JPH05798U - Band material drying device - Google Patents

Abstract

(57) [Abstract] [Purpose] To eliminate the unconstrained part of the wet paper to prevent fluttering and paper breakage, and to improve paper quality. [Structure] In a drying device for a strip-shaped material such as a wet paper web 1, a felt run composed of a pair of upper and lower felts 3, 3 wound around a plurality of hot air blowing rolls 8 is provided, and the wet paper web is placed between the felts 3, 3. Dry while transferring while sandwiched.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a drying device for strip-shaped materials such as wet paper.

[0002]

[Prior Art]

 3 and 4 respectively show an outline of a conventional paper machine dryer part. The wet paper 1 dewatered in the previous process press part enters the dryer part shown in the figure and is felt on a dryer roll 2 using steam as a heat source. It is pressure-bonded by 3, and heated and dried repeatedly until it has a predetermined water content, and then sent to the calendar part in the subsequent step.

FIG. 3 shows a conventional most popular type of dryer part, in which the dryer rolls 2 are arranged in two stages, and felt rolls are provided by felts 3 and 3, respectively, so that both sides of the wet paper web 1 are alternately arranged. It can be heated to. The feature of this type is that it has a free run between the upper and lower dryer rolls, which is a running part only for wet paper, but this free run is apt to cause fluttering due to the surrounding air flow, causing wrinkles and paper breaks. Was often the case. In addition, 4 is a felt roll and 6 is a doctor.

Therefore, as a method for eliminating the free run, the method of FIG. 4 has been proposed in Japanese Utility Model Laid-Open No. 63-89996. The feature of this type is that it has no free run, and stable running of wet paper is expected. In addition, 5 is a suction roll. Further, the dryer roll shown in FIGS. 3 and 4 is generally provided with a doctor 6 for preventing winding of wet paper.

[0005]

[Problems to be solved by the device]

 In the conventional dryer type shown in FIGS. 3 and 4, the wet paper 1 and the felt 3 are wound around the surface of the dryer roll 2 in this order. Therefore, the wet paper web 1 tends to follow the dense roll surface on the exit side of the dryer roll 2. This tendency causes the flapping of the free run in FIG. 3, and also causes the wet paper web 1 to separate from the felt 3 in FIG. These phenomena may lead to paper breaks, making it particularly difficult to pass narrow tail paper.

Further, in these types, it is necessary to provide the doctor 6 for preventing the wet paper web from being wrapped around the dryer roll 2 when the paper is cut, which is one of the factors that complicate the dryer part. .. It is conventionally known that if the wet paper 1 is restrained during the drying process, the elongation is reduced and the dimensional stability is improved, but in the forms of FIGS. 3 and 4, both are unconstrained. Since it has a portion, there was a defect that sufficient dimensional stability could not be obtained.

In the drying using the conventional dryer roll, when the water content of the wet paper is low, the contact heat transfer coefficient between the roll cell and the wet paper is low, and especially the water content is 20% or less. Then, there was a feature that the drying ability was rapidly reduced. Generally, drying in this area is called rate-reducing drying, and this is an issue that cannot be avoided by drying using dryer rolls. The present invention has been proposed to solve the above conventional problems.

[0008]

[Means for Solving the Problems]

 For this reason, the present invention provides a drying apparatus for strip-shaped materials such as webs, in which a pair of upper and lower felt runn wound around a plurality of hot air blowing rolls is provided, and the web is dried while being transported while being sandwiched between the felts. This will be used as a means for solving problems.

[0009]

[Action]

 Since the present invention employs a means for drying the wet paper web while sandwiching it between two felts, it is possible to eliminate the fluttering of the wet paper web during the wet paper web drying process and improve the paper passing property. Therefore, the wet paper web is dried while maintaining the restrained state. Moreover, by adopting a hot air blowing roll as the heating device, it is not necessary to consider the contact heat transfer coefficient between the roll cell and the wet paper as in the past, and it is possible to always perform highly efficient drying.

[0010]

【Example】

 Hereinafter, the present invention will be described with reference to the embodiments of the drawings. FIGS. 1 and 2 show the embodiments of the present invention. In the figure, the wet paper web 1 that has come out of the final press is wound around a plurality of hot air blowing rolls 8 in a state of being sandwiched by two upper and lower felts 3. In the figure, 4 is a felt roll, 5 is a suction roll, and 6 is a doctor.

In addition, if the suction roll 5 is arranged as shown in FIG. 2 in the inter-group portion of the felt run, the delivery of the wet paper web 1 can be made possible while maintaining the restrained state by vacuum. Moreover, the structure of the inter-group portion shown in this embodiment can completely separate the continuous felt runn, and it is possible to warm up the dryer part or partially stop the operation when a defect occurs. The drying device of the present invention is not limited to this embodiment, and can be used in combination with conventional drying means. For example, it is particularly effective when used in the dry area of the conventional dryer.

[0012]

[Effect of the device]

 As described in detail above, according to the present invention, the wet paper web is transported while being sandwiched between the two felts, so that the wet paper web is reliably passed without fluttering or paper breakage. Further, there is no need for a complicated doctor device as in the past. Therefore, workability and operation efficiency are greatly improved. In addition, the paper quality is improved by being completely restrained, and since there is no reduction rate drying area, high efficiency drying is always possible, saving energy and space. Furthermore, since there is no paper corrugation or paper wrapping around the dryer rolls, the gap between the rolls is extremely small and further space saving is possible.

[Brief description of drawings]

FIG. 1 is a side view of a belt-shaped material drying apparatus according to an embodiment of the present invention.

FIG. 2 is a detailed sectional view of an inter-group portion of FIG.

FIG. 3 is a side view showing an example of a conventional paper machine dryer part.

FIG. 4 is a side view showing another example of a conventional paper machine dryer part.

[Explanation of symbols]

 1 Wet paper 3 Felt 4 Felt roll 5 Suction roll 6 Doctor 8 Hot air blowing roll

Claims (1)

[Claims for utility model registration] 1. A drying device for strip-shaped materials such as webs is provided with a pair of upper and lower felt run which are wound around a plurality of hot air blowing rolls, and the web is sandwiched between the felts. An apparatus for drying a band-shaped material, which is characterized in that it is dried while being transferred in a state.