Durable sintered mesh elements for filter cartridges and methods to clean them

Filter cartridges made from sintered wire mesh are suitable for applications that need a robust filter cartridge resistant to extreme chemicals. They are made in varied sizes to suit industry standard filter structures even also in diverse non-standard sizes and specifications. The screens made from 316L grade stainless steel and configured without using resins or adhesives.

Sintered stainless steel mesh filter cartridges use sintered mesh structure for filter configuration that combines filter efficiency with strength. Standard mesh construction would consist of an external protective layer, an internal main filter layer, drainage layer and eventually two strengthening layers to offer strength. The fiver mesh layers are sintered to develop a single sheet of filter media.

The mesh cartridges can be in cylindrical or pleated form and in different lengths, diameters and endcap configurations.

How to clean sintered mesh filter cartridges

Reverse Flow: When much of contamination is larger than the pore size of the filter media, reverse flow of liquid or gas through the element will often be sufficient for cleaning. Usually, a flow of minimum two times the forward flow gives complete cleaning.

Ultrasonic cleaning: Surface contamination can be eliminated by ultrasonic cleaning in bath containing detergent, immersed particulate may not be eliminated.

Chemical cleaning: Different chemicals are used to dissolve the contaminant or process fluid in case of hardening on contact with air.

Heanjia can provide you with a wide set of sintered mesh elements used in filtration. It is crucial in the development of synthetic fibers and we can eventually enhance and innovate your conventional filtration. The metal to metal gaskets used in the polymer industry by the diversity refers to the production and quality of our tools. The screens can be made in any shape or dimensions available in different alloys.

We offer a solution allowing a reduced consumption of filters and an enhanced quality of filtered polymer. We can offer a wide range of material to be used as filling sands in the stainless steel, Inconel, aluminium and other high performance materials.

We are specialized in the development and production of metal filtration solutions. We offer filter elements for industrial gas filtration, depending on the special benefits of metal fiber media. Our filter elements are fit for use in high temperature, corrosive chemical and petrochemical process, for process filtration and exhaust gases. These elements are the perfect solution for applications demanding high mechanical stability, long service life, low pressure drop, easy cleaning and chemical and heat resistant are needed.

Filter materials are used for temperature resistance up to 1000oC. Filtration of elements in applications where small dust loads are separated from a gas stream. The contaminants are held in multiple layer structure of the filter medium. Advantage of our depth filter systems that combine high temperature and corrosion resistance with high dirt retaining capacity and outstanding off-line cleaning feasibilities, the excellent solution for your applications. 

How the use of arc spray coatings improve corrosion protection of a component

Coatings are developed to offer protection from corrosion and erosion to secure the material from chemical and physical interaction with its environment. Corrosion and wear issues are of great relevance in diverse industrial applications as they result in the degradation and eventual failure of components and systems in the processing and manufacturing industries and in the service life of various components. Different technologies are used to deposit the suitable surface protection to provide protection under specific conditions. They are often distinguished by coating thickness.

Most thermal coating processes are used at atmospheric pressure in air, except plasma spraying, usually served in soft vacuum. Plasma spraying can be performed in an inert condition or vacuum and cold spray is usually performed at atmospheric pressure however in a controlled condition chamber to collect reuse the spray gas due to the large gas flow rates required.

Extreme uses of arc spray wire are now in culture against wear and corrosion as well as heat and also for functional purpose. The choice of coating process is firmly based on the required coating properties for the application and coating cost. Coating characteristics are determined by the coating material and the form in which it is used, as well as the setoff parameters used to conduct the coating process. Thermal spray coatings are usually featured by a lamellar structure and the real contact between the splats and substrate or the earlier deposited layers determine to a large level of the coating properties like heat conductivity, Young modulus etc.

The real contact area ranges between 20-60% of the coating surface parallel to the substrate. It increases with impact speed of particles. Therefore the coating density increases with increase from flame, wire arc, plasma and gun spraying and thereafter re-fused.

