CS200474B2 - Method of transfer of the substance between heterogenous systems and device for executing the same - Google Patents

Abstract

1491252 Solid/liquid and liquid/liquid contact DYNAMIT NOBEL AG 1 Nov 1974 [3 Nov 1973] 47454/74 Headings B1F and B1Q A process for the exchange of material in heterogeneous systems, e.g. for liquid/liquid extraction, solid/liquid extraction or washing solid or solid suspension with a liquid, comprises supplying a flow of a first mass to an upper region of an exchange column and a flow of a second mass lighter than the first mass to a lower region of the exchange column to flow in countercurrent with said flow of a first mass, wherein (a) the first mass flow is deflected above a plate disposed within the column and extending over the axis of the column so that the mass flow enters into a vertical rotational motion and is mixed with a lighter mass flow passing through a first passage in the plane of the plate and located adjacent the inner periphery of the column and introduced into the rotational motion (b) a mass system forming as a result of the mixing is increased in concentration with respect to the first mass in a region above a second passage in the plane of the plate and located adjacent the inner periphery of the column and (c) after a sufficient pressure drop has been built up in the region of the second passage, the said mass system increased in concentration with respect to the first mass, flows through the second passage into a space below the plate to be deflected into another vertical rotational motion but in an opposite direction to the earlier rotational motion, and is mixed with mass flow supplied from below, in which process the interior of the column is free from moving constructional parts and the travel of the mass flows therethrough is the result of motion imparted thereto prior to entry coupled with effects of gravity and said deflection. The arrangement of baffles to cause the required flows may be as shown in Figs. 3 or 4a, the flow of heavy phase being indicated by double arrows L, and of light phase by arrows K. The process may be used for the separation of dimethyl terephthalate from a suspension using methanol, separating xylene and acetic acid using water, washing glass microspheres with water, and extracting soya beans with hexane.

Description

BACKGROUND OF THE INVENTION The present invention relates to a method of mass transfer between heterogeneous systems in a column with at least one tray having a first and a second overflow into which a heavier mass stream is introduced from above and a mass stream lighter in countercurrent from below. wherein the heavier phase and suspension are enriched over a second overflow and at least one of the mass streams flows through a continuous column, and apparatus for carrying out the process.

The term mass transfer does not only refer to diffusion processes which take place, for example, during extraction in systems. with two immiscible or non-immiscible phases, or with one solid and one liquid phase, but also with mass transfers in washing processes which are carried out with solids to remove adhering impurities.

In such washing processes, the solids move in a known manner relative to the washing liquid, thereby causing a stronger or lesser transfer of impurities into the washing liquid. If the impurities are soluble in the wash liquid, the separation of solids and wash liquids may occur for example by centrifuging. However, CD centrifuges are very complex to manufacture and operate, particularly when operating continuously, especially when operating at elevated pressure; or be gastight if the washing liquid is toxic and / or flammable. Besides, they have

Yet another disadvantage, which also applies to other processes, such as sedimentation or

This is because, in fact, a certain amount of residual moisture with "impurities" remains on the solid fabric, which can only be compromised by repeatedly complicated washing and re-centrifuging to a permissible amount of impurities.

Furthermore, it is known that multistage fluidized bed devices are used for the continuous mass transfer between heterogeneous liquid and / or gaseous and solid phase particulate systems. These devices are columns for. mass transfer with a plurality of sieve trays, which are arranged horizontally at a spaced apart distance. In one type of these devices, the holes in the sieve trays are sized so that only fluid can pass through them, while the solid phase moves through separate joints. channels from one mesh floor to the next. In another type of device, on the other hand, the holes in the sieve trays are designed so that both the liquid and solid phases can flow in countercurrent. Although these devices are relatively simple in construction, they have the fundamental disadvantage that they need a relatively large amount of liquid countercurrent, i.e. a large amount of washing liquid or extractant, for the necessary solid phase screening. This is undesirable, especially as regards the large amount of liquid and its possible later separation from the solids it has taken over. There is a risk that during operation the sieve trays gradually become more or less clogged by the solid phase, whereby the performance of such a column is gradually reduced.

