阅读说明：本技术 一种金属粉末烧结滤芯及其制备方法 (Metal powder sintered filter element and preparation method thereof ) 是由 赵本勇 赵志勇 朱晓辉 陈解放 于 2019-09-10 设计创作，主要内容包括：本发明的目的在于提供一种金属粉末烧结滤芯的制备方法,通过添加成孔的碳酸钙粉末,在压制过程中采用高压压制,碳酸钙能够起到支撑作用,在烧制的过程中碳酸钙分解生产二氧化碳和氧化钙,在经高压压制,氧化钙粉末起到支撑作用,形成微孔,通过稀酸浸泡并冲洗掉滤芯内的氧化钙,最后通过卷管焊制为滤芯。采用本发明制备的金属粉末滤芯能同时获得高精度、高通量和优良的反冲洗效果,更长的使用寿命。(The invention aims to provide a preparation method of a metal powder sintered filter element, which is characterized in that calcium carbonate powder with a pore is added, high-pressure pressing is adopted in the pressing process, the calcium carbonate can play a supporting role, the calcium carbonate is decomposed to produce carbon dioxide and calcium oxide in the firing process, the calcium oxide powder plays a supporting role through the high-pressure pressing to form micropores, the calcium oxide in the filter element is soaked and washed by dilute acid, and finally the filter element is prepared through coil pipe welding. The metal powder filter element prepared by the invention can simultaneously obtain high precision, high flux and excellent backwashing effect, and has longer service life.)

1. A preparation method of a metal powder sintered filter element is characterized by comprising the following steps:

(1) Powder sieving

Sieving filter element metal powder, wherein the granularity of the powder is-300 +1000 meshes;

Sieving the pore-forming powder, wherein the particle size of the powder is-300 +500 meshes;

(2) Mixing

Uniformly mixing the filter element metal powder and the pore-forming powder in the step (1) in a weight ratio of (30 ~ 40) to 1;

(3) low pressure pressing

Filling the mixture obtained in the step (2) into a shaping mold to be pressed into a plate-shaped green body, wherein the pressing pressure is 100 ~ 200 MPa;

(4) Sintering

Placing the green body in the step (3) in a vacuum environment, and sintering at 1400 ~ 1800 ℃ for 0.5 ~ 1 hours in a heat preservation manner;

(5) high pressure pressing

pressing the filter plate sintered in the step (4) under 800 ~ 1000 MPa;

(6) rinsing

Soaking the filter plate in the step (5) in dilute acid for 20 ~ 30min, and then washing the filter plate for 5 ~ 10min by deionized water;

(7) Pipe coiling and welding

And (4) rolling the filter plate in the step (6) into a tubular shape by a plate rolling machine, and then performing longitudinal seam welding in a full-length welding mode.

2. The method of making a metal powder sintered filter element of claim 1, wherein: the filter element metal powder is austenitic stainless steel or duplex stainless steel.

3. The method of making a metal powder sintered filter element of claim 2, wherein: the pore-forming powder calcium carbonate.

4. The method for preparing a metal powder sintered filter element according to claim 3, wherein the dilute acid solution is a nitric acid solution with the mass concentration of 3% ~ 10%, and a corrosion inhibitor with the mass concentration of 0.1% ~ 1% of the nitric acid solution is added.

5. A metal powder sintering filter element is characterized in that: the filter element is prepared by the preparation method of any one of the claims 1 to 4.

6. The sintered metal powder filter element of claim 5, wherein said filter element has an average gap width of 2.5 ~ 1.0.0 μm and a length of 20 ~ 40 μm.

7. the sintered metal powder filter insert of claim 6, wherein said filter insert has a thickness of 1 ~ 5mm, a length of 50 ~ 1000mm, and an inside diameter of 20 ~ 500 mm.

Technical Field

The invention relates to the field of metal powder metallurgy products, in particular to a preparation method of a metal powder sintered filter element.

