KNIT® Mesh Blankets® are designed to retain liquid particles entrained in a gaseous phase after boiling, vacuum evaporation or bubbling. Liquid droplets – coarse fog – entrained by a gas are retained in the porous network of the demister, whose particular constitution favors their coalescence (phenomenon of droplets coming together), thus creating large droplets that run off and fall.
The gaseous phase leaves the eliminator purified, without having encountered any appreciable resistance, thanks to the high porosity of the chosen metal mesh. This is not a case of filtration, as the size of the “mesh” bears no relation to the size of the droplets, but of stopping by shock and sudden variations in droplet velocity. Coalescence allows the liquid to evacuate by gravity. These are combined mechanical and physical phenomena.
*KNIT® Eliminator is a registered trademark. It applies to products which may also be known as: Drip Eliminators, Mist Eliminators, Mesh Blankets, Separators, Pads, Mats, Anti-entraînement screnn, Demister, Wire Mesh, Ckrinkled Wire Mes (CWM), Impingement, Abscheider, Draht pakete, etc.
ADVANTAGES OF KNIT MESH BLANKETS®
- Improved gas phase quality: In distillation processes, these eliminators prevent the entrainment of less volatile products, guaranteeing cleaner, more efficient separation.
- Elimination of liquid phase losses: In sparging systems or vacuum evaporators, liquid carryover to the vacuum (priming) is eliminated, reducing product losses and improving overall process efficiency.
- Increased gas velocity: Thanks to the high porosity of the wire mesh that makes up KNIT® eliminators, gases can flow more rapidly through the devices. This feature makes it possible to increase production capacity while considering the use of smaller equipment, thus optimizing space and installation costs.
- Low pressure drop: KNIT® eliminators have a very low pressure drop, often considered negligible in normal operating speed ranges.
- Maximum efficiency: With efficiencies in excess of 99%, these devices guarantee near-perfect separation of liquid droplets, even under intensive operating conditions.
- High volumetric contact area: The specific design of the eliminators results in a high volumetric contact area, optimizing phase separation while maintaining a low specific weight.
- Energy-saving operation: Operating statically, these eliminators require no external energy, making them an economical and environmentally-friendly solution.
Raw materials
Metals :
The metals commonly used are :
- Stainless steel (304L,316L)
- MONEL metal (ASTM B 127) *
- Galvanized mild steel
- Mild carbon steel
* These metals are constantly in stock for fast turnaround of all types of eliminators.
Synthetic fiber :
KNIT® Eliminators can be made from the following synthetic fibres:
- Polyethylenes or polypropylenes
- Polyesters
The use of other metals and alloys can be considered on request, such as :
- Chromium steels (for example AISI 430)
- Special alloys with high corrosion resistance (for example NSCD, Uranus B6, Incoloy 825)
- Phosphor bronze
- Brass 1st stock
- Aluminium alloys
- Pure nickel
- Noble metals
- Rare metals
ELIMINATORS CONSTRUCTION
KNIT® Eliminators are made up of a stack of metal knitted fabrics, embossed in a herringbone pattern with metal wires. The embossing increases both the contact surface and the porosity of the elements. The herringbone pattern prevents settlement in service, maintains constant porosity throughout the mass and increases efficiency at low gas velocities. Herringbone embossing facilitates liquid flow and prevents the formation of saturated spots.
Features of eliminator types
The quality and effectiveness of an eliminator is defined by its density and porosity:
Type 150
For example: viscous liquids or liquids loaded with solid particles; dusty gases; very large droplets (greater than 10 microns); large volumes of dense liquid.
It allows higher gas flow speeds than the previous types.
Efficiency is satisfactory, but slightly lower than that of other types.
Recommended thickness is 150 mm.
Herringbone embossed single knit fabric with large corrugations.
| Wire diameter : | 0.28 mm |
| Steel specific weight : | 82 kg/m³ |
| Specific surface : | 150 m²/m³ |
| Free volume : | 98.9 % |
| Belt thickness : | 5 mm |
| Band width : | Standard 360 mm Other widths available on request |
Type 200
This type is designed for easy removal of liquid droplets larger than 5 microns, particularly viscous liquids or liquids slightly laden with solid particles. It allows the use of higher gas velocities than previous types, with lower pressure drops.