The purpose of the invention is to overcome these disadvantages and to propose a method and apparatus for the transfer of mass between heterogeneous systems so that optimum mass transfer without malfunctions is achieved in the least production and operation requirements. In particular, it is important that, for example, in the extraction or washing processes, the amount of extracting or washing agent required for the mass stream to be treated is as small as possible. In addition, it should be possible to carry out mass transfer i. for very different mass streams using the same device, which means that the column should be as versatile as possible.

To solve this problem, the mass transfer method according to the invention is characterized in that the continuous mass flow is a liquid, a heavier mass flow flows between the region of the first overflow and the upper overflow region of the second overflow towards the palate. As a result of the movement, the lighter mass flow flowing from bottom to top of the first overflow is swirling and mixed with a heavier mass flow, with the heavier phase. or the slurry igniting upon the exchange of mass in the mixing zone encompasses the second overflow and flows through the second overflow from top to bottom into the space below the tray at such a speed that the heavier mass stream turns into a further circular or elliptical swirl movement; into which a lighter mass stream is fed from below.

The vertical rotational movement of mass streams during which the phase of the heterogeneous system. they move along more or less closed circular, elliptical, and similar paths about a horizontal axis, advantageously leading to intense phase mixing and thus providing the desired intensive mass transfer. In this case, the vertical rotational movement can be according to the circumstances of the individual. Transverse flows superimposed in the case, without affecting the advantageous effect achieved in the mixing zone. Intensive mixing is also promoted by the fact that the light mass flow passing from below through the first overflow of the palate is collided with the rotating heavy mass flow a. it strongly disperses when it enters this stream.

The heavy phase, slurry or the like that is produced during the mass transfer in the mixing zone is enriched in the region of the second overflow formed on the palate due to the difference in density. This creates a soothing zone for the heavy phase, slurry, etc. over the second overflow. As soon as the enrichment in this soothing zone is advanced so far that the pressure prevailing in the area of the second overflow is sufficiently higher than the pressure at the first overflow, the heavy phase, suspension and the like overflow downwards and is re-vertically rotated under the column bed and mixed with a light, flowing mass stream. In this process, another calming area is formed, below the first overflow of the palate, where the lighter mass stream is enriched and flows therefrom as a result of the pressure drop into the space above the bottom.

The space above and below the floor must have a minimum height for optimum vertical rotation and calming and mixing zones. Due to the pressure gradient between the two weirs, which is necessary for rotational movement and depends inter alia on the concentration difference and the hydrostatic height of the multi-stage system in the overflow region, the free flow cross-sections of the first and second weirs depend on each other and not on the whole . The optimum values that apply here depend on numerous variables. For example, it is important that the mass transfer is carried out, that is to say, for example, by extraction or washing. The substances contained in the mass streams, the behavior of the individual substances on their own and in interdependence, the phase state of the components, their diffusion properties and other quantities influence the flow rates inside the column. Since in practice there are a large number of possible heterogeneous systems, it is advisable to identify the most advantageous in each case. more values for the method and equipment through optimization experiments. By way of example, in washing processes in solid-liquid systems, these optimum values are in the range of 1 to 25% for the free-flow ratio of the first overflow to the second overflow, and between 3 to 33% for the free-flow ratio of the second overflow to the flow cross-section of the column.

According to a preferred embodiment of the invention, the current is converted into a vertical rotational movement by a reversing device which projects into the flow cross section of the column and extends from the edge or near the edge of the column and is inclined downwards. This mechanical Perfecting is structurally simple, reliable in operation and enables a result of its action, which begins plsob jd- ^ ^VN ^ ^ KOSN hundred columns as nejtlipnější use Ruto ^{p N} N ^eh ^ cuts on a position to provide a rotary motion.

It is evident that the mass transfer in a single-storey column is even lesson! The method according to the invention satisfies only small demands on the extraction or purification effect, since the creation of a rotary motion by feeding and discharging mass streams in the head and bottom of the column is subject to disturbances. Thus, with higher demands on the mass transfer achieved, the process is carried out in a column with two or more trays which are spaced one above the other and divide the column into several stages; According to the invention, the mass flows in successive stages are driven into swirling rotational movements of opposite rotation direction. The mixing and settling zone is formed in each stage. The flow currents move the column meapidially, making optimal use of the entire column height. In this case, too, the most distant distance between the individual days is tentatively determined. The redispersion of the individual phases is quite low, so that even at a small number of stages in the column, a very good transfer of material is achieved. Since rotational motions arise even at relatively small hoot currents, the Stelite Stands are working. The process according to the invention is extremely large with respect to the processed products compared to the conventional tapping processes. Relatively high velocities of flow between the individual stages in the first and second overflows result in relatively high flow rates.