Background

At present, the requirements of the whole filter industry on the filter material are that the filter flow is as large as possible, and the filter has very small filter resistance, so that the aim of reducing energy consumption is fulfilled. In practice, however, there is often a conflict with a conventional filter: under the condition of large filtering flux, the filtering precision is not high; and when the filtration precision is required to be improved, the filtration flux is reduced sharply. The reason for this is that during the pressing process, the filter element needs to be pressed within a certain pressure range, if the pressure is too low, the filter accuracy of the finished filter element will not meet the requirement, and if the pressure is too high, the accuracy of the finished filter element will meet the requirement and the flow rate will be reduced. The filter element with the common structure needs a large amount of equipment in special occasions such as petrochemical S-Zorb adsorption desulfurization devices, and meanwhile, the filter element is not easy to backwash due to the structure, so that the filter element is scrapped due to the reduction of the flow rate caused by blockage after being used for about one year, and the normal operation of production is seriously influenced.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a preparation method of a metal powder sintered filter element, which is characterized in that calcium carbonate powder with a pore formed is added, the calcium carbonate can play a supporting role in the pressing process by adopting high-pressure pressing, the calcium carbonate is decomposed to produce carbon dioxide and calcium oxide in the firing process, the calcium oxide powder plays a supporting role in the high-pressure pressing to form micropores, the calcium oxide in the filter element is soaked and washed by dilute acid, and finally the filter element is prepared by rolling pipe welding.

In order to solve the technical problems, the invention adopts the following technical scheme:

A preparation method of a metal powder sintered filter element is characterized by comprising the following steps:

(1) Powder screening: sieving filter element metal powder, wherein the granularity of the powder is-300 +1000 meshes; sieving the pore-forming powder, wherein the particle size of the powder is-300 +500 meshes.

(2) And (3) mixing, namely uniformly mixing the filter element metal powder and the pore-forming powder in the step (1) in a weight ratio of (30 ~ 40) to 1.

(3) And (3) low-pressure pressing, namely filling the mixture obtained in the step (2) into a shaping mold to press the mixture into a plate-shaped green blank, wherein the pressing pressure is 100 ~ 200 MPa.

(4) And (4) sintering, namely placing the green blank in the step (3) in a vacuum environment, and sintering at 1400 ~ 1800 ℃ for 0.5 ~ 1 hours under heat preservation.

(5) And (4) high-pressure pressing, namely pressing the sintered filter plate in the step (4) at 800 ~ 1000 MPa.

(6) And (3) rinsing, namely soaking the filter plate in the step (5) in dilute acid for 20 ~ 30min, and then rinsing the filter plate for 5 ~ 10min by deionized water.

(7) Pipe coiling and welding: and (4) rolling the filter plate in the step (6) into a tubular shape by a plate rolling machine, and then performing longitudinal seam welding in a full-length welding mode.

The filter element metal powder is austenitic stainless steel or duplex stainless steel.

The pore-forming powder calcium carbonate.

the dilute acid solution is a nitric acid solution with the mass concentration of 3% ~ 10%, and corrosion inhibitor with the mass of 0.1% ~ 1% of that of the nitric acid solution is added.

A sintered metal powder filter element, which is produced by the production method according to any one of claims 1 to 4.

The average gap width of the filter element is 2.5 ~ 1.0.0 μm, and the length of the filter element is 20 ~ 40 μm.

The thickness of the filter element is 1 ~ 5mm, the length of the filter element is 50 ~ 1000mm, and the inner diameter of the filter element is 20 ~ 500 mm.

The invention has the beneficial effects that: the metal powder filter element prepared by the invention can simultaneously obtain high precision, high flux and excellent backwashing effect, and has longer service life.

Detailed Description

a preparation method of a metal powder sintered filter element is characterized by comprising the following steps:

(1) Powder screening: sieving filter element metal powder, wherein the granularity of the powder is-300 +1000 meshes; sieving the pore-forming powder, wherein the particle size of the powder is-300 +500 meshes.

(2) and (3) mixing, namely uniformly mixing the filter element metal powder and the pore-forming powder in the step (1) in a weight ratio of (30 ~ 40) to 1.

(3) And (3) low-pressure pressing, namely filling the mixture obtained in the step (2) into a shaping mold to press the mixture into a plate-shaped green blank, wherein the pressing pressure is 100 ~ 200 MPa.

(4) And (4) sintering, namely placing the green blank in the step (3) in a vacuum environment, and sintering at 1400 ~ 1800 ℃ for 0.5 ~ 1 hours under heat preservation.

(5) And (4) high-pressure pressing, namely pressing the sintered filter plate in the step (4) at 800 ~ 1000 MPa.

(6) and (3) rinsing, namely soaking the filter plate in the step (5) in dilute acid for 20 ~ 30min, and then rinsing the filter plate for 5 ~ 10min by deionized water.

(7) Pipe coiling and welding: and (4) rolling the filter plate in the step (6) into a tubular shape by a plate rolling machine, and then performing longitudinal seam welding in a full-length welding mode.

The filter element metal powder is austenitic stainless steel or duplex stainless steel.

The pore-forming powder calcium carbonate.

