The object of the invention is a method for obtaining a high degree of utilisation of feed vapour in the process of concentrating solutions in evaporators consisting of many conical spinning evaporative units, and a device for such concentration, characterised by the possibility to constructionally increase the number of evaporative stages in the unit at a relatively low increase of costs.

The method according to the invention consists in increasing the number of evaporative stages up to six or more, and in separately capturing the concentrate from selected evaporative stages, the said concentrate being immediately introduced into the main line supplying the evaporative device with the primary solution. With today's technology of single flow of the primary solution along evaporation cones, in an amount that ensures immediately obtaining the final concentration, increasing the number of stages in the evaporative unit causes a decrease in the useful temperature difference and a need to distribute, along the evaporation cones, smaller amounts of concentrated solution. The risk of not rinsing the entire surface of the cones and formation of solidified lumps is increased.

In the above-described method according to the invention, recirculation of the concentrate obtained in selected stages of particular evaporative units is introduced. Vapours from individual closed evaporation spaces, when dropping out, dissipate heat in cascade to the boiling solution in successive spaces, having lower and lower vapour pressure. Thermal energy of heating vapours, as a result of increased evaporation heat, along with the drop in temperature and increase in enthalpy of the concentrate, decreases slightly with each successive stage. However, it can be mitigated by delivering, to the device, a solution with a temperature higher than the boiling point on most evaporation cones. Thanks to the invention, the total amount of solution fed to all evaporative stages and its concentration are increased. This ensures a better rinsing of the evaporation surface and makes it possible to increase the number of stages in the evaporative unit. The feature of the evaporative device according to the invention is practically the same heat transfer coefficient for all evaporative stages in the unit, as opposed to multi- partition co-current and counter-current evaporative devices. The heat transfer coefficient in these devices decreases significantly with successive evaporative stages due to the change in properties of the concentrated solution. This limits the cost-effectiveness for installing further stages. Furthermore, introduction of recirculation of consequently concentrated concentrate from evaporative stages with the lowest concentration - temperatures is particularly advantageous as it has a marginal effect on the changes in the finally concentrated solution.

By conducting concentration on spinning evaporation cones, very high heat transfer coefficients of up to 7000 W/m ² .°K are obtained. This allows conducting an effective evaporation at low useful temperature difference. However, it may be too low to bring the boiling solution to the final concentration in a single step. Separate collection of concentrated solution from selected stages and mixing it with the primary solution delivered to the device result in an increase in the amount of solution fed to the evaporation cones. Required concentration increase necessary to obtain the final concentration also decreases. Therefore, a slightly lower useful temperature difference, necessary to obtain the final concentration, is required. In the device according to the invention, it is extremely important to achieve an even spread of the solution on surfaces of the evaporation cones. Therefore, the concentrated solution is fed at paraxial extremities of the cones, in such a manner that causes its outflow perpendicular to the radius of rotation and a spinning motion in distribution spaces. Thus, most of the energy from the solution outflow is used to produce a whirl and it more evenly overflows through the edges of the distribution rings. As a result of improving the evening of distribution of the concentrated solution, the number of evaporative stages in the units can be additionally increased.

The essence of the device according to the invention consists in eliminating float devices of drain valves, from inner spaces, between the eva oration cones, and in permanently integrating all conical evaporative stages of each evaporative unit, circumferentially, with its monolithic walls. Furthermore, within each evaporative unit, paraxially, all the evaporation cones are permanently integrated with the cylinder, having a diameter much larger than the shaft, and having holes for delivering the concentrated solution to each conical evaporation surface. These solutions allow elimination of circumferential gaskets between evaporative stages and of gaskets at the shaft. Thereby, reliability of the device in terms of tightness is increased, and the construction is simplified.

