JP2009092374A - Hot-air drying apparatus and method for drying printed material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solution for achieving required drying effect by a method advantageous more than a conventional approach in respect of process engineering, particularly in mechanical drive cost, relating to a hot-air drying apparatus of a paper sheet printing machine arranged after a varnishing device or an inking device in an area of the printing machine or an area of a rising part of a paper delivery device with a drying effect brought about by applying heated gas, specifically air of a drying machine to the printed material. <P>SOLUTION: The hot-air drying apparatus of the printing machine comprises a blowout device applying a dried air current to the printed material, a guide device carrying the air current passing through the blowout device, a heating device heating the air current, a control device adjusting temperature of the air current and a cooling device cooling the printed material in an area of the rear surface of the printed material which lies on a back side with respect to the blowout device. The hot-air drying apparatus is provided with a preheating heat exchanger for preheating the dried air current by using a hot air current taken in the cooling device or prepared by another method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hot air drying apparatus according to claim 1.

  Such drying devices are suitable for sheet-fed or roll-paper printers, especially after the varnishing or inking device in the area of the printing machine or in the area of the raised part of the paper discharge device. Can be set. The drying effect is brought about by applying a heated gas, in particular a dryer air, often referred to as hot air in the present application, to the material to be printed.

  In order to minimize the deformation of the printing material that may occur in some cases by warming the printing material, the printing material is installed in the area on the back side of the surface to which dry air is applied. It is known to cool by some coolers.

  From Patent Document 1, a method and an apparatus for drying a printed web or a colored web using heat are known. The method of drying printed or colored webs using heat is such that the printed web is exposed to a non-contact heat shock in the first stage and then contacted at a lower temperature than the first stage in the second stage. It is characterized by being heated and subsequently cooled via direct contact in the third stage. In doing so, the energy obtained during cooling is sent to the other device members using the cooling assembly.

  From Patent Document 2, a printing machine having a drying facility is known. The printing press is provided with a plurality of printing devices that are arranged in rows and through which a web of printing material passes. Each printing apparatus is followed by a drying facility. Each drying facility is installed around an individual temperature control roller that supports the web of material to be printed. Here, the heat discharged by the temperature control roller is used to preheat dry air.

  Further, Patent Document 3 describes an apparatus for drying and cooling a web paper just printed. An apparatus for drying and cooling freshly printed web paper includes a dryer, a cooler following the dryer in the direction of passage, and a hot dry gas on the passing web paper installed along the passage section. Alternatively, an injection device for blowing cold air, a recombustion chamber having a suction pipe for drying gas exiting from the dryer, concentrated with a volatile oily or resinous substance, and pure gas to the injection device A feed pipe for feeding and a conduit for discharging excess pure gas are provided. Absorption chillers with refrigerants are coupled in thermal technology with dryers and coolers in such a way that heat deprived from the pure gas exiting through the exhaust gas conduit is sent to the refrigerant. Moreover, the heat removed from the cool air in the cooler or the fresh air flowing into the cooler is sent to the vaporizer of the cooler.

Known devices have a costly construction in order to recharge the thermal energy generated when cooling the device member into another device member such as a dryer.
German Patent Application Publication No. 3324130 German Utility Model Application Publication No. 20206407 German Utility Model Application Publication No. 29819202 Specification

  The present invention addresses the problem of providing a solution in which the required drying effect can be achieved in an easy manner in an advantageous manner over previous approaches in process engineering and in particular in terms of machine drive costs. Is based.

  This problem is solved according to the invention by the features of claim 1.

  At that time, a drying device for a printing press that operates with hot air is used. The apparatus includes: a blowing device for applying a dry airflow onto the printing material; an induction device for carrying the dry airflow through the blowing device; and a heating device for heating the dry or hot airflow; A control device for adjusting the temperature of the dried airflow and a cooling device for cooling the sheet running portion provided for guiding the printing material passing through the hot air drying device are provided. The drying device that operates with hot air is provided with a preheating heat exchanger that is used to preheat the dried airflow using the hot airflow taken through the cooling device in the area of the sheet running section. It is excellent in that it is.

