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What is Perlite Filter Aid?

Perlite for Filtration
Perlite is a naturally occurring siliceous rock of volcanic origin. This rock when crushed and heated under proper conditions expands to 20 times or more of its original volume. A special milling and classification process gives the correct particle size distributions needed for optimum performance as a filter aid.

Perlite FILTER AID improve filtering efficiency by increasing the permeability of the filter cake and is either added to the suspension to be filtered or built on the filter media as a layer through which the liquid must pass.

The physical character of expanded perlite bubbles lends itself to a variety of special purposes – including use as a filter aid separating small solid particles from liquids.

Lightweight expanded perlite bubble structures are milled and classified using clearly defined processes to produce perlite FILTER AID with specific flow characteristics. The various grades utilize the jagged interlocking structures (see image right) to create billions of microscopic channels between the filter aid particles to produce optimum flow rates and clarification abilities for a wide variety of applications.

Perlite FILTER AID are lightweight, inert, impart no taste or odor to liquids being filtered, and are virtually insoluble in mineral and organic acids at all temperatures. Solubility in strong alkaline solutions varies depending on temperature and contact time.

Without using a filter aid the solid particles in the liquid will soon accumulate on filtering surfaces and block them.

A perlite filter aid makes a filtering layer (cake) that transfers the actual filtering from the septum to the whole mass of filter aid. Filtration occurs in the tiny pores formed by the fine particles of filter aid.

Volume-Based Pre-coat Filtration
Perlite FILTER AID provide users with a lightweight material choice. Perlite filter aid grades provide the user with a density advantage from 20 to 50% over other types of FILTER AID. Perlite filter aid dry density ranges from 100 to 200 kg/m3 (6 to 12 lb/ft3), and the filter cake density range is 100 to 270 kg/m3 (7 to 17 lb/ft3). In contrast, other filtration materials produce equal performance filter cakes in the range of 230 to 420 kg/m3 (15 to 25 lb/ft3).

Expanded perlite provides larger volumes with low bulk density compared to other FILTER AID. Experience in a variety of applications has shown that most filter aid users can economically switch to perlite from other pre-coat FILTER AID without sacrificing performance.

Usable With Standard Equipment
Perlite FILTER AID can be used with either pressure or vacuum filtration equipment. Perlite generally replaces other FILTER AID on a one-to-one volume basis - for example; a cubic measure of perlite will replace the same volume of other FILTER AID. Selection of the optimum grade and dosage may require plant or laboratory filtration tests.

Flow Rates of Grades
Perlite filter aid grades from various manufacturers range from 0.2 – 6 Darcies. (The Darcy is a common unit of flow rate for FILTER AID.) A material with a permeability of one Darcy passes 1 milliliter per second per square centimeter of a liquid of 1 centipoise viscosity (approximately that of water) through a cake 1 centimeter thick at a differential pressure of 1 atmosphere.

The higher flow grades are especially applicable to use with highly viscous liquids such as syrup, resins or gelatinous slurries. Productivity, clarity and flow rates may be increased through the use of perlite filter aid grades. These traits are accomplished during the liquid's path through the channels created by the jagged, interlocking particles.

Easy Cake Release
Additional benefits of perlite FILTER AID come at the end of the filter cycle. Perlite filter cakes remain porous and do not compact. Filter cakes built up under pressure release easier when perlite is used. This release facilitates cleaning, potentially reduces manpower requirements, and increases productivity. The lower weight of perlite filter cakes may also reduce disposal costs.

Inert Nature of Perlite
Perlite FILTER AID are both sterile and inert and are used for filtering liquids in the beverage, food and pharmaceutical industries. No tastes, colors or odors are imparted, and, subject to meeting the standards listed in the Food Chemicals Codex (published by the United States' National Academy of Sciences), are deemed safe for their intended use. Note: The Food Chemicals Codex is regarded as a source of information on the quality and purity of food grade substances, and is regarded as authoritative by many government agencies throughout the world.

