DD147402A5 - METHOD AND APPARATUS FOR DRYING PRODUCTS - Google Patents

Abstract

A process and apparatus for drying products by means of a gas stream passing the product with the aim of removing moisture therefrom and a contacting device which produces at least one dehumidifying liquid layer near the product to be dried, this liquid layer emitting moisture removed from the gas. D. Gas stream is bubbled through a substantially horizontal liquid layer or may flow through between liquid film conduit members. The dehumidifying liquid is continuously regenerated. By using several partial gas streams and a contacting device having several separate liquid film aggregates, countercurrent drying is possible. The product to be dried can be replaced by d. Dehumidifying liquid is heated to a predetermined temperature via the drying gas stream.

Description

Process and installation for drying products

Field of application of the invention:

The present invention relates to a process and apparatus for drying products by means of a closed gas stream and a dehumidifying (adsorbing) liquid which reduces the moisture content of the gas stream *

Characteristic of the known technical solutions:

A known process for drying products is to bring the material to be dried into direct contact with any gas, which is in most cases air which is unsaturated with moisture. "By this treatment, the material dries, while the gas is more and more saturated with liquid. Drying systems currently in use, especially those used to dry a relatively large volume of product, usually dry by means of heated, low relative humidity air which is released into the atmosphere after drying. This drying by means of an open gas flow implies a considerable loss of heat energy; and it is also not a satisfactory solution because the products to be dried are in some cases heat-sensitive and the process may also be detrimental due to air pollution.

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In fact, the intolerance of special products (medicines, gelatin, food, etc.) was the reason why drying with low-temperature gas (for example, from room temperature or below this temperature) became necessary. The low relative moisture content of the gas with a low temperature, which is a prerequisite for the effective drying of these kinds of products can v / ground, achieved by reducing the absolute moisture content of the gas. For this reason, it has been proposed, for example, in US Pat. No. 3,257,737, that the drying gas should be contacted with solid adsorbents which extract the moisture content of the gas. "It has also been proposed, for example, in AT-PS No. 317,857 and in British Patent No. 1,152,440 - to use dehumidifying liquids (hygroscopic liquids), such as an aqueous solution of lithium chloride or ethylene glycol, to extract moisture from a gas. A continuous regeneration of the drying gas carried out in this manner also allows the use of a closed gas flow. In the proposed solutions in which a dehumidifying liquid is used, this liquid is brought into contact with the gas stream in sprayed or atomized form; and the liquid particles entrained by the gas flow are retained by a liquid separator. From the point of view of energy balance, such a system is theoretically more advantageous than the heated air system; essentially because the heat loss resulting from the release of air into the atmosphere is avoided. However, closed gas circulation systems have so far been used only in the case of particular drying problems; and the non-occluded air flow method using heated air was used when

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always this was possible with regard to the properties of the products to be dried. The reason for this is to be found in the fact that the conventional embodiment of dry gas circulating dryers requires high investment costs, that the circulation of a very large amount of gas is extremely energy consuming and that the dehumidifying liquid used for regeneration is expensive; so that the two latter factors result in high ongoing operating costs.

Object of the invention:

The main object of the invention is to provide a closed gas flow drying device which is more advantageous than the previous closed gas flow drying devices from the point of view of cost and which can successfully compete with the known non-closed air flow dryers even if to dry a large amount of produce is.

Explanation of the essence of the invention:

The invention is based on the following basic considerations:

(1) The contact between the gas stream and the dehumidifying liquid should not be effected by spraying or atomizing the liquid, but by means of a gas / liquid contacting device inserted in the path of the gas stream, which allows the previously practiced separation of To eliminate drying traction and regeneration space.

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(2) In a closed air circulation system, the amount of air to be used for a particular purpose is a multiple of the amount of air used in an open system. For this reason, the gas contacting device using dehumidifying liquid and the product to be dried must be arranged close to each other and in such a manner that the air flow in the course of circulation undergoes the least possible change in speed and direction.

(3) The aim must not be to allow it to be dried by means of a gas stream of low temperature but at a temperature as high as the characteristics of the product to be dried permit. In order to achieve this, it is favorable to heat the circulated gas flow through the dehumidifying liquid.

(4) When the dehumidifying liquid is regenerated, the heat of vaporization of the vapor withdrawn from the liquid must be returned to the liquid to be regenerated; and this also applies with regard to the heating required during the regeneration process.

(5) The dehumidifying liquid / gas contacting device must be designed so that it can also be constructed on the modular principle, and allow the application of the known countercurrent principle in the drying of continuously moving products.

Thus, an object of the invention is a process for drying products by means of a closed gas stream and a dehumidifying liquid, the following

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ing process steps are carried out: introduction of the Epzeugnisses to be dried in a drying room; continuously circulating a stream of drying gas in such a manner as to cause it to pass through the product to be dried; Contacting (drying) the drying gas stream with a dehumidifying liquid to remove moisture from the gas; and regenerating the dehumidifying liquid by circulating at least a portion thereof through regeneration means which deprive it of moisture. The essence of this method is that at least one layer of dehumidifying liquid is formed in the vicinity of the product in the drying room and that the drying gas stream is brought into contact with said at least one dehumidifying liquid layer.

The use of a liquid layer according to the invention is advantageous from several points of view. First, it eliminates the liquid separator used in the known systems; At the same time it basically excludes the pollution of the gas stream by the liquid droplets, and thus also reduces the loss of dehumidifying liquid. Second, the mass transfer coefficient between the liquid and the gas is more favorable here than in the case of liquid particles; and this fact allows a more compact design resulting in a lower pressure drop of the gas flow. Third, no separate from the drying room contacting space is required; the liquid layer can be built quite close to the product to be dried. Another advantage is that the formation of a liquid layer is by far not as difficult an operation as the known from previous solutions spraying, since the risk of constipation much ge

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ringer is / and therefore the need for maintenance. This latter factor is of particular importance, since the gas flow in addition to moisture often dust and other impurities carries into the dehumidifying liquid / through which the openings in the spray nozzles are clogged »

An advantageous embodiment of the method according to the invention is to produce a substantially horizontal dehumidifying liquid and / or to let the gas flow through this horizontal liquid layer. In this way it is possible / dry bulk materials that are transported for example on a conveyor belt / runs below or above the horizontal liquid layer.

In another exceptionally advantageous embodiment of the method, at least one dehumidifying liquid layer is produced by allowing the dehumidifying liquid to flow over liquid film conducting elements; and said contacting is effected by causing said drying gas flow to flow between said liquid film conduit members. The liquid film conductor elements can be used to produce a curtain-like arrangement / which can, for example, delimit the drying space.

