A pulse nozzle for garbage furnace and preparation method thereof

Abstract

The invention proposes a pulse nozzle for a garbage furnace and a preparation method thereof, and belongs to the technical field of boiler soot blowing. The invention solves the problem that the existing nozzle structure is a straight tube beveled or cut with an elbow, which leads to the weakening or concentration of the force of the deflagration soot blowing, the soot blowing effect is not ideal due to the weakened force, and the concentrated force will cause the tube bundle of the heating surface to be thinned and cause the tube to burst, which will cause a large amount of maintenance and loss of the boiler during shutdown and restart. The invention comprises a guide head and a straight pipe section connected to each other, the guide head is designed to diffuse from the inside to the outside, the guide head and the straight pipe section are both made of ZGCr26Ni14Mo2Cu2Re material, the ZGCr26Ni14Mo2Cu2Re material is composed of 0.15%-0.2% carbon, 26%-28% chromium, 12%-15% nickel, 0.45%-6% molybdenum, 0.40%-7% manganese, 0.2%-3% copper and 0.15%-3% rhenium, and the guide head and the straight pipe section are integrally formed. It is mainly used for the preparation of pulse nozzles for boiler sootblowers.

Description

Technical Field

[0001] The invention belongs to the technical field of boiler soot blowing, and in particular relates to a pulse nozzle for a garbage furnace and a preparation method thereof. Background Art

[0002] At present, boiler soot blowers are usually in several forms such as gas soot blowers, steam soot blowers, sonic soot blowers, and air cannon soot blowers. The working process of the gas soot blower is: gas source → acetylene confluence device pressure reduction → gas pressure, flow regulation and control → distribution, ignition → pulse tank → pulse nozzle. The pulse nozzle of the pulse (shock wave, gas) soot blower is retained inside the boiler. It is usually made of stainless steel pipes. Due to the repeated scouring and corrosion of the high-temperature flue gas in the furnace, it often needs to be replaced in less than a year; the usual structural form is a straight pipe bevel cut, or cut with an elbow, which leads to the weakening or concentration of the soot blowing force of the deflagration. The weakened force is not ideal for the soot blowing effect. The concentrated force will make the tube bundle of the heating surface thinner and cause the tube to burst, which will cause a large amount of maintenance and shutdown losses to the boiler. Summary of the invention

[0003] In view of this, the present invention aims to propose a pulse nozzle for a garbage furnace and a preparation method thereof, so as to solve the problem that the existing nozzle structure is a straight tube beveled or cut with an elbow, which leads to weakening or concentration of the force of the deflagration soot blowing. The weakened force makes the soot blowing effect unsatisfactory, and the concentrated force will make the tube bundle of the heating surface thinner and cause the tube to burst, causing a large amount of maintenance and shutdown and restart losses to the boiler.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A pulse nozzle for a garbage furnace comprises a flow guide head and a straight pipe section connected to each other, wherein the flow guide head is designed to diffuse from inside to outside.

[0006] Furthermore, the guide head and the straight pipe section are both made of ZGCr26Ni14Mo2Cu2Re material.

[0007] Furthermore, the ZGCr26Ni 14Mo2Cu2Re material consists of 0.15%-0.2% carbon, 26%-28% chromium, 12%-15% nickel, 0.45%-6% molybdenum, 0.40%-7% manganese, 0.2%-3% copper and 0.15%-3% rhenium.

[0008] Furthermore, the guide head and the straight pipe section are integrally formed.

[0009] A method for preparing a pulse nozzle comprises the following steps:

[0010] Step 1: 3D modeling of the pulse nozzle through CAD;

[0011] Step 2: Process the model through the CAM system to process the pulse nozzle shape mold;

[0012] Step 3: Select polystyrene foam plastic with a thickness of 0.6-0.8 mm and a density of 21-23 g / cm3 to form a lost foam white mold;

[0013] Step 4: Casting and forming;

[0014] Step 5: After forming, use a shot blasting machine to remove the residue attached to the surface of the workpiece.

[0015] Furthermore, in step 4, the pulse nozzle is formed by a lost foam casting method.

[0016] Furthermore, the lost foam casting method comprises the following steps:

[0017] S1: Start cleaning the pouring cup and riser;

[0018] S2: Turn on the negative pressure device and cast molten steel under negative pressure;

[0019] S3: gasifying the ESP model in the sand box;

[0020] S4: After gasification, let it stand for 12 hours. After it is completely cooled, open the mold and take out the molded workpiece.

[0021] Furthermore, in S2, a slow-fast-slow method is used for casting.

[0022] Furthermore, during casting, the runner must always be kept full of molten steel.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The guide head of the present invention is designed to diffuse from the inside to the outside, and has the function of diffusion. The energy is transferred from a small space to a large space, which increases the soot blowing range of the nozzle, thereby increasing the soot blowing force, so that the pulse airflow is well guided to the dust accumulation heating surface that needs soot blowing, and at the same time greatly reduces the overall number of distribution points, saving users a lot of procurement costs.

