MXPA00008212A - Method and device for drying a rapidly conveyed product to be dried, especially for drying printing ink - Google Patents

Abstract

The invention relates to a method and a device for drying a product to be dried (1, 2) which is rapidly conveyed in a direction of conveyance, especially for drying layers of printing ink on rapidly conveyed paper. According to said method a wet component, especially a solvent is separated from the product to be dried (1, 2) in a drying zone (T) by incident electromagnetic radiation. The separated wet component is evacuated from the drying zone (T) by a conveyor gas stream (D). The invention allows for the efficient and rapid drying especially of printed newsprint or thermoprinting paper at high conveyor speeds.

Description

METHOD AND APPARATUS FOR DRYING A RAPIDLY TRANSPORTED PRODUCT, SPECIFY PRINTING INKS DESCRIPTION The invention relates to a method and apparatus for drying a substance that is being rapidly transported in a transport apparatus, in particular for drying layers of printing ink on rapidly transported paper. The invention is particularly related to paper quickly transported with a transport speed between 2 and 25 m / s. When a rapidly transported substance is to be dried, it is extremely important that the drying operation be carried out quickly. For example, the direction of movement of the material carrying a substance to be dried is changed by a passage over several deflection rollers, in one provided of which one or the other side of the carrier material can make contact with the roller. If, for example, in an apparatus for printing paper, an ink layer is applied to the paper and then the printed paper passes around a deviating roller with its printed surface touching the roller, the ink layer must be dried sufficiently before the paper reaches the roller. For other steps of the processes subsequent to printing, it is also a requirement that the ink dry properly. Examples include stacking simple printed pages, one over the other, or winding a printed strip of paper. A similar situation is found in papermaking, when paper strips that are completely wet are quickly transported for further processing. The object of the invention is to describe a method and an apparatus of the aforementioned type with which the drying of the substance to be dried can be achieved quickly. This object is achieved by a method with the features provided in claim 1 and by an apparatus with the features provided in claim 18. Other developments are apparent from the associated subordinate claims. In the method according to the invention for drying a substance that is being rapidly transported in a direction of the conveyor, in particular for drying layers of printing ink on a rapidly transported paper, the electromagnetic radiation is directed within a drying zone of Such a method separates a moisture component, in particular a solvent, from the substance to be dried and the separated moisture component is transported out of the drying zone by a transport gas stream. Electromagnetic radiation, in particular infrared radiation, has proven to be especially useful and efficient for drying. Even when the carrier material is being transported at high speeds, only one drying zone is necessary, the length of which is short and in the direction of the conveyor. During separation of the moisture component from the substance to be dried, the separated moisture component can form a boundary layer that covers the substance and prevents further drying. In particular, a dynamic equilibrium is established on the surface of the substance to be dried, in which approximately as many moisture particles of the substance emerge as they re-enter from the boundary layer. Therefore, according to the invention, the separated moisture component is removed from the drying zone by a transport gas stream. In particular, when the transport gas is continuously introduced into the drying zone, the production of a boundary layer that would impede drying is avoided, because the particles of the separated moisture component are transported away only for a short time afterwards. that they have emerged from the substance that is going to dry up. The electromagnetic radiation preferably conforms to the absorption properties of the moisture component such that the radiation energy is substantially absorbed only by the moisture component and not by the remaining components of the substance to be dried and / or by a carrier material that is not wet. As a result, the moisture component is not vaporized in the strict sense, but the particles of the moisture component are specifically activated and are expelled from the substance to be dried.

