FI59636B - TORKANLAEGGNING FOER TORKNING AV EN PAPPERS- BOARD- ELLER TEXTILBANA ELLER ANNAN FIBER ELLER POROES BANA - Google Patents

Description

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Patent iTiediclit ^ ^ ^ (51) Kv.lk?/lnt.CI.3 D 21 F 5/00 SUOMI — FINLAND pi) i ^ ttihik.myi-PK «nwiaiuiiii | 7621 + 39 (22) H »k * ml * pllvl - AntBknlngidaf 25-08.76 '' (23) Alkuptivt — GHtlfhatidig 25-08.76 (41) Tullut JulklMkil - BttvH efr« itli | 26/2/78

Patent and Registration Office .... .

_ '. ,, (44) Date of issue of the contract. —- „.

Patent · och registeratyrelaen Ameioui utlsgd och uci.skrMten pubitc «r * d 29 - 05 · 81 (32) (33) (31) Pyydtty« tuolkwi— Begird priori ** (71) Oy Tampella Ab, PO Box 256, 33101 Tampere 10 , Finland-Finland (FI) (72) Jukka Lehtinen, Tampere, Finland-Finland (Fl) (7 * 0 Oy Kolster Ab (5I +) Drying equipment for drying paper, board or textile webs or other fibrous or porous webs - Torkanläggning för The present invention relates to a drying apparatus for drying a paper, paperboard or textile web or other fibrous or porous web, the drying apparatus comprising two windows, the drying matrix being a drying web or a fibrous or porous web. surface guiding means for guiding the surfaces in a part of their common trajectory parallel to each other, between said surfaces their drying wire (s) or blanket moving in the direction 1 i iike in the direction 1 and between the said surfaces and closing the entire width therebetween in, means for heating the surface in contact with the web and means for cooling the surface in contact with the drying wire or felt i.

According to the drying method disclosed in patent application 75 3689, a wet web and a drying wire are passed between two movable, airtight and thermally conductive surfaces enclosing the web 59636 2 over its entire width, one surface being heated and the other surface cooled from the web to evaporate under the influence of cooling. The surface on the web side is heated e.g.

100 ° C degree i with saturated steam and the second surface is cooled, e.g. with tap water. The web and the drying wire supporting it are deaerated as precisely as possible before they enter the interlayer. Heat is transferred to the web from the condensing steam on the other side of the heated surface, whereby the moisture of the web evaporates and the steam is transferred to or through the drying wire to condense on the cooled surface. During the recirculation of the surfaces and the drying wire, condensed water is removed from the wire and from the surface.

In the application example presented in said patent application, it is proposed to use e.m. a pair of endless strips as a surface pair, between which the web to be dried is passed.

It is an object of the present invention to provide a drying apparatus suitable for applying the known method and to provide a drying apparatus which offers certain advantages over a drying apparatus based on the use of two belts. This object is achieved by a drying device 11a according to the invention, characterized by a pair of surfaces formed by a rotating cylinder liner in contact with the web and a strip in contact with the drying wire or felt, between which the web to be dried and the drying wire or felt move, and preferably inside said blade jacket. adapted means for heating it.

According to the invention, there is provided a drying apparatus in which the web-side strip is replaced by a metal cylinder liner 11a, as which either a conventional drying cylinder suitably modified or specially designed drums or cylindrical casings can be used. The Sylln blade jacket can be heated either from the inside with pressurized steam, as in current drying cylinders, or from the inside with saturated steam at a pressure of about 1 bar, or from the outside in the sector of the jacket which is not covered by the web.

The invention will be explained in more detail below with reference to the accompanying drawings, in which Figure 1 shows a schematic cross-section of a drying apparatus according to the invention.

Figure 2 shows a schematic cross-section of Figure 1 along line 1-1. The figure shows the first application example of a drying cylinder.

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Fig. 3 shows a schematic cross-section of another embodiment of a kufvaussy1 fn blade, and

Fig. K shows a section along the line II-11 in Fig. 3.

The drying apparatus shown in Fig. 1 comprises a drying blade I which rotates about a horizontal axis of rotation A. The wet web 2 to be dried is intended to be guided around the metallic cylinder shell 1a of the drying grain 1 and the web path B is perpendicular to the axis of rotation A of the drying grain blade. An inlet roller 3 and an outlet roller * ♦ are arranged to guide the web into and out of the cylinder.