Another subject of the invention is a process for product drying in which the following process steps are carried out: introduction of the product to be dried into a drying room; continuously circulating a stream of drying gas in such a manner that it causes the product to be dried

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happen; Contacting the drying gas stream with a dehumidifying liquid to remove moisture from the gas; and regeneration of the dehumidifying liquid / by circulating at least a portion thereof through regeneration means which deprive it of moisture. The essence of this method is that a heat exchange between the dehumidifying liquid and the product to be dried is effected in such a way that the heat is transferred by the drying gas flow between the dehumidifying liquid and the product to be dried.

It is expedient to increase the temperature of the dehumidifying liquid during the regeneration to such an extent that during the contacting of the dehumidifying liquid with the drying gas flow, the temperature of the gas is increased to a predetermined temperature, preferably above 40 C, in order to produce the product in the to heat required dimensions. This method offers the possibility of reducing the amount and flow rate of the gas to be circulated, since the amount of moisture extractable with one kilogram of air increases at a higher temperature, and allows effective recovery of the heat of vaporization of the dehumidifying liquid discharged in the course of regeneration Steam in the dehumidifying liquid to be regenerated. Another advantage is the elimination of the cooling that has been used in the previously known gas / liquid contactors. This results in a simpler structural design of the gas / liquid contacting device.

According to a specific embodiment of this method, the dehumidifying liquid is a dehumidifying solution; the regeneration is done by evaporation of the

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Entfeuchtungsniittellösung and the steam emitted by the dehumidifier solution is at least partially condensed by the Entfeuchtungsniittellösung to be regenerated. This allows a very economical regeneration _/ in the course of which the energy requirement of the regeneration can be largely reduced by using a multiple boiling or a multi-stage flash evaporation. Compared with the earlier solutions, in which the heat of vaporization of the steam discharged is used to heat the air whose purpose is to pre-dry the product, it has an advantage that the vapor condensation by means of a liquid requires a smaller and cheaper device than that Air working.

It is expedient to boil the dehumidifier solution to be regenerated with the steam released from the solution during the regeneration. The energy requirement can be reduced by concentrating the dehumidifier solution by multiple boiling and using the feed solution that is to be vaporized to at least partially condense the vapor released during the first or last regeneration process of regeneration.

The regeneration can be carried out by heating the dehumidifying agent solution to be regenerated with the steam released from the solution without boiling the dehumidifying agent solution. In this case, it is particularly advantageous to regenerate the dehumidifier solution with the aid of a multi-stage flash dilution.

According to a very advantageous embodiment of the

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According to the present invention, the dehumidifying solution is to be cooled before regeneration depending on the cooling of the dehumidifying solution in the course of the drying process, so that the dehumidifying solution to be regenerated is at a predetermined temperature. The cooling proposed herein is of critical importance to the control of the dehumidification solution circuit and is provided as a supplement to the cooling which occurs in the dehumidifier solution in contact with the drying gas stream. The degree of cooling, for example, must be changed according to the season. The cooling is preferably carried out during the regeneration.

According to another advantageous embodiment of the method, the continuous circulation of the drying gas stream is carried out by passing the drying gas stream on a VVegabschnitt between the product to be dried and the dehumidifying liquid so that on this VVegabschnitt the ratio of maximum and minimum flow rate of the drying gas flow is less than five to is one and the change in the flow direction of the drying gas flow is less than thirty degrees. This procedure results in a relatively small demand for ventilation performance; and this is an important point in terms of the economics of the entire drying procedure. The ventilation performance can be further reduced if the drying gas flow between the product to be dried and the dehumidifying liquid can be conducted with virtually no change in flow rate and flow means.

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It is convenient to use air as a drying gas and an aqueous solution of potassium chloride as a dehumidifying solution. The calcium chloride solution is particularly advantageous because of its low price. The method according to the present invention is applicable not only to the removal of moisture in the form of water. but also for the drying of materials / containing other forms of moisture; provided that a suitable dehumidifying liquid is used. For example, it is possible to use the present process according to this invention for the drying of materials / containing alcoholic moisture components using a closed air stream and gasoline as a dehumidifying liquid.

According to a further embodiment of the method, the drying gas stream consists of at least two parallel partial gas streams / wherein the product to be dried is moved transversely to these partial gas streams and each of said partial gas streams is brought into contact with a dewatering liquid of specific concentration and temperature. In this way, the Trocknungsprograrnm for the product to be dried can be varied greatly. Thus, according to a highly expedient embodiment of the process, for example, each of said partial gas streams is contacted with a dehumidifying liquid / which is more concentrated than the dehumidifying liquid brought into contact with the previous partial gas flow, based on the direction of movement of the product to be dried. This results in an opposite flow between the product to be dried and the dehumidifying liquid,

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The method according to the invention can also be applied _/ by creating at least two separate groups of dehumidifying liquid films of different concentration and connecting these groups of dehumidifying liquid films side by side in the flow path of said partial gas streams, contacting each of said gas streams with at least one distinct group of dehumidifying liquid films It is an advantageous application in which each of the said groups of dehumidifying fluid films is provided with its own fluid circulation, the fluid circulation of the last group being fed with the regenerated dehumidifying fluid, which depends on the direction of movement of the product to be dried the said regeneration means comes; the circulation of each preceding group is fed with the upper course of the subsequent group and the overflow of the circulation of the first group is supplied to said regeneration means. In this way, an opposite movement between the dehumidifying liquid and the product to be dried is achieved.

It is also possible to guide the product to be dried in a direction of movement transverse to the partial gas streams and to change the temperature of the product in a prescribed manner by separately controlling the temperature of the dehumidifying liquid in each individual group of dehumidifying liquid films. In this way, the drying temperature can be easily programmed for each phase of drying even in the case of continuous drying.

Another object of the invention is a system for drying products by means of a closed

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Gas stream and a dehumidifying liquid / the plant having at least one drying room for the product to be dried; at least one contacting device for bringing a drying gas stream into contact with a dehumidifying liquid with the aim of removing moisture from the gas; Gas line elements for guiding the drying gas flow on a substantially closed path through said drying space and said contacting device; Gas Umwälzungseinrichtungen / whose task is to cause the drying gas flow for circulation in the said closed way; Regeneration means for removing moisture from the dehumidifying liquid; and fluid circulation means for circulating at least a portion of the dehumidifying fluid through said regenerating means and said contacting means. The plant is characterized in that said contacting means includes elements for the production of at least one layer of the dehumidifying liquid to be contacted with the drying gas stream, which at least one dehumidifying liquid layer is located in the vicinity of the product located in said drying space.

In one embodiment of the system according to the invention, the contacting device includes a container for forming a substantially horizontal dehumidifying liquid layer, this container being provided on its wall with bells for bubbling the drying gas flow through the known liquid layer; said receptacle is connected to said fluid circulation means so as to cause the dehumidifying fluid to flow along said receptacle; and said drying space above

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is arranged halfway or below said container. Preferably, the drying room includes means for transporting the product to be dried through said drying space / said means being provided with openings / for passing the drying gas stream / without dropping the product to be dried «Advantageously the transport means is an endless conveyor belt / and said gas recirculation means are fans / arranged side by side along said conveyor belt.