Preferably, the transport gas stream (D) flows into the drying zone through a region oriented transversely to the direction of the conveyor, from a direction covering an angle of 60 to 90 °, preferably approximately 80 °. , with the perpendicular to the surface of the substance to be dried, thus striking the substance like a knife. As a result, the transport gas can carry along with the moisture particles that emerge from the substance without transferring a substantial fraction of its kinetic energy to the substance. In this way, mechanical deformation of the substance to be dried can be avoided, which for example can cause sharp edges to blur from an ink print. Preferably, the transport gas stream exerts a narrow range action in the region where it flows into the drying zone, in that it hits the surface of the substance to be dried directly, so that a surface layer formed by the separated moisture component is raised away from the substance as sliced by a knife. The acute angle of incidence, in particular, improves this knife type action. In particular, the combination of the narrow range effect with the orientation of the region within which the transport gas stream flows within the drying zone, i.e. prolonged in the direction perpendicular to the direction of the conveyor, results in a drying effect selling quickly over the entire length of the region. It is also advantageous that the velocity of the transport gas stream is the same over the entire width of the region occupied by the substance to be dried. It is favorable for the transport gas stream to flow along the surface of the substance to be dried either in the same direction in which the substance is being transported or in the opposite direction, for a certain distance. This distance can in particular be greater than the length of the drying zone within which the electromagnetic radiation is incident on the substance. In this way, it is ensured that the moisture particles will be transported away from the entire drying area and even beyond it. To cool the substance to be dried, if heated by electromagnetic radiation, the temperature of the transport gas stream is lower, at least before it hits the moisture component, than the temperature of the substance that it's going to dry up This is advantageous in particular in the case of a heat sensitive carrier material, because by means of the cooling of the substance to be dried, the transfer of heat from the substance to the carrier material can be reduced or prevented. It is useful that an expanded pressurized air transport gas stream be formed. In particular, if the moisture component of the substance to be dried is water, the incident electromagnetic radiation has a maximum of near infrared spectrum intensity, in particular in the wavelength range of 0.8 to 2. Oμm. As a result, a substantial proportion of the radiation energy is introduced into the substance specifically as excitation energy for particles of the moisture component, in particular water. In the specified wavelength range there are several water absorption bands. However, other moisture components, in particular solvents, also have absorption bands in this wavelength range. For efficiency reasons of the relevant thermodynamic processes, in particular to raise the overall efficiency when the method according to the invention is employed, after leaving the drying zone, the transport gauze stream flows to the source of the electromagnetic radiation to be able to cool this source. In particular, when the latter has the form of a thermal radiator operated at a temperature above 2500 K, cooling is required. When the transport gas stream is used in this manner, it is possible either not to use another supplementary cooling form or such supplementary cooling means may have correspondingly smaller dimensions. To ensure that the specified temperature conditions can be maintained, the temperature of the dried substance and / or the temperature of the separated moisture component and / or the temperature of the carrier material is regulated by adjusting the radiation flux density of the incident electromagnetic radiation in the drying zone according to a further development of the method. Preferably, the temperature to be regulated is measured by means of a pyrometer. It is useful to use as a radiation source for electromagnetic radiation an electric incandescent bulb, in particular a halogen bulb, and to adjust the density of the radiation flow by adjusting the current supply to the incandescent filament. In addition or alternatively, to adjust the density of the radiation flow, the distance of the radiation source from the drying zone can be adjusted. The drying is particularly efficient in an additional development of the method, in which components of the electromagnetic radiation that are not absorbed and thus pass through the substance to be dried are returned to the substance. There, the reflected radiation components are at least partially absorbed, so that the total amount of radiation absorbed is increased. Thus, the radiation source employed, or the plurality of such sources may have smaller dimensions with respect to its result of radiation, or can radiate a larger drying area. It is also possible to use reflected radiation components to irradiate areas along the carrier path of the carrier material on which no radiation entering directly from the source or radiation sources is incident. Preferably, cooling a reflector used to reflect the non-absorbed radiation components, in particular to minimize the emission of large wavelength infrared radiation. The method according to the invention can be used especially when the carrier material is paper being transported at a speed between 2 and 25 m / s. In a particular embodiment, the paper is either newspaper printing conveyed at a speed between 10 and 20 m / s, in particular at approximately 15 m / s or thermo-printing paper transported at a speed between 2 and 10 m / s , in particular at approximately 5 m / s.

