Home > Filtration > Hobrafilt® - Depth filter sheets

„Reliable Filtration“ is HOBRA’s comprehensive mark under which all the company’s products and services in liquid filtration are identified. It is a marketing project which covers everything HOBRA manufactures, offers and supplies in this sphere.

Hobrafilt® - Depth filter sheets

A filtersheet is essentially a three-dimensional, deep filter consisting of adsorbents of a large inner surface. This can be imagined as a labyrinth of little chambers and channels of different lengths inside the sheet where dirt is captured.

Contrary to screen filtration, the presence of adsorbents in a deep filtersheet will multiply the total filtration area and, thereby, increase the quantity of the solution being filtered.

Filtration mechanism

Three different filtration types as specified below are applied in the filtration process over filtersheets. In practice, normally, none of the three filtration mechanisms occurs separately during filtration due to the wide range of particle size but they are more or less combined, which is decisive for the filtration result.

  1. Mechanical filtration – direct filtration of foreign substances. All particles greater than the filtersheet holes are captured mechanically on its surface.
  2. Electrostatic adsorption – light molecular interactions, Van der Waals forces, occurring among the particles of solutions and the filtersheet material and ensuring that particles smaller than the dimensions of the sheet's inner pores are captured in the little chambers and channels of the filtersheet.
  3. Electrokinetic adsorption – this is based on the existence of Zeta potential and is applied in microbiologically effective sheets. Excellent filtration/separation effects towards negatively charged particles of dirt, microorganisms and viruses suspended in the liquid being filtered are achieved through the change of the naturally negative electrokinetic charge of the filtersheet to positive - i.e. Zeta potential. This is achieved by a special treatment with polyelectrolytes that are not harmful to health. This treatment makes it possible to capture particles up to ten times smaller than the dimensions of the filtersheet pores.

HOBRAFILT filter sheets are delivered in the format 20x20, 40x40 and 60x61,4 cm. Based on customer requirements are also supplied other dimensions, such as circular or sheets with various holes, etc.

Documents to download:
HOBRAFILT - Depth filter sheets (2.5MB, .PDF)
Hobrafilt instructions with differential pressure specification (670.8KB, .PDF)
CONDITIONS FOR SUCCESSFUL FILTRATION using HOBRAFILT filtersheets of the „N“ and „NT“ Series (563.7KB, .PDF)


Hobrafilt
„N“ series

HOBRAFILT deep filtersheets of the “N” series are produced of special types of high-quality cellulose fibres, diatomaceous earth and perlite, which form...

Applications:
Wine, Beer, Alcoholic beverages, Soft drinks, Food, Chemistry, Pharmacy, Oil and biofuel

Hobrafilt
„NT“ Series

Hobrafilt® depth filter sheets are made of carefully selected and inspected materials, namely from various types of cellulose, high quality kieselguhr,...

Applications:
Wine, Beer, Alcoholic beverages, Soft drinks, Food, Chemistry, Pharmacy, Oil and biofuel

Hobrafilt
„C“ Series

Depth filter sheets are made of carefully selected and inspected materials that are harmless to health, especially from various types of cellulose, high...

Applications:
Wine, Beer, Alcoholic beverages, Soft drinks, Food, Chemistry, Pharmacy, Oil and biofuel

Hobrafilt
„R“ Series

HOBRAFILT deep filtersheets of the “R” series are produced of special types of high-quality cellulose fibres, diatomaceous earth and perlite, which form...

Applications:
Food, Chemistry, Pharmacy, Oil and biofuel

Hobrafilt
„AC“ Series

HOBRAFILT depth filtersheets of an "AC" series are manufactured of special types of high-quality cellulose fibres, diatomaceous earth, perlites and activated...

Applications:
Wine, Beer, Alcoholic beverages, Soft drinks, Food, Chemistry, Pharmacy, Oil and biofuel

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