[0025] 2. The pulse nozzle of the present invention is retained inside the boiler. It adopts the high temperature and corrosion resistant ZGCr26Ni14Mo2Cu2Re material, which has better performance than 316L and 304 stainless steel materials. The main components are Cr and Ni, with added Mo and Cu elements, as well as some trace elements Si, N, Re, and rare elements such as Ta and W, thereby improving the strength and hardness, oxidation resistance, wear resistance and corrosion resistance.

[0026] 3. The pulse nozzle of the present invention is prepared by lost foam casting, so that the accuracy of the workpiece can be guaranteed, and the workpiece is shot peened to release the internal stress. The deformation is small when the nozzle and the soot blower are welded, ensuring the surface cleanliness.

[0027] 4. The present invention adopts the lost foam casting method for preparation, which reduces multiple processes such as cutting and processing, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 The figure is a schematic structural diagram of a pulse nozzle for a garbage furnace according to the present invention.

[0030] 1- flow guide head, 2- straight pipe section. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0032] Specific implementation method 1: See Figure 1 The present embodiment is described as follows: a pulse nozzle for a garbage furnace comprises a guide head 1 and a straight pipe section 2 connected to each other. The guide head 1 is designed to diffuse from the inside to the outside. During the soot blowing process of the pulse nozzle, the pulse wave propagates in the form of a spherical wave along the normal direction of the nozzle outlet. In order to effectively act its energy on the dust accumulation heating surface, a pulse nozzle with a guiding function is required. Specifically, Figure 1 As shown, the guide head 1 and the straight pipe section 2 are integrally formed. The guide head 1 is designed to diffuse from the inside to the outside. The injection direction of the nozzle is determined by a reasonable guide angle, so that the blowing is targeted. The first part of the guide head 1 has a diffusion function. The energy is transferred from a small space to a large space, which increases the soot blowing range of the nozzle, thereby increasing the soot blowing force, so that the pulse airflow is well guided to the dust accumulation heating surface that needs soot blowing, and at the same time greatly reduces the overall number of distribution points, saving users a lot of procurement costs.

[0033] The pulse nozzle is designed with a special angle to concentrate the energy of the explosion, with a strong impact force, which effectively acts on the heated surface of the ash accumulation, increases the sweeping range, and can effectively remove the coked ash in the high-temperature area of ​​the garbage furnace.

[0034] Specific implementation method 2: The guide head 1 and the straight pipe section 2 are both made of ZGCr26Ni14Mo2Cu2Re material, which consists of 0.15%-0.2% carbon, 26%-28% chromium, 12%-15% nickel, 0.45%-6% molybdenum, 0.40%-7% manganese, 0.2%-3% copper and 0.15%-3% rhenium.

[0035] Since the pulse nozzle of the pulse soot blower is retained inside the boiler, the alloy cast steel nozzle adopts high temperature and corrosion resistant ZGCr 26 Ni 14 Mo 2 Cu 2 Re material, performance is better than 316L, 304 stainless steel material, the main components are Cr and Ni, added Mo and Cu elements, and some trace elements Si, N, Re, while adding Ta, W and other rare elements, Cr added to pure iron and cast steel, at a certain Cr content can improve the strength and hardness, for example, in iron-chromium alloy, with the increase of chromium content, the tensile strength and hardness of the alloy increased significantly, in structural steel and tool steel, chromium can significantly improve the strength, hardness and wear resistance, when the chromium content in cast steel exceeds 12%, can It makes cast steel have good high temperature oxidation resistance and oxidation corrosion resistance, and also increases the thermal strength of steel. Chromium is the main alloying element of stainless steel and heat-resistant steel. Cr can improve the corrosion resistance of cast steel. It is the main alloying element of stainless steel and acid-resistant steel. Chromium can increase the electrode potential of steel and prevent the generation of galvanic cell reaction, thereby improving corrosion resistance. Ni element can improve the corrosion resistance of castings, improve low temperature performance, improve plasticity and toughness, improve cold formability and weldability, etc. Mo element maintains sufficient strength and creep resistance at high temperature, improves thermal strength, M o can strongly improve the bonding force of solid solution atoms and improve corrosion resistance, especially for non-oxidizing media, because Mo can form a dense and stable MoO3 film to improve red hardness, Mo and C atoms have strong bonding force, so the tempering stability is relatively good and the formed carbides are stable at high temperatures. The Cu element plays an important role in alloy steel. It can improve the strength and corrosion resistance of alloy steel and is conducive to improving the heat treatment process. Since copper has good forgeability and high plasticity, its addition can also improve the processing performance of steel. Therefore, in the production and processing of alloy steel, copper plays a vital role. The appropriate addition of N element can be used as a strengthening element to form dispersed alloy nitrides to improve the hardness and strength of the surface layer. Re element can optimize the grain structure. In the casting process, the size of the grain directly affects the performance of the casting. Under normal circumstances, fine and uniform grains can improve the yield point, fatigue strength, plasticity and impact toughness of metal materials and reduce the brittle transition temperature. The service life of the pulse nozzle using this material is longer than that of 304 and 316L materials by 4-6 months.