In particular, when a thermo-printing paper is used as the carrier material, the temperature of the carrier material is adjusted and / or regulated to a value below 70 ° C, in particular below 50 ° C. By this means, an undesirable thermally induced change in the carrier material or its properties can be avoided. Preferably, the transport gas stream collides with the particles of the moisture components that are to be removed with a velocity between 20 and 120 m / s, and carries these particles together with it. In particular, the current velocity when it hits the substance to be dried is between 30 and 40 m / s. By using a sufficiently high transport gas velocity, for example in the specified ranges, a layer of moisture particles which has been separated from the substance to be dried, which could interfere with drying, is reliably separated and / or rises away from the surface of the substance, or never forms, at least not directly on the surface of the substance. In comparison with the tests in which the transport gas stream according to the invention was omitted, the drying index of 70 to 80% higher has been observed when this characteristic is used. The apparatus according to the invention for drying a substance that is being rapidly transported in a conveyor direction, in particular for drying quickly transported paper printing ink layers, comprises the following: a radiation source for generating electromagnetic radiation, the radiation source is arranged in such a way that at least a part of the electromagnetic radiation is incident on the substance to be dried in a drying zone along the path of the carrier of the carrier material, in order to be able to separate from the substance a moisture component, in particular a solvent, - a supply of transport gas through which the transport gas is introduced and a transport gas conduit that extends at least in parts transverse to the direction of the conveyor and is constructed and arranged in the manner that the transport gas supplied is guided within the zone of drying and collides with the substance that is going to dry like a knife, to be able to transport the separated moisture component away from the substance to be dried. The advantages of the apparatus according to the invention have been cited above. In particular, the supply of transport gas is a supply of compressed air and the transport gas conduit comprises a distributor of compressed air that extends transverse to the path of the conveyor, in particular, a distribution pipe, to distribute the air compressed flowing from the gas inlet substantially over the entire width of the conveyor path. Preferably, a single supply of compressed air, when connected, is sufficient to introduce compressed air that serves to remove the moisture component of the substance to be dried over the entire width of the conveyor path. Preferably the transport gas conduit comprises a guiding surface which runs approximately along the path of the carrier of the substance to be dried and is separated therefrom by a distance that progressively decreases in the direction of the gas flow. The guide surface terminates in a gas passage space defined by the guide surface itself and the surface of the substance to be dried. The gas enters the drying zone through this space. After passing through the space, the gas may, depending on the configuration of the end of the guide surface either form swirls or continue within the drying zone in about a laminar flow. The eddies, promoted in particular by a construction such that the guide surface end sharply slopes downward, accelerates the removal of moisture particles in the immediate vicinity of the groove but reduces the efficiency of transport at greater distances from the groove. Depending on the application, by adjusting the configuration of the end of the guide surface, the flow of transport gas within the drying zone can be optimized. Especially preferred is a mode in which the width of the gas passage space is between 2 and 15 mm, in particular between 5 and 10 mm. In combination with an acute angle of incidence of the transport gas stream on the separated moisture component or on the surface in the substance to be dried, said narrow gas passage space particularly improves the knife-like action. The moisture particles separated in this way are removed from the surface of the substance to be dried. In particular, the transport gas forms a dividing layer, which flows either in the direction of the conveyor or in the opposite direction over the entire length of the drying zone, between the substance to be dried and the moisture particles which they have already been separated from it. Therefore, in a particular embodiment, as seen from the surface of the substance to be dried at least in the vicinity of the gas passage space, the moisture particles are less densely distributed close to the substance that is going to drying out longer distances, either in the transport gas stream or on the other side of it, become more densely distributed. In any case, the knife-like action results in a higher net emergence index of moisture particles of the substance to be dried, that is, prevents an appreciable diffusion of the moisture particles back into the substance. The aforementioned substantive characteristics of the apparatus according to the invention are expressly claimed as essential to the invention, also for the modalities of the method according to the invention. In a preferred embodiment of the apparatus, the radiation source is an incandescent bulb, in particular a halogen incandescent bulb. Halogen bulbs can be purchased at favorable prices. Its emission temperature can be made suitable for several applications by adjusting the filament current. It is also favorable to provide reflectors in or within the region of the bulb, so that between radiation emitted to the drying zone as much as possible. By a suitable selection of the configuration and arrangement of the reflectors, the spatial distribution of the radiation flow over the drying zone can also be adjusted. Preferably, a reflector is provided to reflect radiation that is not absorbed and passes through the carrier material, this reflector is arranged on one side of the conveyor away from the radiation source. In particular, a water-based cooling system is provided in this reflector. In order to be able to control the temperature conditions in the drying zone and the area beyond this zone in the direction of the conveyor, the apparatus preferably comprises a control circuit for regulating the temperature of the substance to be dried and / or the temperature of the separated moisture component and / or the temperature of the carrier material. The control circuit comprises a pyrometer to measure the temperature to be regulated, and an adjustable current source that feeds the incandescent bulb and a current regulator that adjusts the current source. according to the temperature value detected by the pyrometer to alter the current supply to the bulb properly. Alternatively, or in addition to the combination of the adjustable current source and the current regulator, the apparatus comprises a distance adjuster for varying the distance separating the radiation source from the carrier path of the carrier material and a distance regulator., which activates the distance adjuster according to the temperature value reported by the pyrometer to alter the distance of the radiation source appropriately. In the following, the invention is explained with reference to the example shown in the drawing. However, it is not limited to the exemplary embodiments shown herein. The individual figures in the drawings are as follows: BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a cross section through a carrier material carrying on its upper surface a substance to be dried, Figure 2 shows in perspective an exemplary embodiment of the drying apparatus according to the invention.

