DRIER

Abstract

The present invention relates to a dryer for treating a moving printing web in a rotary printing press with gas, having a nozzle body. The dryer according to the invention is characterized in that the nozzle body has at least one opening for the exit of heated gas and has at least one opening for recirculating the cooled gas.

Claims

1.-15. (canceled)

16. A dryer for treating a moving printing web in a rotary printing press with gas, the dryer comprising: a nozzle body, wherein the nozzle body has at least two openings extending over only part of a width of the printing web for an exit of heated gas; and at least one opening for recirculating a cooled gas.

17. The dryer as claimed in claim 16, wherein the at least two openings are arranged at least partially offset.

18. The dryer of claim 16, wherein the at least one opening has a round or oval shape or a shape approximating such a shape.

19. The dryer of claim 16, wherein the nozzle body has a cavity, through which the heated gas is supplied to the printing web.

20. The dryer of claim 16, wherein the nozzle body has a circumferential surface, and the at least two openings for the exit of the heated gas protrudes from the circumferential surface of the nozzle body.

21. The dryer of claim 16, wherein the at least one opening for recirculating the cooled gas is provided outside the cavity.

22. The dryer of claim 16, wherein a suction unit is provided for recirculating the cooled gas.

23. The dryer of claim 16, wherein the nozzle body has essentially at least the width of the printing web.

24. A method for drying a running printing web in a rotary printing press, wherein the running printing web is dried by means of heated gas from a dryer as claimed in claim 16, wherein the cooled gas is at least partially returned into the dryer along a surface of the nozzle body opposite to the printing web, and there is a negative pressure at least essentially in the region between an exit of the heated gas and the printing web.

25. The method of claim 24, wherein the negative pressure is permanently present during operation.

26. The method of claim 24, wherein ambient air is used as the gas.

27. The method of claim 24, wherein the cooled gas is returned by means of suction.

28. The method of claim 24, wherein the cooled gas is supplied to filtration.

29. A use of the dryer as claimed in claim 16 as an intermediate drying nozzle in a rotary printing press.

30. A rotary printing press comprising: a printing cylinder for printing a moving printing web, and the dryer as claimed in claim 16, wherein there is a negative pressure at least essentially in a region between an exit of the heated gas and the printing web.

Description

[0028] In the drawings:

[0029] FIG. 1 shows a perspective view of a nozzle body according to one preferred embodiment of the invention;

[0030] FIG. 2 shows a detailed view of the nozzle body according to one preferred embodiment of the invention;

[0031] FIG. 3 shows a perspective sectional view of the nozzle body according to one preferred embodiment of the invention;

[0032] FIG. 4 shows a cross section of the nozzle body of FIG. 3;

[0033] FIG. 5 shows a detailed view of the nozzle body of FIG. 1; and

[0034] FIG. 6 shows a dryer according to a further preferred embodiment in an installed state.

[0035] FIG. 7 shows a completely assembled nozzle body in a top view.

[0036] FIG. 1 shows a perspective view of a nozzle body 1 according to one preferred embodiment of the invention, wherein the structure thereof is represented as an intermediate drying nozzle in the following by way of example. The dryer consists according to the embodiment shown of a so-called excess pressure region and a negative pressure region.

[0037] The heated gas required for drying, for example, air, flows out of openings 2 which protrude from the nozzle main body 5 and are formed as nozzles, small holes here, is incident on the freshly printed material web or printing web, and is suctioned in again by other provided openings 3. It is thus possible to prevent air-solvent mixture from reaching the atmosphere. The openings can be seen well in FIG. 2, a detailed view. FIG. 1 shows the region out of which the air flows and is simultaneously suctioned in again. The structure of the drying nozzle is visible from the zoom view of FIG. 2.

[0038] In the embodiment shown, a type of plate 4 is provided on the nozzle body, which is formed here as a grid plate, which is fastened by means of rivets, for example, on the base body 5, which is milled, for example. This base body 5 is in turn fastened in a main frame, for example, by means of screws.

[0039] According to the illustrated preferred embodiment, there is a uniform permanent negative pressure in the region between dryer and counter pressure cylinder, which prevents the solvent-laden air from flowing into the environment, on the one hand, and suctions in and discharges the solvent-laden air from the entire printing unit, on the other hand.

[0040] FIG. 7 shows a nozzle body in a view of the outlet nozzles. In this case, the nozzles are the openings 2, which have an essentially round shape and are all designed essentially the same. The openings are arranged transversely in the direction of movement of the printing web in a kind of line, while they are arranged offset at an angle in the movement direction of the printing web. The angle can be in a range of 2 to 30, preferably 5 to 15 here.

[0041] An exemplary structure of a nozzle body 1 is shown in a perspective view in FIG. 3. FIG. 4 shows a cross section of this nozzle body.

[0042] The air, which is either already heated or is still being heated, passes through a connecting piece 6 into the cavity 7 of the nozzle body or the excess pressure region. The air leaves this through the small outlet openings 2 (arrow 8), strikes against the material of the web to be printed, reverses (arrow 10), and reaches the lateral ends 11 through the openings in the milled base body (arrows 9 and 10). Arriving there, the medium flows above the excess pressure region or past the excess pressure region in the direction of the suction opening 12. Preferably so-called stud bolts 13, to which the air suction unit is attached, are located above this suction opening. Depending on the width of the nozzle, the air suction unit consists of different screwed-on connecting pieces. A flexible, solvent-resistant, and heat-resistant hose is attached to these connecting pieces, which transports the solvent-laden air to a manifold.

[0043] FIG. 5 shows a detailed view of the nozzle body 1 from FIG. 1, the inlet or connecting piece for the heated air or gas or air or gas to be heated is shown here.

[0044] FIG. 6 shows a dryer according to a further preferred embodiment in an installed state.

[0045] It can be seen that the entire drying unit is arranged here, for example, between a cross member 14 and a central cylinder 15 in a rotary printing press. Two dryers are visible for this purpose in FIG. 6, wherein more dryers can also be arranged. The nozzle body 1 is fastened by means of a holder 16 in a printing unit. According to the embodiment shown, a manifold 17, in which the exhaust air is discharged, is located on plate holders 18, which are suspended in the cross member 14. By using flexible hoses to connect the nozzle body 1 to the manifold 17, it is possible, for example, to move/pull the nozzle body somewhat in the direction of the cross member, to be able to remove material residues which have caught on the plate.

[0046] As can be seen clearly from FIG. 6, it is additionally possible using a dryer according to the present invention, due to the modular structure, to install it and remove it in and from the printing unit for cleaning purposes without dismantling further components. With appropriate attachments, individual components may also be installed without tools due to the modular structure.