DE102008042122A1 - Thermo-air drying device and method for accomplishing the drying of a printing material - Google Patents

Abstract

The invention relates to a thermo-air drying device for a sheet-fed printing machine as may be arranged in particular subsequent to a paint or inking unit in the printing press or the rise of a boom, wherein the drying effect is brought about by pressurizing the printing material with a heated gas, in particular dryer air , The invention is based on the object to provide solutions by which a required drying effect can be achieved in a procedurally and in particular with regard to the machine operating costs over previous approaches more advantageous manner. This object is achieved by a thermo-air drying device for a printing press, with an inflator for directing a dry air flow to a substrate, a conveyor for promoting the drying air flow through the inflator, a heater for heating the dry air flow, a control device for adjusting the temperature of the dry air stream , and a cooling device for cooling the printing material in the region of a back side facing away from the inflator Bedruckstoffrückseite, this thermoluft drying device is characterized in that a Vorwärmwärmetauschereinrichtung is provided for preheating the dry air stream using a picked up in the region of the cooling device by this or by the cooling device. ..

Description

The The invention relates to a thermo-air drying device for a sheetfed press as she especially following in a Paint or inking unit in the area of the printing press or the entrance a cantilever may be arranged, the drying effect by charging the printing material with a heated gas, in particular dryer air is brought about.

Around Any occurring as a result of the heating of the printing material It is to minimize deformation of the same as possible known, the substrate in the area of the Trockenluftbeaufschlagungsseite reverse side by cooling one here to cool arranged arch track.

From the DE 33 24 130 A1 For example, a method and apparatus for drying printed or dyed webs by means of heat is known. The process of drying printed or dyed webs with heat is characterized by subjecting the printed web to a non-contact heat shock in a first stage, then contact heating in a second stage at a lower temperature than in the first stage, and then in one third stage is cooled via direct contact. In this case, the energy obtained during cooling is transferred by means of a cooling unit in other parts of the system.

From the DE 202 06 407 U1 is a printing machine with a drying station known. The printing machine is equipped with several arranged in series construction and traversed by a printing material printing units. Each printing unit is followed by a drying station. Each of the drying stations is in each case arranged on the circumference of a single, the printing material web-supporting temperature control. It is envisaged here that the heat dissipated by the tempering roller is used for the preheating of drying air.

Furthermore, in the DE 298 19 202 U1 a device for drying and cooling freshly printed paper webs described. The apparatus for drying and cooling of freshly printed paper webs is provided with a dryer, a downstream in the direction of the dryer cooler along the passage line arranged nozzles for blowing hot drying gas or cold air to the continuous paper web; a Nachbrennkammer provided with a suction for enriched with volatile oil or resinous substances drying gas from the interior of the dryer and with supply lines for clean gas to the nozzles and an exhaust passage for excess clean gas. An absorption refrigeration system with refrigerant is thermally linked to the dryer and the radiator in such a way that heat is supplied to the refrigerant, which is withdrawn from the clean gas flowing through the exhaust duct. In addition, heat is supplied to the evaporator of the refrigeration system, which is withdrawn from the cold air in the cooler or the fresh air flowing to the cooler.

The known devices have expensive designs, to heat energy used in the cooling of plant parts accumulates, in other parts of the system, such as a dryer again use.

Of the Invention has for its object to provide solutions through which a required drying effect in a simple manner in a procedural and in particular in terms of machine operating costs compared to previous approaches more advantageous Way can be achieved.

These Task is solved according to the invention the features of claim 1.

there is provided a working with thermal air drying device to use for a printing press. This has an inflator for directing a dry air flow onto a substrate, a conveyor for promoting the drying air flow by the inflator, a heater for heating the dry air flow or Thermoluftstromes, a control device for adjusting the temperature of the dry air stream, and a Cooling device for cooling a guide of the printing material provided by the thermo-air drying device Bogenbahn on.

The Working with thermo-air drying device is characterized from that a preheating heat exchanger device is provided for preheating the dry air stream using one in the region of the arcuate path through the cooling device used absorbed heat flow.