On both sides, to the cylinder of each evaporative unit, shaped blocks are permanently fixed, at extremities, which position it axially on the shaft. They have grooves for receiving gaskets, and through the holes thereof screws pressing together all the evaporative units are vertically introduced. Thanks to this solution, one hermetic, cylindrical space is obtained between the drive shaft and walls of evaporative unit cylinders, wherein the concentrated solution is delivered to the said space through a number of holes in the hollow drive shaft. Through holes in the shaped blocks, the axes of which intersect with axes of feed holes in the evaporative unit - - cylinders, long cylindrical valve assemblies are introduced. Through holes of the valve assemblies are located exactly at the height of the feed holes of the cylinders which have grooves with embedded gaskets. Rolls with valve assemblies have a length that includes all the cylinder feed holes and are pressed against their gaskets by long wedges driven into cut-outs of valve holes of the shaped blocks of the extreme cylinders. Sections of the through holes of the valves, at the height of individual evaporative stages, are experimentally chosen so as to obtain a concentrate having a desired degree of concentration from evaporative stages of final concentration. An inner stem of the roll of the valve assembly has the ability to turn and change the clearance of all the through holes by the same percentage. The above solutions allow a significant reduction in the shaft diameter. Valve hatch in the housing cover above the valve rolls allows removing them outside the device space. Furthermore, these solutions make it possible to install a large number of valves according to the number of evaporative stages. There is also the possibility to relatively easily replace the rolls with valve assemblies for others with different flow characteristics.

The feed holes on the side of the evaporation cones are covered with plates while preserving outflow channels. The plates on one of the sides obliquely close the outflow channel of the concentrated solution and, with the extremities of the evaporation cones and with the cylinder wall, form circular outflow holes in one direction. This solution allows reducing the pressure jump between flow openings of the valves and evaporation spaces, and directing the outflow streams perpendicularly to the radius of rotation of the cones, thereby causing a spinning motion of the solution within the distribution rings. This solution facilitates an even overflow through the edge of the rings, especially at lower spin speeds of the evaporative units. In the device according to the invention, U-tube outflow nozzles for the concentrate, individual for each evaporative stage, are completely eliminated. They are replaced with "ordinary" nozzles, the ends of which are located in the interior of vertical flow channels having overflow outflows, wherein extremities of their overflows are located accordingly closer to the axis of rotation of the drive shaft than outflow extremities of the nozzles for initially and finally concentrated solution. This solution allows obtaining the same U-tube effect collectively.

In the case of evaporative units having peripheral walls having the shape of a regular cubic, the outflow nozzles for initially and finally concentrated solution extend from the comers of the peripheral walls obliquely to their diagonal axes, but on opposite sides, to fold in parallel positions, at a certain distance from their axes. This solution allows discharging the initially and finally concentrated solution into separate flow troughs at such a mutual distance that between - - them, there are vertical flow troughs for condensate in the inner spaces of which, ends of outflow nozzles for condensate are located which extend from the corners of peripheral walls, in the axes of their diagonals. Extremities of overflow outflows of condensate troughs are located accordingly closer to the axis of rotation of the drive shaft than outflow extremities of the condensate nozzles.

In the case of evaporative units having peripheral walls of cylindrical shape, the outflow nozzles for initially and finally concentrated solution are straight, and their axis overlaps with the radius of rotation or is close to these radii.

All the outflow nozzles of conical evaporative units have, in a vertical section perpendicular to the axis, a cross-section of a rectangle with its vertical sides shorter. This solution allows reducing the distance between the evaporation cones and the cones of condensate catchers. This makes it possible to reduce the height of individual evaporative units. The use of flow troughs makes it possible to easily discharge the initially concentrated solution from many evaporative units mounted on one drive shaft and to abandon the installation of gutters for catching the concentrated solution and condensate for each evaporative stage. Furthermore, the use of "ordinary" outflow nozzles provides ease of outflow of impurities and sediments from the inner space of the evaporative units to the flow troughs. In the peripheral walls of the evaporative units, directly above the evaporation cones, there are plugs closing the inspection holes. They are located in the middle of the distance between cuboid corners of the evaporative units. Location of inspection holes in these places provides insight into the evaporation cones. Besides, these are the places most susceptible to sediment accumulation. Access to external parts of evaporative units is ensured by a hatch in the upper wall of the housing, in the light of which there is a circular part of the upper element with hatch holes between each corner assembly of troughs.

