US2442888A

US2442888A - Stock consistency responsive device

Info

Publication number: US2442888A
Authority: US
Inventors: Hervey G Cram
Original assignee: Manitowoc Shipbuilding Inc
Current assignee: Manitowoc Shipbuilding Inc
Priority date: 1944-03-30
Filing date: 1944-03-30
Publication date: 1948-06-08
Anticipated expiration: 1965-06-08

Description

June 8, 1948. CRAM 2,442,888

s'rocx CONSISTENCY RESPONSIVEDEVICE Filed March 30, 1944 3 Sheets-Sheet l mvembn l HERVEY 4G.CRAM

ATTORNEYS 3 Sheets-Sheet 2 INVENTOR HERVEY G.CRAM

H. G. CRAM ATTORNEYS STOCK CONSISTENCY RESPONSIVE DEVICE June 8, 1948.

Filed March 30, 1944 June 8, 1948.

H. G CRAM STOCK CONSISTENCY RESPONSIVE DEVICE 3 Sheets-Sheet 3 Filed March 30, 1944 INVENTOR HERVEY G.CRAM

ATTORNEYS Patented June 8, 1948 STOCK CONSISTENCY RESPONSIVE DEVICE Hervey G. Cram, Appleton, Wis., assignor to Manitowoc Shipbuilding Company, Manitowoc,

Wis.

Application March 30, 1944, Serial No. 528,670

7 Claims. 1

This invention appertains to means responsive to the consistency of pulp or stock for use in the making of paper or similar fibrous products and more particularly to an apparatus responsive to low consistency pulp or paper stock in liquid suspension ranging from .05% to 1% bone dry content and is an improvement over the Van de Carr Patent #1,665,425, issued April 10, 1928.

One of the primary objects of my present invention is to provide a, consistency responsive device for use in converting any required amount of unregulated pulp or paper stock to a predetermined consistency.

Another salient object of my invention is the provision of novel means for arranging a consistency responsive device in a sample line leading from the screen head box 'in such a manner that it will respond to any variation in the desired consistency of the pulp or stock will be immediately reflected on the control for the gate of the unregulated stock, so that more or less stock, as the case may be, will be delivered to the white water pump without any appreciable time lag.

A further important object of my invention is the provision of a consistency responsive device embodying a housing for receiving the pulp or stock from the sample line having a rotary reticulated or perforated cylinder in said housing and immersed in the pulp or stock, with means for receiving the pulp or stock from the housing and the filtrate from the interior of the cylinder, the rate of flow of filtrate through the perforated shell of the cylinder and the pulp mass accumulating thereon depending on the consistency or thickness of the stock.

With these and other objects in view, the invention consists in the novel construction, arrangement and formation of parts, as will be hereinafter more specifically described, claimed, and illustrated in the accompanying drawings, in which drawings:

Figure 1 is an enlarged, front, elevational view of my novel consistency responsive device showing the same positioned in the sample line leading from the screen head box, parts of the view being shown broken away and in section to illustrate structural detail.

Figure 2 is a vertical, sectional View taken substantially on the line 3-3 of Figure 2 looking in the direction of the arrows, illustrating my novel consistency responsive device.

Figure 3 is an enlarged, detail, sectional view through the control float, float chamber and pilot valve used in connection with my apparatus,

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views, the letter R generally indicates my novel consistency responsive device located in a sample line 5 leading from the screen head box 6 which supplies consistency regulated pulp to the screens of a paper or other machine.

As illustrated, the sample line 5 leads from the bottom of the head box 6 and the inlet for the sample line is inclosed in an open ended housing 8. The open end of the housing 8 is covered by a knot screen 9 so that knots will not be delivered from the head box to the consistency responsive device.