According to another embodiment of the system, the contacting device comprises liquid film line elements / which are arranged so that the drying gas flow flows through between these liquid film line elements. A high degree of operational safety and a simple structural design can be achieved if the contacting further a container for receiving the inflowing dehumidifying liquid; at least one lock to bring the liquid in film form from said container; Liquid distribution elements having at least one distribution surface which is connected to the at least one lock and directed downwards; and liquid discharge elements, said film-line elements being connected between said liquid distribution surface and said liquid discharge elements, so as to direct liquid films of said surface into said outlet elements. This embodiment is not very sensitive to the fouling that could flow from the drying gas stream into the dehumidifying liquid. It is convenient / the liquid film line elements - preferably

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Strip or fiber structures - to be arranged in at least one substantially vertical plane. The heat and mass transfer between the dehumidifying liquid films formed on the thin fiber structures and the drying gas flow is excellent. The strip or fibrous structures may be made of a metal which is resistant to the dehumidifying liquid or of a plastic material which can withstand the highest possible temperature of the dehumidifying liquid.

A possible embodiment of the drying plant according to the invention is applicable for products such as wood "This embodiment comprises a basement hallway, a shell roof, and an intermediate roof, provided with openings for the passage of the drying gas stream and located between said basement corridor and-called shell roof, wherein said drying chamber located between the basement floor and the intermediate roof; said gas recirculation means are fans which are housed between the intermediate roof and the shell roof; and said contacting means is disposed on said drying space such that said at least one vertical plane formed by said liquid film conduit elements is substantially perpendicular to the drying gas flow and extends between said lower floor corridor and said intermediate roof. Gas contacting arranged on a boundary surface or a cross-sectional area of the drying space, said boundary surface or cross-sectional area extending substantially perpendicular to the flow direction of the gas stream. This arrangement ensures that the gas flow experiences only a small pressure drop, resulting in a

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Low energy consumption due to ventilation results.

A very advantageous embodiment of the plant according to the present invention is / in which the contacting device consists of at least two juxtaposed liquid film aggregates / wherein each liquid film aggregate has its own liquid film conduit elements and its own fluid circulation means which provide a liquid circulation for the formation of the liquid filaments on said own conduit components and said fluid filtration units are provided with a common fluid passage interconnecting said fluid circulation means, said common fluid passage being connected to said fluid circulation means. In this way, only one regeneration device belongs to the system, and yet each liquid film unit is supplied with a dehumidifying liquid whose activity differs from that of the others.

According to a further embodiment, the ratio of any two flow cross sections of said gas duct elements between said drying space and said contacting means is between 0.2 and 5; and said contacting means is disposed on said drying space such that the flow of drying gas flows between the product to be dried and said contacting means with a direction change of less than thirty degrees. It is very advantageous / when said flow cross-section ratio is between 0/5 and 2 / said flow direction change

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is practically zero degrees and the distance between said drying space and said contacting device is smaller than the hydraulic diameter of said gas line element between them.

According to a highly economical embodiment of the plant, the dehumidifying solution regenerating means comprise a multi-evaporator or a multi-stage depressurizer, the latter being more advantageous from the aspect of its simple operation. This embodiment ensures very economical regeneration also from the point of view of energy consumption.

A further subject of the present invention is as an article of manufacture - the product treated according to the present method.

For us, but not all ;

Further details of the invention will be described with reference to the accompanying drawings. Show it:

£ JLSÜ ^r »_lJL a schematic representation of a first embodiment of a drying plant according to the invention; ·

Figure 2 is a sectional view of a second embodiment of the drying plant, taken along the line B - B in Figure 4;

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Fi gur 3; another sectional view of the second embodiment, taken along the line AA in Figure 4;

p, 4: a plan view of the second embodiment shown in Figure 2 and Figure 3 of the drying unit /;

For 5; a sectional view in perspective of a third embodiment of the drying plant;

a sectional top view of the third Ausführungsforiii, taken along the line C - C in Figure 5;

Figure 7: a

Circuit diagram of the dehumidifying liquid keitsregenerators the second embodiment / shown in Figures 2 to 4;

Figure, 6 and

Figure 9 : Circuit diagrams of two other dehumidifying liquid regenerators / suitable for use in the drying plant according to the invention;

Figure 10; a circuit diagram of a multi-stage flash evaporator S / which is suitable for use as a dehumidifying liquid regenerator in the drying plant according to the invention.

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Like reference numerals refer to the same or similar elements throughout the drawings.

In the figure 1, an outer structure 42 of a drying plant is shown schematically. In the system for circulating a gas stream, such as an air flow / dries the product 50 - for example, bulk, as shown in the figure - in a closed circuit in the direction of arrow 64. Circulation is effected by a fan 66, which is driven by an electric motor 46 which is disposed above an intermediate roof 54, which is shown in the figure schematically and without its brackets and fasteners. The intermediate roof 54 is provided with openings 47 through which the air flow can flow. The product 50 is located in a drying room 40 under the intermediate roof 54. After the air flow has passed the product 50, the now moist air flow passes into a contacting device 43, whereby the air flow is brought into contact with liquid films 41 of a dehumidifying liquid. The dehumidifying liquid is circulated by a pump 141 in a regeneration device 150. The active and hot dehumidifying liquid enters the contacting device 43 from a pipe 44 arranged above it; she gets into a cup-shaped receptacle 55; and from here via a sluice 56 to a downwardly directed liquid distribution surface 57. From the liquid distribution surface 57, the dehumidifying liquid passes downwardly directed liquid supply line elements 58 - for example fibrous structures -; and these elements direct the dehumidifying liquid to a liquid outlet channel 62 from which it exits through a conduit 45.

The thinning due to the contact with the air flow

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The regenerating device 150 shown in the drawing as an example comprises a multi-stage flash evaporator 151, a liquid circulating pump 14I _7, a pump 142 for discharging the distillate of the multi-stage flash evaporator 151 through one Pipe connection 149 / and a Wärmeaustauscher.143 / which is supplied through pipe connections 144 with cooling water. The cooling in the heat exchanger 143 is essential for making appropriate operation of the multi-stage Entspannungsverdompfers 151. The active liquid leaving the regeneration means 150 / heated / when it passes through the condenser 145 / and then passes back to the contacting device 43. The condenser 145 is a pipe connection 146 supplied with heating steam, while the condensate is discharged by means of a pump 147 through a pipe connection 143. The elements of the regeneration device 150 and the heating after the regeneration are known as such, so that a detailed description of the same is not required.

The embodiment according to Figure 1 is particularly advantageous when drying products with high heat tolerance / such as bricks; With this arrangement, since the temperature of the dehumidifying liquid returned from the contactor 43 and "cooled" there is still high enough to eliminate the moisture during the flash evaporation process.