The carrier material shown in Figure 1 consists of paper 1 and carries on its surface a layer of wet printing ink 2. The paper 1, in the representation shown here, is being transported to the right, as indicated by an arrow pointing in the direction of the conveyor R. The infrared radiation 4 incident on the ink 2 is partially absorbed by the solvent, water, which constitutes a large proportion of the ink 2, for example, 90%. In this way, within the area of incidence of the infrared radiation 4 or beyond thereof in the direction of the conveyor, a thin boundary layer of the water vapor 3 formed by the particles ejected from the printing ink 2 is formed. The water vapor 3 prevents further drying of the ink, as schematically indicated by the arrow pointing downwards to the right. At least two processes play a role here: The dynamic equilibrium between the water particles that enter the ink 2 and those that emerge from it, and the absorption of the radiation in the water-vapor layer. Figure 2 shows an apparatus 8 according to the invention for drying wet printing ink 2 containing water, on the surface of a rapidly transported paper strip 1, in particular a printed strip of the newspaper. The paper strip 1 is transported at a speed of approximately 15 m / s. As can be seen from the arrow with double head that indicates the direction R of the conveyor, the paper can be transported either from right to left or from left to right, although during any given drying process, the paper strip moves only in one direction. In the following description, it is assumed that the paper shown in Figure 2 is being transported from left to right. The arrangement of the compressed air duct 14 could, however, be the same for the case in which the paper is transported from right to left. The only difference of the arrangement shown in Figure 2 would be that a pyrometer 11 (whose function will be described later) would be disposed beyond the compressed air line 14 in the direction of the conveyor, ie to the left in the figure. Along the path of the conveyor of the paper strip 1 there is a drying zone T, inside which the radiation emitted by the halogen line sources 10 are influential on the printing ink 2; The highest energy component of this radiation is substantially infrared radiation 4. In particular, between the halogen line sources 10 and the substance to be dried, a spectrum filter (not shown) can be placed. A certain amount of infrared radiation 4, depending on the absorbance of the moisture component in the printing ink 2 and on the absorbance of the paper strip 1, is not absorbed but passes through the paper strip 1 and crashes against it. an infrared reflector 20 placed below the paper strip 1. As indicated by an arrow, the infrared reflector 20 reflects the infrared radiation striking it so that this reflected radiation is sent back to the paper strip 1. Part of the reflected radiation 5 reaches the substance 2 to be dried and is absorbed here, mainly by the aqueous components of the printing ink 2. Through the compressed air inlet 12 connected to the compressed air duct 14, compressed air is fed into a distributor pipe 15 which extends over the entire width of the conveyor path of the paper strip 1. The distribution pipe 15 shows an open cut at its front end, to be visible its profile. However, in fact, the distributor pipe 15 is closed at both ends, so that air emerges through an outlet opening 16 that extends across the full width of the conveyor path. On its way to the compressed air opening, at first it moves in a direction opposite to the direction of the conveyor and then turns at approximately a right angle, passing through a section of transverse conduit towards the paper strip 1. Adjacent to the transverse conduit section is a guide surface 17, which similarly extends across the entire width of the conveyor path. The air flows along the guide surface 17 and through a passage space 18 within the drying zone T. The guide surface 17 and the paper strip 1 define a space that gradually becomes narrower in the direction of the air flow, through which the compressed air passes. The guide surface 17 and the paper strip 1, which is conveyed from the deviator roller 7 in a straight direction, includes an angle a of about 10 °. In the passage space 18, which extends across the entire width of the conveyor path, the guide surface and the paper strip are separated by approximately 7 mm. The air supplied through the compressed air line 14 flows through the passage space 18, within the drying zone T, with a speed of approximately 35m / s. Distributed over the entire drying zone T, the vapor-water particles which have been ejected from the ink 2 by the infrared radiation 4 are transported away by the air stream D. The flow paths of the air stream D are indicated in Figure 2 by many arrows slightly curved upwards. A pyrometer 11 is directed towards a place in the path of the conveyor of the paper strip 1, located beyond the drying zone T in the direction of the conveyor. By means of a radiation measurement, the pyrometer 11 thus verifies the temperature of the surface layers carried by the paper strip 11, which consists substantially of an already dry printing ink 2. The temperature value of this measured mode is sent to a controller (not shown). The controller, for example, a Pl controller or a PID controller responds by sending a control signal that can be received by two final control elements. A current modulator, which averages short-term rapid adjustments of the electric current of the filament of the halogen line source 10, is activated