US2673763A - Shower for pulp washers - Google Patents

Description

March 30, DUNN HOWER FOR PULP WASHERS Filed Jan. 26, 1953 .-1--- -----I--l---i--li-l- I I Ii! INVENTOR. L/O/I/N A? .Da/v/v AGENT Patented Mar. 30, 1954 SHOWER FOR PULP WASHERS John Raymond Dunn, Gatineau, Quebec, Canada,

assignor to Canadian International Paper Company, Montreal, Canada,

Quebec a corporation of Application January 26, 1953, Serial No. 333,160

3 Claims.

This invention relates to new and useful improvements in equipment for washing wood pulp and particularly seeks to provide a novel form of showers therefor.

One of the problems in washing wood pulp, particularly that which has been prepared by any of the known systems of chemical digestion, arises from the necessity of washing the spent cooking liquors from the freshly prepared pulp. A similar problem arises whenever the pulp is to be further purified by chemical refinement, in which case it is necessary to wash the treating chemicals into or out of pulp in a completely uniform manner.

Many efforts have been made in older designs of showers for pulp washers to create a uniform sheet of water which flows from the individual shower pipes onto the adjacent mat of pulp on the washer drum. Many forms of weirs have been tried but in every instance it has been found impossible to secure either uniform velocities of the washing liquor or uniform volumes of flow thereover. Other types of showers have been used in which the shower pipes are provided with a plurality of independent discharge jets, but

these have been unsatisfactory because the action of the jets on the mat of pulp on the washer drum tends to disrupt the pulp formation thereon which makes for inefficient washing and also causes channeling of the washing liquor and con sequent inequalities in washing across the width of the pulp mat. This condition is true even where deflector shields have been employed adjacent the streams emanating from each of the jets.

Shower pipes constructed in accordance with this invention overcome all of the deficiencies in the earlier forms of showers in that a uniform sheet of wash water or wash liquor can be flowed upon the pulp mat supported on the surface of the washer drum under conditions of uniform velocity and uniform volume of flow across the full width thereof.

An object of this invention, therefore, is to provide a novel shower for use in connection with pulp washers so constructed that a sheet of wash water of uniform velocity and volume may be flowed directly upon the mat of pulp carried on the surface of a washer drum without disrupting the formation of the pulp mat and without channeling the wash water along the surface thereof.

Another object of this invention is to provide a shower of the character stated which includes a main shower pipe extending across the full width of the washer and having positioned therein a hollow segment dividing the interior into major and minor sectors in which communication is provided from the major sector into the minor through a plurality of aligned, relatively closely spaced apertures extending through one face of the hollow segment, and in which communication is provided from the minor sector to the outside through a plurality of near-continuous slots formed in the outer surface of the main pipe.

Another object of this invention is to provide a device of the character stated in which the sheet of wash water emanating from the nearcontin..ous slots is deflected onto the surface of a pulp mat carried by the washer drum.

A further object of this invention is to provide a device of the character stated in which the total area of the apertures formed in the hollow segment is less than the cross-sectional area of the major pipe sector whereby to provide a throttling effect from the major sector into the minor sector and in which the total area of the near-continuous slots is greater than the total area of the apertures whereby to provide a decelerating effect of the wash water as it passes out of the milled slots onto the deflecting devices.

A further object of this invention is to provide a device of the character stated in which the hollow segment is provided with end walls whereby to force all of the wash water entering the main shower pipe to pass from the major sector into the minor sector only through the apertures formed in the segment wall.

A further object of this invention is to provide a device of the character stated in which the main shower pipe is provided with a removable cap and in which the hollow segment is removably positioned within the main pipe whereby to provide for ready disassembly and cleaning thereof as may be required from time to time.

A further object of this invention is to provide a device of the character stated which is simple in design, rugged in construction and economical to manufacture.

With these and other objects in view, the nature of which will be more apparent, the invention will be more fully understood by reference to the drawings, the accompanying detailed description and the appended claims.

In the drawings,

Fig. 1 is a fragmentary side elevation of a part of a drum-type washer showing the relative positions with respect thereto of washing showers constructed in accordance with this invention;

Fig. 2 is a bottom plan view, partly in section, of one of the showers shown in Fig. 1;

Fig. 3 is a transverse section taken along line 3-3 of Fig. 2; and

Fig. 4 is an enlarged fragmentary longitudinal section taken along line 44 of Fig. 3.

Referring to the drawings in detail, the invention as illustrated is embodied in a shower for pulp washers and includes a pipe 5, of sufficient length to extend across the full width of the washer with which it is associated and provided with a plurality of aligned, near-continuous slots 5 formed by milling through the side wall thereof. It will be noted from Figs. 2 and 4 of the drawings that adjacent slots are separated by generally wedge-shape sections of metal 1 terminating in a feather edge at the outer surface of the pipe 5 so that the outer portions of the slots 6 form a substantially continuous elongated slot across the width of the washer While the inner faces of the slots 5 are somewhat more discontinuous due to the wedge shape of the residual metal sections 1.

A hollow quadrantial segment 8, which may be conveniently formed from angle iron or the like, is removably positioned within the pipe 5 and is of a length somewhat greater than the combined lengths of the slots 6. The angle iron from which the segment 8 is formed is positioned in such a manner that its legs span the slots 6 as illustrated in Fig. 3 of the drawings.

