US2765712A - Breaker traps - Google Patents

Description

D. M. SUTHERLAND Oct. 9, 1956 BREAKER TRAPS 4 Shaets-Sheef 2 Filed Jan. 18, 1952 lllll ll Oct. 9, 1956 D. M. SUTHERLAND BREAKER TRAPS 4 Sheets-Sheet 5 l N V EN TOR:

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BREAKER TRAPS Daniel Manson dutherland, Morrisville, P2,, assignor to Lionel M. Sutherland and Douglas G. Sutherland, trustees Application January 18, 1952, Serial No. 267,147

4 Claims. (Cl. 92--28) This invention relates to breaker traps useful, for example, in paper manufacturing plants to provide a selective defibering action on pulps and to remove foreign matter such as tramp metal, hard knots and the like from fluent pulp stock.

In the manufacture of pulp and paper there is presented at various stages of the operation a problem of reducing oversize particles of wood while at the same time remov ing tramp materials such as pieces of metal. For instance, in connection with the operation of high yield pulp systems it is important to prevent tramp metals which are normally present in the cook following the digesting step from finding their way to the refiners. Since the refiners in such systems must operate on the pulp while it is hot, the usual screening step is not feasible and various alternatives have been suggested such as Jordans and magnetic separators. While devices of this sort may be used, there are certain inherent disadvantages in their use which the present invention overcomes. Likewise in the semi-chemical and waste paper fields as the paper comes from the pulper it normally needs additional defibering of a selective nature. The soft oversize fiber bundles must be broken down while foreign material such as cellophane, rubber bands, articles of metal, e. g., nails, and large dirt particles should be eliminated from the pulp. The device of the present invention operates to break down partially cooked chips and soft oversize fiber bundles, while at the same time permitting the diluted cook to pass through with practically no action on the individual fibers. The bulk of the fibers thus go through the refiners without any substantial work being done upon them. While work is done on the fiber bundles certain materials are prevented from passing through the machine. The term breaker trap has, therefore, been applied to the present invention as an indication of the dual function of trapping certain ma terials and preventing their passage through the machine while at the same time breaking up some of the chips and fiber bundles which go through the machine.

The chief aim of my invention is to provide an efiicient and reliable device or apparatus for accomplishing the above stated purposes which is simple in construction, reliable in operation, and capable of continuously defibering soft, oversize fiber bundles and at the same time separating tramp material from the pulp stock delivered thereto; and which, moreover, requires but a minimum of power to operate.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings wherein:

Fig. l is a view in top plan of a rotary breaker trap conveniently embodyin my invention.

Fig. 2 is a side elevation of the breaker trap of Fig. 1.

Fig. 3 is a longitudinal section taken as indicated by the angled arrows llllll in Fig. 1.

Fig. 4 is a transverse-section taken as indicated by the angled arrows IVIV in Fig. 1.

l atented Oct. 9, 1956 Fig. 5 shows the rotor of the breaker trap in perspective.

Fig. 6 shows the periphery of the rotor in linear development, with a development of the stator indicated in broken lines in its relative position.

Figs. 7 and 8 are fragmentary views drawn to a larger scale showing the opposite ends of the rotor in elevation.

Fig. 9 shows the internal periphery of the stator of the trap in linear elevation; and

Figs. 10 and 11 are larger scale views showing the opposite ends of the stator in elevation.

With more detailed reference to these illustrations, the numeral 15 comprehensively designates the casing of the trap, the same having a horizontal cylindric portion 16 between end induction and eduction chambers 17 and 18 (Fig. 3) which are closed by removable end wall plates 19 and 26. Chamber 17 is convolute relative to the axis of the medial portion 16 of casing 15 as will be seen from Fig. 4, this being also true of chamber 13. Fluent paper pulp stock, delivered under pressure, enters induction chamber 17 laterally by way of a tangential port 21, and after traversing the intermediate cylindric portion of the casing 15, leaves eduction chamber 18 by way of an upward tangential port 22. Extending longitudinally through the casing 15 in the axis of the cylindric portion 16 is a shaft 23 which passes through the wall plates 19 and 2d, and which (Fig. 3) is journalled in roller thrust bearings 25 and 26, the latter being closed in oil tight boxes 27 and 28 on outward bracket extensions 29' and 30 of said wall plates. Shaft 23 protrudes beyond the box 27 and is connected by a coupling 31 to a driving motor 32.

Alfixed to shaft 23 by a key 33 is a rotor 35 which has a number of longitudinally positioned peripheral ridges 36 and 37 or" obtuse angled configuration. As shown in Fig. 3, the rotor 35 projects somewhat into chamber 17 and at the projecting portion, alternate ridges 37 are radially prolonged in the form of lugs 38, and the ridges 36 are beveled as at 39 for a purpose later on explained.