by the controller when a usually light fast response adjustment of the radiation flux density is required. If the temperature measured by the pyrometer 11 reaches the limit of a predetermined range within which the current modulator can operate, a distance adjuster is activated to alter the distance of the radiation source 10 from the path of the conveyor of the strip 1. of paper. Although it is slow in comparison to the action of the current modulator, the distance adjustment expands the total control range making the range of relatively narrow current control usable over a wide range of temperatures or radiation flux densities. In this way, the short duration alteration of the flow density of the incident radiation in the drying zone, and in this way a regulation of the temperature can be carried out with low inertia over the entire range within which the control operates by means of a distance adjustment. Preferably air is sent with low residual moisture inside the compressed air inlet 12; it is then cooled by the subsequent expansion in the distribution pipe and / or after flowing out of the distribution pipe. In this way, cold, dry air is introduced into the drying zone T. This has the advantage that on the one hand the removal of the moisture component from the drying zone T is improved, while on the other the temperature of the drying zone is improved. the printing ink 2 and therefore the temperature of the paper strip 1 can be kept low. In particular, it is possible to maintain the temperature of the paper strip 1 below 50 ° C, when the paper strip 1 is transported at a speed of about 5 m / s and the air flow velocity in the passage slot 18 is approximately 35 m / s. The drying apparatus according to the invention can, in particular, also be used in equipment to produce printed page-size material such as leaflets, magazines or drawing pages, when said equipment comprises a conveyor device suitable for transporting the carrier material which is going to be printed. In addition, the method according to the invention and the apparatus according to the invention can advantageously be used in printing equipment that produces individualized printing products such as consecutively numbered train or bus tickets or sheets or sections in sequence of paper strips carrying individual bar codes. Many installations very often employ inkjet printers, in particular with a print resolution of 240 dpi or better. With the apparatus and the method according to the invention, it is possible, for example, to produce 54,000 A4 DIN sheets printed per hour.

List of reference numbers 1 Paper strip 2 Printing ink 3 Water vapor 4 Infrared radiation 5 Reflected radiation 7 Deviator roller 8 S ector 10 Halogen line source 11 Piróme t ro 12 Compressed air inlet 14 Conduit of compressed air Distribution pipe 16 Exit opening 17 Guide surface 18 Passage space 20 Infrared reflector D Air current R Transport direction T Drying area guide surface angle

Claims (14)

1. CLAIMS 1. Method for drying a substance that is rapidly transported in a conveyor direction, in particular drying layers of printing ink on a rapidly transported paper, characterized in that: in a drying zone by means of incident electromagnetic radiation, in a Particular infrared radiation, a moisture component, in particular a solvent, is separated from the substance to be dried and the separated moisture component is transported away from the drying zone by means of a transport gas stream. The method according to claim 1, characterized in that the transport gas stream within a region disposed transverse to the direction of the conveyor flows into the drying zone from a direction that includes an angle of 60 to 90 ° with the perpendicular to the surface of the substance to be dried, preferably approximately 80 °, and collides with the substance like a knife. 3. The method according to claim 1 or 2, characterized in that the temperature of the transport gas stream, at least before it meets the moisture component, is lower than the temperature of the substance to be dried . The method according to one of claims 1 to 3, characterized in that the transport gas stream is formed by expanded compressed air. The method according to one of claims 1 to 4, characterized in that the incident electromagnetic radiation has a maximum intensity of the near infrared spectrum, in particular in the wavelength range of 0.8 to 2.0 μm. The method according to one of claims 1 to 5, characterized in that the transport gas stream after leaving the drying zone flows to the source of the electromagnetic radiation in order to be able to cool it. The method according to one of claims 1 to 6, characterized in that the temperature of the dried substance and / or the temperature of the separated moisture component and / or the temperature of the carrier material is controlled by adjusting the flow density of the incident electromagnetic radiation in the drying zone. 8. The method according to claim 6, characterized in that the temperature to be controlled is measured by means of a pyrometer. 9. The method according to claim 6 or 7, characterized in that an electric incandescent bulb, in particular a halogen bulb, is used as the source of electromagnetic radiation, wherein to adjust the radiation flux density, the supply of radiation is adjusted. current to the filament of the incandescent bulb. The method according to one of claims 6 to 9, characterized in that in order to adjust the radiation flux density, the distance of the radiation source of the drying zone is adjusted. 