IMMEDIATE PRICE QUOTE      +39 0805367090      info@tecnicaindustriale.com
 
Dust Filtration Technology
 
De-dusting a gaseous current is usually done to purify the gaseous phase of powders which is dragged along for some reason (e.g. controlling dust emissions to limit environmental pollution) or to recover powders intentionally carried along by the gas (e.g. picking up solid materials in pneumatic transport systems).
Different types of devices can be used for collecting the dusts, such as scrubbers, electrostatic separators, centrifugal separators and filtering systems. This document describs the principles underlying filtering systems made up of modular elements which, because of their manufacturing and operating characteristics, provide maximum efficiency in terms of cost/benefits ratio.

Basically, a filtering system comprises an inlet chamber of the gaseous phase to be purified, containing the filtering elements, and a chamber through which the filtered gas passes, housing the cleaning systems for the filtering elements. 

The retention of solid particles by the filter may occur in two main ways:

1) surface filtration: mainly based on depositing of the collision or screening particles. Reduction of porosity may be caused by:
- retention of very fine particles in the pores;
- formation of a cake of particles on the filter surface.
2) deep filtration: achieved by thicker filtering means, where the particles are forced to follow a longer path, thus increasing the probability of interaction with the fibres, in terms of direct interception or screening effect.

The main properties of filtering means are:
- separation efficiency
- pressure drop
- capacity for accumulating dusts

Generally, the filtering element requires frequent cleaning to guarantee that it remains effective throughout its life.
The cleaning operation may be achieved in different ways:
- by mechanically shaking the filtering element;
- by inverting the flow, e.g. conveying compressed air on the filtering means in counter-current relative to the gaseous current to be purified;
- using reverse pulse jets, which create vibrations in the fabric that cause the particles to be detached.

Replacement of a filtering element is necessary when its separation capacity can no longer be guaranteed (laceration of filtering medium or alteration in its porosity), or when - even after a prolonged cleaning cycle - passage of the gaseous current causes an excessively high pressure drop for working with the nominal flow rate required (blockage of the filtering medium).

Once the characteristics of the gaseous current to be subjected to filtration, in terms of properties of the solid particulate, and solid content, density, viscosity, flow rate, temperature and pressure of the gas stream, are known, it is possible to choose the most suitable filtering medium and configuration - in terms of efficiency, ease of cleaning, space required and economy - for setting up the filtering system.

The materials most commonly used as filtering media are:

PAPER
TEXTILES
NEEDLE FELTS
SPUNBONDED

The materials used to prepare these filtering media, generally polypropylene and polyester, may be subjected to treatment with PTFE by impregnation or for membrane application, thus obtaining a surface layer that impacts with the product that is extremely smooth and free of supporting points for adhesion.
It is also possible to carry out anti-static treatments to prevent the formation of discharges or sparks due to electrostatic phenomena between the product conveyed and the filter; basically, stainless steel fibres incorporated in the weft of the media are used, to achieve a continuous conductor connected to the entire structure of the purifying filter, suitably earthed.

The configurations that can be adopted to prepare the filtering element are:

BAG
CARTRIDGE
ELLIPTICAL BAG
POCKET
POLYPLEAT

Choice of the material and the filtering element configuration, which represent the fulcrum of such systems for dusts collection, is almost always the result of a compromise between economy of the filtering system - in terms of the costs of purchase and machine running - and the filtration efficiency that it can provide. 
 
  Applications
Animal By-Products Processing Washing Powder Processing Asphalt Mixing Plant (batch-type)
Cement - Lime - Plaster Production Concrete Batching Plant (German Dragline-Type) Concrete Batching Plant (German Tower-Type)
Concrete Batching Plant (Italian Scraper-Type) Concrete Batching Plant (Japanese Type) Concrete Plant (US-Type)
Dry Batch Concrete Plant (Italian Type) Dry Batch Concrete Plant (US Type) Shot Blasting - Grinding - Polishing
Flour Mill Food Packaging Silos for Building Materials
Foundry Sand Processing Glass Industry - Raw Material Processing Animal Feed Processing
Sludge Treatment Mixing Municipal Waste Water Treatment
Oil Extraction - Sludge Treatment Paint, Varnish and Adhesive Production Plasma and Laser Cutting
Plastics - Raw Material Processing Pneumatic Conveying System Premixed Building Materials
Rubber Processing
 
Wamgroup
 


Wamgroup catalogues
 
Bulk Solids Handling and Processing Technologies
 
Characterization of Powders and Granular Materials Mechanical Conveying Technology in Handling Powdery and Granular Materials
Vertical Conveying of Powdery and Granular Materials Technology Technology in Discharging Powdery and Granular Materials
Powdery and Granular Material Feeding Technology Powdery and Granular Material Metering Technology
Material Flow Control Technology Silo Safety Technology
Dust Filtration Technology Components for Pneumatic Conveying Systems
Components made from Engineering Polymers Vibration Technology
Mixing - Blending - Conditioning - Granulating Technology Sludge, Viscous and Adhesive Material Handling Technology
Solids-Liquid Separation Technology Ship Unloading Technology

 
Bulk Solids Handling & Processing
Products Catalogues Info & Free Quotes High quality & Reliability
Here you can view and download all the Wamgroup brochures and products catalogues. Do not hesitate to contact us calling +39 080.5367090
or sending an email to info@tecnicaindustriale.com.
We offer our customers high quality and reliable products to satisfy large and diversified needs.