Technical problem The technical problem solved by this invention consists of : How to solve constructively the device for fruit and vegetable drying in vacuum, in order to make the integral generators of the drying chambers, the condenser of the secondary steam, condensate recipient and vacuum forechamber into a unique whole, attaining the following effects: reduction of dimensions, of investment price and facilitated handling.

State of technics All the devices, known until now, as well as the plants for fruit and vegetable drying at the atmospheric pressure, have clear defects reflected in the following: - drying process is carried out at relatively high temperatures, which leads to degradation of the most important nutritious ingredients of dried products, - drying is operated in presence of air, which causes colour change-darkening of dried products and other negative chemical and biological modifications that influence the quality of the product.

The aforesaid defects are very efficiently eliminated by drying of the thermo-sensitive products-fruit and vegetable in vacuum.

The main advantages of fruit and vegetable drying in vacuum are the following: Low drying temperature, Drying process is carried out without presence of oxygen from the air No degradation of the biologically valuable components in the dried products, Shorter drying period, Significant reductions of energy consumption The devices for condensative and non-condensative drying in vacuum YU P 1091/91 have the same defects as the devices and plants for drying at atmospheric pressure.

The device for condensative drying of the thermosensitive products in vacuum YU P 493/95 represents a significant improvement in comparison with the device YU P 1091/91 but due to the frigoric heating of the chamber and complex construction it is not adequate for fruit and vegetable drying.

The device for drying in vacuum, according to this invention introduces a significant improvement regarding such solutions from the state of technics.

Presentation of the invention essence The device for drying in vacuum, according to this invention, serves for the continuous-condensative fruit and vegetable drying. The continuous method is based on a non-stop maintenance of vacuum from the beginning till the end of the drying process. To realize that, drying chamber must be manufactured from metal cylinder, diameter 1,2 to 2,5 m, length 2,4 to 24 m. The chamber must be thermally well insulated.

By establishing of vacuum, with the simultaneous heating up, a stormy water evaporation from dried product. Water leaves dried fruit in the form of steam and transforms into liquid in the condenser. Products dried in vacuum are heated by radiation from the surface of the heating bodies, so it is essential that their surface be as big as possible and to be placed as close as possible to the drying product.

Air is admitted from the drying chamber until the desired pressure is obtained in the chamber-vacuum. Then the chamber is heated and heating is continued throughout the drying period with control of the measure-regulation equipment.

Vacuum supports water evaporation from the surface of the dried product and therefore its surface temperature is reduced. Because of that, it is necessary to bring continuously new quantities of heat through the heating bodies, which represents the only default of this drying method.

However, due to low drying temperature of 35-45°C and thermal insulation of the drying chamber, this defect is moderated because the heat is introduced only when its value is reduced below the assigned, while the advantages of the continuous drying in vacuum has regarding the other methods, justifies the presented method of fruit and vegetable drying.

Short description of figures and schemes The invention is represented in details on the drawing together with the way of carrying out of particular integral generators, where Figure 1 illustrates the longitudinal section the device for fruit and vegetable drying in vacuum according to the invention Detailed description of the invention The device for fruit and vegetable drying in vacuum, according to the present invention consists of : chamber 1, secondary steam condenser 2, condensate recipient 3, separator 4, vacuum forechamber 5 and vacuum pump 6.

Variatively, in the case of usage of a dry vacuum pump, the plant is provided with the part for isothermal dehydration of air.

Chamber 1, consists of : cylinder 11, cart 12, insulation coat 13, connection with atmosphere 14, condensate outlet 15, exhaust pipe 16, heating bodies 17, stand 18 and chamber door 19.

Secondary steam condenser 2, consists of : chamber 23, cooling body 21, adapter for connection with atmosphere 22, valve 24, tubes for secondary steam discharge 25, condensate outlet 26, connection for cooling agent supply 27 and connection for cooling agent exhaust 28.

Condensate recipient 3 consists of : cylinder 21, dished end plate 32, exhaust pipe 33 and connection with atmosphere 34.

Separator of the solid materials 4, consists of : centrifugal separator of particles 41, cone tube 42, exhaust pipe 44.

Separator of the solid materials is placed concentrically in the condenser 2 and tangentially in the condensate recipient 3 Vacuum forechamber 5 is placed in the extension of the pipe, detached from the condensate recipient by the partition wall 51, dished end plate 52 and condensate outlet.

53.

Vacuum pump 6, dry or oiled is situated on the chamber itself of the plant, beneath or beside the drying chamber.

Plant control can be manual, semi-automatic or automatic.

The device for fruit and vegetable drying in vacuum, according to this invention, functions in the following way: Due to the action of heat emitted form the heating bodies, water from the dried product evaporates in a stormy way.

Steam form the chamber with the exhaust pipe 16 is being taken into the secondary steam condenser 2, where it is condensed and by the pipe taken into the condensate recipient 3, and upon the finished drying process into the atmosphere by the pipe 33 Humid air by the exhaust pipe 44, is taken into the forechamber 5, where it is additionally condensed and by the pipe 34 admitted in vacuum pump 6, and from it into the surrounding atmosphere.