If a solid phase particulate is removed from the bottom of the column during the mass transfer, depending on the behavior of the particulate matter and the residual liquid phase, there may be a failure of solid phase removal under certain ocoonooties. In this case, according to another feature of the invention, liquid is introduced into the bottom of the column to release the solid phase. The same liquid, solution, mixture of solutions and the like, constituting the washing liquid fed to the bottom of the column, for example, is chosen, for example, in the wash, in view of the undesirable additional mixing, which must optionally be followed by separation. ‘

In order to assist in mass transfer in a heterogeneous system whose heavy mass stream contains or consists of a particulate solid phase, to promote particulate enrichment in the region of the second overflow at the start of the column operation, the invention proceeds as follows: During the initial phase of operation of the column, no bottom is fed or a relatively small amount of feedstock is fed in. This advantageously reduces the initially undesirable mass deposition in the region of the second overflow and shortens the initial phase of operation of the device. .

The apparatus according to the invention is characterized in that the tray overlapping the flow cross-section of the column is provided with a first overflow and a second overflow at the edge, and is located in the region of the first overflow. perfecting. The overflows are preferably located immediately at the edge of the tray, i.e. directly on the inside of the column, but may also be located some distance from the tray edge. The size of the two overflows is selected such that, due to the pressure drop that occurs in the calming zone of the second overflow, the mass flow flows sufficiently quickly through the second overflow to produce the desired vertical rotational movement even below the patreo. . In general, this can be ensured by having a first overflow having a smaller flow cross section than the second overflow according to another feature of the invention.

If a column with several spaced trays is used instead of a single-bed column, the overflows of the same kind are offset to one another and are preferably opposed to one another for intensive mass transfer on trays of successive overflows. For example, on one floor, the first overflow is on the left district, while on the next floor on the right, preferably directly against the first overflow. This ensures that the passageways are precisely where the calming zones associated with the vertical rotary movement are formed automatically, so that no additional auxiliary inverting devices are required. · And advantageous utilization of the whole column height is ensured.

. Λ

According to a further feature of the invention, the tray is arranged horizontally and the inverting device is formed by a guide plate, guide plate or an embossment which extends from the outer edge of the column, lies obliquely and is located above the tray, omitting the gap between its inner edge and tray. In addition, the behavior of the lighter mass stream flowing from below through the first overflow is influenced by the size of the gap between the lower edge of the guide plate or plate and the tray.

A particularly preferred embodiment of the device according to the invention is characterized in that the tray is inclined to the longitudinal axis of the column and its upper section simultaneously forms a reversing device. There is therefore no need to install a separate inverting device in the column. The first overflow is created at the top of the bottom and the second overflow is located at the bottom. In addition, the inclined tray support promotes the formation of calming zones at the corners above the second overflow or below the first overflow, since in normal steady-state operation of the column, the vertical rotational movement affects these areas to little or no effect. If this inclined tray arrangement is also used for multistage columns, a multistage column with inclined trays is formed, which is relatively small in height compared to the mass transfer achieved, since both of the plates are of a low height. the zones separated by the eighth storey lie side by side, while in the horizontal tray column they always lie one above the other. For columns with several trays, the successor trays are always inclined in the opposite direction.

The angle of inclination of the tray or trays in such a column is again governed by the type of heterogeneous system where the mass transfer is to be carried out. For example, when washing with a heavy mass stream which contains a solid phase in the form of particles, the angle of inclination is preferably chosen so as to enrich the free layer of solids in the lower palate, i.e. above the second overflow, to achieve compared to the first overflow of the optimum pressure drop necessary for rotational movement. If the inclination angle is too large and the bottom is too high, there is a danger that solids will form above the second overflow that would. it disturbed or possibly prevented further flow into the obstrum below the palate.

This would unnecessarily increase the column height. Other ratios, on the other hand, apply to the liquid extraction of a liquid, since in this case large storage zones or zones are preferred. settling areas so that large angles of inclination are suitable. In this case, since the column does not contain a solid phase in the form of particles, there is no danger of an interfering particle over the second overflow. For the most steepest operation, it is also advisable in this case that the inclination angle best suited for each individual case for the occurrence of rotational movement and phase separation in both calming zones is determined by trial. .

