Introduction to the types, standards and technical parameters of wire mesh demisters

Introduction to the types, standards and technical parameters of wire mesh demisters

Wire mesh demister, also known as: wire mesh demister, wire mesh demister, demister, stainless steel wire mesh demister.
It is mainly used to separate droplets with a diameter greater than 3μm to 5μm. When the gas with mist rises at a certain speed and passes through the filter wire mesh in the middle of the grid, due to the inertia of the rising mist, the mist collides with the filaments and adheres to the surface of the filaments. The mist on the surface of the filaments further diffuses and the gravity of the mist itself settles, so that the mist forms larger droplets that flow along the filaments to its intersection. Due to the wettability of the filaments, the surface tension of the liquid and the capillary action of the filaments, the droplets become larger and larger until their own gravity exceeds the combined force of the buoyancy of the rising gas and the surface tension of the liquid, and then they are separated and fall. As long as the operating gas speed and other conditions are properly selected, the defoaming efficiency of the gas after passing through the wire mesh demister can reach more than 99.2%, which can achieve the purpose of completely removing the mist.

Common materials for wire mesh demisters:
1. Stainless steel: 304, 304L, 321, 316Ti, 316L.
2. Titanium and titanium alloys: TA2, TA10.

HG/T21618-1998 Wire Mesh Defoamer Standard Introduction:

The standard of "HG/T21618-1998 Wire Mesh Defoamer" is revised on the basis of the original chemical industry standards HG5-1404-81, HG5-1405-81, HG5-1406-81, combined with the actual use experience of wire mesh defoamers and the advanced technology of the imported devices. The structural design of general wire mesh defoamers can be based on this standard; the technical parameters of the filter screen for wire mesh defoamers can refer to: "HT-2001 Wire Mesh Defoamer Standard", "HG/T21618-1998 Wire Mesh Defoamer Standard", "HG/T21586-1998 Drawer-type Wire Mesh Defoamer Standard". The newly revised "HG/T21618-1998 Wire Mesh Defoamer" standard has the following changes compared with the original standard:
A. The original three standards are merged into one standard for easy selection.   
B. The diameter range and specifications of the defoamer are adjusted, and the nominal diameter specifications are appropriately encrypted.   
C. Added the wire mesh types used in demisters and provided the basic parameters of the wire mesh.   
D. Added the material varieties of wire mesh and grilles.   
E. Added the process calculation content about wire mesh demisters to facilitate selection.

This standard specifies the structure, type, specification, size, technical requirements, marking, selection and use of wire mesh demisters. This standard applies to gas-liquid separation devices used in vertical cylindrical equipment in industries such as chemical, petrochemical, pharmaceutical, light industry, and environmental protection. It is used to separate mist with a droplet diameter greater than 3 to 5 μm entrained in the gas. The specification range of wire mesh demisters is: DN300 to DN5200mm (non-standard products are not limited by the specification range).

 The structure of wire mesh demister:
The wire mesh demister is composed of two parts: gas-liquid filter screen pad (composed of several mesh blocks) and supporting parts.   
The mesh block is composed of several layers of flat (wound) corrugated gas-liquid filter screens, grilles and distance rods.   
The supporting parts of the wire mesh demister generally include: beams, pressure strips, pressure plates, lugs, supporting plates, supporting rings, sealing plates, retaining rings, etc. The supporting parts are made by the container equipment manufacturer. If necessary, the wire mesh demister manufacturer can also provide it, but it must be stated when ordering.
The wire mesh demister can also be made according to user requirements: detachable (screw distance rod), non-detachable wave type, drawer type, etc. The filter type is made according to the "HT-2001 Wire Mesh Defoamer Standard" or user requirements.