  Thereby, preferably, the hot air flow discharged from the sheet running section cooling device can be directly used for preheating dry air in the region of the drying device operated by hot air. Overall, this will greatly reduce the amount of waste heat of the printing press and the energy consumption of the drying device, thereby greatly reducing the energy consumption of the machine itself.

  A powerful heat output that is generated by an IR / TL dryer that can be attached to the area of the paper discharge device and that also affects the sheet running section disposed below it to heat it very intensely. In particular, it can be used for preheating a dry airflow. The heating device provided for heating the air of the dryer is placed behind the heat exchanger for preheating in the air flow path. Thus, the heating device need only inject the energy required to heat the dryer air to the required final temperature into the already preheated dryer air.

  The cooling device is preferably implemented as a sheet running section cooler, and the heat radiation from the sheet running section is preferably performed by a liquid heat medium. The heat medium is preferably carried by a circulation device through the preheating heat exchanger according to the invention used for preheating the dried air stream.

  It is also possible for the heat medium to be carried by other cooling grids or cooling assemblies. When carrying the heating medium further by means of a cooling assembly, it is possible in particular to collect and use the waste heat generated in the area of the cooling assembly in order to preheat the dry air stream. The dried air stream is then heated, preferably according to the principle of the heat pump, and the heat medium carried through the sheet transport preferably also forms the working medium of the cooling assembly.

  The drying device according to the invention is preferably highly encapsulated with respect to heat. This heat encapsulation is realized in particular by means of a coating device, which itself covers the blowing device and preferably also the sheet running section as much as possible from the further periphery of the printing press. In order to further support the effectiveness of the dryer, a radiator is preferably provided for applying radiation to the printing material that aids the drying process. This radiation can be generated by an IR radiator or even by a UV radiator.

  In particular, an exhaust device is preferably provided for exhausting the polluted exhaust gases produced in the area of the drying device. The exhaust gas exhaust device is preferably adapted to further transport the exhaust gas to the exhaust gas exhaust device via a heat exchange device, where the hot air stream taken from the exhaust gas likewise preheats the dryer air. Can be collected and used.

  The jetting device provided for blowing heated dryer air onto the printing material is, inter alia, formed by a blow box, which preferably comprises a jet nozzle plate and is heated air. Is sprayed sufficiently uniformly on the printing material by the jet nozzle plate. In particular, when the blow-out device is realized by using a blow box, a pre-heating heat exchanger provided for pre-heating the dryer air according to the present invention, and in some cases, for example, an electric heating coil is formed. The generated heat generating device can also be incorporated in the blow box.

  According to a further aspect of the invention, the problem described at the outset is solved by a method for carrying out the drying of a printing material guided through a printing press. In that method, a dry air stream is applied to the printing material using a blow-out device, and the sheet running section provided for guiding the printing material is cooled, the area of the sheet running section The dried air stream is preheated by using the heat taken in.

  The dryer so that the air jetted onto the printing material through the jet nozzle is taken up again by the jet area, ie in the inclusion area of the blow box, and circulated through a substantially closed air circulation section. Can be driven. In order to prevent excessive evaporation of the evaporated medium in the air of the “closed” circulated dryer, a part of the air flow is taken out of this closed circulation part and a dry air cleaner, in particular a low-temperature condenser, is installed. To separate a condensable fraction of dry air. The cooled and rapidly cooled cold airflow generated at this time is sent to the sheet transport unit cooler, and is used to cool the sheet transport unit. Returned to In this respect, the dryer can be driven as a sheet processing module with very no discharge problems.

  Further details and features of the present invention will become apparent from the following description in conjunction with the drawings. The figure shows the following:

  The drying apparatus shown in FIG. 1 is used for drying a printing material guided through the drying apparatus. The drying device includes a blowing device 1. In this embodiment, the blow-out device 1 is implemented as a combined IR dry air dryer, and is suitable for generating so-called hot air for drying. Through the blowing device, it is possible to blow a dry air current represented by an arrow on the printing material. In order to supply the dried airflow to the blowing device 1, a guiding device 2 is provided. The guide device 2 is implemented as a blower in the embodiment shown here. Heating the dried air stream to the required drying temperature is performed by the heating device 3. The heating output of the heating device 3 is controlled by the control device 4.