Finally, the device according to the invention is characterized in that the tray has, in addition to the first overflow in the area adjacent to the first overflow, log holes, cut-outs. This measure is advantageous, for example, in order to prevent the solid phase, which tends to form bridges, for example platelet crystals, from the inclined floor in unfavorable circumstances. This deposition is also prevented if the lighter mass flow supplied from below does not merely pass through the first overflow but upwards in a small amount through these additional openings, cut-outs and the like into the area above the palate, thereby additionally releasing a layer of solids. These auxiliary openings or slots are limited to the upper part of the tray to prevent disturbances due to a lighter mass flow in the region of the lower licensing zone.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a mass transfer column for a solid-liquid system. FIG. 2 shows a column for a liquid-liquid system, FIG. 3 shows the flow conditions in a column with horizontal trays, field. 4a, 4b the flow ratios in the sloping tray column; and FIGS. 5a, 5b different tray shapes.

The mass transfer column 1, abbreviated in FIG. 1, has a head 2, a bottom J, and a sloping tray 4 with a first overflow J and a second overflow 6. At point A, the heavier feed line · located in the center 2 is heavier a mass gas, which may be, for example, a suspension of dimethyl methyl stearate and the filtrate to be purified. The filtrate is a methanol solution of unnecessary residues of crude dimethyl tert-phthalate, which contains primarily dimethyl dimethyl isophthalate and dimethyl tert-phthalate, in addition to other high-boilers and a small amount of dimethyl dimethyl terephthalate.

At point B, the mass flow is removed after the mass transfer has been carried out, which can be purified dimethyltetra-tthalate in the washing liquid, i.e. methanol. A lighter mass stream, in this case methanol, is fed at point C through a circular duct located at the bottom J of column 2, flowing through column J from bottom to top in countercurrent to the heavy mass stream. A lighter mass stream is discharged from the head 2 at point D, in the chosen example the stream being a mixture of methanol filtrate. An additional mixing liquid, in this case again meeanol, is added to the bottom J of column 2 at point E in order to facilitate the removal of the heavier mass stream from point B.

Unlike protipooudové scrubbing column 2 of FIG. 1 shown in FIG. 2 · column for liquid-liquid extraction, for example JEKA used to distribute the solution ^to xylene and alkyl einy acetate. In this case too, a heavy mass stream, in this case water, is introduced into the head 2 of the column 2, provided with trays 4 and overflows, in the point F, and in this case the so-called water extract in acetic acid solution. is removed from the column. A lighter mass stream, in this case a solution of xylene and acetic acid, is fed at point H to the bottom J of column 2, and at point I.

Separate xylene is removed in Title 2. · In a similar way, analogous mass transfer columns could be used for · liquid-solid extraction, such as when extracting soybeans with hexane; however, the flow ratios would be more similar to those of a solid-liquid wash.

Fig. 3 shows a partial cross-section of the mass transfer column 4 with horizontal trays 4. Above the first overflow J there is an inverting device formed by a guide plate 2, which protrudes into the column J and is closed at the lower side by the horizontal plate 8. Unintentionally trapping and adhering particles between the guide plate 2 and the inner wall J of the column 6, a gap 11 remains between the lower edge 10 of the guide plate 2 and the tray 4. A light mass flow, shown by a simple arrow K, is flowing from bottom to top. the heavier mass flow, drawn by the arrow L, flows through the lower overflow 6 of the floor 4 from top to bottom. ''

In the mixing zone M, the heavier mass flow is guided by the guide plate 2 to rotate vertically, to which the lighter mass flow is also attracted. Thus, in the mixing zone M, the mass transfer takes place, and the distribution of the two mass streams is again due to differences in density. In the steady-state operating state, the heavier mass stream is enriched in the calming area N, which is shown by welding. and lies above the second overflow 6, while the lighter mass stream is enriched in the circumference of P below the upper overflow J. From there, the two mass streams * pass to the subsequent stages of the column 6, their composition constantly changing due to mass transfers.

Giant. Figures 4a, 4b show sections through a multi-storey column with sloped trays. The column according to FIG. 4a has lower weirs 6 which are relatively large in relation to the upper weirs J and are suitable for mass transfer in solid-liquid systems, for example as a countercurrent washing of dimethylene terephthalate.

