A jet pipe and casting process thereof

Abstract

A jet pipe, characterized in that it includes an outer wall and a wear-resistant layer, the outer wall is a seamless steel pipe, the upper end of the seamless steel pipe is a feed port, the lower end of the seamless steel pipe is closed, and the side wall of the seamless pipe is provided with a discharge port; the inner wall of the seamless steel pipe is provided with a wear-resistant layer, and the wear-resistant layer is cast from KmTBCr26 material. A jet pipe casting process, characterized in that it includes the following steps: (1) processing the seamless steel pipe so that its bottom surface is closed, the upper part is a feed port, and the side wall is provided with a discharge port; (2) arranging a casting cavity in the seamless steel pipe; (3) arranging a pouring port and a riser at the feed port of the seamless steel pipe; (4) injecting the molten wear-resistant layer material KmTBCr26 liquid from the pouring port; (5) cooling the wear-resistant layer and the seamless steel pipe. It overcomes the casting defects such as sand holes, pores, looseness, etc. that may appear in key parts of the jet pipe during the casting process, and prolongs the service life.

Description

Technical Field

[0001] The invention relates to a jet pipe and a casting process thereof. Background Art

[0002] In the Bayer process of alumina beneficiation, there is a process called high-pressure dissolution. The fluid in this process contains ore powder particles, high-temperature, high-pressure alkali solution, and after 10 levels of flash evaporation, the ore is gradually dissolved into alumina to facilitate the subsequent processing.

[0003] There is a component called a jet pipe in the dissolution process equipment, which is used to divert and limit the flow of high-temperature and high-pressure ore slurry. Due to the high temperature of the slurry, the maximum temperature reaches 300℃, the maximum pressure is 3.5MPa, and the alkali solution: sodium hydroxide (NaOH) content exceeds 200g / l. Therefore, the characteristics of the fluid slurry are high temperature, high pressure, strong corrosion, and high flow rate.

[0004] At present, the injection pipe is usually made of 16Mn material, but its service life is only about 10 days. It is easily damaged by erosion and corrosion of ore slurry. The service life is too short, which seriously affects the normal operation of production. Summary of the invention

[0005] To solve the above problems, the present invention provides the following solutions:

[0006] A jet pipe comprises an outer wall and a wear-resistant layer. The outer wall is a seamless steel pipe, the upper end of the seamless steel pipe is a feed port, the lower end of the seamless steel pipe is closed, and the side wall of the seamless pipe is provided with a discharge port; the inner wall of the seamless steel pipe is provided with a wear-resistant layer, and the wear-resistant layer is cast by KmTBCr26 material.

[0007] Furthermore, the KmTBCr26 material used in the wear-resistant layer has a Cr content of 23%-30% and a C content of 2.0%-3.3%.

[0008] A jet pipe casting process comprises the following steps:

[0009] (1) The seamless steel pipe is processed so that its bottom surface is closed, the top is the feed inlet, and the side wall is opened with a discharge port;

[0010] (2) Arranging a casting cavity in the seamless steel pipe;

[0011] (3) Arrange pouring nozzle and riser at the feeding port of seamless steel pipe;

[0012] (4) injecting the molten wear-resistant layer material KmTBCr26 liquid from the pouring port;

[0013] (5) Cooling wear-resistant layer and seamless steel pipe;

[0014] Furthermore, the pouring port and the riser are arranged relative to each other with the axis of the feed port of the seamless steel pipe as the axis, and the pouring port is located above the discharge port.

[0015] Beneficial effects of the present invention:

[0016] 1. Set the riser at the feed port to make the riser position higher. During the pouring process, the pouring liquid can fully utilize its own gravity to effectively fill the space in the pouring cavity, discharge the air in the pouring cavity to the maximum extent, reduce the sand holes and pores in the wear-resistant layer, and effectively improve the problem of loose texture of the wear-resistant layer.

[0017] 2. The injection pipe is made of a mixed material with a seamless steel pipe on the outer wall and a cast wear-resistant layer on the inner lining, which increases its wear resistance and corrosion resistance and effectively increases its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the present invention.