The flow troughs for initially and finally concentrated solution have centrifugal bottoms inclined in the direction of outflows. Directly at the surfaces of centrifugal bottoms and overflow outflows, there are holes for direct outflow of initially and finally concentrated solution. These holes, through the overflow outflows, are connected by a channel which has in its central part an overflow valve. These valves have a needle adjusted to a constant flow of a small portion of the concentrated solution. The valve stem is connected to a stop plate for the outflowing solution, which maintains the said stem extremely closed. Clogging and lack of flow causes, by means of a spring mechanism, full opening of the valve, allowing it to be unclogged and returned to throttled outflow. Maximum flow is always lower than total outflow from the - - flow trough. Inclinations of the centrifugal bottoms of the flow troughs should be large enough to cause spontaneous mixing of sediments towards the outflow holes. From the lateral holes of the upper part of the drive shaft, hollow to the height close to the upper extremity of the conical upper element, vapour lines feeding first evaporative stages extend. They are connected to nozzles extending from the peripheral walls of evaporative units, at the height of first evaporative stages. This solution simplifies the structure and allows reserving the entire space of the lower hollow of the shaft for the concentrated solution, thereby reducing its diameter.

Conical spaces between extreme walls of the evaporative units are filled with a heat insulating material, thereby minimising the loss of heat flow from the vapour jackets of the first evaporative stages to conical chambers for vapours of last stages from neighbouring units. A condensate catcher cylinder is tightly attached directly to the housing bottom. The drainage nozzles for condensate extend vertically from the flow troughs downwards through holes in a circular bearing plate, and their extremities are located below the upper extremity of the condensate catcher cylinder. This solution allows reduction of the diameter of the device housing as the condensate catcher cylinder is located below the spinning rotor of the evaporative units.

A condensate catcher cylinder for the initially concentrated solution of such a diameter and height that the extremity of the outflow nozzle for the initially concentrated solution is located below its upper extremity is tightly attached directly to the device bottom.

The extremity of the outflow nozzle for the finally concentrated solution is located above the upper extremity of the condensate catcher cylinder for the initially concentrated solution.

Explanation of figures in the drawing

Embodiment 1

Fig. 1 The evaporation device in a top view.

Fig. 2 The device in a side view, with vertical contours through the flow trough for the initially and finally concentrated solution.

Fig. 3 The evaporation device in a vertical, axial section.

Fig. 4 The evaporation device in a horizontal section.

Embodiment 2

Fig. 5 Horizontal section of vertical contour of the evaporation device with cylindrical peripheral walls. - -

Embodiment 1

The device consists of two evaporative units mounted on a common drive shaft. Each evaporative unit consists of eight evaporative stages. The initially concentrated solution from the four last evaporative stages of both modules is discharged outside of the device and there, delivered to the main line feeding the concentrated primary solution to the device.

This was structurally solved in such a way that in each evaporative unit a cone 1_ of a jacket fed with external vapour, evaporation cones 2, cones 3 of condensate catchers and a cone 4 of a jacket for vapours of the last evaporative stage are integrated, by means of rims of their reversed bases, to horizontal contours of plates 5 giving the outline of a square which is, in the middle of its sides, tangent to the base of the cone. All the cones at a fixed mutual distance and order are permanently integrated with square rims to vertical, monolithic, rectangular plates which are peripheral walls 6 of the evaporative unit. Paraxially, the cone 1 of the vapour jacket, the evaporation cones 2, and the cone 4 of the jacket of the last evaporative stage are integrated to a cylinder 7 having holes 8 delivering the concentrated solution to each conical evaporation surface.