The individual tray of this column operates as follows: a light liquid is passed from bottom to top in the direction of arrow K while a suspension of solid particles of higher density is fed from above. The particles move downwards according to their mass. At the beginning of operation in column 1, the velocity in the overflows g, 6 is so high from a certain amount of solid matter particles or from a certain amount of countercurrent liquid supplied from below, that the particles cannot pass through these overflows 2.6. the inclined positions of the tray 4 in the region above the lower weir 6. In doing so, they are lifted by a liquid which flows in the upstream of the lower weir 6 and are brought into a vertical rotational movement which, however, has a relatively small spatial extent.

Upon further addition of the solid particles, the particles accumulate in the lower region of the tray 4 and form a layer which flows according to the (pressure ratios of the two mass streams) and as soon as a sufficient difference is formed in the area of the lower overflow. the solid particles in the direction of arrow L through the lower overflow 6 of the tray 4 downward to the next stage, while the lighter mass flow formed by the countercurrent fluid flows in the direction of the arrow K upper, through the overflow g of the same tray 4 upward. 14 of the following tray 4 'is deflected and entrains with a piggy-back flowing liquid passing through the upper overflow 5' of the next tray 4 ', in the direction of arrow K. This countercurrent liquid is dispersed and mixed with the particle suspension.

There is a strong flow along the middle and upper part of the tray 4 'which is deflected at the bottom of this tray 4' along the layer of particles lying there. - This produces a vertical rotational movement which is the same as the rotational movement at the start of the operation in a clockwise direction, but occupies a large space of this stage, unlike the initial phase. In this mixing zone M both mass streams intensively mix with each other so that mass transfer can take place at the most favorable conditions at this point. The mixing zone M is limited downwardly by the settling-or-calming zone N, which is shown in FIG. 4a by narrower hatching. Upwardly, the mixing zone M is constrained by an approximately horizontal plane which extends - the lower edge of the tray 4. In the space above this cleared plane, a settling or calming zone P is formed. In this calming zone P there is practically only a light countercurrent liquid. Under normal operating conditions, in this area of velocity - the flow is too low - to keep the particles in the air - or even to transport them. Above the restless heterogeonic level: zone M forms an almost clear layer of liquid.

The processes which have been explained - for one stage of column 1, are analogously repeated in the other stages, but - however, the rotation of the rotational movement from one stage to the next is simulated. Virtually the same forms of flow excel in all stages, although the composition of the mass streams from stage to stage is constantly less. According to the example explained in connection with FIG. 1 for countercurrent washing of di-tert-butyl terephthalate, this would mean that at the uppermost stage - or in the uppermost stages of the column j - The flow of the heavier mass stream in column 1 downstream is continued until finally at the bottom 4 of column j. a practically pure suspension of dimethyl dimetaphthalate in methanol can be removed. The downstream countercurrent liquid, in this case methanol, changes in the opposite way, which enriches in the quiescent zones P and thus contains more filtrate, the closer it reaches the head of the column.

This steady-state operation of the mass transfer column described in FIG. 4a for the solid-liquid system is an equilibrium state between mass streams which is self-adjusting and which is preferably in a wide load range it automatically regulates it; that is, the mass transfer column is automatically adjusted to the desired power. For example, if a constant moiety is considered! countercurrent scaling, which is very easy to control and maintain, increases the heavier mass flow and thus increases the particle flow over the lower overflow when the particle flow is increased. However, this increases the pressure difference, which again results in an increase in pressure. the absolute velocity of the particle flow through the lower overflow - 6 downwards to the next stage.

On the other hand, if the particle flow is considerably weakened with a constant amount of countercurrent liquid, a pulsating flow of particles through the lower overflow 6 to the next lower level occurs. The countercurrent liquid then flows both through the upper overflow 2 and also in a pulsing manner through the lower overflow 6 upwards. In the latter case, the countercurrent fluid enters the vertical rotational motion which originates above the tray in a tangential direction and intensifies the formation of this rotational flow.

Even with a very small amount of countercurrent, the self-regulation of the mass transfer column according to the invention is so excellent, i.e. to maintain the rotational movement and thus the particle residence in the individual stages so reliable that the column can be emptied quickly only in parallel with both mass streams.