In order to assure a close fit against the inner surface of the pipe 5 the inner corners of the legs of the segment 8 may be ground or otherwise shaped to provide a rounded contour generally conforming to the contour of the pipe. One of the webs or legs of the segment 3 is provided with a plurality of aligned, closely spaced, relatively small diameter apertures 9 to provide for passage of the wash liquid from the major chamber area or sector of the pipe 5 into the minor area as defined by the segment 8. In order to cause the wash water to pass from the major pipe sector into the minor only through the apertures 9 the segment 8 is provided at each end with a generally quadrantial plate l rigidly secured thereto.

The segment 8 is removably fastened within the pipe as by a plurality of clamp studs ll threadably engaged with bushings H! which radially extend through the wall of the pipe 5. The outer portion of the clamping studs ii may be turned at an angle to provide suitable handles [3.

A deflector plate l4 having a splash board l5 at each end is removably secured to the pipe 5 by a plurality of screws l5 and, as illustrated, is so positioned that its general plane defines an angle of approximately 60 with the radial plane passing through the center lines of the slots 6, but this angular relationship is not critical since the shower will work well if the slots are disposed substantially above the deflector plate to permit the water to cascade 4 can be supplied from both ends or from the center if desired.

In operation it has been found that a pulp washer of the type disclosed herein is effective to cause uniform distribution of the wash water within the limits defined by the segment 8 due to the use of the plurality of the aligned apertures 9 formed in one wall thereof and to cause the uniformly distributed water to pass from the minor pipe sector within the segment 8 through the. near-continuous slots 6 in such a manner that a substantially uniform sheet of water emanates therefrom. The deflector 14 serves to change the direction of the sheet of Water from the slots onto the mat of pulp carried by the washer drum. It is believed that the efiicacy of showers of the present type stems from the ability to flow the wash water onto the deflector l4 at reduced velocities instead of increased velocities as had been common with all prior known showers. Depending upon the pressure of the input water to the pipe 5 and the relative areas of the major sector and the aggregate of the apertures 9 there could be some throttling eifect taking place between the major and minor sectors within the pipe, but there is definitely a decelerating effect which takes place within the minor sector of the pipe to the outside thereof through the slots 5 since the total area of the slots is greater than the total area of the apertures 9.

In a typical installation each shower pipe 5 might be, say, of 3 /2" inside diameter, the segment 8 may be formed from 1% angle iron, the apertures 9 thereof could be of 1%" diameter on centers, and the slots 6 would be wide. The foregoing dimensional relationships are set out purely by example to indicate the manner in which the internal volume of the pipe 5 may be divided into major and minor sectors by the segment 8 and to show typical relative area relationships between the cross-sectional area of the pipe 5, the total areas of the apertures 9 and of the slots 6.

It is, of course, to be understood that various details of arrangements and proportions of parts may be modified within the scope of the appended claims.

I claim:

1. A shower for pulp washers or the like comprising a pipe connected to a source of wash liquid, said pipe being provided with a longitudinally extending slot defined by a series of nearcontinuous longitudinally aligned slots, a hollow generally quadrantial segment positioned within said pipe and spanning said slot, means for clamping said segment into position, said segment dividing said pipe into major and minor volumetric sectors, one face of said segment being provided with a plurality of longitudinally aligned apertures whereby to permit passage of wash liquid from the major sector into the minor sector and thence outwardly through said slot as a uniform sheet, and means attached to the exterior of said pipe adjacent said slot for deflecting the flowing sheet of liquid into a different direction.

2. A shower for pulp washers or the like comprising a pipe connected to a source of wash liquid, said pipe being provided with a longitudinally extending slot defined by a series of nearcontinuous longitudinally aligned slots, and a hollow generally q adrantial segment positioned within said pipe and spanning said slot, means for clamping said segment into position, said segment dividing said pipe into major and minor volumetric sectors, one face of said segment being provided with a plurality of longitudinally aligned apertures whereby to permit passage of Wash liquid from the major sector into the minor sector and thence outwardly through said slot as a uniform sheet, the total of the areas of said apertures being less than the cross-sectional area of said major sector and the area of said slot being greater than the total of the area of said apertures.

3. A shower for pulp washers or the like comprising a pipe connected to a source of wash liquid, said pipe being provided with a longitudinally extending slot defined by a series of nearcontinuous longitudinally aligned slots, a hollow generally quadrantial segment positioned within said pipe and spanning said slot, means for clamping said segment into position, said segment dividing said pipe into major and minor volumetric sectors, one face of said segment being provided with a plurality of longitudinally aligned apertures whereby to permit passage of wash liquid from the major sector into the minor sector and then outwardly through said slot as a uniform sheet, the total of the areas of said apertures being less than the cross-sectional area of said major sector and the area of said slot being greater than the total of the areas of said apertures, and a deflector blade attached to the exterior of said pipe with it surface disposed in a plane lying at an angle with respect to the radial plane passing through th center of said slot.

JOHN RAYMOND DUNN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 388,930 Thayer Sept. 4, 1888 1,751,960 Veenstra Mar. 25, 1930 2,642,314 Dupasquier June 16, 1953

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