The use of the multi-stage flash evaporator 151 / as shown in Figure 1 / in the plant according to the invention is particularly advantageous because it is under the

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Regarding the control, the operation and the reliability is more favorable than other tviefachverdarapfer with the same energy efficiency. The evaporation does not take place along the walls of the intestine, so that the multi-stage flash evaporator is less susceptible to encrustation and corrosion; and its constructive structure does not become complicated even if the degree of energy utilization is improved. Of course, a known as such evaporator other design or construction can also be used for regeneration.

Economically very advantageous is equally the application of the contacting device 43 shown in Figure 1 in the system according to the invention. This construction is not sensitive to the pollution that enters the liquid from the air stream; and it ensures that the contact of contact between the liquid and the air stream is characterized by a good heat and mass transfer coefficient.

In the plant according to the invention, the structural design of the Tro, cknungsraumes and the spatial arrangement of the product to be dried 50 in many forms (hanging, with fluidized bed, continuous heating, chamber or tunnel arrangement or somehow different). The product may be agitated during the drying process, and the drying gas may flow the products in counter-rotating, transverse or rectified flow directions.

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Figures 2, 3 and 4 show an embodiment of the drying plant according to the invention _/ which is operated with a iia essentially moving in the horizontal direction liquid layer 1 and with a above the liquid layer and also in the horizontal direction moving product 2. The product 2, for example, soybeans, passes through a funnel-like component 3 on a transport device, which is shown in the drawing as a belt conveyor. The conveyor belt 4 has air passage openings 5 which allow the air to pass while preventing the product 2 from falling down. The conveyor belt 4 is guided by two rollers 6, which are designed to tension and drive the conveyor belt. For this purpose, they can be stranded, for example, with serrations or rubber coating. One of the rollers 6 is driven by an electric motor 8 via a drive gear 7. The conveyor belt 4 of the belt conveyor transports the product from its hopper-like member 3 through the drying space 25 located in an external structure 9 of the drying plant, and then through the passage 10 to a hopper 11, from v / o the dried product by means of a belt conveyor or a drum, which are not shown in the figure, is transported to the storage or use location. The empty strand of the belt conveyor runs below the outer structure. 9

The lower part of the outer structure 9 comprises a lower air collecting space 12 below the conveying run of the belt conveyor; and above this air-collecting space 12, but below the conveying run of the belt conveyor, there is a liquid container 13. In the liquid container 13, a dehumidifying liquid flows in the direction of the arrow 14, that is, opposite to the direction of movement of the product 2, which is in the flow direction.

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tion of the arrow 15 moves. Above the conveying strand of the belt conveyor, enclosed by the upper part of the outer structure 9, there is an upper air collecting space 16. Four fans, 17 A, 17 B, 17 C and 17 D, which by the electric motors 23 A, 23 B, 23 C and 23 D driven suck the air through suction ports 22 A, 22 B, 22 C and 22 ü from the upper Luftauffangraura 16 and push them through pressure pipes 13 A, 18 B, 18 C and 18 D and through openings 19 A, 19 From here, the air bubbles through Einperlglocken 20, which are located in the wall of the liquid container 13 - one of the Einperlglocken 20 is shown in Figure 2 in an enlarged form - in the Direction of the arrow 21 in the dehumidifying liquid layer 1 a; then passes, by exiting through the openings 5 of the conveyor belt from aer liquid layer 1, in the layer formed by the product to be dried 2 and, after having passed this layer, back into the upper air-collecting space 16; so that in this way results in a closed air circulation. The liquid container 13, which is equipped with Einperlglocken 20, acts in this embodiment as a contacting device 43, which makes contact between the air flow and the dehumidifying liquid.

The four fans 17 A, 17 B, 17 C and 17 D cause four partial air streams, which are circulated in a closed circuit. The first partial air flow passes through the suction port 22 D and meets the entering into the plant moist product 2. The second partial air flow flows through the suction port 22 C, the third through the suction port 22 B, the fourth through the suction port 22 A; and this last partial stream of air escapes

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Produce 2 the last part of the., .. au extracting moisture. The dehumidifying liquid passes into the liquid container 13 through the pipe connection piece 26 and leaves the liquid container 13 through the pipe connection piece 27. The incoming hot and active liquid is bubbled by the air of the last partial air flow, while leaving the liquid container, cooled and diluted liquid from the first partial Airflow is bubbled through.

The use of several partial air flows, which are caused by the use of multiple fans, 17 A, 17 B, 17 G and 17 D, is advantageous not only in terms of flow conditions, but also because in this way a countercurrent drying is ensured in which the product 2 and the dehumidifying liquid 1 move in opposite directions. Obviously, if there were only a single stream of air circulated by a fan, there would be no countercurrent drying, although the product 2 and the dehumidifying liquid 1 moved in opposite directions. The countercurrent drying effect would be optimal if there were an infinite number of partial air streams circulating side by side. From this point of view, it is expedient to use as many partial air streams as possible in the drying according to the invention.

It can be seen from FIGS. 2 to 4 that the drying space 25 and the contacting device 43 are arranged directly above one another and, as it were, form two "floors" within the outer structure 9.

Another embodiment of the same type and arrangement / but different from the embodiment shown in Figures 2 to 4, characterized in that the liquid container 13 is housed above the conveying strand of the belt conveyor. This is advantageous when the product 2 also contains particles small enough to fall into the liquid container 13 through openings 5 of the conveyor belt 4 and thus contaminate the dehumidifying liquid to a detrimental extent. "In such an embodiment, it flows through the openings 19 A, 19 B, 19 C and 19 D air flow first the product 2, and then penetrates the liquid layer 1 "Another advantage of this embodiment is that particles of .Product 2, which have fallen through the openings 5 of the conveyor belt 4 , collected on the bottom of the outer structure 9 and can be discharged from there as a dried product either from time to time or continuously. It is also advantageous that liquid droplets that might have been entrained by the air flow from the liquid layer 1, not get to the product 2, but after passing oer fans 17 A, 17 B, 17 C and 17 D in receptacles or Channels can be collected on the lower side of the tubes 18 A, 18 B, 18 C and 18 D and can be returned from there into the fluid circuit.

In the embodiment shown in Figures 2 to 4, the contamination, which has passed through the openings 5 from the product 2 into the liquid layer 1, for example, be removed by means of a separation vessel , aer as such is sufficiently known and in the dehumidifying liquid circulation preferably behind the piping connection 27 and, for example, in such a way that the liquid

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speed, which flows into the separation tank _# can only escape through openings, which, based on the full height of the liquid level in the separation vessel / are arranged at half the height. Of course, the separation tank must be cleaned in a suitable manner; the liquid must be defoamed / and deposited solids must be removed.