  As materials to be printed, webs or sheets of various materials are known, and they are suitable. In this case, the printing material is guided in the area of the drying device by a guide surface which can be implemented as a guide running section or a sheet running section. In the following, an embodiment for a sheet-like printed material will be described.

  Accordingly, the drying device further comprises a cooling device 5 implemented as a sheet running section cooler or a guide running section cooler, which guides the material to be printed in the area of the drying apparatus. This is used for cooling the sheet running section provided for the purpose.

  The drying apparatus according to the present invention is characterized in that a preheating heat exchanger 6 is provided in order to preheat the dried airflow using the hot airflow taken in from the sheet running section. The cooling effect generated through the cooling device 5 is controlled by the cooler control device 7.

  In the embodiment shown here, the heating device 3 is located in the passage of the airflow that is placed behind the preheating heat exchanger 6 in the passage of the airflow. This ensures that the heating device 3 can heat the air that has already been preheated by the preheating heat exchanger 6 to the final temperature required if necessary.

  Here, the cooling device 5 implemented as a sheet running unit cooler is structurally configured to radiate heat from the sheet running unit using a heat medium sent by the conduit system 8. This heat medium is preferably a liquid heat medium or, in particular, a refrigerant circulating through the preheating heat exchanger 6 used for preheating the air of the sheet running section cooler or dryer. obtain. The heat medium can also be sent through an auxiliary cooling assembly to ensure a particularly low cooling temperature if necessary. The cooling assembly can be configured to collect and utilize waste heat generated in the region of the cooling assembly for preheating a similarly dry air stream. In addition, it is also possible to exhaust the waste heat that has been exhausted from the heat medium in the dry air preheating frame via the auxiliary heat exchanger 9 exemplarily described here. In the embodiment shown here, the blow-out device 1 is immediately next to the path through which the sheet passes, and for this purpose is arranged between the side frames of the printing press or in some cases the discharge device.

  FIG. 2 shows a very reasonable supplement to the embodiment of the drying device of FIG. 1 and relates to the pretreatment of the air prepared for drying.

  Here, the air supply for the hot air to be generated can be newly adjusted at the entrance to the drying device. The fundamental purpose of this treatment is to remove moisture from the hot air to be obtained for drying in order to increase the drying effect obtained.

  Therefore, the following model of the drying apparatus shown in FIG. 2 can be considered. Air is no longer supplied directly by simply taking the untreated outside air, but is supplied through the air conditioner 12. The air conditioner 12 is formed by being combined with a condensed water separator. The temperature T drops at the location of the air conditioner in the process of preparing dry air or hot air. This is because the humidity Ψ is condensed through the ingress of cold air or the release of heat. Similarly, the humidity Ψ of dry air or hot air decreases. This is because moisture is separated and removed. This basic thermodynamic process can be derived from the Mollier diagram.

  The loss of temperature associated with the air-conditioning of dry air or hot air in the region of the first air supply is again in a relatively easy manner within the framework of the heat recovery system already described with the heat exchanger 6 again. It can be compensated by transferring excess thermal energy through 9.

Furthermore, the heat energy necessary to raise the temperature of the air as it is,
From the cooling device 5 (for example, a water cooling device) of the sheet running section to be cooled, or as a partial air stream in which the warm air supply is branched in the drying device 1 for the drying section, or as a drying section as the reheating device 14 The energy obtained from excess warm air suction 13 at
You can win again and make up for dry air.

  At this time, the temperature T of the dry air or hot air supplied and dried in the meantime rises again. However, the humidity Ψ is kept constant.

The air is heated to the optimum temperature T _Optimum for the drying operation from time to time in a simple heating register 3, which is placed directly in front of the dry-air spraying device 1. At that time, the fumes from the dry-air jetting device 1 are carried out through a jet outlet adapted to optimize the air flow for the drying result and the running of the sheet.