Shaped blocks 9 are attached to each cylinder 7 on both sides and at extremities. In the corners of the regular cubic of peripheral walls 6, there are holes at the height of each space separated by the cones. The outflow nozzles 10 for the finally concentrated solution are integrated obliquely, in relation to the diagonal axis of the corners, to holes of evaporation space of the four first stages. At a certain distance from the diagonal axis, the nozzles 10 are bent parallel thereto. The outflow nozzles J_l for the initially concentrated solution are integrated obliquely, in relation to the diagonal axis of the corners, to holes of evaporation space of the four last stages, but oppositely in relation to the nozzles 10. At a certain distance from the diagonal axis, the outflow nozzles ϋ are bent parallel thereto. The outflow nozzles 12 for condensate are integrated to holes of condensate catcher spaces. Their axes overlap with the corner axes of condensate catcher spaces. The outflow nozzles 10. 11, 12 have a cross-section of a rectangle with its vertical sides shorter. In the middle of the distance between the corners of the walls 6, at the height of the evaporation space, there are inspection holes with plugs 13. In the middle of the distance between the corners of the walls 6, at the height of the space of the jacket feeding with external vapour of first evaporative stage, there are vapour nozzles 14. Upper edges of the walls 6 have inwardly extended rims. - -

Each evaporative unit has evaporation cones with a base diameter of 4 m. Total evaporation surface of the device is 332 m ² . Total height of both evaporative units measured from the wall 6 extremities is lm.

Two evaporative units are mounted on a vertical shaft 15 with a conical bearing element 16, with a large circular rim extending from a drive unit 17 below a base 18. Shaped block of cylinders 7 of evaporative units partially come out towards the shaft 15, thereby positioning the evaporative units precisely in its axis. The shaped blocks 9 on the extension of the cylinder 7 walls have grooves on which gaskets are mounted. On the upper evaporative unit, a conical upper element 19 with a large circular rim is mounted on the shaft 15. It has, in its paraxial circular part, holes with grooves. Long screws 20 tightly comprising a bearing thickening of the shaft 15, the bearing element 16, the cylinders 7 of eva orative units and the upper element 19. In the grooves of the upper element 19, and in the shaped blocks 9 of the extreme cylinders

7, there are valve holes 2! having a common vertical axis intersecting the axes of the feed holes

8. Rolls 22 of valve assemblies are introduced thereto. Their through holes are located precisely at the height of the feed holes 8. The valve holes 2J_ have cut-outs towards the shaft 15 in particular shaped blocks, which correspondingly decrease downwards. Long wedges 23 are driven thereto which press the rolls 22 of the valve assemblies against the gaskets 24 mounted in the feed holes 8. The rolls 22 of the valve assemblies have internal, rotating stems with flow holes. Between these holes, the stems have a smaller diameter, and the free space is filled with an elastomer. The grooves in the upper element 19, with screws 20 and valve rolls 22, are covered hermetically with covers 25. On the abaxial side, all the feed holes 8 are covered with obliquely bent plates 26 of spinning motion, with integrated rims with cylinder 7 walls and evaporation cones 2 in such a manner that in the counterclockwise direction, there are triangular outflow holes perpendicular to the radius of rotation of evaporative units. In the clockwise direction, bends of the plates 26 completely close the outflow. Distribution rings 27 for the concentrated solution are attached to the evaporation cones 2, axially in relation to the shaft 15, near the plates 26. Each time, the conical space on the outer side of the vapour jacket is filled with a heat insulating material 28. All the outflow nozzles 10 of the four first stages of both evaporative units, of each corner, are located respectively in internal spaces of vertical troughs 29, screwed at the extremities to the circular rim of the bearing element 16 and the upper element 19. The outflow nozzles ϋ of three consecutive stages of both evaporative units, of each corner, are located respectively in internal spaces of vertical troughs 30, screwed at the extremities to the circular rim of the bearing element 16 and the upper element 19. The nozzles - -

11 of the eighth evaporative stages of both evaporative units, of each corner, are shorter and their extremities are located before the interior space of the troughs 30. All the outflow nozzles

