Food &Beverage Filters: what they are for and what they are

In the Food & Beverage sector, filters FOR SOLID-LIQUID SEPARATION find wide application particular for the extraction and processing of starch from agricultural raw materials.

It is one of the most important agro-industries in the world.

In fact, using maize, wheat, potatoes, tapioca and rice as raw materials, around 49 million tonnes of starch are produced and processed every year. In particular, at Tecniplant we deal with maize filtration.

The most commonly used filters in the Food & Beverage sector are of three types:

1. rotary filters

2. horizontal filters

3. pressure filters

Let’s take a closer look at the features and applications of these filters.

Rotary filters for Food & Beverage

Rotary vacuum filters are used in various processes example starch and gluten dehydration and for refining syrup with filter aids.

Not only that, in the processes of filtration of fruit juices , the operating principle consists in creating a vacuum inside the drum, which is partially immersed in the tank containing the product to be filtered.

In this way, the liquid passes through the drum and a layer of kieselguhr allows the separation of the solid part from the juice.

There are various types of rotary vacuum filters:

  • roller discharge
  • cable discharge
  • a pre-coating
  • outgoing canvas
  • blade discharge

For the separation of the gluten contained in the maize rotary cloth filters are used.

These systems are designed for the separation of solids and liquids during filtration. This type of filter is suitable for suspensions that require washing of the filter cloth after discharge.

In particular, continuous screen washing is essential to ensure continuous operation, maintaining performance, and to prevent solids from clogging the filter medium.

In particular, numerous substances are derived from maize, including starch, yeast, dextrose, ethanol, fructose and palm oil.

The protein dehydration process and the equipment used varies from case to case. In the wet milling process of maize, after the extraction of the germ and fibre, centrifugal separators are normally used to separate the gluten from the starch, resulting in a thin glutinic liquid with a density of 15-25 g/l.

This, in turn, is thickened with gluten thickener (GT) to obtain a dense gluten liquid of 80~110g/l density. The thick gluten liquid must be further dehydrated and dried to obtain the final commercial gluten powder.

Currently, the rotary vacuum filter and the plate and frame filter press are widely used for this application. Another alternative is the decanter centrifuge.

However, the rotary vacuum filter process is preferable for three reasons:

  • continuous operation mode for a long time
  • high level of automation to simplify the operational procedure, reduce human interference in the operational process and reduce labour costs
  • clean production environment, as the entire dehydration process takes place within the closed chamber of the equipment.

Horizontal filters for Food & Beverage

Horizontal vacuum filters are used in the food industry in various applications and in particular in the processing of spirulina or for drying other food products.

Horizontal filters for spirulina treatment

Spirulina treated with these filters allows most of the water to be removed, making it ready to eat fresh.

If necessary, you can continue with the dryer to remove additional water from the product.

Horizontal filters for drying food products

With the same process used for spirulina, other food products such as flavourings and plant extracts can also be prepared for drying.

For example, our references include the drying of mushrooms, which are then used to create flavourings for stock cubes and other similar products.

Horizontal vacuum filters can be:

  • ribbon
  • cloth

Visit the page dedicated to horizontal vacuum filters: click here

Pressure filters for Food & Beverage

Pressure filters are used in the food industry for the separation of solids and liquids.

An example: the extraction of pectin and gelatine.

These filters consist of a pressure vessel containing the filter elements, while the filter cake discharge can be either wet or dry.

Our range includes three types of pressure filters:

  • vertical leaves
  • with horizontal leaves
  • candle

Visit the page dedicated to horizontal vacuum filters: click here

At Tecniplant we offer various solutions for filtration in the food industry.

Contact us to find out more.

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