Thereby it is possible in an advantageous manner, directly in the Area of working with thermo-drying device a heat flow tapped from the arc cooling to use for preheating the dry air. Overall results This results in a significant reduction of waste heat the printing press as well as the energy consumption of the drying device and thus the machine itself.

In particular, it is possible for the produced by any installed in the range of the jib IR / TL dryer intensive heat output, which also affects the very intense heating of the underlying arc path to Vorhei to use the drying air flow. The heater provided for heating the dryer air is arranged downstream of the preheating heat exchanger device in the air flow path. The heater thus only has to make the energy required to heat the dryer air to the required final temperature in the already preheated dryer air.

The Cooling device is preferably as a sheet-race cooler executed, the withdrawal of heat from the Sheet career preferably by means of a liquid heat transfer medium he follows. This heat transfer medium is preferably by a circulation device by the invention for preheating of the dry air flow used preheat heat exchanger guided.

It is possible to continue the heat transfer medium also by another cooling grid or a cooling unit respectively. In the further guidance of the heat transfer medium a cooling unit makes it possible in particular also the waste heat generated in the area of the cooling unit to use for preheating the drying air flow. The Heating of the dry air flow is preferably carried out after the principle of a heat pump, which by the sheet course cooler guided heat transfer medium preferably also forms the working medium of the cooling unit.

The Drying device according to the invention is preferably largely thermally encapsulated. This thermal encapsulation can be achieved in particular by a covering device, the as such, the inflator and preferably also the arc track cooler from the wider environment of the printing press, as far as possible, shields. To further support the dryer effect Preferably, a radiator device is provided for applying the printing material with a drying process supporting the radiation. This radiation can in particular by an IR emitter or else a UV emitter can be generated.

Especially for the derivation of the resulting in the drying device, Emissions laden exhaust air is preferably an exhaust device intended. This exhaust air discharge device is preferably designed so that in this case a further leadership of the exhaust air over a heat exchanger device takes place, wherein this case the exhaust air tapped heat flow also for preheating the dryer air can be used.

The intended to inflate the heated dryer air on the substrate In particular, the nozzle arrangement can be provided by a blow box be formed, this blow box preferably a Ausblasdüsenplatte includes, by which a sufficiently uniform Inflation of the heated air to the substrate is achieved. In particular, in the realization of the inflator using a blow box, it is possible according to the invention for Preheating the dryer air provided Vorwärmwärmetauschereinrichtung and possibly also, for example, designed as an electric heating coil Heating device still in this blow box integrate.

According to one Another aspect of the present invention is the object specified above also solved by a procedure for the accomplishment of the Drying of a substrate guided by a printing press, in which by means of an inflator a dry air flow is fed onto a substrate, and one for guidance a substrate provided sheet is cooled, the dry air flow using the in the area of the arc path preheated heat is taken.

It is possible to operate the dryer so that through the blowing nozzles on the printing material blown air in near the inflation area, so still in the Umgriffsbereich the blow box again and taken over a substantially circulated closed air recirculation. To an excessive chartering this "closed" circulated dryer air with steamed media can prevent this closed circuit, a partial air flow withdrawn and a dryer air washer, in particular low-temperature capacitor can be performed to separate condensable fractions of the dryer air. The hereby Generated, washed and frozen cold air stream can introduced into the Bogenbahnkühler and thus for cooling used the bow path, if necessary filtered and back into the cycle to be led back. The dryer can so far operated as a largely emission-neutral sheet treatment module become.

Further Details and features of the invention will become apparent from the following Description in connection with the drawing. It shows:

1 a schematic representation of the structure of a drying device according to the invention for effecting the drying of a preferably sheet-shaped substrate and

2 a variant of the schema representation after 1 ,

In the 1 As shown drying device serves as the drying of a through the Drying device guided substrate. The drying device comprises an inflator 1 , which is designed in this embodiment as a combined IR / dry air dryer and is suitable for generating a so-called thermo air for drying. About this inflator, it is possible to inflate a here indicated by the arrow symbols dry air flow to the substrate. For feeding the dry air flow into the inflator 1 is a conveyor 2 provided, which is executed in the embodiment shown here as a blower device. The heating of the dry air stream to the required drying temperature is effected by a heater 3 , The heating power of this heater 3 is through a control device 4 regulated.

