Stainless steel sintering felt knowledge summary

The filter element serves as the core filter element. In many cases, the final filtration value depends on the filter material used as the working layer except for the support layer. As a kind of main working layer filter material, stainless steel sintered felt has a wide range of applications in many industrial fields. Now it makes a brief summary of its relevant knowledge to the industry friends.

●Introduction

Stainless steel sintered mats, also known as metal non-woven fabrics, are made of non-woven metal fibers with a diameter of micrometers, stacked, and sintered at high temperatures. Stainless steel sintered felts are formed with different pore size gradients, which can be controlled to obtain extremely high filtration accuracy and greater dirt holding capacity. With the characteristics of three-dimensional mesh, porous structure, high porosity, uniform pore size distribution, etc., it can continuously maintain the filtering effect of the filter cloth. Due to the above structure and characteristics, the stainless steel sintering felt can effectively make up for the weaknesses of the metal net, which can be easily blocked and fragile, and can compensate for the fragility of the powder filter product and the small flow rate. The conventional filter paper and the filter cloth cannot match the temperature and pressure resistance. Characteristics, so stainless steel sintered metal mat is an ideal corrosion resistance, high temperature, high precision filter material.

●Material

00Cr17Ni14MO2 (316L), OCr17Ni14MO2 (316), OCr18Ni9 (304), pure nickel;

●Production process

The metal fiber sintered felt is a composite fiber bundled with a multi-metal wire and then stretched to a usable fiber diameter, and then bundled into filaments with the same weight and a standard diameter, cut, and made into a fluffy felt by a suitable method, and then put a few The fluffy felts of different diameters are arranged in order to form a certain thickness of stacked fibers, so that the fibers cross each other into voids, and then sintered and rolled into a finished sintered felt.

● Features

(1) high porosity and excellent permeability, low pressure loss, large flow;

(2) Large capacity for receiving pollution, high filtration accuracy, slow rise of pressure curve during use, long replacement cycle;

(3) excellent temperature resistance and corrosion resistance, long-term use at 600 °C, resistance to corrosion of nitric acid, alkalis, organic solvents, and pharmaceuticals;

(4) high strength, not easy to deform: can be folded wave, to increase the filter area, and welding processing;

(5) It can be cleaned and regenerated, even if the liquid is strongly washed and strongly shaken, the fiber does not fall off;

(6) Can be used multiple times.

● Structural optimization (increase in thickness and efficiency)

The metal fiber sintered felt filter material is an arrow-type filter material, which belongs to depth filtration, that is, three-dimensional filtration. If the filter material is modified into a loose metal fiber sintered felt filter material, the spacing between the fibers is often several times or even several times larger than the diameter of the filtered dust, but the filtering effect is still obvious. Each monolayer (or single) fiber has a low dust catching rate, but as the thickness increases, the depth of the filter material plays a broad role in filtering. The filter material is affected by the thickness, the filtration efficiency increases to 1.4 times, and the dust holding capacity increases. To 1.9 times. The filter material with an increased thickness has a loose structure with a porosity of more than 90% and is widely used in air filtration.

●Use

(1) chemical fiber, thin film industry: polyester, nylon, polyester and other polymer melt filtration, melt filter, textile parts;

(2) filter layer;

(3) Filtration and dust removal of various high-temperature and corrosive gases in petroleum, chemical, and metallurgical fields;

(4) Filtration of various high-temperature and corrosive liquids in petroleum and chemical industries;

(5) Precise filtration of hydraulic oil and lubricants in the fields of machinery, ships, power, electronics, aerospace and aerospace;

(6) Clarification and filtration of various liquids in the pharmaceutical, biological and beverage industries.

●Cleaning method

The metal fiber sintered felt has a long service life as a filter medium that can be cleaned. Its production cost is higher than other disposable filter materials. Due to the dual considerations of the environment and cost, the metal fiber sintered felt filter is either Unscheduled maintenance is also very necessary.

(1) Principles and methods of chemical cleaning:

The most common chemical cleaning method is the acid-alkali cleaning solution cleaning method. The most effective method for collecting polyester-container filters is to use an acid-base solution for chemical cleaning.

(2) Ultrasonic cleaning method:

Ultrasound is a kind of wave energy that continuously pressurizes and expands. This energy is applied to the liquid to generate cavitation. Continuously broken cavitation can produce a cleaning effect on the sintered felt.

(3) heat treatment cleaning:

Vacuum pyrolysis, heating ovens, liquefaction beds, and hot salt baths are all methods of cleaning the sinter mats. They are often used when the chemical cleaning method does not work.

It should be noted that after the cleaning of the sintered felt core, the bubble point test is also performed to check its integrity and to determine the pressure drop of the filter element.

Effect of Wave Deformation on Filtration Properties of Sintered Stainless Steel Fiber Sintered Felt

Stainless steel fiber mats are often processed into bellows when used. After the fiber mat has been deformed by waves, its internal aperture, shape, and size will change at the peaks and troughs. What changes in the filtration performance of the fiber mat after its deformation?

(1) After the stainless steel fiber mat is deformed by a wave, the pore diameter is generally enlarged, and its expansion value increases with the decrease of the angle of the buckling deformation. In addition to the felt with a filter accuracy of 10 μm, the increment of the aperture after the buckling deformation decreases linearly with the increase of the included angle of the buckling.

The increase of the flow after the deformation of the fiber mats was increased with the decrease of the angle between the folds and the increase in the pressure difference, the greater the increase in the change, but the flow after the deformation of the carpet with a filter accuracy of 10 μm was almost unchanged.

The above is a brief summary of the stainless steel sinter felt and I hope to help my friends. Limitation of understanding, inadequacies hope correction!