The diluted dehumidifying liquid - in this embodiment, it is a dehumidifying solution - enters the regeneration device. In the case of the embodiment shown in FIGS. 3 and 4, this is a solution condensation device consisting of a liquid circulation pump 28; a steam condenser 29 which is cooled by the inflowing dilute solution; a pump 30 for the discharge of the distillate; a steam-heated evaporator 31 and a pump 36 is. The pump 28 pumps the dilute solution as a cooling medium through the condenser 29; from where the solution passes through the pipe 32 into the evaporator 31. The evaporator 31 is heated by steam, which is supplied through the pipe connection 33, while the condensate of the heating steam is discharged through the pipe connection 34. The vapor released from the solution passes from the evaporator 31 through a pipe 35 into the condenser 29; There it is condensed, and the distillate is removed by means of the pump 30. The design of the pump 30 is such that it is capable of removing non-condensable gases together with the distillate. From the evaporator 31, the condensed, active solution is pumped by a pump 36 through a conduit 24 to the pipe connection 26, through which the solution passes back into the liquid container 13. This dehumidifying solution regenerating means becomes the purpose

further clarified by the Kreislaufdiagramrn in Figure 7 illustrates.

In the interests of illustrative presentation, Figures 2 to 4 show an evaporator of the simplest possible embodiment, in which only the inflowing solution to be regenerated is used as the cooling medium for the condensation of the steam which is evaporated from the solution during regeneration. However, according to the invention, in practical applications it is more convenient to use instead a multiple evaporator whose degree of energy efficiency is higher, and as shown for example in Figures 8 or 9, or a Kiehrstufen-Entspannungsverdanipfer, as shown for example in Figures 1 or 10 becomes"

Of course, instead of the belt conveyor as well as another transport device can be used; and the product 2 can be guided not only horizontally but also on an inclined path through the drying space 25. The cross-section of the liquid container 13 is much larger than that of the pipe connections 26 and 27. For this reason, it is expedient to ensure a uniform course of flow , The dehumidifier solution not only through a single inlet and a single outlet pipe connection to flow into the liquid container 13 or to flow out of this, but by many such pipe connections, which are distributed over the width of the liquid container 13.

FIGS. 5 and 6 show another embodiment,

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which operates with a horizontally moving product 50 and a contacting device 43 arranged adjacent to the product 50, which produces a vertically extending liquid film 41 of a dehumidifying liquid.

The product. 50 - in the drawing it is cut wood - is placed on trolleys 51, which are provided with wheels, which are mounted in bearings on the axis 52, and moves on the basement floor 49 very slowly in the direction of the arrow 53rd forward. Above the product 50, the drying room 40 is completed by an intermediate roof 54.

The entire drying plant finds its upper closure by a shell roof 65, with which the intermediate roof 54 is connected via suspension supports 65 A. The shell roof structure 65 is completed on both sides by walls 37 and 38, respectively; the walls are with doors

39 for the passage of the product 50 strand. The air flow circulates in the direction of the arrows 64 as a result of the function of the fans 66 and 66 'which are driven by the electric motors 46 and 46' installed in a partition 69, respectively. After exiting the fans 66 and 66 ', the air flow passes through the space between the shell roof 65 and the intermediate roof 54, and then enters the drying space through an opening 47 in the intermediate roof 54

40 between the basement floor 49 and the intermediate roof 54 a. From here, the air flow reaches liquid films 41, which are formed by the contacting device 43; and then flows through another opening, 47 A, between the shell roof 65 and the intermediate roof 54 back to the fans 66 and 66 '. As shown

- 28 - 917168

Embodiment with two fans 66 and 66 ', equipped, in this case, two parallel partial air flows are generated.

The contacting device 43 in this embodiment, as shown in Figures 5 and 6, consists of three liquid film aggregates, 48 A ₇ 48 B and 48 C, which are arranged directly adjacent Oedes single aggregate hat.eine own fluid circulation / and all units have one common lower Flüssigkeitsauslaßkanal 62 / through which they are connected to a regeneration device, which is not shown here, via the pipe connection piece 67 and 68. The hot dehumidifying liquid coming from the regenerating means enters through the pipe fitting 67, then becomes more and more diluted by circulation in the liquid film aggregates 48A, 48B and 48C, passing the channel 62 in the direction of the arrow 63, and then passes then through the pipe connection piece 68 into the regeneration device,

The regeneration means may be similar to those regenerators shown in Figure 1 or Figure 4; but also suitable are multiple evaporators, as shown in Figures 8 and 9; and also the multi-stage flash evaporator according to FIG. 10 »

The liquid film aggregates 48 A, 48 B and 48 C are similarly constructed. "For this reason, only the liquid film aggregate 48 A is described here. An upper receptacle 55 A is below the intermediate roof

- ₂₉ - 2171

54 and is limited by a lock 56 A. With the liquid lock 56 A is a downwardly directed Flüssigkeitsverteilungsf pool 57 A connected. From the liquid distribution surface 57 A lead liquid film line elements 58 A down - for example, fiber structures / as shown in the drawing. Along the peripheral surface of each of the Flüssigkeitsfilnileitungselemente 58 A forms a liquid film; and all the liquid handling elements 58A to / together form the liquid film aggregate 48A, the characteristic feature of which is that all the liquid pipe conduits within the group pass a dehumidifying liquid of the same concentration.The liquid film line elements 58A extend A suction pipe 59 A is attached to the lower side of the channel 62 and supplies the dehumidifying liquid in this way to a liquid circulation pump 60 A. The liquid circulation pump 60 A conveys the liquid through a pipe 61 A into the tank upper receptacle 55 A, from where the liquid 'passes through the liquid lock 56 A to the Flüssigkeitsverteiluncjsfläche 57 A and then, along the liquid film line elements 58 A ₁ in the lower collection channel 62.

The upper receptacle 55 A is separated from the upper receptacle of the adjacent Flüssigkeitsfilmagqregats 43 B; the common lower channel 62, however, offers the possibility that the fluid circuits belonging to the pipelines 61A, 61B and 61C deliver liquid to one another via this channel. The sections of the lower channel 62, which belong to the liquid film aggregates 48 A, 48 B and 48 C, are separated by Trennelemen-

te 162 separated from each _/ which are provided with openings _# so that the liquid stream is always flowing in the direction of arrow 63 / without a backward acting .Mischungseffekt occurs "Starting in the direction of arrow 63, the first liquid circuit / the first liquid film aggregate is obtained , 48 C, is the hot and active liquid from the regenerator. This liquid is diluted by the air flow / coming from the drying room 40 / so that the liquid / the second liquid circuit belonging to the liquid film aggregate 48 Form of an overflow of the first fluid circuit is fed / slightly diluted. It is the overflow of the last - in the drawing / the third - liquid circuit that returns as diluted and cold Entfeuchtungsflüssigkeit to the regenerating means, said liquid containing all the moisture contents, which have been the product withdrawn through the air flow 50th

The flow rate of each of the partial air streams should be selected so that the liquid films along the liquid film line elements 58A, 58B and 58C do not interfere with the air flow; that is, that the air flow from the liquid film entrains no liquid particles. A flow rate of 1 to 5 m / s represents a suitable value. In the embodiment illustrated in FIGS. 5 and 6, similar to that illustrated in FIGS. 2 to 4, countercurrent drying takes place: while the product 50 is in transit moved slowly through the drying space 40 in the direction of the arrow 53, it encounters air streams flowing with increasing active wetness liquid

21716

have been brought into contact. A prerequisite for this countercurrent drying is also here that at least two partial air streams are available. It is advantageous if for each individual liquid aggregate, 48 A, 48 B and 48 C, a corresponding partial air flow is present; that is, when the number of fans is equal to the number of Flüssigkeitsfilniaggregate.