Exceeding the column power by feeding too much particle stream causes a strong build up of the particle layer above the lower overflow 6; firstly, the rotational movement is limited to a smaller space of the respective stage, and when the amount of particles is further increased, the rotational movement completely disappears. With still further increase of the amount of the supplied particles, they flow upwards and thus clog the column.

With a constant flow of particles and a variable amount of countercurrent liquid, opposite ratios occur.

Fig. 4b shows the flow patterns that occur in the steady-state operation of the column in the liquid-liquid system. The same reference numerals as in FIG. 4a are used for each detail. The difference from Fig. 4a is only that there is no solid phase in the form of particles in column 1, so that the lower weir 6 is not much larger than the upper weir 2 · Depending on the type of heterogeneous system being processed, upper overflow 5 in order to achieve the optimum pressure drop necessary for rotational movement. For example, assuming a heterogeneous system in the separation of xylene and acetic acid in conjunction with FIG. 2, the mass stream enriched in the sedation zone N, in this case water, has an acetic acid content increasing from top to bottom, the stream enriched in the quiescent zones P contains less and less acetic acid from bottom to top, until virtually pure xylene can be removed in the head 2 of column 2. In the mixing zone M there is a mixture of both mass streams. In this case too, the process according to the invention is very advantageous, because, as a result of the intensive mass transfer compared to conventional processes with the same amount of water as the countercurrent fluids, the equipment and operation requirements are lower.

Giant. 5a, 5b show two examples of possible tray 4 configurations. According to FIG. First weir 2 O ^e formed as a narrow annular gap between the inner wall of the column 2 and tray 4, which is for instance of sheet metal. This first overflow 2 passes directly into the second overflow 6, but could be separated from it by a wider or narrower intermediate web. The tray 6 is fixed in column 1 by struts, angles or similar parts (not shown).

The tray 4, also shown in plan view in FIG. 5, has a first overflow which is positioned opposite and separated from the second larger overflow 6. This embodiment is generally more preferred than the structure of Fig. 5a. Optionally, additional openings, slits 12 or the like may be provided in the region adjacent to the first overflow 2.

The method according to the invention, which has been explained above by means of countercurrent washing and extraction, and which serves for the continuous mass transfer between heterogeneous systems, can be used advantageously wherever the mass transfer processes associated with possibly heat exchange are to be carried out with minimal redispersion. , the highest operational stability, the lowest amount of countercurrent and / or strongly fluctuating mass flows.

In order to further explain the method of the invention, several experimental examples are given below.

Example 1

System: · apparatus: floors:

supplied:

paid:

dimethyl terephthalate / filtrate-methanoO;

glass column, diameter 225 mm, height 4 000 mm, cross-section 395 cm ² ;

slant of the trays, the distance between the trays, measured between the same points, · 240 mm, inclination to the horizontal plane of 40 °; a flow cross section of the first overflow of about 16 cm 2; flow cross section druyéyo overflow 154 cm ² ;

320 1 / У suspension contains 300 g dimethyllephthalateUlite filtrate,

350 1 / met methanol;

290 1 / susp of a suspension containing 350 g of diethyl terephthalt per liter of methanol and 380 1 / roztoku of a solution of the filtrate in methanol;

Acid number: feed product 1,8 product (washed with dimethyl leephthalate)

0.6; The acid number is a measure of the purity of dimethylleephthalate and indicates how many milligrams of potassium yydroxide is required to neutralize the dim. 1 g product flow.

By way of comparison, the acid value of the same product fed after the usual complex double blasting, with mee-anol of the same purity as in the example, being added, is 0.4. The process according to the invention thus produces a substantially pure product in a substantially simpler manner.

Example 2

System: apparatus: Diimtrylfreffiltfilttaltetolol; Vanadium steel column, · diameter 900 mm, height 5 000 mm, cross-section 6 360 cm ² ; floors: 8 inclined floors, distance between the same points 450 mm, inclination to the horizontal plane 30 ^o ; a flow cross section of the first overflow of about 90 cm ² ; flow cross section druyéyo overflow 278 cm ² ; supplied: 6,000 1 / y suspension with 300 g of di-ethyl-terephthalate Ullte filtrate, 4800 l / y of methanol; paid: 5 500 l / y suspension with 330 g of diethyl ether, 5300 l / y of a filtrate solution in methanol. kyseeosti number: fed inlet 1.2, fed product 0.15.