The consistency responsive device includes a cylindrical casing 30 having a substantially circular outer wall 3| and side walls 32 and 33. Each of these side walls can be provided respectively with

removable end discs

34 and 35. The end disc is provided with an inwardly extending annular flange 36 which is adapted to abut one end of a centrally disposed consistency responsive device cylinder 31. This cylinder includes hub plates 38 and a cylindrical outer shell 39. The shell can be formed from reticulated material, or as illustrated, can be in the nature of a perforated drum. The hub disc 33 can be provided with openings 40 and the axial centers of the hub discs are keyed or otherwise secured to an axial shaft 4!. This shaft 4! is rotatably mounted in suitable bearings 42 carried by the

end wall discs

34 and 35. The cylinder 3! can be rotated from a motor 43 mounted on brackets M carried by the casing or housing 30. As is clearly shown in Figure 2, the upper section 45 of the sample line pipe 5 communicates with the upper end of the housing or casing 30 while the lower section 45 of the line pipe 5 communicates with the lower end of the housing or casing. Between the inlet and outlet of the housing is arranged a transversely extending opening 41 for the discharge of filtrate and this opening receives the filtrate chamber 48. The filtrate chamber 48 is provided with a flange 49 adjacent to its outer end and this flange is firmly secured to the walls of the opening 41 and closes said opening. The chamber 48 is the same width as the cylinder and extends entirely across the cylinder and has its inner end shaped to conform to the contour of the cylinder, so that the chamber can be placed in close proximity to the cylinder. The upper edge of the chamber has secured thereto a flexible blade or doctor 50 for engaging against the periphery of the cylinder, whereby to wipe off the pulp adhering to the cylinder.

Communicating with the outer end of the chamber is a filtrate discharge pipe 5| and this pipe communicates with the section 46 of the sample line pipe 5. A by pass pipe 52 communicates with the housing through the end disc 35 and this communication is disposed within the flange 36 carried by said end disc. The lower end of the by pass pipe 52 communicates with the filtrate discharge pipe 5| and serves as an additional means for carrying filtratefrom the. cylinder, should the chamber 43 prove inadequate for this purpose.

Still referring to Figure 2,.it: carr beseeir that a fixed orifice 53 is arranged in the section 46 of the sample line pipe 5 just'below the consistency responsive device housing and above the connection of the filtrate discharge pipe M with, said section. This orifice can be formed in a plate 54 bolted between parts of the sample line pipe; The section 45 ot the sample line pipe between the consistency'responsive device and the screen head box 6' can be provided with a hand operated valve 55.

Leading off from the-housing of the consistency responsivedevice abovethe cylinder 3-1. is a pipe 56 which communicates with the lower end oi a float chamber 57. The float chamber 51- has mounted therein a float 5Bwhich moves up and down with the level of the pulp in saidfloat chamber The float is guided in its movement by a guide rod 59-. The float opens and closes a pilot valve 65' in awater pressure line 6|. The pilot valve 60 includes a' valve body- 62 mounted. on a valve stem'63 connected withthe float. The valve body moves toward and away from a valve seat 64 carried by the valve casing 65. The water pressure pipe Bl communicates with the valve casing on one side of the valve seat and when the valve body moves off of the seat, water from the pressure line 61 flows into the float val-ve chamber.

A water over-flow conduitpipe 65 communicates with the float chamber 51 at the desired level;. and acts as means for preventing the risin of the water in the float chamber above an undesired level. Leading off from the pressure line 61 between the float chamber 51 and the pressure regulator 6'1 is a water conduit pipe 69. and this pipe leads tothe lower end of a regulator'cylinder 19 supported by the pulp regulator .box IE]. Mounted in the control-cylinder 'Hlis a piston H. Connected'to, the piston H is a-piston rod' 12 which leads; out of the cylinder and the piston rod isfpivotally connected'to a crank lever 13. The crank lever i3 is keyed or otherwise secured to'a rockshaft 14 mounted on the regulator box. Also fixed to the rock shaft is the control gate 15 for the unregulated pulp and this gate opens and closesthe opening [4 and'controls the amount of pulp flowing'through said opening. Normally. the flow of pulp through the opening tends to move the gate 15 to an open position and as pressure increases in the cylinder 10 below the piston, the piston will be moved upwardly to move thegate toward the opening It.