Arranged to cooperate with rotor 35 is a tubular stator 40 which is removably secured within the cylindrical portion 16 of casing 15 by means of bolts 41 as best seen in Fig. 4. As shown, stator 40 has longitudinally positioned peripheral ridges 42 internally thereof which, like the ridges of stator 35, are of obtuse angular configuration but oppositely disposed with respect to the rotor ridges as will be seen from Fig. 6. From Figs. 6 and 7 it will be noted that the ridges 36, 37 and 42 of rotor 35 and stator 46 taper in the direction of the fiow of the paper stock. As a consequence, the bottom rounded channels between the ridges 56 and 37 of rotor 35 and the ridges 42 of stator 4d are flared to facilitate passage of the stock from chamber 17 to chamber 18. It is to be further noted that the rotor 35 clears the stator 40 by a slight circumferential interval, and that the lugs 38 overreach the corresponding ends of the ridges in the stator.

Surrounding the portions of shaft 23 within chamber 17 and 18 are sleeves 43 and 44 which extend to the exterior of housing 15 through stuffing boxes 45 and 46 (Fig. 3) in the wall plates 19 and 20. The inner ends of sleeves 43 and 44 abut opposite sides of rotor 35, and the outer ends abut slingers 47 and 48 interposed between them and spacing collars 49 and 50.

Casing 15 is provided with an inspection opening 51 into chamber 17 with a removable cover 52 at one side, and, at the other side, a clean out opening 53 into said chamber with a removable cover 54. Casing 15, moreover, has at one side thereof auxiliary outlets 55 and 56 with connecting pipes 57 and 58 whereby chambers 16 and 17 can be completely drained when desired by opening the normally closed valves shown at 59 and 60 in Fig. 2.

The breaker trap of the present invention is normally installed between the pulp storage and subsequent equipment. In a high yield system it is installed between the blow tank and the brown stock refiners; in alow yield system it is located between the blow tank and the washers.

Operation With rotor 35 revolving at high speed, e. g., 2,000- 3,000 R. P. M., in the direction of the arrow thereon in Figs. 4 and 5, any relatively large obstructional pieces of tramp metal, hard knots or the like which may find their way into the pulp stock entering the breaker trap are deflected by the lugs 38 on said rotor and flung aside to fall by gravity to the bottom of chamber 17 from which the accumulation can be removed from time to time through the opening 53. The fluent paper stock thus cleared of the tramp metal passes through the channels between the ridges 36, 37 and 42 respectively of the rotor 35 and of the stator 40 from induction chamber 17 to eduction chamber 18, such passage being facilitated as a consequence of the beveling of ridges 36 at the entrant end of the channels, the flaring of said channels, and the opposing obtuse angular relation of the ridges of said rotor and stator without any attendant pumping action. Accordingly, the removal of the tramp metal is accomplished with a minimum consumption of power. When, by reason of excessive wear of the rotor 35 and/or of the stator 40 after protracted periods of use of the trap, these parts can be readily withdrawn from casing 15 and replaced by new ones upon removal of wall plate 19 as will be readily understood from Fig. 3. Flushing of the trap is accomplished by opening valve 59, then, after chamber 17 is cleaned, by closing said valve and opening valve 60.

It should be particularly noted that the construction of the breaker trap of the present invention is such as to avoid a pumping action. This is accomplished by the selection of the rotor and stator grooves and ridges as shown. By thus avoiding the work required in pumping the pulp the over-all power requirements and power consumption are reduced.

Having thus described my invention, I claim:

1. In a rotary breaker trap for selectively treating paper pulp or the like, a casing providing an induction chamber, an eduction chamber, and a hollow cylindric connecting portion with circmnferentially-spaced longitudinallyarranged stator ridges internally thereof, said ridges being tapered in width and the intervening channels being flared in the direction of pulp flow between the induction chamber and the eduction chamber and being bottom rounded; a rotor within cylindric portion of the casing with one end thereof projecting partway into the induction chamber, said rotor having circumferentially-spaced longitudinally-arranged ridges being tapered in Width and the intervening channels likewise being flared in the direction of flow between the induction chamber, and eduction chamber and are bottom rounded, said stator being spaced from said rotor a suflicient distance to provide for the continuous passage of diluted pulp through the breaker trap with substantially no refining action on the individual fibers.

2. A rotary breaker trap according to claim 1, wherein the ridges on the stator and the rotor are obtuse angular in configuration and those of stator arranged oppositely in direction to those of the rotor.

3. A rotary breaker trap according to claim 1, wherein the stator ridges are formed on a cylindric shell secured Within the casing with capacity for ready removal and replacement.

4. A rotary breaker trap according to claim 1, wherein the casing is provided with removable end walls; wherein the rotor is mounted on a shaft which extends through stufiing boxes in the end Walls; and wherein the shaft is' journalled in bearing boxes supported by external bracket extensions on said end walls.

References Cited in the file of this patent UNITED STATES PATENTS 6,784 Clarke Oct. 9, 1849 794,187 Pfeifer July 11, 1905 1,001,599 Willis et al Aug. 22, 1911 1,056,461 Simonds Mar. 18, 1913 1,527,818 ONeill Feb. 24, 1925 1,806,272 Wessell et al. May 19, 1931 1,873,199 Haskell Aug. 23, 1932 1,939,747 Wiener Dec. 19, 1933 1,961,808 Welsford June 5, 1934 1,994,061 Bolton Mar. 12, 1935 2,133,449 Hang Oct. 18, 1938 2,409,453 Stuch Oct. 15, 1946 2,532,885 Berges Dec. 5, 1950 FOREIGN PATENTS 226,399 Germany Oct. 3, 1910

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