12 for condensate of both evaporative units from the corners are located in internal spaces of vertical troughs 31,, screwed at the extremities to the circular rim of the bearing element 16 and the upper element 19 between the troughs 29 and 30. A condensate catcher cylinder 32 is axially and tightly attached to the base below the extremity of the bearing element 16. Further, an upper cylinder 33 for catching the initially concentrated solution is abaxially and tightly attached. The troughs 29 have abaxial bottoms 34 oblique towards the overflow outflows 35 located above the upper extremity of the cylinder 33. The troughs 30 have abaxial bottoms 36 oblique towards the overflow outflows 37 located below the upper extremity of the cylinder 33. The troughs 31 for condensate have overflow outflows 38 in their lower extremities with vertical drainage nozzles 39, below the circular bearing element 16. The flow troughs 31 for the finally concentrated solution have, at centrifugal bottoms 34, holes 40 connected to each other by a channel 41 with overflow valves 42, in the light of overflow outflows 35- The flow troughs 30 for the initially concentrated solution have, at the centrifugal bottoms 36, holes 43 connected to each other by channels 44 with the overflow valves 42, in the light of the overflow outflows 37. Apart from the nozzles of the eighth evaporative stages, all the remaining ones have outflow extremities spaced from the axis of rotation of the shaft 15 by 3.1 m. While all the overflow edges are spaced from the axis of the shaft 15 by 3.3 m.

A cylindrical streamlined housing 45 is attached to the rims of the bearing element 16 and the upper element 19.

Below the base 18, there is a nozzle 46 for condensate and a nozzle 47 for the initially concentrated solution (concentrate I). To the rim of the circular base 1_8, a cylindrical lateral housing 49 with thermal insulation is tightly attached, to which a cover is tightly attached, in which a shaft 15 _, with a vapour head 51 is mounted, which is hollowed from top to the height of two lateral holes in which vapour lines 52 are mounted which are connected to the vapour nozzles 14 for feeding jackets of first evaporative stages. In the cover 50, above the rotating valve rolls 22, there is a hatch 53 for the valves, and above hatch holes 54 of the circular part of the upper element 19, an inspection hatch 55 is made. A roll 15, from the lower extremity to the height of upper lateral outflow holes, is hollowed, and its lower extremity is mounted in a feed head to which the concentrated solution is delivered through a pipe line 56. The vapour head 51 is fed by a pipe line 57. In the space between the cylindrical housing 49 and the condensate catcher cylinder 32, there is a spiral drainage trough 58 for the finally concentrated - - solution (concentrate II) to a flow channel 59 connecting a hole in the lateral housing 49 to a vapour cyclone separator 60.

The separator 60 has, at the bottom, an outflow nozzle 48 for the finally concentrated solution (concentrate II), and, axially in the upper wall, a vapour nozzle 61.

The pipe line 56 is connected to a mixing collector to which a pipe line for the primary solution and a pipe line for delivering the initially concentrated solution (concentrate I) received by the nozzle 47 are connected. Mode of operation

