SU1227754A1 - Head box of paper-making machine - Google Patents

Description

The invention relates to mass transfer devices of paper machines and can be used in the pulp and paper industry.

The purpose of the invention is to improve the quality of the cast sheet due to the uniform distribution of fibers in the structure of the sheet.

FIG. 1 shows the pressure head: general view; figure 2 - the same cross section.

The press box of the papermaking machine comprises a housing 15 with side stacks, equipped with an inlet device with an upper lip 2 located along the grid 3 and inclined towards it. The device for collecting paper pulp for recycling is made in the form of a groove 4, placed on the lower lip 5 across the flow, closed on top of a flexible membrane 6, forming with the side walls of the slot dp of mass collection and connected to the vibrodrive 7.

Pressure pshkk works as follows.

The paper pulp moving along the channel of the headbox has an uneven distribution of flow velocities across the width. Arrivals to the device 4 for separating the paper pulp for recycling, the flow is subjected to acoustic vibrations, which are transferred to it by a flexible membrane 6 connected to the vibrodrive 7. improve

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uniform distribution of the fibers across the flow width and disorient the fibers in the longitudinal direction. At the same time, in the slots formed by the flexible membrane 6 and the walls of the chute 4, under the action of pressure in the pressure box, layers of paper pulp that have low dynamic flow characteristics are removed from the walls. Channel 4, which is closed on top of the flexible membrane 6, is not only an active flow wiping device, but also a damping device for smoothing low-frequency oscillations in the paper pulp, which cause the weight of 1 m of paper to oscillate.

The design feature of the pressure box is the absence of a narrow inlet slit, where the fibers are oriented in the longitudinal direction, so a high dispersive flow is immediately supplied to the sieve table in the dewatering and forming web, which leads to an increase in the quality of the sheet of paper produced.

The choice of the optimal frequency and amplitude of the oscillation of the membrane is carried out separately from each type of paper produced and is set to vibrate through to 1-1, for example, cam or electromagnetic.

The use of the invention makes it possible to reduce the mass of 1 m of processed products, improve its quality indicators due to uniform distribution of fibers in the sheet structure and to ensure economical use of forest resources.

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Claims (1)

HEADER BOX OF A PAPER MACHINE, comprising a housing with side walls and an inlet device for the pulp flow, Fig. 1, consisting of a lower lip and an upper lip located along the net of the machine obliquely to it, and means for selecting part of the pulp for recycling, characterized in that, in order to improve the quality of the molded web due to the uniform distribution of fibers in the structure of the web, for selecting mass consists of trough overlapped membrane, and connected thereto vibration drive, and the lower lip has a slit disposed transverse to the direction of mass flow, which is trough the membrane with ob- _l mation from the side enkami korpu- S sa gap for the selection of the mass to the trough. yo yo * 4 SI z