Itcan be seen that as the cylinder 3'! of the regulator R revolves in the mass of pulp in liquid suspension in the housing of the regulator, a mass of pulp will continuously accumulate on the perforated shell 39 thereof relative to the thickness or density of the consistency of the pulp in liquid suspension in the surrounding body. Thus the rate of flow of filtrate through the perforated shell of the cylinder and the pulp mass accumulating thereon is inversely proportional to the thickness or density of the accumulation thereon. With a constant rate of volume flow of the sample preferably maintained by the valve 55 and by a constant head in the box 6 passing through the cylinder housing maintained by'a head on the inlet side of the housing and the fixed orifice 53 at the outlet side of the housing, filtrate passed through the perforated cylinder shell and discharged by the chamber 48 and the filtrate discharge pipe 5| to the downstream side. of. the fixedorifice will effect the head in the section "450i theisa-mple line pipe 5 in direct relation to the consistency of the passing sample. By connecting this. head variation on the cylinder to the float chamber 51, the float 58 will raise and lower with said head variation and the valve body 62 will move toward or away from its seat causing. achange in pressure in. thewater pressure lin'ev 69 .and-thisivariation in pressure in: the line willcausethe opening and closingof-. the: gate 75.. Actually, by interconnecting the, head variaF tion on. the cylinder 31,..throughmechanical means, to. the gate IE-controlling the rate of volumeflow of the parent stream of pulp,-the rate of flow will be made to :-vary in, inverse relation to consistency, and; theactualrate of flow of solids willbe. constant. i i

The apparatusv operates. as follows: A. continuous sample is delivered from the-scneenheadubox 6 through adjustable orifice or-valve-=55a at a sufficient rate of volumefiow to-establish. ahead in the sampleline pipe. 5 at the level. of the float 58 in thefloat chamber 51-. 1

The cylinder 31' being completely submergedv in the sample stream accumulates: a mat. of pulp on its: periphery. This matv of pulp; varies. in thickness in direct. relation to. the consistency of the pulp inthe sample stream...

The rate. of flow oi'filtrate through the cylin der-face is inversely'proportionalto the thickness of the mat of pulp through which it has to pass.

The filtrate from 'the. cylinder 31'. being discharged to the downstream side of the fl-xed' discharge orifice 533 the rate of flow of filtrate passed through the cylinder and by passing the discharge orifice 53 determines the rateof flow through the fixed discharge orifice 53- and the head on the float 58 An increase in the consistency of the sample effects an increasein the head which lifts the float 58 and the valve body 62' of the pilot valve 60. "This increases the pressure in the pipe 69 to the cylinder 10, causinggthe raising of ,the piston H. The piston, in turn, causes a relative closing of the gate 15 and reduction in the volume flow of unregulated stock to theintake of the whitewater pump 23. This reduces the consistency in the stock delivered to the screen head box 6. 4

A decrease in the consistency effects a decrease in the head and a consequent decrease in pressure in the gate cylinder 70. This allows a, relative opening of the gate i5 and an increased flow of unregulated stock to the intake of the whitewater pump 23 and an increase in. the consistency of the stool: delivered to the screens 7.

As the lapsed time. is usually less than twelve seconds between the control gatel5 in the. regue lator box ID and the delivery of the sample, and the reaction by the regulator, a continuousrecheck and adjustment, if necessary, of the consistency of the stock delivered to the screens 1 is on approximately a twelve second basis.

The regulator box I!) being located at a higher elevation than any possible level of white Water in the white water chest 25, the rate of flow of pulp from the regulator box It] to the intake of the white water pump 23 is automatically reinforced with white water from the chest 25 to make up the volume fiow to the screen head box 6 as determined by the adjustment of the volume control valve 25.

Any required change in consistency is accomplished by means of the adjustable orifice or valve 55. Hence, to increase consistency, the valve 55 is adjusted toward a closed position and to decrease consistency, the valve is adjusted toward an open position.

Changes in details may be made without departing from the spirit or the scope of my invention, but what I claim as new is:

1. A consistency responsive apparatus for stock or pulp, comprising a source of stock at a constant head, a body having an inlet opening for stock communicating with said source and a discharge opening for stock, the size of said openings being fixed, a continuously rotating cylinder immersed in the stock in the body and having its periphery provided with means for the passage of filtrate therethrough and the collection of solid matter thereon at a rate depending on the consistency of the stock, the level of the body of stock surrounding the cylinder being proportional to the consistency of the stock and means snugly engaging the periphery of the cylinder for receiving the filtrate therefrom.

2. A consistency responsive apparatus for stock or pulp, comprising a body having an inlet opening for stock and a discharge opening for stock, the size of said openings being fixed, a continuously rotating cylinder immersed in the stock in the body and having its periphery provided with means for the passage of filtrate therethrough and the collection of solid matter thereon at a rate depending on the consistency of the stock the level of the body of stock surrounding the cylinder being proportional to the consistency of the stock, means snugly engaging the periphery of the cylinder for receiving the filtrate therefrom, and means for regulating the flow of stock to provide a constant feed of stock into the body through said inlet opening.

