Installation for Dewatering of Agricultural Raw Materials and Wild Plants

This invention relates to the processing of agricultural plants and wild plants for the production of powders used in the food industry.

Known is (RU Patent 2323030, publ. 27.04.2008) an installation for the separation of moisture from materials including agricultural raw materials comprising an external drum inside which a screw insert and a filter are installed, an inlet port and filtrate and condensed fraction output ports.

Disadvantages of said known device are its limited technical capacities due to an insufficient flowrate, frequency and interaction power of the processed materials during their transfer from the loading to the unloading side.

Also known is (RU Patent 2469768, publ. 02.12.2012) a device for the separation of liquid phase from materials including agricultural raw materials comprising an external drum inside which a screw insert and a filter are installed, said filter being made from three or more perforated trapezium shaped ribbons of different widths that are helically wound in the longitudinal direction and helically bent in the transverse direction, an inlet port and filtrate and condensed fraction output ports.

Disadvantages of said known design are large longitudinal dimensions, complex manufacture and limited technical capacities.

Known is (RU Patent 2013058, publ. 30.05.1994) a device for the production of powder from agricultural raw materials comprising a raw material preparation unit and a drying chamber. The raw materials of vegetable origin are crushed in said preparation unit to a puree condition and mixed with dry vegetable components to achieve a dry content of 20-30% in the mixture. Then the resultant mixture is sprayed in a flow of carbon dioxide gas at a temperature of 180-150 °C at a pressure of 250-150 kPa. The mixture is dried in said drying chamber in vacuum spraying mode at a residual pressure of max. 50 kPa.

Disadvantages of said known device are the high temperature of drying causing coagulation of the proteins and destruction of the molecules of the vegetable raw materials and hence to a degradation of the biological properties of the product, as well as non-uniform crushing of the prepared vegetable raw materials due to their different initial viscosities and moisture contents. Furthermore the final product is not intended for long-term storage because the high spraying rate causes electric charging of the resultant powder resulting in lumping during its storage.

Known is (RU Patent 2060670, publ. 27.05.1996) a device for the production of powder from agricultural raw materials comprising a unit for grinding the raw materials to a uniform mixture, a drying chamber adjacent to said rubbing unit and a crusher. Said drying chamber comprises an ultrasonic sprayer and a UHF emitters and said crusher is in the form of a rod-shaped ultrasonic sprayer installed in said drying chamber. Drying is achieved by applying UHF currents with simultaneous crushing in the course of spraying by ultrasonic vibrations with a frequency of 18-80 kHz.

Disadvantages of said known device are its complex design and high power consumption.

Patent search did not reveal any source of information that could be used as the closest counterpart.

The object of this development is to provide a dewatering installation having a simple design and low power consumption during operation.

It is suggested to achieve said technical result using the installation for dewatering of agricultural raw materials and wild plants developed herein. The abovementioned installation comprises a source raw material loading port the outlet of which is connected to the inlet of a preliminary crushing unit, the outlet of said preliminary crushing unit is connected via a screw conveyor to the inlet of a sprayer the outlet of which is connected to the inlet of an aerodynamic tunnel allowing adjustment of the density of the flow containing the crushed product being dried, steam and air, and the dried material outlet of said aerodynamic pipe is connected to an aerodynamic drying unit.

The operation principle of said device is based on the complexing method allowing one to achieve the optimum combination of advantages of many known drying and crushing methods while being free from their significant drawbacks.

The use of this complexing approach resulted in an installation in which

1. Drying and crushing of the product being processed occur simultaneously in an intense mass and air exchange process.

2. The high drying efficiency is achieved not due to the high temperature of the drying agent but at the expense of

- maximizing the relative humidity gradient between the product and the drying agent;

- optimum choice of centrifugal forces and the forces of macro and micro impacts on the product being processed;

- maximizing the pressure gradient combined with intense movement of the dried raw materials during dewatering.

3. The drying and crushing process is accelerated due to the intense mutual friction and collisions of the product particles in a dense layer during movement with a high circumference speed.

4. A reduction in the dimensions is achieved by using a high flowrate of the drying agent (25-28 mps) relative to the product particles.

5. The use of the design and process solutions developed herein provided for an efficient solution of the problems of lumping and sticking of the dried raw materials to the equipment caused by a high content of hydrocarbons including mono- and disaccharides in vegetables and fruits.

The use of the technical and process solutions developed herein provided for the achievement of the main objective, i.e. obtaining a high-quality product with minimum power and equipment consumption.

The abovementioned installation is primarily intended for the preliminary intense dewatering of vegetables, fruits, berries, greenery, mushrooms, weeds, meat and fish at their natural initial moisture content for further final drying in aerodynamic installations for obtaining polydisperse powder with the following parameters:

- particle size: 5+ μπι;

- moisture content: 6+ %;

- almost complete preservation of all the vitamins, enzymes, biologically active components due to a processing temperature limitation to within 50 °C and drying time limitation to 3-5 minutes;

- dissolution of the powder in drinking water leads to complete restoration of the properties of the initial product.

The product is used for:

- baby, medical, prophylactic and professional nutrition;

- production of natural food additives and dyes;

- raw material for pharmaceutical and cosmetic industries;

- production of fast food products;

- raw material for 3D food printers.

However, the above list does not preclude a wider use of the installation provided herein.

Preferably said preliminary crushing unit is a grinder.

Said sprayer can be in the form of two rotors installed on the same axis and rotating in opposite directions, the preliminarily crushed material being fed into the gap between said rotors. Furthermore, hammers can be provided on the facing surfaces of said rotors.

In the preferred embodiment said aerodynamic tunnel has tangentially oriented supply of the processed product flow.

The installation according to this invention operates as follows.

The raw materials are loaded through the port after which the raw materials are preliminarily crushed in the crushing unit. Then the crushed raw materials are fed by the screw batch feeder to the sprayer in which the impacts of the rotors rotating in opposite directions the moisture is intensely separated from the material being dried. Then the partially dewatered raw materials are fed with air vapors to the aerodynamic tunnel where the density of the raw material flow is adjusted by way of tangential supply, along with laminar flow. Then the flow of the material being dried mixed with air vapors is fed to the aerodynamic drier in which the difference in the weights of air vapors particles and dried material particles provides for intense mass and air exchange. As a result the material is dewatered to the required moisture content.

Finally the vegetable raw materials with an initial moisture content of 88- 92% is transformed at the output to polydisperse powder with an average effective particle size of 200-500 μηι and a moisture content of 45-50%.