She said d 3

The pad system and equipment were ^{2 1} 9 ⁰ cm ² and the trays were the same as in Example 2, except that the flow cross section of the second Inbound: 5 000 1 / Ά suspension with 300 g of dimethyl terephthalt per liter of filtrate, 550 1 / met methanol. paid: 4,500 l / y suspension with 350 g of dimethyl tertiaryl per liter of methanol, 6000 L / y solution of the filtrate in methanol; Acid number: product feed 1.18, product feed 0.21, Compared to the numbers ee o s bi · od Example 2, as a result of the standardly selected overflow at a higher tabulated product, the consumption of methanol is much higher. _t

Example 4 System: glass beads in polluted water-water, median ball diameter < 0.15 mm. apparatus: floors: ^KL en ^of n ^{and k} Olona Rumer ^P 40 mm, height 1000 ^mm, ma ^ of ^12.6 cm ^2; 10 SJ ^ kmý.cy floors stejnolehlými distance between points 35 mm, inclination ^{to the} horizontal ^of Equation 3 ^and n ^{0 p p} r růtočný ^{ur P} ez RVN RX ^iy ^ and ^ u, and ^{a 0.5-cm2} flow cross-section druyéyo overflow 2.95 cm ² ; supplied: 100 1 / y suspension with 150 g of goblet of polluted water, 120 1 / y.washing water. -

100 l / h of suspension with 150 g of glass beads / liter of water, 120 l / h of contaminated water. .

Example 5,

The system and equipment were the same as in Example 4. _ч

Floors: 10 sloping floors, the distance between the equal points 55 n, tilt to the horizontal plane 50 °, flow cross section of the first overflow approx 0.6 cm ² , the second flow cross section at ^p beet ^{d 2 4} cm ^2; supplied: 100 l / h suspension with 100 g glass CujičeeClitr polluted water, 105 1 / h wash water. paid: 100 1 / h suspension with 100 g glass beads of water, 105 1 / h and purified water.

SUBJECT OF THE INVENTION

Claims (9)

A method of mass transfer between heterogeneous column systems. with at least one tray provided with first and second overflows into which a heavier mass stream is introduced from above, and a lighter mass stream which is vortexed in the mixing zone whilst the heavier phase, suspension, is enriched above the second overflow and at least one of The mass flows flow continuously through the column, characterized in that the continuous mass flow is a liquid, the heavier mass flow flows between the first overflow region and the second overflow region from top to bottom and turns into a circular or elliptical swirl motion above that level. the mass flow flowing from bottom to top through the first overflow is swirled and mixed with a heavier mass stream, wherein the heavier phase or suspension in the mixing zone is enriched above the second overflow in the mixing zone and current :! this second dispute. dropping from top to bottom into the space below the palate at such a rate that the heavier mass stream turns into another circular elliptical or swirling motion, into which a lighter mass stream is supplied from below. 2. A method according to claim 1 with a column divided into several stages by at least two spaced apart trays, characterized in that the mass flows are successively rotated in rotational steps of opposite direction of rotation. . 3. The process of claims 1 and 2, wherein a particulate solid phase is removed from the bottom of the column, characterized in that liquid is introduced into the bottom of the column to release the solid phase. ’ 4. Apparatus for carrying out the method according to any one of item] *. to 3, wherein the mass transfer column has at least one tray, characterized in that the tray (4) overlying the flow cross-section of the column (1) is provided at the edge with a first overflow (5) and a second overflow (6), A reversing device is disposed about the first overflow (5). Device according to claim 4, characterized in that the first overflow (5) has a smaller flow cross section; than the second overflow (6). Device according to claim 4 or 5, characterized in that, in successive trays (4), the overflows (5, 6) of the same kind are offset from one another and preferably lie opposite one another. Device according to one of Claims 4 to 6, characterized in that the tray (4) is arranged horizontally and the inverting device consists of a guide plate (7), a guide plate or an embossment extending from the outer edge (9) of the column (1). , it lies obliquely and is located above the tray (4), omitting the slot (11) between its inner edge (10) and the tray (4). Device according to one of Claims 4 to 6, characterized in that the floor. (4) is inclined to the longitudinal axis (13) of the column (1) and its upper section (14) at the same time forms a reversing device. Device according to claim 8, characterized in that the tray (4) has, in addition to the first overflow (5) in the area adjacent to the first tray (5), further openings, slits (12).