US1145097A - Centrifugal strainer for wood-pulp and cellulose. - Google Patents

Description

APPLICATION FILED JULY 29, I913.

Patented J uly 6, 1915.

COLUMBIA PLANOORAPH (20., \VASHXNGTDN. D4 c.

barren snares in ar ricer HALLGBIM TI-IORESEN, OF VES'IRE AKER, NEAR GHBIS'IIANIA, AND JONAS CORNELIUS FALCH, 0F CHRISTIANIA, NORWAY; SAID THORESEN ASSIGNOR TO NILS ROTH HEYEH'DAHL, OF CHRISTIANIA, NOR-'WAY.

GENTRIF'UGAL STRAINER F03, WOOD-PULP AND CELLULOSE.

Application filed July 29, 1913.

To all whom it may concern:

lie it known that we, HALLGRIM Tnonn- SEN and Jonas CORNELIUS FALGH, subjects of the King of Norway, residing at Gunvang, Vestre Alter, near Christiania, and L fikeberggaten 5, Christiania, Norway, have invented certain new and useful Tnr provements in Centrifugal Strainers for -Wood-Pulp and Cellulose; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

This invention has for its object a centrifugal sorting apparatus.

In the type of centrifugal sorting apparatus now in use for wood pulps and cellulose having a stationary cylindrical strainer and a centrifugal fan on a horizontal shaft it proves that the power consumed for driving the fan is relatively very large in comparison with the work done. This is owing partly to an uneven distribution of the pulp water around the fan and partly to the shock producing action of the pulp water against the fan.

The present invention now has for its object to produce an arrangement whereby the pulp water is distributed as uniformly as possible around the whole strainer plate and whereby the supply of pulp water to the fan rotating with great velocity is effected without the production of shocks and consequently with a good hydraulic efficiency. Further the said arrangement makes it possible to effect an automatical control of the supply openings, whereby the level in the supply channel is maintained constant so that no changes in the velocity of the pulp water supplied to the fan take place. The velocity of the pulp water supplied to the fan is namely proportional with the square root of the pressure in the supply chamber and it is therefore of importance to maintain the said velocity constant.

The invention is illustrated in the accompanying drawing in which Figure 1 is a vertical sectional elevation through a sorting apparatus, Fig. 2 illus Specification of Letters Patent.

Patented July 6, 1915.

Serial No. 781,708.

trates the arrangement of the vanes or wings of the centrifugal fan.

The pulp water is supplied through the openings (Z to the one end of the fan at the periphery. The inlet openings (Z, which are distributed in such manner as to obtain an even distribution of the pulp water are in connection with one or more closed chambers, in which the pulp water stands under a pressure determined by the level of the pulp water in the supply channel with which the said chamber or chambers directly communicate.

In order to obtain a smooth entrance (without shocks) of the pulp water into the fan the wings a of this latter are on the supply end arranged under such an angle with the direction of rotation that the supply velocity (to) (which is determined by the pressure in the supply chamber) and the peripherical velocity (y) of the fan and the inclination line of the wings form a closed triangle as shown in Fig. 2. In this manner the best possible hydraulic efliciency is obtained. As shown in Fig. 2 it is only in that end, where the pulp water is supplied that the wings are given the said strongly inclined position. At that part (c) of the wings where the straining is to take place the wings are only given such inclination as is necessary in order to impart to the pulp an axial movement and at the portion 7) the wings are bent backward relatively to the direction of rotation in order to effect the throwing away of the fibers, which have not passed through the strainer. In order that the said smooth entrance of the mass shall take place it is necessary that the supply velocity of the pulp water is main tained as constant as possible during the working. To obtain this the supply openings are arranged so as to be controlled and are connected with the supply channel in such manner for instance by means of a float that the level of the liquid and accordingly also the supply velocity is maintained constant.

When the liquid level in the supply channel is raised the float is also raised and by a lever and link arrangement, this upward movement of the float effects a movement of the ring controlling the entrance channels in such manner that the supply openings are enlarged. The quantity of liquid entering through the channels cl is thereby increased. The level of liquid in the pulp channel is then brought down to the normal height. The resulting lowering of the float then effects a reduction of the quantity of pulp supplied through (Z. The controlling arrangement described above may of course be substituted by any other suitable means for maintaining a constant velocity of the pulp jet passing through the channels d toward the edges of the fan Wings a. The number and area of the openings (Z may, of course, also be varied accordingto the circumstances.

We claim:

In a centrifugal strainer for Wood pulp and cellulose having a stationary perforated member and a rotary member on a horizontal shaft surrounding said perforated member, means for driving the rotary member at a predetermined speed, and means for supplying liquid pulp in an axial direction to the rotary member near its periphery and at a'constant head, the rotary member having blades opposite the supply opening, the latter having their initial portio-ns a inclined to the axis at an an gle determined by the speed of rotation at the head at Which the pulp is supplied to receive the material and increase its velocity in the direction of the axis, the acceleration being substantially harmonic, the blades also having portions 0 and b to rotate the material and throw it against the screen and to expel the unstrained portion respec tively.

In testimony that'We claim the foregoing as our invention, We have signed our names in presence of tWo subscribing Witnesses.

HALLGRIM THORESEN. JONAS CORNELIUS FALGH.

Witnesses:

M. E. GUT'roRENsEN, HENRIKKA HAIGH SOl-IMlDl.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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