The web is fed to the cylinder with the drying wire n 5 and a roll 6 is arranged before the inlet roll, by means of which the web and the drying wire are guided into contact with each other. In order to guide the drying wire away from the blade of the drying core, a roll 7 is arranged before the web removal roller k to deflect the drying wire from the cylinder. In order to guide the drying wire on the inlet side of the cylinder, a number of guiding, guiding and tightening means 8 are provided.

The drying device 1 also includes a gas-tight endless belt 9, which is guided to and from the cylinder by means of the aforementioned inlet roll 3 and the drying wire pots roll 7. To guide the strip along a closed path, a plurality of guide, guide and tension rollers are arranged on the inlet side of the cylinder.

An exhaust outlet II is arranged between the inlet roll 3 and the roll 6, which is provided with nozzles 12 for introducing superheated steam (e.g. approx. 120 ° C, 1 bar) into the box and an outlet 11a 13 for introducing steam and air for heat recovery. The box is closed on both sides and sealed with seals 1U against the roll 6 and the web passing through it, with a seal 15 against the strip 9 running on the inlet roll and with a seal 16 against the blades of the drying cylinder.

In the area between the inlet and outlet of the drying blade, the housing 17 is provided with a housing 17 provided with nozzles 18 for spraying cooling water towards the belt 9 circulating in the cylinder. The water centrifugally ejected from the strip is collected in a trough 19 · A scraper 20 is provided before scraping the water remaining on the outer surface of the strip before the strip removal roller 7 ·

For drying, the web is guided on a roll 6, where it rests against the drying wire 5 and moves together with it through a passage 11 on the inlet roll 3 · On the inlet roll the drying wire with its web comes against the strip 9 and moves with it on the surface of the drying roll. The web thus gets between the drying cylinder and the drying wire and the drying wire in turn between the web and the belt.

The drying of the web takes place between the surface of the hot drying cylinder and the outermost cooled strip 9 in the same way as disclosed in patent application No. 75 3689. Heat is transferred to the web from the drying cylinder and water evaporates from the web at low pressure, as a strong vacuum is created between the surface of the drying blade and the outer belt after the point where the outer belt 9 is cooled. The water then evaporates from the web at a very high rate (about 5 ... 10 times as fast as without vacuum) and this steam condenses on the inner surface of the outer strip and on the strip side of the weaving wire.

The twisted drying cylinder of the web is approx. 180 ° ... 330 °, depending on e.g. the size of the cylinder, the input and output system, the heating system and the speed - the outermost belt 9 and the drying wire 5 leave the roll 7 around the drying cylinder. The web is left for a while for drying-> y 1 interi 1 le, because condensed water splashing from the drying wire and the strip onto the roll 7 must be prevented from entering the web. For this purpose, a splash tray 21 is arranged at the discharge roll 7 of the drying wire. The dried web leaves the cylinder around the discharge roll k.

On the way back, the drying wire 5 and the strip 9 differ from each other. Scraper 22 is used to scrape off the remaining condensate from the strip. This condensate is also splashed onto the chute 23 on the folding roll 10. · The drying wire is washed with a water jet 2k and dried, e.g. with a suction box 25.

If the drying wire is formed of several separate layers, as disclosed in patent application No. 76 1516., it is necessary to arrange a separate return apparatus for each separately moving part of the wire.

A scraper 26 is provided for scraping the drying blade clean.

In some cases it may be in place to heat the strip 9 on top of the drying cylinder before it enters the cooling housing 17. For this purpose, a steam box 27 with an inlet 28 for introducing steam is arranged between the inlet roll 3 and the cooling housing 1. Steam The purpose of the heating is to prevent suction between the strip 9 and the drying zone 1 Inter too close to the deaeration box 11. If the suction were generated near the deaeration box 1, a lot of steam could pass through the wire 5 in its longitudinal direction from the air outlet box to the strip 9 and to condense on the inner surface of the tape. This condensate could accumulate so much that the steam coming from the web later would no longer have enough condensing space.

If the blades of the drying cylinder are heated conventionally, it is quite a conventional cylinder with steam supply and dehumidification.

On the other hand, if only 100 ° C, I bar of saturated steam is used for heating inside the cylinder, the blade of the drying cylinder can be built much lighter and cheaper than today.