The drying device furthermore comprises a cooling device designed as a curved path cooler 5 , which as such serves the cooling of the intended for guiding the printing material in the drying device arc path.

The drying device according to the invention is characterized in that a preheating heat exchanger device 6 is provided for preheating the dry air flow using a tapped from the arc path heat flow. The about the cooling device 5 generated cooling effect is by a radiator control device 7 regulated.

In the embodiment shown here is the heater 3 in an air flow path of the preheating heat exchanger device 6 downstream air path section. This will ensure that the heater 3 already through the preheat heat exchanger device 6 preheated air - as far as necessary - can heat up to the required final temperature.

The cooling device 5 , which is designed here as a sheet-fed cooler, is structurally designed so that the withdrawal of heat from the sheet career using a through a piping system 8th guided heat transfer medium takes place. This heat transfer medium can be a preferably liquid heat transfer medium or, in particular, a refrigerant that passes through the sheet tunnel cooler and the preheating heat exchanger used to preheat the dryer air 6 circulated. This heat transfer medium can still be performed by an additional cooling unit to ensure, if necessary, particularly low cooling temperatures. This cooling unit can be designed so that the heat generated in the region of the cooling unit waste heat is also used to preheat the dry air flow. Otherwise, it is also possible, in the context of the preheating of the dry air still not sufficiently dissipated from the heat transfer medium waste heat over the here exemplified auxiliary heat exchanger 9 dissipate. In the embodiment shown here is the inflator 1 in the immediate vicinity of a Bogenlaufpfad and this is between the side frames 10 . 11 the printing press or optionally also a boom arranged.

In 2 is a very useful addition to the embodiment of the drying device according to 1 shown, which relates to the pretreatment of the air to be provided for the drying.

Here is provided that the air supply for the Thermo air additionally at the entrance to the drying device can be conditioned. The basic goal of this treatment is that to increase the achievable drying effect Dehumidification of the for the drying to be won Thermo air is performed.

Therefore, the following is in 2 Model provided for the drying device:
The air supply is no longer directly by simple receipt of untreated outdoor air, but is via a conditioning device 12 carried out. The conditioning device 12 is designed in conjunction with a condensate separator. At this point of the preparation process of the drying air or thermo air, the temperature T decreases, since the moisture ψ is brought to condensation via the supply of cold or heat removal. Likewise, the moisture ψ of the drying air or thermo-air decreases because water is separated and disposed of. This thermodynamic basic process is shown in the Mollier diagram.

The associated with the conditioning temperature losses of the drying air or the thermal air in the primary air supply can in a relatively simple manner in the context of the already described system for heat recovery again via the heat exchanger 6 . 9 be supplemented by the transfer of excess heat energy.

• – von der Kühleinrichtung 5 (z. B. einer Wasserkühlung) an der zu kühlenden Bogenführungsbahn oder
• – als abzweigenden Teilluftstrom der Warmluftversorgung an der Trocknereinrichtung 1 für die Trockenstrecke
• – oder
• – von einer Warmluftabsaugung 13 überschüssiger Warmluft an der Trocknerstrecke als Nachwärmeeinrichtung 14 abgeführten Energie

wieder zu gewinnen und in der Trocknungsluft zu ergänzen.For this it is possible to use the heat energy required for increasing the temperature of the raw air

• - from the cooling device 5 (For example, a water cooling) on the sheet to be cooled sheet or
• - As a branching partial air flow of the hot air supply to the dryer device 1 for the drying section
• - or
• - from a hot air extraction 13 Excess warm air at the dryer section as after heat device 14 discharged energy

recover and supplement in the drying air.

there the temperature T rises again the fed and meanwhile dried drying air or thermo air on again. The humidity ψ remains but now constant.

The air heating to the optimal for the respective drying operation temperature T _Optimum then takes place in a commercial and simple heating 3 directly in front of the drying nozzle 1 , The air outlet from the drying nozzle 1 takes place on the drying result and on the sheet flow flow optimized tuned outflow.