The variety of corrosions particularly for coatings can be categorized as general corrosion, related to 30% failure, where the average rate of corrosion on the surface is uniform and localized corrosion, about 70% of failures. The galvanic corrosion occurs when two different metals are in contact with each other in a conductive solution, the more anodic metal is attacked where each other in a conductive solution, the more anodic metal is attacked, while the more cathodic one is uninfluenced. The electrolyte plays a significant role, and the relative surface contact area, small anodic to cathodic area ratio refers to severity of anodic metal corrosion.

The corrosion can also be intergranular as well as transgranular when cracking occurs. The coating material and is microstructure plays a crucial role in this type of corrosion. The coatings provide protection from corrosion, sacrificial coatings, thicker coatings offer longer protection.

Corrosive wear occurs when the influence of corrosion and wear are combined, resulting into faster failure of material surface. A surface that is oxidized can be mechanically weakened and can wear at a higher rate. Stress corrosion failure results from the combined influence of stress and corrosion. With thermal spray coatings, such types of metallic failures can be significantly reduced. 

Performance of Nickel based super alloys in industrial chloride conditions

The commonly accepted application of commercially pure nickel is to handle the highly concentrated solutions. Nickel shows lower corrosion rates in hot caustic solutions than alloyed nickel as alloying elements like chromium and molybdenum dissolve commonly from alloy in hot caustic solutions. Nickel can also withstand cold reducing acids due to slow discharge of hydrogen on its surface. Hot reducing acids and oxidizing acids quickly attack pure nickel. 

The key application of Monel bars is in handling pure hydrofluoric acid. Although if oxidants like oxygen exist in hydrofluoric acid, Monel alloys may experience intergranular attack. Monel alloys are slightly more resistant to general corrosion than Nickel 200 in hot reducing and oxidizing acids like sulfuric acid and nitric acid. Ni-Mo alloys usually called as Hastelloy B type alloys, are made to withstand reducing HCl at all concentration and temperature limits. As costlier materials like Hastelloy alloys are also used in handling other corrosive reducing conditions like dilute sulfuric, acetic, formic and hydrofluoric acids. Alloy B2 has the minimum corrosion rate in boiling 10% sulfuric acid. Although Hastelloy alloys show poor performance in oxidizing acids, for instance, in hydrochloric acid contaminated with ferric ions.

There are several commercially available Ni-Cr-Mo alloys. They are derived from original C alloy, the advanced grade is Hastelloy C2000. Although the more common grade in industrial applications is Hastelloy C276. NiCrMo alloys are the most versatile nickel alloys as they comprise of molybdenum for protection against corrosion under reducing conditions and chromium that secures the component from corrosion in oxidizing conditions.

Hastelloy C276 has nominal corrosion rates in reducing and oxidizing conditions. One of the major applications of NiCrMo alloys is in the presence of hot chloride containing solutions. In these environments, most of steel grades receive crevice and pitting corrosion as well as stress corrosion cracking. Although NiCrMO alloys are extremely resistant it is not immune to chloride induced corrosion in major industrial applications.

Nickel based corrosion resistant alloys are NiCrFe alloys. They also contain smaller magnitudes or molybdenum and copper as in Incoloy 825. Nickel-Chromium-Iron alloys are usually less resistant to corrosion as compare to Nickel-Chromium-Molybdenum alloys, although they could be less costly and hence find a great range of industrial applications where the application of stainless steels is limited. The corrosion rate of Inconel 600 in sulfuric acid is higher than corrosion rate of Incoloy 825 as grade 825 contains nominal magnitudes of molybdenum and copper that are advantageous alloying elements for resistance to sulfuric acid. Incoloy 825 has nominal corrosion rate in nitric acid as it comprises of larger magnitudes of chromium. The common applications of Ni-Cr-Fe-Mo alloys like Hastelloy G30 is in the industrial development of phosphoric acid and in highly oxidizing conditions like nitric acid.

Cold processed Nickel 200 is resistant to cracking in NaCl and in chloride concentration of CaCl2 and MgCl2 at 121oC, 149oC, 177oC, 204oC and 232oC.