Drying and gas or vapor contact with solids – Apparatus – For diverse operations on treated material
Reexamination Certificate
1999-12-21
2001-05-01
Gravini, Stephen (Department: 3749)
Drying and gas or vapor contact with solids
Apparatus
For diverse operations on treated material
C034S062000, C034S636000, C034S638000, C034S643000
Reexamination Certificate
active
06223448
ABSTRACT:
FIELD OF THE INVENTION
The invention concerns a device for conditioning a preferably freshly printed paper web with a dryer and remoistening apparatus, wherein the dryer has a heating zone, a temperature maintenance zone and a cooling zone and the remoistening apparatus has spray jets, through which moisturising agents can be admitted, arrayed above and below the transport surface of the paper web and spray chambers containing the same.
BACKGROUND OF THE INVENTION
A device of this kind is known from DE 44 05 332 A1. In this known array, between the exit of the dryer and a chilling roller stand situated immediately downstream of it, provision is made for a tunnel housing through which the paper web passes and which presents two sections arrayed one after the other, of which the section more distant from the dryer takes the form of a remoistening apparatus with chambers containing spray jets, set above and below the transport surface of the paper web, through which moisturising means can be admitted, while the section closer to the dryer is equipped with air squeegees arrayed above and below the transport surface of the paper web, through which compressed air can be admitted, whose function is to scrape off solvents that have been transported together with the paper web. The tunnel housing built onto the dryer constitutes a comparably large volume between the dryer and the chilling roller stand. The cooling zone of the known dryer generally includes air jets through which cool air can be admitted. As the air's heating capacity is relatively small, a relatively large volume is also required in this case, quite regardless of the construction outlay.
SUMMARY OF THE INVENTION
Starting from this, it is therefore the task of the present invention to improve a device of the kind mentioned above with simple, cheap means, so that it is possible to obtain a compact overall method of construction.
According to the invention, this task is achieved in that the cooling zone of the dryer contains a moisturising apparatus for remoistening and cooling the paper web.
As the remoistening device according to the invention is integrated into the dryer, the distance between the said dryer and a chilling roller stand arrayed immediately downstream of it can be relatively small, so that the result is a relatively short assembly array. The dryer itself can also be relatively compact as a consequence of the cooling liquid being applied to the paper web. This is because the liquid applied for the purpose of moistening the paper web has a relatively high heat capacity in comparison to the heat capacity of air, so that even a relatively small amount of moisturising agent can be relied upon to be sufficient for bringing about a cooling of the web. This means that relatively few spray jets are necessary, which saves volume and has an advantageous fallout effect in terms of avoiding disturbance to the paper web as its runs. One further advantage of the measures according to the invention can be seen in the fact that, as a result of their high penetration force and also a result of the increased volume produced by the vaporisation, the moisturiser jets can be relied on to break down the laminate air layer laden with solvent that flanks the paper web. This ensures that this solvent-laden air is already brought to separate from the paper web in the dryer, which facilitates disposal, as the dryer is certainly fitted with suitable equipment, and avoids any undesirable external dissemination of solvent. At the same time, this also ensures that no additional means are necessary for breaking the laminate air layer down, as in the case of the tunnel with and without blow jets to be found in the state of the art, which also saves in terms of volume and construction outlay.
Advantageous embodiments and functional further developments on the above-listed measures are described in the sub-claims. Thus the amount of moisturising agent channelled to the spray jets is functionally greater than the amount of remoisturising agent. This guarantees that, in addition to the remoistening, there is also a reliable cooling of the paper web.
One further advantageous measure may consist of the fact that the spray jets can be provided with moisturising agents and compressed air to be blown out. This achieves a good distribution of the said moisturising agent and in particular also a high penetration force of the same in an advantageous manner.
One further, particularly preferable, measure may consist of arraying the spray chambers each in a dedicated suction chamber, which can be sucked out by means of at least one dedicated extraction fan blowing out into the dryer. This results in exhaust shafts flanking the spray chambers on the entry and exit sides, which guarantee a reliable extraction of the large air volume to be expected. As the extraction shafts are sucked out, it is certain that no air can make its way outside. The air squeegees can thus either be eliminated completely or have relatively modest dimensions, which has an advantageous effect on avoiding outlay and avoiding any disturbance to the web. At the same time, this also guarantees that no moisture makes it way outside. There is therefore no need to fear that condensation will collect outside the moisturising apparatus. As the blower(s) blow(s) into the dryer, the resulting method of construction is also relatively simple. Moreover, this measure also proves to be energy-economic, as the air blown out is already tempered.
At least one cooler can be arrayed functionally with each extraction fan. This ensures that the oil and water transported with the air are separated, which facilitates disposal.
Additional advantageous embodiments and functional further developments on the above-listed measures are described in the other sub-claims and can be deduced in greater detail from the following description of examples, with the aid of the drawing.
REFERENCES:
patent: 3599554 (1971-08-01), Aelterman
patent: 4462169 (1984-07-01), Daane
patent: 4523391 (1985-06-01), Smith et al.
patent: 5571564 (1996-11-01), Helms et al.
patent: 5642671 (1997-07-01), Winheim
patent: 5813332 (1998-09-01), Reichel-Langer et al.
patent: 5845415 (1998-12-01), Sundqvist
patent: 5906862 (1999-05-01), Yapel et al.
patent: 5970626 (1999-10-01), Schmidt et al.
Brischler Bruno
Motzke Michael
Baldwin Grafotec GmbH
Gravini Stephen
Jones Tullar & Cooper P.C.
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