Mounted on the shaft 15, two eight-stage evaporative units spin at the speed of 190 rev/min. Primary beet juice with a sugar content of 14% and temperature of 80 °C is fed to the mixing collector at the rate of 22.5 t/h. At the same time, all the initially concentrated juice (concentrate I) received by the nozzle 47 at the concentration of 50% and temperature of 45 °C in the amount of 6.3 t/h is fed to the same collector. To the conical vapour jackets, thought the nozzle 14, heating vapour at the temperature of 125 °C and the pressure of 232 kPa is fed in the amount of 2.4 t/h. Inside the vapour chamber, vapour pressure at the level of 96 kPa and the temperature of 45 °C is maintained. Pre-concentrated juice at the concentration of 21.9% and the temperature of 73 °C is fed through the pipe line 56 to the head feeding the shaft 15. Through the holes in the shaft 15, the pre-concentrated juice is delivered to the cylinder 7 space from which it flows through the through holes in the roll 22_of valves and through the holes 8 for delivering to the plates 27_of spinning motion, and through the outlet channels, it flows out perpendicular to the radius of rotation of the evaporative units. The spinning pre-concentrated solution filling the internal spaces of the distribution rings overflows through their edge and evenly pours out onto the surfaces of the evaporation cones 2. In a one-second time interval, while boiling, in an increasingly thinner film, it flows to the peripheral walls 6 and along their inclinations, due to the centrifugal force, to the nozzles 10 or Π_. Beet syrup from the first four stages as concentrate II at the concentration of 70% flows out into the troughs 29. Beet syrup from the four last stages as concentrate I at the concentration of 48% flows out into the troughs 30. Vapours from above the evaporation cones 2 flow towards the shaft 15 and further through peripheral slots upwards towards the bottom surfaces of the evaporation cones 2 of higher stages in order to condense on them, thereby dissipating the condensation heat. Condensate particles are immediately broken off and thrown, by the centrifugal force, onto conical condensate catchers along which they run down to the peripheral walls 6, further to the condensate nozzles 12 and to the condensate troughs 31. The troughs 29. 30 and 31 have overflows 35, 37. 38 maintaining centrifugal difference of levels inside the nozzles 10. 11. 12 and in the troughs 29. 30. 31 equal - - to 0.21m. It balances the pressure differences between the vapour chamber, the internal spaces of vapours of evaporative stages and the vapour jackets fed by external vapour because the centrifugal force in the troughs reaches 1230 N. The condensate from the vapour jackets is removed in the same manner as the condensate of evaporative stages. The condensate having the temperature of 85 °C is thrown from the troughs 31 through the nozzles 39 to the condensate cylinder 32 in which it spins while being received with the nozzle 46 to a heat exchanger. Due to the centrifugal force, the concentrates I and II, and the condensate do not boil in the troughs 29, 30 and 3 L For the same reason, the condensate do not cool down as a result of self- evaporation also in the cylinder 32. Through the overflows 35, the concentrate II is thrown onto the cylindrical housing 49. It runs down the said housing to the spiral trough 58, while boiling and cooling down as a result of self-evaporation to the temperature of 45 °C, and its concentration rises to 76.8%. Further, through the hole in the housing 49 and the vapour channel 59, it flows to the cyclone separator 60 and therefrom it is received by the nozzle 48 in the amount of 4.1 t/h. The concentrate I is thrown through the overflows 37 onto the cylinder 33 wall along which it runs down to the base 18, while boiling so that its temperature drops to 45 °C, and the concentration rises to 49.8%. It is received by the nozzle 47 and fed with a pomp to the mixing collector. The last eighth evaporative stages have their vapour chambers opened and there is the same pressure as in the vapour chamber of the device. Vapours together with the concentrate I are thrown through the holes towards the troughs 30, where the vapours and the concentrate are separated. 2.2 t h of vapours flows out from the eighth stages. As a result of self-evap oration, 0.59 t/h of vapour is produced. The whole flows together with the concentrate II through the channel 59 to the separator 60. The heat transfer coefficient is 4000 W/m ² .°K.

Embodiment 2

The bearing element 16 and then 8 conical evaporative units are mounted on the shaft 15 extending form the base 18. Each evaporative unit is constructed in such a manner that 6 reversed truncated evaporation cones 2 together with the conical condensate catchers 3, the conical vapour jacket I and the cone of jacket 4 of the last stage are permanently integrated with the external rims to the cylindrical peripheral wall 6 of the diameter of 4 m. All the cones are integrated with their paraxial holes to the cylinder 7 having holes 8 delivering the concentrated solution, and extreme shaped blocks 9 positioning the unit on the axis of the shaft 15. The holes 8 are permanently covered with the plates 26 of spinning motion. The distribution rings 27 are attached to the evaporation cones, near the lower extremity. The integrated evaporative stages are permanently mounted with their cylindrical wall 6 in a bracket - - integrating all the drainage troughs 29.30,31 for the concentrate and the condensate. The total height of the evaporative units, measured from the extreme rims of the cylindrical walls 6, is 2.4 m. The integrating bracket 62 has a rectangular shape with cut corners and walls extending at full height of the cylindrical peripheral wall 6. The rim of the bracket extends broader beyond the extremity of the cylindrical wall 6, thereby forming an inlet for the lower edge of the bracket