The advantage of such a device is in particular that the dry hot air produced has the following properties: That is,
・ Firstly, it is possible to secure a hot air temperature that is unchanged and high with respect to the standard.

In this way, the output of the drying device can be further increased. This is especially true for usages that do not have additional parameters that can be affected to obtain more output. In this context, the following are given as examples.
・ Drive when machine operating speed is fast ・ Established very wide spectrum of production ・ Or execution of print orders where process stability is particularly significant

  Similarly, the advantage is that the required hot air temperature can be significantly reduced if the humidity does not change with respect to the values in the standard process.

  If the temperature is lower, a perishable material or coloring or varnish can be efficiently dried. From both points of view, most of the heating energy can be saved relatively easily with the described method.

  In general, certain process parameters can be obtained by using the apparatus described in connection with FIG. This is because, after all, the temperature T and the humidity Ψ are kept constant. This applies to the equipment shown, for any installation location of a printing press equipped with this equipment anywhere in the world and for the production process during the production shift.

  Thus, in view of the above, the input thermal energy is utilized in an accurate and efficient manner, including recovery of the converted energy. This means clear energy saving and contributes to making and operating a printing machine that is both energy saving and cost saving by using the drying system according to the present invention. The drying system is modular and can be parametrized, so that the results of the drying can be optimized more flexibly and cheaply for various application areas at the time of development and use. Is possible.

  The drying device shown here can be separated with respect to heat from the periphery of the printing press by means of a coating element not described in detail here, so that the hot air drying device according to the invention in the peripheral region of the printing press The waste heat that comes out is minimal.

  The modules, in particular the preheating heat exchanger 6 and the heating register 3, which are provided for adjusting the dryer air in terms of heat can be arranged in the side area of the printing press. The blow-out device 1 and the sheet transport unit cooler 5 can be implemented as a plug-in module that can be easily attached to and removed from the machine, and preferably for incorporating the module into the system shown here. The machine has an interface. The interface can be functionally connected to the module by simply plugging in ("plug and play") or in another way that can be handled quickly and without special assembly efforts. Can be linked.

  With the concept according to the invention, the ambient air in the preheating heat exchanger is preheated by the cooling circle of the sheet running section. The drive temperature of the hot air dryer is subsequently raised further in the heating register and adjusted to the required temperature value. The heating register 3 is controlled by the control variable TL so that the temperature TL reaches a predetermined set value. As the drive temperature rises in the machine, the output of the heat exchanger also rises. The preheating of the air will thereby become stronger. The heating register is then preferably down-controlled according to the output. The transmitted electrical power is thereby reduced.

  The heating register and the heat exchanger are preferably arranged directly in the dryer, so that the hot air path from the heating register to the dryer and the refrigerant path from the sheet running section to the heat exchanger are It can be kept as short as possible, which improves the efficiency of the device.

  The problem of the hot air box according to the invention is to generate the hot air flow (regularity, strength, profile, direction) required for its properties and to apply dry air correspondingly to the sheet. This box is preferably implemented as a sheet metal construction and can thus be made relatively inexpensively.

  The implementation of the dryer system according to the present invention can be implemented as a combined IR / UV radiator drying system incorporating a warm air suction device. Overall, the blow box system according to the present invention can be used in many fields and can be made into a box shape at a low cost.

  The heat exchanger for preheating provided according to the present invention can at least reliably suppress the temperature TB in the region of the sheet cooling guide to be lower than the maximum temperature Tmax. In some cases, the heat exchanger 6 can be actuated via a control unit 7 having an operating variable TB.

  The configuration of the dryer system according to the present invention makes a great contribution to building an energy-saving printing press. The system according to the invention can be made modular and the effect of the dryer can be optimized flexibly and inexpensively. The heat output discharged in the cooling frame at the sheet running level is used in the present invention for preheating the dryer air. By preheating the outside air supplied to the heating register with a heat exchanger for preheating in the cooling circle of the sheet running section, consumption of electric energy required for heating hot air is suppressed by the concept according to the present invention. Thanks to this treatment, most of the energy supplied to the system can be recovered for drying, improving efficiency.

