SU735267A1 - Film evaporation apparatus - Google Patents

Description

(54) FILM STEAM DEVICE

one

The invention relates to devices for carrying out processes of film evaporation of solutions in a downward twisted strand.

A evaporator is known for film-extracting solutions, which contains a rotating cylindrical body, evaporation tubes in tube plates, evaporation tubes, and a separation device i located in the lower mortar chamber.

In this apparatus, the vapor-liquid mixture is separated due to inertial forces and gravity, which is less effective with centrifugal separation.

Also known is a film apparatus with a descending motion of a rastor containing a vertical cylinder {) of a casing, inside of which are placed evaporation tubes with, film-forming inserts, hardened in the upper to the lower tube sheet, a separator located underneath the lower lattice, a reverse cone installed in it, upft . an apparatus for cleaning secondary steam, fastened to the lower tubular sieve and placed beneath it, made in the form of circumferentially curved blades forming tangential slots between each other, branch pipes for supplying solution withdrawal and secondary steam.

ten

The separation of liquid and vapor is carried out by centrifugal forces arising at. a tangential outflow of a gaeo-liquid flow from the slots and a tangential impact of the flow on the cylindrical wall of the apparatus 2.

The drawback of the apparatus is that the liquid comes from the cracks; it flies out with a vapor flow, in the form of droplets, and a dfi strike

20, a cylindrical wall is formed with tiny drops, which are held by the clamps with a steam-packed yutok compacted against the wall and carried away from the device; 373 The chain of invention is more efficient than the separation of second pair and pacTBdpa. This, and the goal is achieved by providing a separator ;; the reflective element is placed 11 m) 1 m outside the blades and is made in the form of a truncated cone with spiral guides on the inside surface; A straight-centrifugal separation plate is installed between the truncated cone and the housing, and the ratio of the average diameter of the truncated cone to the smallest diameter of the reverse cone is 2-2.5. FIG. 1 schematically shows the proposed apparatus, a longitudinal section; in fig. 2 shows section A-A in FIG. one; in fig. 3 - node B in FIG. 1. The evaporator film apparatus comprises a housing 1, tube plates 2 and 3, with evaporation tubes 4 rigidly fixed and in ifflx, a switchgear in the form of a shell 5 and inserts 6 installed at the top of the evaporation tubes. Spiral swirlers 7 are arranged along the length of the tubes 4. Underneath the bottom tube plate 3 there is a reverse body 8, and a device for cleaning the secondary steam placed under it is made in the form of curved blades 9, forming angular slots 10. At the exit ifflx from the gap to the wall The apparatus has a reflective element 11 in the form of a truncated cone on the inner surface of which there are spiral guide 12, the direction of rotation of which coincides with the direction of flow of the phase from the tangential slots 1O, set under the sharp angle to the surface of the cone. In the gap. A cone 8 and a wall 13 of the safety part of the apparatus are housed with a multi-element, continuous and centrifugal separation plate 14 with cylindrical nozzles 15 rigidly attached to it, in the lower part of which a multi-slot paratrooper swirls are mounted; through pipe 18. The proposed apparatus works as follows. The original solution enters through the nozzle 19 into the upper part of the apparatus, flows through the edges of the shell 5 qaems through the evaporator pipes and, thanks to the film-forming inserts 6 in the form of plesh, moves down the heated walls 674. The juice pairs formed during the evaporation of the solution together with the solution pass the spiral vortexes 7 and acquire a rotational movement. The liquid film is pressed against the wall of the evaporator tube and, due to the tangential pressure of the rotating steam flow, moves B1shz in a spiral, due to which evaporation of the solution occurs. From the evaporator tubes, the vapor-liquid stream enters the reverse cone 8, which has a double purpose. In order to create / resist the vapor-liquid flow exiting the peripheral evaporator tubes when the liquid overflows through the edge of the shell 5, more solution flows into the outer tubes of the evaporator than into the central ones, and when creating resistance in the extreme tubes more solution flows into the central tubes and ensures uniform distribution of fluid across all pipes. The tapering cone allows to increase the speed of the vapor-liquid flow entering further into the separation unit into the cleaning unit 9 and the passage through the tangential slots 10, is twisted, is thrown by centrifugal force on the downward guides 12 of the reflection element 11. The efficiency of vapor-phase flow separation in the field The centrifugal forces depend on the flow velocity in the tangential peaks; the higher the speed, the better the separation. Moreover, the magnitude of the speed depends on the smallest diameter of the inverse cone. The two-stage separation in the field of centrifugal forces ensures reliable separation of the phases at high speeds of the vapor-liquid flow, which makes the separation part of the apparatus compact and not metal-consuming. After exiting the tangential slots, the steam rotating flow loses its speed, rises up and enters the nozzles 15 of the centrifugal plate, where the final cleaning of the vapor from the solution drops takes place. At the inlet to the nozzles, the steam passes through a rock-swirling swirl 16 and acquires a rotational motion. If there are drops of solution in the juice pair, the last ones in the field of centrifugal forces are thrown onto the inner walls of the pipes and move upwards in the form of a film. At the outlet of the nozzles, the solution film cuts off5 with the fender caps 17 and the nozzles is directed onto the plate 14, from where the liquid drains down the apparatus through the drain pipe 18. The cleaned juice pairs pass through the center of the baffle caps and out through the nozzle 20 from the apparatus. The quality of the separation depends on the geometrical dimensions of the inverse and truncated cones. The main parameters are the average diameter of the truncated cone and the minictal diameter of the reverse cone. The change from Hoiueime is in the range of 1.5-3.5. The results of the study of the film blanket apparatus are shown in the table.

Claims (2)

From the table it can be seen that when comparing Ratio 2-2.5, a stable phase separation mode is observed and its efficiency is 99-99.8%. An increase in the ratio above 2.5 substantially influences the efficiency of the separation, but does not lead to an increase in the diameter of the apparatus and, consequently, an increase in metal consumption. The optimal ratio is 2-2.5. During the evaporation of the urea solution, the investigations of the apparatus show that, in the present apparatus, in addition to high separation efficiency, with a uniform distribution of the solution in the tubes and a decrease in the residence time of the liquid in the heating zone, the decomposition of urea to biuret is reduced. Claim 1. A film in a spherical apparatus with downward motion of a solution containing a vertical cylindrical body inside which are placed evaporation tubes with film-forming inserts fixed in the upper and lower tube sheets, with a separator located underneath the bottom grid, attached thereto to the lower tube sheet and a device located under it for cleaning the secondary steam, made in the form of circumferentially curved lopasgei, forming between Special slots, nozzles for supplying and discharging the solution and secondary steam, characterized in that, in order to enhance the separation of secondary vapor and solution, the separator is equipped with a reflective element placed outside the blades and made in the form of a truncated cone with spiral-shaped directions on the inner surface. 2. The apparatus according to claim 1, which is also distinguished by the fact that it is equipped with a cenapaimoiffloft rotary-centrifugal plate mounted between the truncated cone and the body. 3. The apparatus of claim 1, wherein the ratio of the average diameter of the truncated cone to the best diameter of the reverse cone is 2-2.5. Sources of information taken into account in the examination 1. USSR author's certificate in application No. 2354000/26, cl. O1 L 1/22, 04/29/76. 2. Patent of the USA. No. 2742083, cl. 159-13, 1956.