The dilute acid solution is a nitric acid solution with the mass concentration of 3% ~ 10%, and corrosion inhibitor with the mass of 0.1% ~ 1% of that of the nitric acid solution is added.

A sintered metal powder filter element, which is produced by the production method according to any one of claims 1 to 4.

The average gap width of the filter element is 2.5 ~ 1.0.0 μm, and the length of the filter element is 20 ~ 40 μm.

The thickness of the filter element is 1 ~ 5mm, the length of the filter element is 50 ~ 1000mm, and the inner diameter of the filter element is 20 ~ 500 mm.

A metal powder sintered filter element, which is prepared by the preparation method.

The average gap width of the filter element is 2.5 ~ 1.0.0 μm, and the length of the filter element is 20 ~ 40 μm.

the thickness of the filter element is 1 ~ 5mm, the length is 50 ~ 1000mm, and the inner diameter is 20 ~ 500mm

The preparation method of the austenitic stainless steel powder sintered filter element comprises the following steps:

Sieving filter element metal powder, wherein the granularity of the powder is-300 +1000 meshes; sieving the pore-forming powder, wherein the particle size of the powder is-300 +500 meshes.

Uniformly mixing the filter element metal powder and the pore-forming metal powder in a weight ratio of 30: 1.

Filling the mixture into a shaping mold to press a plate-shaped green body, wherein the pressing pressure is 100 MPa.

And placing the green blank in a vacuum environment, and sintering at 1500 ℃ for 1 hour.

And pressing the sintered filter plate under the pressure of 800 MPa.

Soaking the filter plate in dilute acid for 30min, and washing the filter element with deionized water for 5 min; the dilute acid solution is a nitric acid solution with the mass concentration of 3%, and a corrosion inhibitor accounting for 0.1% of the mass of the nitric acid solution is added.

the prepared filter element has the average gap width of 2.5 ~ 1.0.0 μm, the length of 20 ~ 40 μm, the length of 1000mm and the inner diameter of 500 mm.

The preparation method of the duplex stainless steel powder sintered filter element comprises the following steps:

Sieving filter element metal powder, wherein the granularity of the powder is-300 +1000 meshes; sieving the pore-forming powder, wherein the particle size of the powder is-300 +500 meshes.

Uniformly mixing the filter element metal powder and the pore-forming metal powder in a weight ratio of 40: 1.

Filling the mixture into a shaping mold to press a plate-shaped green blank, wherein the pressing pressure is 150 MPa.

And placing the green body in a vacuum environment, and sintering at 1800 ℃ for 0.5 hour.

and pressing the sintered filter plate under the pressure of 900 MPa.

Soaking the filter plate in dilute acid for 20min, and then washing the filter element for 10min by deionized water; the dilute acid solution is a nitric acid solution with the mass concentration of 10%, and a corrosion inhibitor accounting for 1% of the mass of the nitric acid solution is added.

The prepared filter element has the average gap width of 2.5 ~ 1.0.0 μm, the length of 20 ~ 40 μm, the length of 500mm and the inner diameter of 250 mm.

The preparation method of the austenitic stainless steel powder and duplex stainless steel powder mixed sintered filter element comprises the following steps:

Sieving filter element metal powder, wherein the granularity of the powder is-300 +1000 meshes; sieving the pore-forming powder, wherein the particle size of the powder is-300 +500 meshes.

Uniformly mixing the filter element metal powder and the pore-forming metal powder in a weight ratio of 35: 1.

Filling the mixture into a shaping mold to press a plate-shaped green blank under the pressure of 200 MPa.

And placing the green body in a vacuum environment, and sintering at 1800 ℃ for 0.8 hour in a heat preservation manner.

And pressing the sintered filter plate under the pressure of 1000 MPa.

Soaking the filter plate in dilute acid for 25min, and washing the filter element with deionized water for 5 min; the dilute acid solution is a nitric acid solution with the mass concentration of 6%, and a corrosion inhibitor accounting for 0.5% of the mass of the nitric acid solution is added.

The prepared filter element has the average gap width of 2.5 ~ 1.0.0 mu m, the length of 20 ~ 40 mu m, the thickness of 1mm, the length of 50mm and the inner diameter of 20 mm.

The prepared metal powder sintered filter element is arranged in an S-Zorb adsorption desulfurization device for test detection, wherein the table 1 shows the field filtering performance of the metal powder sintered filter element, and the table 2 shows the pressure difference comparison between a reactor and a filter in one period.

As can be seen from the table, the metal powder filter element prepared by the invention can simultaneously obtain high precision, high flux and excellent backwashing effect, and has longer service life.

TABLE 1

TABLE 2