In most cases, a thickness of 150 mm is recommended.
Herringbone embossed single knit fabric with large waves.
| Wire diameter : | 0.28 mm |
| Steel specific weight : | 110 kg/m³ |
| Specific surface : | 200 m²/m³ |
| Free volume : | 98.6 % |
| Belt thickness | 5 mm |
| Band width : | Standard 350 mm Other widths available on request |
Type 270
This type is suitable for routine work. Its efficiency is excellent for jobs with defined data: in particular, the quantity of liquid entrained and the droplet size. It admits certain deviations in gas flow rates.
Used in thicknesses of 100 mm, greater thicknesses of 150 or 200 mm should be considered in special cases.
Double-knit herringbone embossed fabric with large waves.
| Wire diameter : | 0.28 mm |
| Steel specific weight : | 145 kg/m³ |
| Specific surface : | 265 m²/m³ |
| Free volume : | 98.2 % |
| Belt thickness | 5 mm |
| Band width : | Standard 350 mm Other widths available on request |
Type 350
The most common type, this high-efficiency eliminator is considered standard due to its wide range of uses. Its specific surface area makes it ideal for heavy-duty applications and where liquid reentrainment must be reduced to negligible quantities.
Designed to accept large variations in gas or liquid flow rates, it offers a wide safety margin.
Generally used in 100 mm thicknesses, greater thicknesses can be considered to increase efficiency in cases of wide flow variations.
Double-knit herringbone embossed fabric with large waves.
| Wire diameter : | 0.28 mm |
| Steel specific weight : | 190 kg/m³ |
| Specific surface : | 350 m²/m³ |
| Free volume : | 97.55 % |
| Belt thickness | 5 mm |
| Band width : | Standard 350 mm Other widths available on request |
Type 450-16
This is the very high-efficiency type used when a maximum degree of separation is required, and especially when a large proportion of fine droplets are entrained, such as aerosols, condensations, retention of poorly wetting droplets or difficult liquids (e.g. glycols, amines, etc.). Particularly recommended for radioactive liquids (decontamination).
The 100 mm thickness is suitable for most applications.
If absolute 100% safety is required, thicknesses of 200 mm or more are recommended.
Waffle-knit double fabric with fine mesh and small waves.
| Wire diameter : | 0.16 mm |
| Steel specific weight : | 130 kg/m³ |
| Specific surface : | 450 m²/m³ |
| Free volume : | 98,3 % |
| Belt thickness | 3,35 mm |
| Band width : | Standard 350 mm Other widths available on request |
Type HE (synthetic)
The characteristics of eliminators made from synthetic fibers differ from those of metal fabrics due to their particular behavior. The general characteristics correspond to the very high-efficiency metallic TYPE 450-16.
The choice of a synthetic fiber is a delicate one, depending among other things on :
- the desired chemical resistance ;
- temperature of use ;
- the wetting power of the liquid relative to the fiber ;
- variable dry and wet corrosion phenomena;
- possible incompatibility between the fiber and the liquid to be retained;
- Etc.
We carefully study the technical constraints submitted to us and recommend the synthetic fiber best suited to the intended use.
| Specific weight : | 46 kg/m³ |
| Polypropylene : | 650 m²/m³ |
| Specific surface : | 95 % |
Eliminators support grids
As the KNIT® Eliminator’s wire mesh is not a rigid material, it must be supported. In order not to lose any of the eliminator’s advantages (low pressure drop, high efficiency), a lightweight reinforcement with a free passage of over 90% is required. Support products with excessively tight meshes are not recommended, as their small free surface area can slow down the flow of liquid and impair the eliminator’s operation. We offer support grids specially designed to support KNIT® Eliminators. The following sketches show our standard products. Any shape or type of grid can be studied. For example, KNIT® Eliminator grids can be rectangular, elliptical, etc. We can provide safety hatches, inspection doors or any other accessory.
Thanks to the diversity of our materials and our technical expertise, our raw knits can be used in a wide range of industries.