3. A consistency responsive apparatus for stock or pulp, comprising a body having an inlet opening for a constant head of stock and an outlet opening for stock the size of said openings being fixed, a supply pipe for stock leading to the inlet opening, an outlet pipe for stock communicating with the outlet opening, a continuously rotating cylinder immersed in the stock in said body, having its periphery provided with means for the passage of filtrate therethrough and the collection of solid matter thereon, at a rate depending on the consistency of the stock the level of the body of stock surrounding the cylinder being proportional to the consistency of the stock, means snugly engaging the periphery of the cylinder for receiving filtrate therefrom, means governing the flow of stock through the inlet pipe to provide a constant feed of stock to the body, and said outlet pipe having a fixed orifice.

4. A consistency responsive apparatus for thin stock comprising a source of stock at a constant head, a body having an inlet opening for stock communicating with said source; and an outlet opening for stock the size of said openings being fixed, a cylinder in said body immersed in the stock, having its periphery formed for the passage of filtrate therethrough and the collection of solid matter thereon at a rate depending on the consistency of the stock the level of the body of stock surrounding the cylinder being proportional to the consistency of the stock, means extending across the width of the cylinder snugly engaging the periphery thereof whereby, to insure the flow of all filtrate from the interior of the cylinder without leakage and for conducting the filtrate exteriorly of the body, and a doctor carried by said means for receiving the filtrate from the cylinder for scraping the solid matter oil of the cylinder, as the cylinder passes said means, and means for rotating the cylinder.

5. A consistency responsive apparatus for stock, comprising a source of stock at a constant head, a body having an inlet for stock communicating with said source and an outlet for the stock the size of the inlet and outlet being fixed, a delivery pipe for stock, communicating with the inlet pipe, a discharge pipe for stock communicating with the oulet opening, a continuously rotating cylinder in said body immersed in the stock having its periphery formed to permit the passage of filtrate therethrough and the collection of solid matter thereon at a rate depending on the consistency of the stock the level of the body of stock surrounding the cylinder being proportional to the consistency of the stock, a chamber in said body extending transversely across the cylinder in snug engagement with the periphery thereof whereby, to insure the flow of all filtrate from the interior of the cylinder without leakage, and a filtrate conduit pipe for conducting filtrate from said chamber to the discharge pipe below the outlet opening.

6. A consistency responsive apparatus for thin stock comprising a source of stock at a constant head, a body having an inlet opening for stock communicating with said source; and an outlet opening for stock, the size of said openings being fixed, a continuously rotating cylinder in said housing immersed in the stock, having its periphery formed to permit the passage of filtrate therethrough and the collection of solid matter thereon at a rate depending on the consistency of the stock the level of the body of stock surrounding the cylinder being proportional to the consistency of the stock, a chamber housing in said body extending transversely across the cylinder in snug engagement with the periphery thereof whereby, to insure the flow of all filtrate from the interior of the cylinder without leakage, means for rotating the cylinder, means in the supply pipe for regulating the flow of stock therethrough, said discharge pipe having a fixed orifice therein, and a filtrate conduit pipe for conducting filtrate from said chamber housing to the discharge pipe below said fixed orifice.

'7. A consistency responsive apparatus for thin stock comprising a source of stock at a constant head, a body having an inlet opening for stock communicating with said source and a discharge opening for stock, the size of said openings being fixed, a continuously rotating cylinder in said body immersed in the stock, having its periphery formed to permit the passage of filtrate therethrough and the collection of solid matter thereon at a rate depending on the consistency of the stock the level of the body of stock surrounding the cylinder being proportional to the consistency of the stock, means for rotating the cylinder, a chamber housing in said body extending trans- HERVE'Y' G. CRAM.

8 BEFERENGES CITED The following references are of record in the file of this patent:

STATES, PATENTS.

Number Name Date Re'.19,997 Witham June 2, 1936 1,178,193 Trimbey Apr. 4, 1916 1,374,286 Decker Apr. 12, 1921 1,665,425 Van De Carr Apr. 140, 1928 2,210,027 Gram Aug. 6; 1940 2,353,149 Gram July 11', 1944