[0019] Figure 2 This is a schematic diagram of the traditional process.

[0020] 1. Seamless steel pipe; 2. Wear-resistant layer; 3. Casting cavity; 4. Feed inlet; 5. Discharge outlet; 6. Casting gate; 7. Riser. DETAILED DESCRIPTION

[0021] The present invention is now described in detail with reference to the accompanying drawings:

[0022] Example 1: Figure 1 As shown, a jet pipe includes an outer wall and a wear-resistant layer 2. The outer wall is a seamless steel pipe 1. The upper end of the seamless steel pipe 1 is a feed port 4. The lower end of the seamless steel pipe 1 is closed. The side wall of the seamless steel pipe 1 is provided with a discharge port 5. The inner wall of the seamless steel pipe 1 is provided with a wear-resistant layer 2, and the wear-resistant layer 2 is cast with KmTBCr26 material.

[0023] Furthermore, the wear-resistant layer 2 adopts KmTBCr26 material, in which the Cr content is 23%-30%, and the C content is 2.0%-3.3%.

[0024] A jet pipe casting process comprises the following steps:

[0025] (1) The seamless steel pipe 1 is processed so that its bottom surface is closed, the upper end is a feed inlet 4, and the side wall is opened with a discharge port 5;

[0026] (2) Arranging a casting cavity 3 in the seamless steel pipe 1;

[0027] (3) arranging a pouring port 6 and a riser 7 at the feed port 4 of the seamless steel pipe 1;

[0028] (4) injecting the molten wear-resistant layer 2 material KmTBCr26 liquid from the pouring port 6;

[0029] (5) Cooling the wear-resistant layer 2 and the seamless steel pipe 1;

[0030] Furthermore, the pouring gate 6 and the riser 7 are arranged relative to each other with the axis of the feed port 4 of the seamless steel pipe 1 as the axis, and the pouring gate 6 is located above the discharge port 5 .

[0031] The pouring riser 7 is changed from the traditional discharge port 5 (such as Figure 2 As shown in the figure, the riser 7 is moved to the feed port 6. After this improvement, the shrinkage compensation effect of the riser 7 during casting is improved. Since the riser 7 is at the highest position, the pouring liquid can fill the casting cavity 3 of the casting as much as possible under the action of its own weight, and at the same time, the air in the casting cavity 3 is better emptied, so that the wear-resistant layer 2 can be prevented from having defects such as pores, looseness, and sand holes to the greatest extent. After the wear-resistant layer 2 is processed, there are no above defects at the discharge port 5 (the original riser). After actual use by users, the service life of the product has been increased by more than 50%, generally reaching about 60 days, meeting the user's requirements.

Claims

1. A jet pipe casting process, characterized in that: The following steps are involved: (1) The seamless steel pipe is processed so that its bottom surface is closed, the top is the feed inlet, and the side wall is opened with a discharge port; (2) Arrange a casting cavity in the seamless steel pipe; (3) Arrange pouring nozzle and riser at the feeding port of seamless steel pipe; (4) Injecting the molten wear-resistant layer material KmTBCr26 liquid from the pouring port; (5) Cooling the wear-resistant layer and seamless steel pipe.

2. A jet pipe casting process as claimed in claim 1, characterized in that: The pouring port and the riser are arranged relative to each other with the axis of the seamless steel pipe feed port as the axis, and the pouring port is located above the discharge port.

3. An injection pipe made by the casting process according to any one of claims 1-2, characterized in that: It includes an outer wall and a wear-resistant layer. The outer wall is a seamless steel pipe. The upper end of the seamless steel pipe is a feed port, the lower end of the seamless steel pipe is closed, and a discharge port is opened on the side wall of the seamless pipe. The inner wall of the seamless steel pipe is provided with a wear-resistant layer, and the wear-resistant layer is cast with KmTBCr26 material.

4. An injection pipe as claimed in claim 3, characterized in that: The KmTBCr26 material used in the wear-resistant layer has a Cr content of 23%-30% and a C content of 2.0%-3.3%.

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