• – Zum Einen ist eine auf einen Standard bezogen unveränderte und hoher Thermolufttemperatur vorhanden und
• – es ist zusätzlich eine deutlich vergrößerte Feuchtigkeitsaufnahmefähigkeit vorhanden als zuvor.

The advantages of such a device are, above all, that the dry and hot air produced has the following properties:

• - On the one hand there is a standard air intake temperature that is unchanged and high
• - There is also a significantly increased moisture absorption capacity available than before.

• – Betrieb bei hohen Maschinenlaufgeschwindigkeiten,
• – veranschlagtes sehr breites Produktionsspektrum oder
• – die Ausführung von Druckaufträgen, bei denen Prozessstabilität von besonders großer Bedeutung ist.

In this way, the performance of the dryer device can be additionally increased. This is especially true for applications in which no further influenceable parameters would be able to achieve even more performance. In this connection are to be mentioned by way of example

• Operation at high machine speeds,
• - Quoted very wide production spectrum or
• - the execution of print jobs, where process stability is particularly important.

As well simply there is the advantage that over the values in standard processes with unchanged humidity allows a much lower required air temperature becomes.

Here at lower temperatures, sensitive materials, or paints / varnishes are dried efficiently. Under both views It will possibly be a large part of the heating energy saved by the described means in a relatively simple manner.

Generally, it will be through use of in conjunction with 2 described device with a conditioning 12 It is possible to achieve constant process parameters, because in the end both the temperature T and the air humidity ψ are kept constant.

These Statement applies to the device shown both in terms on any site of an equipped with it Printing machine anywhere in the world, as well as for the Production process during a production shift.

In order to So is the heat energy used including the converted Energy recovery in a more precise and efficient Used way. This means a significant energy saving and the use of the dryer system according to the invention contributes to the design and operation of an energy and thus also cost-saving printing press. As the drying system modular and can be parameterized enabled it already in the development and even more in the application one flexible and economical optimization of drying results for various fields of application.

It is possible, the drying device shown here by not shown here lining elements thermally decouple from the environment of the printing press, so that the waste heat discharge from the thermo-air drying device according to the invention in the surrounding area of the printing machine as low as possible is.

The provided for the thermal conditioning of the dryer air modules, in particular the preheat heat exchanger 6 and the heating register 3 can be arranged in the side area of the printing machine. The inflator 1 and the bow track cooler 5 can be implemented as plug-in modules that can be easily inserted into or removed from the machine, wherein for incorporation of these modules in the system shown here preferably interfaces are prepared on the machine either a functional combination of the modules by simple plug-in ("plug and play"), or in other ways, quickly and without special installation effort developable way.

The inventive concept, the ambient air is preheated in the preheat heat exchanger from the cooling circuit of the arc. The operating temperature of the thermo-air dryer is then further increased in the heating register and adjusted to the required temperature value. For this temperature TL reaches a certain setpoint, the heating register 3 regulated with the controlled variable TL. As the operating temperature in the machine increases, the performance of the heat exchanger also increases. The air preheating is thus becoming more intense. The heating register is then preferably regulated in terms of power down. The supplied electrical power is thus reduced

The Heating register and the heat exchanger are preferably direct installed on the dryer, thus the way for the thermo-air from the heater to the dryer and the path for the cooling medium kept as short as possible from the arc to the heat exchanger can be, whereby the efficiency of the system is improved.

task the thermal air box according to the invention is the hot air flow required in its properties (uniformity, Intensity, profile, direction) and to create the arc to be charged accordingly with dryer air. This box is preferably designed as a sheet metal construction and can be made relatively inexpensive.

The Embodiment of the dryer system according to the invention can be used as a combined IR / UV lamp drying system with integrated Hot air extraction can be performed. Overall, that can Blaskastensystem invention universal and cost-effectively manufactured in cassette form.

The inventively provided Vorwärmwärmetauscher should at least ensure that the temperature in the arc cooling duct TB is less than the maximum temperature T max. Optionally, the heat exchanger 6 via a control element 7 be switched on with the control variable T _B.