The concentration of the dehumidifying liquids circulated in the liquid film aggregates 48A, 48B and 48C may be increased in an order different from the order of the spatial arrangement of the liquid film aggregates. The order may be chosen as most advantageous by appropriately connecting the individual sections of the channel 62 associated with the individual liquid film aggregates. Thus, the dehumidifying liquid may be directed from the portion of the channel 62 associated with the liquid film aggregate 48C, for example, into the channel portion associated with the liquid film aggregate 48A, rather than into the channel portion associated with the liquid film aggregate 48B; and from here into the channel section associated with the liquid film aggregate 48B. In this way, the plant according to the present invention can be programmed with respect to the drying pre-prints for the product 50 passing through the drying room 40.

In the embodiment shown, the contacting device 43 forms the delimitation of the drying space 40 on the left side, forming a kind of "liquid curtain". Since aer liquid film 41, which is prepared according to the invention, the essential

can be arranged on the right side of the Trocknungsraurnes 40 the contacting device 43 can also be arranged in such a way that it divides the drying room 40 into two spaces; that is, between the two stacks of wood shown in FIG. According to the present invention, the only essential factor is that the closed air flow passes through the contacting device 43 during the circulation, and that the contacting device 43 and the drying space 40 are designed and accommodated in such a way that the air flow undergoes the least possible change the flow rate and the Strömungsrichtunq undergoes as it flows from one to the other of these Anlagenkoraponenten. It is obvious that these conditions are met in all mentioned embodiments *

The embodiment of the contacting device 43, which is shown in FIG. 5, is the same as that shown in FIG. 1, but the contacting device can also be embodied in a different form. Various contactors that can be used in the plant according to the present invention are described in U.S. Patent No. 3,857,911 and U.S. Patent No. 4,009,229, Hungarian Patent No. 168,451 and British Patent No. 1,363,523 described. In the plant according to the present invention, it is highly advantageous to use as dehumidifying liquid an aqueous solution of calcium chloride at a concentration of forty to fifty percent. The pollutants which enter the dehumidifying solution can be removed by means of a separating tank operating in the same way as the separating tank.

21 7168

ter, which has been described in connection with the embodiments which are illustrated in Figures 2 to 4.

In FIGS. 5 and 6, no regenerating device is shown, as it may be made in the same shape as any of those shown in FIGS. 1, 4, 8, 9 and 10. By proper design of the regeneration system, there is also the possibility to ensure that the active solution supplied through the pipe fitting 67 is as hot as is required to heat the air stream and heat the product 50 thereover. With the aid of the liquid film units 48 A, 48 B and 48 C, it is possible to set a temperature program for the product 50, which passes through the drying room 40.

Figures 7, 8, 9 and 10 show different solutions for the implementation of the regenerator. Due to the consideration that the regeneration device is based on the different combination of known apparatus and plant elements, the various regenerators that can be used in the present invention are illustrated in Figures 7, 8, 9 and 10 only by circuit diagrams. In the interest of clarity, each process step in the circuit diagrams has been identified by a separate schematic symbol; However, the invention can also be realized in such a way that, for example, in a housing more than one plant element is housed.

FIG. 7 shows the circuit diagram of the regeneration device shown in FIGS. 2 to 4 and shown in FIG

21 7 1

Reference to these figures will be described in detail.

Figure 8 illustrates a regeneration device in which the steam released by the dehumidifying liquid is used / to boil the liquid to be regenerated; and the vapor coming from the exiting active liquid heats the incoming dilute liquid. This regenerator is a multiple evaporator.

The dilute liquid is pumped by a pump 70 into a condenser 71 where the liquid serves as a cooling medium for the condenser 71. Subsequently, this liquid is further heated while cooling the liquid which evaporates in the heat exchangers 72 and 73; and finally said liquid passes through a conduit 74 into the evaporator 75. This evaporator 75 is heated by thermal energy supplied from the outside. According to the embodiment shown, for example, steam is supplied through a pipe connection piece; this steam condenses and the condensate exits through a conduit 77. Of course, flue gas, radiant heat, solar energy or any other heat source can be used for heating. From the evaporator 75, the liquid is passed through a heat exchanger 73 and a throttling device 78 into an evaporator 79 where it undergoes another boiling process caused by the steam generated in the evaporator 75. From the evaporator 79, a pump 83 pumps the liquid through the heat exchanger 72. to a piping port 80 which is connected to a piping port through which the active liquid is passed into the actual drying plant; So for example with the

21 71 68

Pipe connection stubs 67 in FIG. 6 · The steam generated in the evaporator 79 passes through a pipe 84 into the condenser 71 / while the condensate of the steam, which heats the evaporator 79, passes into the condenser 71 via a throttle device 81. Here both are used to heat up the incoming diluted dehumidifying liquid. The condensed distillate and the non-condensable gases are removed by means of a pump 82.

Figure 9 shows the circuit diagram of an embodiment of the regeneration device, which is also a multiple evaporator and in which the vapor released from the dilute liquid is used to heat up the incoming dilute liquid to be regenerated.

The diluted liquid is supplied by means of a pump 90 to a condenser 91 as a cooling medium and heats up here. The liquid then undergoes further heating by cooling the already condensed liquid leaving the regenerator in the heat exchanger 92 and then entering the evaporator 93. From here, the liquid is pumped by means of a pump 94 through a heat exchanger 95 in which they further heated upon cooling Oer active liquid, and then fed to an evaporator 96th Here, the liquid is evaporated by means of heat energy supplied from the outside; For example, by means of steam, aer is supplied through a pipe connection 97. The condensate of the steam exits through a pipe connection 98. The vapor which has been produced in the evaporator 96 causes the diluted liquid in the evaporator 93 to boil.

-36- 217168

The active liquid passed passes through a pipeline into the heat exchanger 95 / subsequently into the heat exchanger 92; and then leaves the regenerator through a pipe connection 100 in the direction of the drying plant in the strict sense; such as in the direction of the pipe connection piece in Figure 6. The steam produced in the evaporator 93 reaches 67 through a pipeline 101 into the condenser 91 while the condensate of the steam is heated with your Oer evaporator 93, via a Throttle device 102 is also supplied to the capacitor 91. Here, both are used to heat up the diluted dehumidifying liquid. Subsequently, the condensed distillate and the non-condensable gases are removed by means of a pump 103.

