SU1124170A1 - Freeze vacuum drier - Google Patents

Abstract

SUBLIMATION VACUUM DRYER, comprising a housing with a vibrating conveyor in the sublimation zone and a freezing condenser section, separated from the sublimation zone by means of a thermal screen with windows, characterized in that, in order to improve the quality of drying, the screen is rotatably mounted and provided with filters placed in his windows.

Description

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The invention relates to freeze drying and can be used in the chemical, microbiological, food and other industrial sectors.

A sublimation vacuum dryer is known, comprising a vertical case with a vibrating conveyor and condenser-freezer sections located inside it, which are separated from the sublimation zone by a heat shield with windows p1.

A disadvantage of the known dryer is the low quality of drying due to the increased entrainment of the dried material together with the vapors to the desublimation zone.

The purpose of the invention is. improving the quality of freeze-drying.

This goal is achieved by the fact that in a sublimation vacuum pump containing a body with a vibrating conveyor in the sublimation zone and a freezing condenser section, separated from the sublimation zone by a heat shield with windows, the heat shield is rotatable, and on its windows by which the sublimation zone (drying) is connected to the desublimation zone (vapor co-evaluation), filters are placed.

FIG. 1 shows the proposed dryer, a general view; in fig. 2 - the same, top view; in fig. 3 - transport tray, transverse section; FIG. 4 shows a sequence diagram for switching the desublimator sections.

The dryer includes a housing 1, a vibrating conveyor 2 located inside it, sections of a condenser-freezer 3. Between the vibrating conveyor 2 and sections of a condenser-freeze, the rotary screen 4 with windows 5, on which filters 6 are mounted, is placed 3. through gear 8. Each section. the condenser-freezer 3 is separated from the adjacent walls 9 with seals 10, an interchangeable cone 12 with a feeder 13 is installed on the top cover of the apparatus 11, a receiving box 15 with flaps 16 and an auger heated press 17 are placed on the bottom 14, which are respectively used to receive , transport and disposal of desublimate without

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violation of the mode of operation of the apparatus. The vibrotransporter 2 is mounted on a hollow pipe 18 and is made in the form of screw-shaped flume channels 19 for moving the material being dried, which consists of two parts, the top 20 is fixed with devices 21 for radiant power supply and the bottom 22 is movable with vibrators 23 and devices 24 for contact heating, the upper part 20 is fastened to the pipe 18 by means of the brackets 25 with the possibility of changing their inclination angle, and the lower part 22 by means of spring fastenings 26 is suspended with a gap to the upper parts 20, forming within rata stepped-helical chute, which over its entire length in the ground it is provided with a gap filter elements 27 made of elastic material at the encoding function of the solvent vapor pti dried material pretreatment (final ochistk- is effected in filters 6); for monitoring and controlling the day process, the flume channels 15 are equipped with sensor blocks 28. Communications of technological supply systems (supply and removal of energy carriers, washed solutions, etc.), lines for connecting control and monitoring systems are located inside the hollow pipe 1-8 and input vehicle inside the device through sealed connectors 29.

The sublimation vacuum dryer works as follows.

Pre-frozen and ground material through the feed-. Tel 13 and interchangeable cone 12 (where during free fall it undergoes sublimation) enters the screw chute channels 19 of the vibrating conveyor 2. During the transportation of the dried material through the channels 19 from the loading zone to the unloading zone, intensive sublimation drying takes place with two-way energy transfer and efficient mixing material. The solvent vapors released during the drying process from the materials, the passage successively through the filtering elements 27 and then the filters 6, are cleaned of dust and enter one of the sections of the freezing condenser 3, where they condense on its cooled surface. The dried matter is removed from the bottom of the apparatus by means of a sealed discharge device, and the non-condensing gases are pumped out of the working section of the freezing condenser by means of a vacuum pump unit (not shown). The switching of the freezer condenser sections is carried out as follows. After a certain time interval, the duration of which depends on the performance of the device for evaporated moisture and the ice capacity of the condenser-freezer 3 sections, the drive 7 is turned on, and the screen 4 is rotated, switching window 5 from the spent section to the sublimation temperature mode and pressure. After window 5 is completely switched to the adjacent section, the previous section switches from to off mode (the vacuum is turned off and the refrigerant supply stops). When this section also runs in desublimation mode, window 5 of screen 4 is similarly transferred to the next section, and this section is switched to shutdown mode with simultaneous switching of the first section to the regeneration mode (coolant is supplied to it, heating of the damper 16 serving this section connected to the vacuum line box 15). The ice in the first section, sliding down from the surface of the condensate separator section, through the valve 16 and the receiving box 15 enters the heated screw press 17, where the other bit is melted and removed from the apparatus through the drainage. After the third section runs in desublimation mode (window 5 is transferred to the last fourth section), it switches to shutdown mode, the second section switches to regeneration mode, and the first to preprocessing mode (the supply of coolant is turned off, the vacuum is turned on and refrigerant supply). Thus, sequentially in the course of rotation of the screen 4, the sections of the condenser-freezer 3 are switched to the required operation speeds (Fig.4). This necessarily maintains such an order of mode switching, in which the section operating in the desublimation mode can never be adjacent to the section operating in the regeneration mode, which eliminates leakage of solvent vapors from the regeneration zone to the desublimation zone and thereby eliminates their mutual negative influence on the operation mode of each zone. The design of the dryer allows both cyclic (intermittent screen rotation) and continuous (screen rotation at a constant speed) operation on the desublimation side. The invention allows improving the quality of freeze-drying by eliminating the loss of dried material and eliminating the negative thermal effects of the regeneration mode on the modes of sublimation and desublimation in freeze-dryers.

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Claims (1)

SUBLIMATION VACUUM DRYER, comprising a housing with a vibratory conveyor in the sublimation zone and sections of the condenser-freezer, separated from the sublimation zone by means of a heat screen with windows, characterized in that, in order to improve the quality of drying, the screen is mounted for rotation and equipped with filters placed in it the windows.