  The present invention can be used with dryers in which IR radiators, UV radiators or microwave radiators are used internally for energy conversion.

1 is a schematic view of the configuration of a drying apparatus for carrying out drying of a sheet-like printing material, preferably according to the present invention. FIG. 2 is an embodiment of the schematic diagram of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blowing device 2 Induction device 3 Heating device 4 Control device 5 Cooling device 6 Preheating heat exchanger 7 Cooler control device 8 Conduit system 9 Auxiliary heat exchanger 10 Side frame 11 Side frame 12 Air-conditioning device 13 Warm air suction 14 Reheating T _L Air temperature T _B Printed material temperature T _max Maximum temperature in the dryer

Claims (15)

A hot air operated drying device for a web or sheet-fed printing press,
A blow-out device (1) for applying a dry air current on the printing material;
A guiding device (2) for carrying a dry air flow through the blowing device (1);
A heating device (3) for heating the dried air stream;
A control device (4) for adjusting the temperature of the dried air stream;
In a drying apparatus comprising: a guide traveling unit or a cooling device (5) for cooling a sheet traveling unit provided to guide a printing material passing through the drying device;
A preheating heat exchanger (6) is provided in order to preheat the dried airflow using the hot airflow taken in by the cooling device (5) in the area of the guide running section or the sheet running section. And
The drying apparatus, wherein the heating device (3) is disposed in a passage portion of the airflow that is placed behind the preheating heat exchanger (6) along the passage of the airflow.   The cooling device (5) is implemented as a guide travel unit cooler or a sheet travel unit cooler, and performs heat dissipation from the guide travel unit or the sheet travel unit using a heat medium. The drying apparatus according to claim 1.   A liquid is used as a heat medium, and the liquid is sent through the guide travel section cooler or the sheet travel section cooler and the preheating heat exchanger (6). Item 3. The drying apparatus according to Item 2.   4. A drying apparatus according to claim 2 or claim 3, wherein the heat medium is sent by a cooling assembly to form a working medium for the cooling assembly.   The drying apparatus according to any one of claims 2 to 4, wherein waste heat generated in the region of the cooling assembly is collected to preheat the dried air stream.   6. A coating device according to claim 1, wherein a coating device is provided for isolating the blowing device (1) and / or the sheet transporter cooler from the outside with respect to heat. The drying apparatus described in 1.   A radiator device is provided for irradiating the printing material with radiation that accelerates the drying process, the radiator device being implemented as an IR radiator, a UV radiator or a microwave radiator. The drying apparatus as described in any one of 6.   The exhaust gas exhaust device is provided, The drying measure according to any one of claims 1 to 7 characterized by things.   9. Exhaust gas is likewise sent through the heat exchange device in order to preheat the dryer air with a hot air stream taken from the exhaust gas heat exchange device. Drying measures described in the section.   The drying apparatus according to any one of claims 1 to 9, wherein the blowing device includes a blow box.   The drying measure according to any one of claims 1 to 10, wherein the heat exchanger for preheating is incorporated in the blow box.   12. The device (12) according to any one of the preceding claims, characterized in that a device (12) for adjusting the air of the dryer is provided for the preheating heat exchanger (6). Drying measures.   13. The device (12) for adjusting the air of a dryer comprises a device for reducing the humidity in the air, the device comprising a water separator. Drying equipment. A method for carrying out drying of a printing material guided through a printing machine, comprising:
A dry air current is applied to the printing material using a blowing device, and the sheet running section provided for guiding the printing material is cooled,
A method characterized in that the dried air stream is preheated using heat captured in the area of the sheet running section. The dried air stream is dehumidified by the cooling effect,
Thereafter, the sheet is reheated by using heat taken in the area of the sheet running section or the waste heat area of the drying apparatus, and further preheated to be raised to the driving temperature. The method described in 1.

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