Figure 2 shows an embodiment of a drying apparatus suitable for the latter heating method and a first application example of a drying blade. The shell 30 of the drying blade 29 can now be quite thin in terms of strength. The shell 31 communicates with the shell in connection with the end plates 32 and possible support sides. In addition, the support may be supported by an inner complete cylinder, whereby the steam coming through the shaft is led to the space between the inner cylinder and the shell. The connection frame 11 of the end plates and the shell has condensation holes 33 »from which the condensate 34 flows out due to the gravity and centrifugal effect of the ground. The condensate thus discharged is discharged or drained into fixed 1-suction chutes 35 * which surround the end or ends of the cylinder. No other dehumidification system is required in the drying blades. The steam will kuivaussy1in the blades through the hollow shaft 36. Vapor pressure is the amount of outside air pressure higher · in that the titanium ratio I re i 'i p s 35 constantly leaks out little steam. This enters inert gases that accumulate on the condensing surface of the cylinder. ,

Figures 3 and 4 show another embodiment of a cylinder used in a drying apparatus, in which the tip of the heated core is formed by a metal drum 39 ... 1 mm thick. This drum rotates around its center line A supported by rollers or rollers 40 and is rotated on rollers 41. The bearings 42 at the ends of the rollers 40 are outside the stationary end plates 43 of the dryer. The rollers 40 can be set to the desired distance from the center line of the drum by means of devices 44, 45.

The shafts 46 of the rollers 40 pass through sealed holes 47 in the end plates 43.

State of the end plates 43 and 39 inside the drum during the run is filled with approx. 100 ° C, the saturated vapor pressure, which is slightly above the exterior atmospheric pressure. Steam is continuously fed through a pipe 48. Between the rollers 40, for example, there may be tef1 on-pin 1i u - shoes 49 supported on a fixed support structure 50. This structure does not prevent steam from passing to the drum or condensate from splashing. The rollers 40 each remove the condensate 51 formed on the inner surface 1 of the drum 39 and spray it inside the condenser collecting vessel 52 below the dryer, from which the condensate flows through the end out of the tube 53. A tube 54 can be blown for repairing and adjusting the web moisture profile. superheated steam on the inner surface of the drum 39 in different amounts or at different speeds or at different temperatures at different points along the length of the tube 54.

The drawings and the related explanation are only intended to illustrate the idea of the invention. The details of the drying apparatus according to the invention can vary considerably within the scope of the claims. The phrase cylindrical jacket used above is intended to cover not only the geometrically completely cylindrical shape but also the multi-shaped non-heated movable drying surfaces. Instead of or in addition to heating the blade jacket as described above, it is possible from the inside of the cylinder to heat the blade jacket from the outside in a sector which is not covered by the web.

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Claims (6)

1. Drying for drying a paper, cardboard or textile web or other fibrous or porous web, the drying plant comprising two movable, airtight surfaces (9, 1a; 9, 30; 9, 39), devices (3, 4) for controlling the surfaces mutually parallel over a portion of their path of movement, a drying wire (5) moving between said surfaces in their tube 1 direction for conducting the web (2) to be dried between said surfaces and for enclosing the same over its entire width between them, means (36, 48) for heating the surface touching the web and means (17, 18) for cooling the surface touching the drying wire or felt, characterized by a surface pair formed by a web (2). ) touching rotating cylinder mandrel1 (la; 30; 39) and a drying wire or felt (5) touching belt (9) moving between said web and drying wire or felt, and preferably within means arranged ( 36; 48) for heating the same. Installation according to claim 1, characterized in that the cylinder mandrel 1 n (1a) is formed by a drying cylinder (1) known per se, which rotates about an axis (A), which is perpendicular to the tube 1 direction (B). ) for the web (2) to be dried. Installation according to claim 1, characterized in that the cylinder manifold (30) is formed by a thin-walled cylinder, which rotates about a perpendicular to the pipe direction of the web to be dried, standing shaft and which is provided with a steam feeding device (36) leading into the cylinder. ) and also at the end edges of the cylinder-shaped wall (30) is provided with discharge from the inner conducting heel (33) of the cylinder, for removing condensate water from the cylinder. 4. Installation according to claim 1, characterized in that the drying cylinder comprises a thin-walled cylinder mandrel 1 (39) supported by supporting elements (40, 49) and set in motion with a drive mechanism (41) around a shaft (A) which perpendicular to the direction of movement (b) of the web (2) to be dried, motionless end walls (43), a meadow feeding means (48) and a condensate water collector (52, 53) located inside the drum · Plant according to Claim 1, characterized in that the inner surface of the cylinder is of polygon construction and that the outer surface moves at the same speed as the web in the direction of movement of the web.