US2191999A

US2191999A - Cylinder paper machine

Info

Publication number: US2191999A
Application number: US163907A
Authority: US
Inventors: Thaler Wilhelm
Original assignee: American Voith Contact Co
Current assignee: American Voith Contact Co
Priority date: 1936-09-18
Filing date: 1937-09-15
Publication date: 1940-02-27
Anticipated expiration: 1957-02-27

Description

Feb. 27, 1940. w THALER 2,191,999

CYLINDER PAPER MACHINE Filed Sept. 15, 19:7

INVE/VTQ/E. Wrumm Thus/2 Patented Feb. 27, 1940 PATENT OFFICIE CYLINDER PAPER MACHINE Wilhelm Thaler, Heidenheim-on-the-Brenz, Germany, assignor to American Voith Contact Co.,\ Inc., New York, N. Y., a corporation of New York Application September 15,1937; Serial No. 163,907

In Germany September 18, 1936 1 Claim.

This invention relates to a cylinder'paper machine provided with a guiding device with the purpose to ensure a faultless sheet formation even at high working speeds of the said paper machine.

It is a generally known fact that the stock necessary for sheet formation does not settle on the cylinder mould in a layer which is strictly separated from the 'stockwater; on the contrary, there is an almost slight passing over between the stock layer closely settled on the wire-and the stockwater.

Besides the thickened stock settled on the wire, there is moving along with the cylinder another layer of less thickened stock formed by fibres suspended in the water on the top side of the sheet. On emergence of the cylinder mould, this' second layer will be raised by the fibre layer settled on the latter, however it will slide off after a short way, in consequence of the slight bind ing, and flows back into the stock vat. So a counter-current between the proper sheet layer and the sliding layer takes place at the emerging spot. In this process, the stock particles already settled on the wire will be partly and irregularly torn. ofi, the undesired consequence of this is an irregular formation of sheet causing a large amount of broke and hereby a corresponding manufacturing loss.

, According to the invention, this inconvenience will be removed by providing for a guiding device on the outlet side of the vat which divides the raising stock current into an inside and an outside current and which is formed on its inner side as a lip. turned to the cylinder mould, and further in such a manner that .all stockwater accumulations on and above its outlet edge will be avoided. The correct deflection and diversion of the -necessary conveying liquid will be provided for. This formation of the lip, which besides is adjustable, serves the purpose to accelerate, according to the adjustment, the fibre layer settled on the cylinder mould, and especially will be of great importance when the rotation speeds of the cylinder mould and the raising stock current are different so that the sheet formation could be endangered. I

Hereby the damming pressure, determining the acceleration of the fiber layer, can be adjusted, whereby on the other hand the free passage of the stock fibres settled on the wire will be guaranteed. The conveying liquid is diverted away from the wire insuch a manner that any risk of sliding off and damage of the stock layer already formed is removed.

The lip hasalso the function of draining the liquid contained in the stock layer formed immediately on the cylinder mould into the interior of the latter. In spite of this, remainders of liquid go through the nozzle; but these will be led off by the top side of the lip, the form of which avoids the formation of damming and accumulating spaces.

Devices that have been known hitherto did not fully recognize the task to be solved.

One of these shows a knife edged deflector 10 which is so formed that the conveying liquid will substantially be led off the cylinder. The position of the wall of the deflector leading upwards along the cylinder mould however is such that it forms a nozzle enlarging upwardly where the stock water with this older device is accumulated. This dammed up liquid partly sweeps away the fiber layer formed on the cylinder mould so that the above mentioned detrimental effect takes place. With another design, a roll was provided'for which should deflect the con. veying liquid from the cylinder. On the top side of the roll, i. e. between cylinder mould and roll circumference, in a similar manner as described, a damming space enlarging upwardly is formed. The consequences of this are the same as those of the first mentioned design. Any arrangement 7 of such a device allowing the accumulation of liquid in an enlarging nozzle or damming channel has the disadvantage thatthe very sensitive fiber layer already formed will be damaged .b sweeping away.

In opposition to the mentioned forms of known designs, according to the invention a device has been made which eliminates the said disadvantages and which offers the guaranty of a faultless sheet formation and paper quality.

' The figure schematically shows an example of the device according to the invention.

The suspension of fibers enters in a well known way at a into stock vat c surrounding the cylinder mould b. The direction of rotation of the cylinder mould is indicated by the arrow marked on the figure. It is the same as that of the stock current.

As already explained, the stock necessary for the sheet formation does not settle in a layer strictly separated from the conveying liquid on the cylinder mould; a layer of less thickened stock floats with it upwardly and flows back again, whereby fine stock particles already settled on the wire, will be torn off. In order to avoid this disadvantage, according to the invention, aguiding device it has been provided for which on the bottom side eis so formed that the con-- 55 veying liquid m, which might damage the layer already formed, will be diverted. On the top side h this device at is formed in such a manner that any stockwater accumulations on or above its outlet edge will be avoided. Theguiding device d is adjustable in any direction. The wall I facing the cylinder mouldib, forms, together with the cylinder, a discharge nozzle g directed in the direction of rotation of the cylinder mould.

In case the circumferential speed of the cylinder mould should not be in accordance with that of the fibre layer, the fibre layer can be speeded up within the nozzle space g according to the adjustment oi the guiding device d. In consequence of the pressure arising in the nozzle 9, the fibre layer i settled on the wife will besides be effectively dewatered, by pressing the water out of the layer into the interior'of the cylinder mould. a

In case small liquid "quantities should pass through the nozzle 9, these will be deflected at once so that the formed fibre layer cannot be damaged by stockwater accumulation.

The fibre layer i formed on the cylinder mouldf b will be carried in a well known way by the taking ofi roll 7:: to the detaching felt I and from there goes to the ordinaryworking process.

'It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiments of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claim.

I claim as new:

In a cylinder paper machine having a rotatable cylindrical sieve and a stockvat partially surrounding the same for holding stock, whereby a sheet of fibers is formed on the sieve during its rotation in the stock vat the combination therewith of a stock guiding;device disposed at the outlet of the stock vat, having a wall upwardly inclined to the sieve surface forming a narrow nozzle-like converging space therewith, the highest point vof said wall being nearest the sieve' zle-like space and divert it in a curved uninterrupted flow away from the sieve.