Approval for the use of perlite as an additive in animal feeds was recently extended in the European Union. Generally, spent filter aid cakes from wineries, breweries or other food-related industries may be added to animal feed. Such practices reduce the environmental footprint of those industries as well as reducing disposal costs for the used material.

TOPKEL - Perlite Filter Aid

  • Topkel Perlite filter aid is manufactured in India by Keltech Energies Ltd, a company of the Chowgule Group of companies, with several decades of experience in the manufacture and application of perlite products.
  • Keltech uses advanced technology from Showa Chemical Industry Co Ltd, Japan a leading company specialized in the manufacture of FILTER AID for over 75 years.
  • Topkel is an improved filter aid, manufactured from selected perlite ore which is expanded, milled and specially classified to different grades.
  • Topkel is inert, sterile, light weight having a unique interlocking structure that affords fast flow rate with excellent clarity.
  • Topkel does not impart taste, colour or odour to the filtered product. Therefore it is ideal for filtering food beverage and pharmaceutical products.
    Why TOPKEL
  • TOPKEL filter aid with its rigid intricately shaped porous individual particles has the special ability to remove small particles of suspended matter at fast flow rate.
  • TOPKEL FILTER AID provide the fastest flow rate maintaining an excellent degree of clarity. TOPKEL FILTER AID forms a highly permeable stable and in-compressible filter cake ensuring consistent flow rate and long cycle time.
  • Chemically inert and insoluble in the liquids being filtered.
  • Non –hazardous waste with the form of filter cake that can be easily disposed off.
  • Easy cake discharge and disposal.
    Remarkable cost advantage
  • Due to its light weight and 20% to 50% density advantage.
  • TOPKEL offers twice as much filtration, kg to kg than any other filter aid.
  • Hence customers can save substantially in the filtration operation with a better filter aid at lower cost.

How to use TOPKEL in Filtration

Pre-coat Perlite Filter aid slurry is filtered through the filter media or leaves. A thin layer of 1.5-3mm (1/16-1/8 inch) filter cake protects the septum from being clogged by initial solid impurities and bridges the screen opening allowing additional finer media application. It also allows easy cake removal during cleaning cycle.

The filter aid grade used for pre-coat must be carefully selected to allow faster flow rate and at the same time trapping the solid impurities.

Bodyfeed is the continuous addition of filter aid to the unfiltered liquid being filtered in order to keep the dirt solids apart; this in turn maintains a porous cake. Bodyfeed maintains clarity and flow rate throughout the filter run, hence the type and grade of Perlite filter aid used is important to ensure optimum performance. Bodyfeed is added directly to the tank of the liquid to be filtered, or dosed from a slurry tank into the filter inlet. The correct dosage of Bodyfeed will significantly increase yield and offer the longest cycle length.

Filter equipment where you can use TOPKEL
• Rotary vacuum drum filter
• Pressure Filter
• Horizontal self-cleaning plate Filter
• Candle or Tube Filter
• Plate and frame Filter
• Vertical leaf Filter
• Nutsche Filter
• Horizontal Belt Filter
• Sparkler Filter


Food Processing
• Edible Oils
• Corn syrup
• Mono sodium Glutamate
• Juices
• Wine and Beer
• Sugar
• Citric Acid
• Vinegar
• Casein
• Pectin
• Vegetable oil
• Soft Drinks

• Sweeteners

• Industrial oils
• Brine
• Adhesives
• Titanium Dioxide
• Polymers
• Varnishes
• Plastic
• Resins
• Alginate
• Agar agar
• Sulphuric acid
• Paints
• Uranium
• Sodium Silicate
• Chemical carriers
• Fertilizers

• Active Pharmaceutical Ingredients/Intermediates
• Enzymes
• Antibiotics
• Fish oils
• Epsom Salts

• Grease
• Lard
• Waxes
• Additives

• Waste water treatment
• Oil Exploration
• Pool water treatment
• Sizings
• Solvent recovery


Our Perlite Filter Aid (PFA) are approved with food licensing agencies like FSSAI/ HALAL & KOSHER

What is Perlite Filter Aid?
TOPKEL - Perlite Filter Aid
How to use TOPKEL


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