11. The method according to one of the rei indications 1 to 10, characterized in that the components of the electromagnetic radiation that are not absorbed but pass through the substance to be dried are reflected back to the substrate. . The method according to one of claims 1 to 10, characterized in that the carrier material is paper, which is transported at a conveyor speed between 2 and 25 m / s. 13. The method according to the rei indication 12, characterized in that the paper is newspaper printing, which is transported with a conveyor speed between 10 and 20 m / s, in particular about 15 m / s. 14. The method according to claim 12, characterized in that the paper is thermo-printing paper ion, which is transported with a conveyor speed between 2 and 10 m / s, in particular about 5 m / s. The method according to one of claims 1 to 14, characterized in that the temperature of the carrier material, in particular the thermo-printing paper is adjusted and / or adjusted to a value below 70 ° C, in particular below 5 ° C. The method according to one of claims 1 to 15, characterized in that the speed at which the transport gas stream collides with the particles of the separated moisture component that will be transported away, and that carries them with it, it is between 20 and 120 m / s, in particular 30 to 40 m / s. The method according to one of claims 1 to 16, characterized in that the transport gas stream strikes the surface of the substance to be dried such that a surface layer formed by the moisture component separated from the it rises from the substance as if by a knife. 18. An apparatus for drying a substance that is rapidly transported in a conveyor direction, in particular for drying layers of printing ink on a rapidly transported paper, characterized in that: a source of radiation for generating electromagnetic radiation, in particular infrared radiation, wherein the radiation source is arranged so that at least part of the electromagnetic radiation is incident on the substance to be dried within a drying zone in the carrier path of the carrier material, in order to be able to separate the moisture component , in particular a solvent, of the substance to be dried, - a transport gas inlet through which transport gas is introduced, and a transport gas conduit which at least in parts extends transversely to the direction of the conveyor, which is constructed and arranged so that the transport gas introduced through the Transport gas inlet is guided inside the drying zone and collides with the substance to be dried like a knife, to transport the separated moisture component away from the substance to be dried. 19. The apparatus according to claim 18, characterized in that the supply of transport gas is a supply of compressed air and wherein the transport gas conduit comprises a distributor of compressed air, in particular a distribution pipe to distribute the air compressed that flows into the compressed air intake substantially over the entire width of the conveyor path. The apparatus according to claim 19, characterized in that the compressed air distributor has an outlet opening, so that the compressed air is guided inside the drying zone, which extends substantially over the entire width of the path of the compressed air. conveyor. The apparatus according to one of claims 18 to 20, characterized in that the transport gas conduit comprising a guide surface extending approximately along the path of the carrier of the substance to be dried, is it separates from the path of the conveyor by a distance that gradually becomes smaller in the direction of gas flow, and ends in a gas passage space that is defined by the guide surface of the substance to be dried. 22. The apparatus according to claim 21, characterized in that the spacing between the guide surface and the substance to be dried in the gas passage space is between 2 and 15 mm, in particular between 5 and 10 mm. The apparatus according to one of claims 18 to 22, characterized in that the source of radiation is an incandescent bulb, in particular a halogen incandescent bulb. 24. The apparatus according to claim 23, with a control circuit for regulating the temperature of the substance to be dried and or the temperature of the separated moisture component and / or the temperature of the carrier material, characterized in that it comprises the following: a pyrometer to measure the temperature to be regulated, a final control element to adjust the current to the filament of the incandescent bulb; and a current controller that activates the final control element according to the temperature measured by the pyrometer in order to adjust the current of the filament. The apparatus according to one of claims 18 to 24, with a control circuit for regulating the temperature of the substance to be dried and / or the temperature of the separated moisture component and / or the temperature of the carrier material, characterized in that it comprises the following: a pyrometer for measuring the temperature to be regulated, a final control element for adjusting the distance separating the rtion source from the carrier path of the carrier material, and an activating distance controller the final control element according to the temperature measured by the pyrometer, in order to adjust the distance of the rtion source. 26. The apparatus according to one of claims 18 to 25, with a reflector, in particular one that is cooled by water, to reflect the rtion that passes through the carrier material without being absorbed, wherein the reflector is arranged to one side of the path of the conveyor opposite the rtion source.