62 of the next evaporative unit. A projection below the circular rim of the upper element 19 enters the inlet of the upper evaporative unit. In the cylindrical peripheral wall 6, near the diagonals of the bracket 62, at the height of the condensate running down from the first three (the lowest) evaporation cones 2, there are horizontal outflow nozzles 10 for the finally concentrated solution (concentrate II). Nearby, on the opposite side of the diagonals of the bracket 62, at the height of the condensate running down from the last three (upper) evaporation cones 2, there are horizontal outflow nozzles 11 for the initially concentrated solution (concentrate I). In the diagonal axes of the bracket 62, at the height of the condensate running down from each evaporative stage, there are horizontal nozzles 12 for condensate. In a top view, the nozzles form three overlapping series. Each series of the nozzles is closed in a rectangular displacement housing from holes of which nozzle extremities extend. Displacement housings

63 have the height of the cylindrical wall 6 and are integrated thereto with the rims. The nozzle rims are also tightly integrated to the displacement housings 63. In a top view, between the displacement housings 63, there are slots of such width that they are entered by the walls of the troughs 29, 30, 31 with their flat common bottoms, resting on the internal surfaces of cut corners of the integrating bracket 62. The troughs 29,30,31 have the shape of long, open, rectangular tanks with common internal walls separating flows of concentrates and condensate. In centrifugal bottoms of the upper extremities of the troughs 29,30 for concentrates, on two levels, there are overflows with overflow valves 42. The troughs 31 for condensate have their overflows close to the lower extremities. Extremities of all the outflow nozzles for concentrates and condensate are spaced from the axis of the shaft 15 by 0.4 m more than the overflow edges of the troughs 29,30,31. Other construction details of the device are identical to the device described in the embodiment 1. The evaporated surface of the device is 835 m ² .

Mode of operation

Carbonation beet juice at the concentration of 14% (primary solution) is subjected to concentration. All the flow directions are the same as in the device from example 1. However, there is a different operating temperature range for the evaporator, a different pressure range - - and a different concentration of the syrup. The first three evaporative stages of each evaporative unit finally concentrate the syrup, while the syrup concentrated as a consequence of the last three stages is returned to the carbonation juice fed to the evaporative device, thereby pre- concentrating it.

The evaporative units spin at the speed of 290 rev/min. At the extremity of the outflow nozzles, the centrifugal force exceeds 2190 N. Inside the vapour chamber and in the separator 60, the pressure of 101 kPa and the temperature of 100 °C are maintained.

Beet juice (primary solution) at the temperature of 100 °C is fed to the mixing collector at the rate of 65 t/h. The concentrated syrup as a consequence of the last three stages of the evaporative units of the device, at the concentration of 54% and the temperature of 116 °C, flows to the mixing collector in its entirety at the rate of 16.7 t/h. Pre-concentrated juice at the concentration of 22% and the temperature of 103 °C is fed to the evaporation cones 2 at the rate of 81.7 t h. Vapour at the temperature of 170 °C and the pressure of 792 kPa is delivered in the amount of lOt/h to the vapour line 57. Beet juice at the temperature of 145 °C and the concentration of 8o% is thrown onto the housing 49 in the amount of 11.4 t/h. After self-evaporation to the temperature of 100 °C, carbonation syrup at the concentration of 88% in the amount of 10.3 t h is obtained. 7.5 t/h of wet vapour at the temperature of 100 °C is discharged from the separator 60. The heat transfer coefficient for the evaporation surface is 4000 W/m ² .°K.