FIG. 10 shows the circuit diagram of another embodiment of the regeneration device, in which the heat energy released during the condensation of the vapor released from the aerosol by flash evaporation only heats the liquid to be regenerated, while it does not evaporate. This regenerator is a multi-stage flash evaporator.

The dilute liquid is forced through the capacitors 112, 113 and 114 by means of a pump 111. After the liquid has left the condenser 114, it passes through a throttle device 115. The pump 111 and the throttle device 115 are designed and arranged such that oer pressure of the liquid as it passes through the capacitors 112, 113 and 114 is always higher than the saturation pressure, so that no evaporation can take place anywhere. The temperature üqi- diluted liquid · = ·

21 71 68

Increased speed, which serves as a cooling liquid in the capacitors 112/113 and 114, increases. Behind the throttle device 115 is released in an evaporator 116 of the liquid without heat transfer steam. This vapor is condensed in the condenser 113. The liquid continues to flow to an evaporator 117, where more vapor is released from it / its condensation takes place in the condenser 112. The condensed active liquid left over is returned by means of a pump 118 to the actual drying plant / for example to the piping connection stub 67 shown in FIG. The condensed in the condenser 113 distillate passes through a pipe into the condenser 112, where it is subjected to a flash evaporation. The distillate and the non-condensable gases are removed by means of a pump 120.

In the condenser 114, the diluted liquid to be regenerated should be heated by steam supplied from the outside. This heating steam may be supplied, for example, through a pipe connection 121, while the condensate of the steam is discharged through a pipe connection 122.

From the viewpoint of control of the equipment units of the regenerator, it is desirable to change the above-described embodiments in such a manner that only a part of the diluted dehumidifying liquid reaches the concentrated state while the other part is mixed with the concentrated part to be used as active dehumidifying liquid in the drying plant.

In the interests of a simpler description of the above embodiment, only two evaporators / that is / only two evaporation stages, represented "But of course it is possible / and in the sense of increasing the energy efficiency recommended to apply more than two stages.

From Figure 10 it can be seen that when the generated by the regenerator excess heat in the drying plant can not be used or when the heat loss of the drying system is low (for example in summer), the Entfeuchtungsflüssigkeits regeneration system these conditions should be adjusted accordingly. The illustration in FIG. 10 illustrates two expedient solution variants which can be used individually, but also together. As far as the first variant of the solution is concerned, the condenser 112 requires an externally supplied cooling medium /, for example, cooling water, as well as a coolable additional surface, for example in the form of a coil. The latter can be accommodated in a separate housing, in which case a connection between the steam chambers must be established by means of pipelines. Cooling water can enter, for example, through a pipe connection 123 in the heat exchanger, and flow out of the same through the pipe connection 124. According to the second variant of the solution, the dilute liquid entering the condenser 112 is pre-cooled in a heat exchanger 127 which is cooled by a medium, such as water, entering through a pipe connection 125 and re-flowing through a pipe connection 126.

In the exemplary embodiments according to FIGS. 7, 8 and 9, these two solution variants are also applicable.

21 71 68

bar. In this regard, the equivalents of the capacitor 112 / which is additionally cooled according to Figure 10, the capacitor 29 in Figure 7, the capacitor 71 in Figure S and the capacitor 91 in Figure 9. The heat exchanger 127, in the Figure 10 is shown / must be connected between the capacitors 29, 71 and 91 and arranged in front of said capacitors pumps 28, 70 and 90, respectively, which are shown in Figures 7, 8 and 9 respectively.

As various changes could be made to the embodiments disclosed in this specification without departing from the spirit of the invention, it is believed that all that is illustrated or described in this specification is illustrative and not is to be construed as limiting.

Claims (22)

