SU1368352A1 - Ventilation hood of drying section of paper-making machine - Google Patents

Abstract

The invention relates to the equipment of the pulp and paper industry and can be used in the drying section of paper or potato machines when drying paper or paperboard on drying cylinders. The purpose of the invention is to intensify the drying process by creating optimal conditions for the evaporation of moisture from the web. The ventilation hood contains frame 1, ceiling 2, sheet 3, side walls 4 with lifting and sliding shields 5 and 6, suction nozzles 7, control valves 8, pressure air ducts 9, air distributors 10 and 11 with air outlet devices S

Description

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12, transverse partitions 13 with sliding doors 14, guiding screens with a swing door, ventilators; Tilators, heaters 18 and local drying zones corresponding to heating periods, maximum and falling drying rates. The air heated in the heaters 18, through the air distributors 10 and 11, is directed towards the paper web, forming counter air screens separating the cap into separate drying zones, each of which is supplied with hot dry air with a temperature appropriate to the drying mode. 1 hp fg-ly, 3 Il. ,

one

The invention relates to the equipment of the pulp and paper industry and can be used in the drying section of paper or board separators when drying paper.

or cardboard on the drying cylinders.

The purpose of the invention is to intensify the drying process by creating optimal conditions for the evaporation of moisture from the web.

Fig. 1 shows a hood with installation of devices for dividing the hood into separate local drying zones, a general view; FIG. 2 is a section A-A in FIG. one; on (Fig. 3 - graph of drying cardboard (curve a), graph of moisture content of the steam-air mixture under the hood on existing machines (curve g) and according to the invention (curve c), where I is the heating zone; II - II - zones of intense evaporation; III - zone of decreasing intensity of evaporation of moisture.

The ventilation hood contains frame 1, ceiling 2, sheet 3, side walls 4 With lifting and sliding shields 5 and 6, end walls (not shown),

suction nozzles 7, control valves 8, pressure air ducts 9, air distributors 10 and 11 s for air discharge devices 12, transverse bulkheads 13 with sliding doors 14, guided the screen 15 with a rotary flap 16, fans 17, air heaters 18, local areas 19-21 drying, corresponding to the periods of heating, maximum and falling speed of drying.

Air distributors 10 and 11 are made in the form of pressure flows

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Devices that are installed in pairs between the beds of the drying part in the transverse direction to the movement of the paper web and are directed towards the movement of the paper web towards each other.

The transverse partitions 13 and the guiding screens I5 are installed under the hood dp to prevent the flow of moist air into the adjacent zones.

Fans 17 and heaters 18 for preparing hot air can be installed on the ceiling of the hood 1, as well as outside the hood (not shown).

The principle of operation of the vent cap is as follows.

The drying part under the hood is divided into separate drying zones 19-21 with separate drying modes.

The air heated in the heaters 18 by means of the fan 17 through the air ducts 8 and 9 is injected into the air distributors 10 and 11. From the air distributors 10 and 11 using the air outlet devices 12, the air is directed towards the paper web, forming counter air screens, section 1st cap on separate drying zones. Hot air is supplied to each drying zone 19-21 at a temperature appropriate to the drying mode.

To prevent overflow of humid air to adjacent zones, wide high-performance machines in the service areas of the drying part have transverse partitions 13 and, in the ceiling, guiding screens 15 with a rotary flap 16 for adjusting the direction

the movement of air entering from the air distributors 10. Evaporating from the paper web, the moisture in each zone is assimilated by hot air and removed outside the cap

The cap provides an intensification of drying due to the creation of optimal conditions for the evaporation of moisture from the paper web. At the same time, the air flow rate is reduced, since the drying mode of the paper web allows to significantly increase the moisture content of the steam removed from the air-steam mixture.

Claims (2)

1. Ventilation hood of the drying part of the papermaking machine, containing a ceiling and binder, end walls, side walls with lifting sliding shields, suction of air flow from the drying zones of the nozzles and regulating valves, characterized in that, in order to intensify the drying process by creating op- conditions of evaporation of moisture from the canvas, the cap has inside it and divide it into separate zones according to the number of drying zones, pairwise built-in air distribution distributors with air outlet devices oriented in the corresponding drying zone towards one another. 2. Vent cap according to claim 1, characterized in that it has transverse partitions to prevent air from flowing from one drying zone to another and mounted in the ceiling overlap, and screens with a pivoting flap for controlling the direction of air flow coming from the outlets. 2016 (rig.1   Ig "sj XE J-C4l movg noMai dDu :) n oguJDahnvo} I j IIIII g § s s gu / 2 taye noHmffgfggodou dpno much better Th s ija § § 5i c. c 1 CM rr 5G CO evj C H- CSJ o  to CSl CO