[0036] Specific implementation method three: A method for preparing a pulse nozzle, which comprises the following steps:

[0037] Step 1: 3D modeling of the pulse nozzle through CAD;

[0038] Step 2: Process the model through the CAM system to process the pulse nozzle shape mold;

[0039] Step 3: Select polystyrene foam plastic with a thickness of 0.6-0.8 mm and a density of 21-23 g / cm3 to form a lost foam white mold;

[0040] Step 4: Casting and forming;

[0041] Step 5: After forming, use a shot blasting machine to remove the residue attached to the surface of the workpiece.

[0042] Step 4: The pulse nozzle is molded by using a lost foam casting method.

[0043] Furthermore, the lost foam casting method comprises the following steps:

[0044] S1: Start cleaning the pouring cup and riser;

[0045] S2: Turn on the negative pressure device and cast molten steel under negative pressure;

[0046] S3: gasifying the ESP model in the sand box;

[0047] S4: After gasification, let it stand for 12 hours. After it is completely cooled, open the mold and take out the molded workpiece.

[0048] Due to the lost foam casting method, the accuracy of the workpiece is guaranteed. The workpiece is shot peened to release the internal stress. The deformation is small when the nozzle and soot blower are welded, ensuring the surface cleanliness. The composition of the molten steel is detected online during casting, the material of the workpiece is guaranteed, and multiple processes such as cutting and processing are reduced, reducing the production cost. This method can be used for mass production and shorten the delivery cycle.

[0049] Furthermore, in S2, a slow-fast-slow method is used for casting.

[0050] Furthermore, during casting, the runner must be filled with molten steel from beginning to end. If it is not full, due to the limited strength of the coating layer, it is easy to cause sand collapse and air intake, resulting in casting defects. When pouring molten steel, you must grasp it to ensure that it is stable, accurate and fast, instantly fill the pouring cup, and flow quickly and continuously. One ton of molten steel takes about one minute. If the molten steel of the casting in the same box is cut off, air will be sucked in, which may cause sand collapse or increase the porosity of the casting, resulting in the scrapping of the casting. Lost foam casting adopts negative pressure closure, and it must be closed below the pouring cup. When the molten steel enters the molding mold, it begins to liquefy and burn, and gasifies and disappears. A temporary cavity is formed in a short distance at the front end of the molten steel. Therefore, the speed of designing the molten steel filling is roughly the same as the speed of disappearance of the foam model. When pouring, pay attention to adjusting and controlling the negative pressure vacuum within a certain range. After pouring, keep it under a certain negative pressure for a period of time, and then take it out of the box after the negative pressure stops and the molten steel condenses.

[0051] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well.

Claims

1. A pulse nozzle for a garbage furnace, characterized in that: It comprises a flow guide head (1) and a straight pipe section (2) which are connected to each other, and the flow guide head (1) is designed to diffuse from the inside to the outside.

2. A pulse nozzle for a garbage incinerator according to claim 1, characterized in that: The guide head (1) and the straight pipe section (2) are both made of ZGCr26Ni14Mo2Cu2Re material.

3. A pulse nozzle for a garbage incinerator according to claim 2, characterized in that: The ZGCr26Ni14Mo2Cu2Re material consists of 0.15%-0.2% carbon, 26%-28% chromium, 12%-15% nickel, 0.45%-6% molybdenum, 0.40%-7% manganese, 0.2%-3% copper and 0.15%-3% rhenium.

4. The pulse nozzle for garbage incinerator according to claim 1, characterized in that: The flow guide head (1) and the straight pipe section (2) are integrally formed.

5. A method for preparing the pulse nozzle according to any one of claims 1 to 4, characterized in that: It includes the following steps: Step 1: 3D modeling of the pulse nozzle through CAD; Step 2: Process the model through the CAM system to process the pulse nozzle shape mold; Step 3: Choose 0.6-0.8mm, density 21-23g / cm 3 The polystyrene foam is used to form a lost foam white mold; Step 4: Casting and forming; Step 5: After forming, use a shot blasting machine to remove the residue attached to the surface of the workpiece.

6. A method for preparing a pulse nozzle according to claim 5, characterized in that: Step 4: The pulse nozzle is molded by using a lost foam casting method.

7. A method for preparing a pulse nozzle according to claim 6, characterized in that: The lost foam casting method comprises the following steps: S1: Start cleaning the pouring cup and riser; S2: Turn on the negative pressure device and cast molten steel under negative pressure; S3: gasifying the ESP model in the sand box; S4: After gasification, let it stand for 12 hours. After it is completely cooled, open the mold and take out the molded workpiece.

8. A method for preparing a pulse nozzle according to claim 7, characterized in that: In S2, the slow-fast-slow method is used for casting.

9. The method for preparing a pulse nozzle according to claim 7, characterized in that: During casting, the runner must always be kept full of molten steel.

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