-40.- 21 E r f i η du η g s approach ; A process for drying products comprising the steps of introducing the product to be dried into a drying gray; continuously circulating a stream of drying gas in such a manner as to cause it to pass through the product to be dried; Contacting the drying gas stream with a dehumidifying liquid to remove moisture from the gas; and regeneration of the dehumidifying liquid by circulating at least a portion thereof through regeneration means which withdraw moisture therefrom; and characterized in that at least one layer of the dehumidifying liquid is formed in the vicinity of the product in the drying room and that the drying gas stream is brought into contact with said at least one dehumidifying liquid layer. 2 _e procedure according to point 1; characterized in that said at least one dehumidifying liquid layer is a substantially horizontal liquid layer and that said drying gas stream is bubbled through said substantially horizontal liquid layer. « 3. Method according to point l; characterized in that said at least one dehumidifying liquid is produced by causing the dehumidifying liquid to flow along liquid film grinding elements, and said contacting takes place by causing said drying gas stream to flow between these liquid-conducting element elements. 2t 71 68 Method according to item 1, characterized in that a heat exchange between the dehumidifying liquid and the product to be dried is effected in such a way that the heat is transferred by the drying gas flow between the dehumidifying liquid and the product to be dried. Method according to point 4 », characterized in that said heat exchange is carried out by heating the dehumidifying liquid in the course of said regeneration, so that the drying gas is heated to a predetermined temperature by contact with the dehumidifying liquid during said gas recirculation. 6, method according to point 5 », characterized in that the predetermined temperature of the drying gas is at least 40 ⁰ C. 7. A method according to any one of items 1 to 6, characterized in that 'said dehumidifying liquid is a dehumidifying solution that -42- said regeneration is by evaporation of the dehumidifying solution and that the vapor released from the dehumidifying solution is at least partially condensed by the dehumidifying solution to be regenerated. 8, procedure according to point 7; characterized in that said vaporization is realized by multiple evaporation and that the vapor released during the first boiling of the dehumidifying agent solution is at least partially condensed by the incoming dehumidifying solution to be regenerated. 9, procedure according to point 7; characterized in that said evaporation is realized by a high-speed evaporation and that the vapor released during the last boiling of the dehumidifying solution is at least partially condensed by the incoming dehumidifying solution to be regenerated. 10. Procedure according to point 7; characterized in that said evaporation is realized by a multi-stage flash evaporation. 11. Method according to any one of items 7 to 10; characterized in that it further includes the step of cooling the dehumidifying solution after said contacting and said regeneration in response to cooling of the solution of erythrous water during said contacting such that the incoming dehumidifying solution to be regenerated has a predetermined temperature. 21 71 6 12, method according to any one of items 4 to 6; characterized by further including the step of producing at least one layer of dehumidifying liquid in the vicinity of the product in the drying room and contacting said gas stream with said at least one dehumidifying liquid layer. 13 · Procedure according to one of the items 1 to 12; characterized in that said circulation of the drying gas stream is carried out by passing the drying gas stream in a flow path section between the article to be dried and the dehumidifying liquid / on this flow path section the ratio between the maximum and minimum flow rates of the drying gas stream is less than five is one and the change in the flow direction of the drying gas flow is less than thirty degrees. 14. Procedure according to point 13; characterized in that said drying gas flow is passed between the product to be dried and the dehumidifying liquid substantially without any change in flow rate and flow direction. 15. Method according to any one of items 1 to 14; characterized in that said dehumidifying agent solution is an aqueous solution of potassium chloride and the drying gas is air. 16 »method according to one DER points 1 to 15; characterized in that said drying gas stream consists of at least two parallel partial gas streams; that the product to be dried is moved transversely to these partial gas streams and that each of the partial gas streams is brought into contact with a dehumidifying liquid having a specific concentration and temperature. 17. Procedure according to point 16; characterized in that each of said partial gas streams is brought into contact with a dehumidifying liquid which has a higher concentration than the dehumidifying liquid which is contacted with the previous partial gas stream in relation to the direction of movement of the product to be dried » 18. Procedure according to any one of items 16 or 17; characterized in that it further includes the steps of producing at least two separate groups of dehumidifying liquid films of different concentrations and including the juxtaposed groups of dehumidifying liquid films in the path of said partial gas streams, such that each of said partial gas streams is at least a separate group of dehumidifying liquid films is contacted. 19 · procedure according to point 18; characterized in that each aer called groups of Entfeuchtungsflüssigkeitsfilmen is provided with its own fluid circulation; that the circulation of the liquid, relative to the direction of movement of the product to be dried, 21 71 6 the last group of dehumidifying liquid films are fed with the regenerated dehumidifying liquid coming from said keying means; that the circulation of each preceding group of dehumidifying liquid films is fed respectively to the upper course of the subsequent group and that the upper course of the circulation of the first group of Entfeuchtungsf lussigkeitsfilmen the said regenerating means is supplied. 20. equipment for drying products; comprising at least one Trocknungsrauni for the product to be dried; at least one contacting device for contacting a drying gas stream with a dehumidifying liquid for the purpose of removing moisture from the gas; Gas line elements for guiding the drying gas flow on a substantially closed path through said drying space and said contacting device; Gasuniwälzeinrichtungen whose task is to cause the Trockyyasstrom to circulate in the said closed way; Regeneration means for removing moisture from the dehumidifying liquid; and fluid circulation means for circulating at least a portion of the dehumidifying fluid through said regenerating means and said contacting means; and characterized in that said contacting means (43) includes elements (13, 58) for the production of at least one layer (1, 41) of the dehumidifying liquid to be contacted with the drying gas stream, said at least one dehumidifying liquid layer (1, 41) in the Near the product (2, 50) located in said drying space (25, 40) is located. 21. system according to item 20; characterized in that said contacting means includes a liquid container (13) for forming a substantially horizontal dehumidifying liquid layer (1); that this liquid container (13) is provided on its wall with Einperlglockcn (20) for the bubbling of the drying gas flow through said dehumidifying liquid layer (1); said liquid container (13) is connected to said liquid circulation means (36) so as to cause the dehumidifying liquid to flow along said liquid container; and that said drying space (25) is located above or below said container (13). 22. Appendix according to item 21; characterized in that said drying space (25) includes means (4) for transporting the product (2) to be dried through said drying space (25) and that said transport means (4) are provided with openings (5) for passing the drying gas stream without dropping the product to be dried (2), 23 · Installation according to item 22; characterized in that said transport means is an endless belt conveyor (4) and that said gas recirculation means are fans (17A, 17B, 17C, 17D) arranged side by side along said belt conveyor (4). 24. Appendix according to item 20; characterized in that said contacting means (43) includes liquid film conduit members (58) which are so attached to 21 7168 are arranged, that the drying gas flow flows between these Flüssigkeitsschichtleitungsmenienten (58). 25. Installation according to item 24; characterized in that said contacting means (43) further comprises a receptacle (55) for receiving the inflowing dehumidifying liquid; at least one lock (56) for extracting the liquid in film form from said receptacle (55); Fluid distribution elements having at least one distribution surface (57) connected to said at least one sheath (56) and directed downwards; and fluid outlet members (62), said fluid film conduit members (58) connected between said fluid distribution surface (57) and said fluid outlet members (62) in such a manner as to deliver liquid films (41) from said over surface (57) into said outlet members (62) conduct. 26. Installation according to one of items 24 or 25; characterized in that said liquid film conduit members (58) are disposed in at least one substantially vertical plane that is substantially perpendicular to the flow direction of the drying gas stream. 27. Appendix according to item 26; characterized in that it further comprises a lower floor corridor (49), a shell roof (65) and an intermediate roof (54) provided with openings (47, 47 A) for the passage of the drying gas flow and between said lower floor corridor (49) and the said shell roof (65) is arranged, wherein 6 71 6 said drying room (40) is located between said basement floor (49) and said intermediate roof (54); said gas recirculation means are fans (66, 66 ") interposed between said intermediate roof (54) and said shell roof (65), and wherein said contacting means (43) is disposed on said drying space (40) said at least one vertical plane formed by said liquid film conduit members (58A, 58B, 58C) substantially perpendicular to the drying fluid stream and extending between said subcuff groove (49) and said intermediate roof (54) , 28. Installation according to one of the items 24 to 27; characterized in that said contacting means (43) consists of at least two liquid filtration units (48A, 48B, 48C) arranged side by side, each individual liquid film aggregate (eg 48A) having its own liquid film conducting elements (eg 58A) and its own fluidity circulation device (for example 60 A, 61 A), which provides a liquid circulation for the formation of the liquid films on said own liquid film line elements, and said liquid film aggregates (48 A, 48 B, 48 C) are stranded with a common liquid channel (62), the interconnecting the liquid circulation devices mentioned, said liquid passage (62) is connected to said liquid circulating means (e.g. 36). 29 «Appendix according to one of the items 20 to 28; characterized in that the ratio of any two 21 71 68 Flow cross sections of said gas line elements (37, 38, 49, 54) between said drying space (40) and said contacting means (43) is between 0.2 and 5; and that said contacting means (43) is disposed on said drying space (4o) such that the flow of drying gas flows between the product (50) to be dried and said contacting means (43) with a change in direction of less than thirty degrees. 30. Appendix according to item 29; characterized in that said flow area ratio is between 0.5 and 2, and said flow direction change is substantially zero degrees. 31. Installation according to one of the items 29 or 30; characterized in that the distance between said drying space (40) and said contacting means (43) is smaller than the hydraulic diameter of said gas conduit members (37, 38, 49, 54) between them. 32. Appendix according to one of the items 20 to 31; characterized in that said regeneration means (150) comprises a multiple evaporator (for example, 70 to 84). 33. Annex according to one of the items 20 to 31; characterized in that said regeneration means (150) comprises a multi-stage flash pervator (151). 34. As finished article, a product treated in accordance with the method of any one of items 1 to 19, for the drawings