Of the inventive design of the dryer system makes a significant contribution to the design of an energy efficient Press. The system according to the invention can be modular and allows the flexible and inexpensive optimization of drying results. The under the Cooling the sheet travel level dissipated heat output is used according to the invention for preheating the dryer air used. By the concept according to the invention is the consumption of the heating air for the heating air necessary electrical energy is reduced by turning the heating register supplied ambient air thanks to preheating heat exchanger preheated in the cooling circuit of the arc path. Thanks to this measure can be a large part of the system supplied Recover energy for drying, the efficiency will be improved.

1

inflator

2

Conveyor

3

heater

4

control device

5

cooling device

6

Vorwärmwärmetauscher

7

Cooler controller

8th

Piping

9

Additional heat exchanger

10

side frame

11

side frame

12

conditioning device

13

hot air exhaust

14

reheating

T _L

temperature the air

T _B

temperature of the printing material

^T max

maximum Temperature in the dryer

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 3324130 A1 [0003]
• - DE 20206407 U1 [0004]
• - DE 29819202 U1 [0005]

Claims (15)

Thermo-air drying device for a sheet-fed printing press, comprising: an inflator ( 1 ) for directing a dry air stream onto a printing substrate and a conveyor ( 2 ) for promoting the drying air flow through the inflator ( 1 ), - a heating device ( 3 ) for heating the dry air stream, - a control device ( 4 ) for adjusting the temperature of the drying air flow, and - a cooling device ( 5 ) for cooling an intended for guiding the printing material by the drying device arc, characterized in that a preheating heat exchanger ( 6 ) is provided for preheating the dry air flow using one in the region of the arcuate path through the cooling device ( 5 ) and that the heating device ( 3 ) in an air flow path of the preheating heat exchanger device ( 6 ) downstream air section is arranged. Drying device according to claim 1, characterized in that the cooling device ( 5 ) is designed as a sheet path cooler, and that the withdrawal of heat from the sheet career using a heat transfer medium takes place. Drying device according to claim 2, characterized in that as the heat transfer medium, a fluid is used by the sheet course cooler and the preheating heat exchanger ( 6 ) is guided. Drying device according to claim 2 or 3, characterized characterized in that the heat transfer medium through a cooling unit is guided and its working medium forms. Drying device according to one or all of the claims 2 to 4, characterized in that in the region of the cooling unit accumulating waste heat for preheating the dry air flow is used. Drying device according to at least one of claims 1 to 5, characterized in that a covering device is provided, for thermal foreclosure of the inflator ( 1 ) and / or the Bogenbahnkühlers of the environment. Drying device according to at least one of the claims 1 to 6, characterized in that a radiator device is provided is to act on the printing material with a drying process supporting radiation and that the radiator device is designed as an IR or UV emitter. Drying device according to at least one of the claims 1 to 7, characterized in that an exhaust air discharge device is provided. Drying device according to at least one of the claims 1 to 8, characterized in that the exhaust air also over a heat exchanger device is guided, for Preheating the dryer air with a from the exhaust air heat exchanger device tapped heat flow. Drying device according to at least one of Claims 1 to 9, characterized in that the inflator includes a blow box. Drying device according to at least one of Claims 1 to 10, characterized in that the preheating heat exchanger device is involved in this blow box. Drying device according to at least one of claims 1 to 11, characterized in that the preheating heat exchanger ( 6 ) An institution ( 12 ) is assigned to the conditioning of the dryer air. Drying device according to claim 12, characterized in that the device ( 12 ) for conditioning the dryer air has a device for reducing the humidity of the air and that the device comprises a water separator. Method for accomplishing the drying of a by a printing machine guided substrate at where: - By means of an inflator a dry air flow is fed to a substrate, and - one for guiding a printing material provided arc path is cooled, the dry air flow is under use preheated in the area of the arc traced heat becomes. Method according to claim 14, characterized, that the dry air flow - under cooling effect dehumidifies and - then using the in the area taken the arc or the waste heat of the drying device Warmed up the heat and then further preheated and brought to operating temperature.