the three arc-shaped seats 421 are evenly distributed at an angle of 120°, and the arc-shaped seats 421 present annular seat dividing lines 423; the annular seat 42 is integrally formed, the annular seat 42 is processed with a mounting groove one 424 of a pipe clamp 44, after the pipe clamp 44 is mounted, the annular seat 42 can be limited to move left and right, the annular seat 42 is further processed with a mounting groove two 425 of a pipe clamp 43, and the mounting groove two 425 corresponds to a groove on the helical blade set 41, the annular seat 42 is further processed with a threaded hole 426 of a fastening screw 45. The boss 422 on the annular seat 42 is correspondingly inserted into the positioning notch 413 on the single helical blade 411, the pipe clamp 43 is two groups and is clamped at the head and tail of the helical blade set 41, the pipe clamp 43 is selected from a steel wire spring pipe clamp, only a semicircular groove needs to be processed, and has the characteristics of simple structure and convenient disassembly and assembly; further, the pipe clamp 44 is two groups and is clamped on the annular seat 42. The pipe clamp 43, the pipe clamp 44 and the fastening screw 45 are used to assemble the entire helical mechanism 4 into a fixed structure, the single helical blade 411 and the arc-shaped seat 421 in the helical mechanism 4 are identical in structure and size, and have the interchangeable advantage during installation, and are convenient for maintenance; if a damaged single helical blade 411 is found, the damaged single helical blade 411 can be replaced alone, without the need to replace the entire helical blade set 41.

[0038] Preferably, the height of the helical blade set 41 is 2 / 3 of the interval between the inner diameter of the coal water slurry pipe 2 and the outer diameter of the central oxygen pipe 3.

[0039] Preferably, the annular seat 42 has an inclination angle of 1.5-2° from outside to inside, which can offset the thermal expansion caused by heat conduction when the process nozzle central oxygen pipe 3 is used, and also increases the fastening force of the helical mechanism 4 on the central oxygen pipe 3 during coal water slurry conveying.

[0040] The assembly principle of the present application is as follows: first, two groups of annular seats 42 are pre-installed on the central oxygen pipe 3, the length of the helical blade set 41 is reserved, then three single helical blades 411 are installed at corresponding positions between the two groups of annular seats 42, a pipe clamp 43 made of steel wire is used to clamp the semicircular groove of the helical blade set 41, then a pipe clamp 44 is used to clamp the annular seat 42, finally, the helical mechanism 4 is adjusted to a reasonable position calculated by a model, and two groups of fastening screws 45 are used to firmly fix the helical mechanism 4.

[0041] The above is only a preferred embodiment of the present application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the concept of the present application, and these improvements and refinements should also be regarded as within the scope of protection of the present application.

Claims

1. A process nozzle with screw mechanism, comprising, from outside to inside, an outer oxygen pipe, a coal water slurry pipe and a center oxygen pipe arranged concentrically, characterized in that: The detachable spiral mechanism is arranged between the coal water slurry pipe and the central oxygen pipe, so that the coal water slurry is spirally transported around the central oxygen pipe, the spiral mechanism can slide along the axis of the central oxygen pipe, and the distance between the spiral mechanism and the outer oxygen end surface ranges from 300 mm to 1500 mm. The spiral mechanism comprises a spiral blade group, the spiral blade group is combined by three identical single spiral blades, the three single spiral blades are uniformly distributed at an angle of 120 degrees, the length of the single spiral blade ranges from 500 mm to 1500 mm, and the helix angle of the single spiral blade ranges from 60 degrees to 85 degrees. The spiral mechanism further comprises an annular seat, a pipe clamp and a fastening screw, the annular seat is provided at the front and rear ends of the spiral blade group in two groups, the annular seat is fixed to the central oxygen pipe through the fastening screw, the boss on the annular seat is inserted into the positioning gap on the spiral blade group in correspondence, and the pipe clamp is clamped at the head and tail of the spiral blade group in two groups.

2. A process nozzle with a screw mechanism according to claim 1, characterized in that: The annular seat can be equally divided into three identical arc-shaped seats, and the three arc-shaped seats are uniformly distributed at an angle of 120 degrees.

3. A process nozzle with screw mechanism according to claim 1 or 2, characterized in that: The spiral mechanism further comprises a pipe clamp, and the pipe clamp is clamped on the annular seat in two groups.

4. A process nozzle with a screw mechanism according to claim 1, characterized in that: The height of the spiral blade group is 2 / 3 of the distance between the inner diameter of the coal water slurry pipe and the outer diameter of the central oxygen pipe.

5. A process nozzle with a screw mechanism according to claim 1, characterized in that: The spiral blade group is integrally formed by using high-temperature wear-resistant material.

6. A process nozzle with a screw mechanism according to claim 1, characterized in that: The inner diameter of the annular seat has an inclination angle of 1.5-2 degrees from outside to inside.

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