MEANS FOR DISPERSING PAPER, CARDBOARD AND PULP

Abstract: A means for dispersing paper, cardboard and pulp, comprising a basin (1) open on top, into which the raw material to be dispersed is fed e.g. from a paper machine located thereabove, and wherefrom it is removed when dispersed with the aid of a pump, and one or several dispersing units (3) placed on the wall (6) of the basin (1), preferably a rotor/rotors. A problem with this kind of apparatus known in the art is that the pulp-circulation effect of the dispersing rotors is poor, whereby the material to be dispersed cannot enter the effective range of the rotors well enough. With the aid of the invention, the problem is solved in that one or several mechanical or flow-technological apparatus (7) providing pulp flow for the rotors is mounted on the wall (5) of the basin (1) opposite to the rotors (3).

Description: The present invention concerns a means for dispersing paper, cardboard and pulp, said means comprising a basin open on top into which the raw material to be dispersed is fed, e.g. from a paper machine located thereabove, and wherefrom it is removed in dispersed state with the aid of a pump after being dispersed, and one or several dispersing units, placed on the wall of the basin, preferably a rotating rotor/rotors and wherein one or several devices generating pulp flow in the rotors are mounted on the wall of the basin opposite to the rotors. This kind of means (a pulper) is primarily used underneath big paper machines for dispersing paper and cardboard. Fluted guide members are provided above the means which guide the paper and cardboard to be dispersed, coming from the paper machine to a basin open on top. On one wall of the basin are placed dispersing units, these being rotors. Most often there are two rotors, each being provided with a drive motor of its own. The rotors are usually placed side by side at the same height from the basin bottom, and their shafts are as a rule parallel. Outside the basin, between the rotor shafts, is usually placed a removal pump for the dispersed pulp. The greatest drawback embarrassing the apparatus known in the art is that the pulp circulating effect of the rotors is poor, whereby the paper or cardboard to be dispersed does not efficiently enter the effective region of the rotors. At the same time, sizing and various fillers have developed, and the production quantities and requirements of machines have increased. US-A-2 796 006 describes a vertical pulper for dispersion and disintegration of paper and paperboard materials, comprising a tank for material to be treated and having mounted on the cover of the tank a helical vane, intended to force the material against a rotor mounted on the bottom of the tank. The vane is a long massive screw extending from the tank cover to near the rotor at the bottom of the tank, which is required for the thick pulp treated in vertical pulpers. The big massive screw occupies quite a lot of space in the tank and its rotation at relatively high speed creates big mass forces and requires much energy. The object of the present invention is to improve the circulation of pulp, so that the entrance of pulp into the effective range of the rotors is enhanced. The aim is achieved with the means of the invention which is characterized in that the means providing pulp flow is a pump producing liquid flow through a pipe mounted in said wall of the basin. An advantagoeus embodiment of the invention is characterized in that the pipes provided on the wall of the basin opposite to the rotors are located on an imagined continuation of the rotor shafts. As one of the most remarkable advantages of the invention may be mentioned saving of energy which is based on the fact that the dispersing rotors are started only in the event of web break and that the rotor receives a filling in axial direction which corresponds to the radial output of the dispersing rotor, whereby the paper entering the means will pass efficiently with the liquid flow to the dispersing rotor. In the following is presented the invention in detail by referring to the drawings attached, in which - Fig. 1 presents in elevational view, and partly sectioned, a means for dispersing paper, cardboard and pulp. Fig. 2 presents the means of prior art in top view and simplified. Fig. 3 presents an embodiment of the invention in top view and simplified. In Fig. 1 is presented a means for dispersing paper, cardboard and pulp. The means is most advantageously placed below a large paper machine, whereby the feeding of material to be dispersed into the basin 1 is through the open top part of the basin. For said purpose, above the basin are provided oblique guides 2, visible only in Fig. 1. Dispersing paper, cardboard and pulp in the basin 1 takes place by means of dispersing units 3, which most advantageously are rotating rotors. In the embodiment examples presented in the present application there are two rotors, these being located at the same height and on the same wall 6 of the basin 1. The drive motors 4 of the rotors 3 are placed outside the basin. In Fig. 2 is presented a dispersing means likewise of prior art, and the mutual location of the rotors in relation to each other is shown therein. In apparatus of prior art, the pulp circulation inside the basin 1 is not efficient enough. In Fig. 3 is presented the means of an embodiment of the invention, considerably simplified, for dispersing paper, cardboard and pulp, in which the pulp flow is provided by a flow-technological means. Therein, liquid is pumped into the basin 1 through pipes 9 disposed in the wall 5. In this way is provided again the pulp flow indicated by the arrows. It is obvious to a person skilled in the art that the invention is not confined to the embodiment presented above, and that it may vary within the scope of the claims stated below.

Claims: A means for dispersing paper, cardboard and pulp, comprising a basin (1) open on top, into which the raw material to be dispersed is fed, e.g. from a paper machine located thereabove, and wherefrom it is removed in dispersed state with the aid of a pump, and one or several dispersing units (3) placed on the wall (6) of the basin (1), preferably a rotating rotor/rotors, and wherein one or several devices generating pulp flow in the rotors are mounted on the wall (5) of the basin opposite to the rotors, characterized in that the means providing pulp flow is a pump producing liquid flow through a pipe (9) mounted in the said wall of the basin. Means according to claim 1, characterized in that the pipe (9) provided on the wall (5) of the basin (1) opposite to the rotors (3) are located on an imagined continuation of the rotor shafts.

Inventors: PAAVOLA, JYRKI
Applicants: SUNDS DEFIBRATOR JYLHAE OY
Application year: 1987
Main classification: D21B1
IPC codes: D21B1