US3519532A - Continuous digester discharger containing automatic temperature and level sensing means and method thereof - Google Patents

Continuous digester discharger containing automatic temperature and level sensing means and method thereof Download PDF

Info

Publication number
US3519532A
US3519532A US631291A US3519532DA US3519532A US 3519532 A US3519532 A US 3519532A US 631291 A US631291 A US 631291A US 3519532D A US3519532D A US 3519532DA US 3519532 A US3519532 A US 3519532A
Authority
US
United States
Prior art keywords
discharger
pulp
digester
temperature
housing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US631291A
Inventor
Douglas G Sutherland
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Black Clawson Co
Original Assignee
Black Clawson Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Black Clawson Co filed Critical Black Clawson Co
Application granted granted Critical
Publication of US3519532A publication Critical patent/US3519532A/en
Assigned to WALTER E. HELLER & COMPANY, INC. reassignment WALTER E. HELLER & COMPANY, INC. SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BLACK CLAWSON COMPANY, THE
Assigned to BLACK CLAWSON COMPANY, THE reassignment BLACK CLAWSON COMPANY, THE RELEASED BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: HELLER FINANCIAL, INC. F/K/A/ WALTER E. HELLER & COMPANY INC.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C7/00—Digesters
    • D21C7/08—Discharge devices

Definitions

  • a cold blow discharger for use with a continuous digester for wood pulp in the manufacture of paper which receives the treated wood chips from the digester, reduces the temperature thereof, and expands them through an orifice from where they are transferred to the subsequent steps in the manufacturing process.
  • the discharger utilizes no moving parts, and liquor, at a specific temperature and pressure, is admitted tangentially to the discharger establishing a swirling flow pattern in the discharger, thus maintaining circulation in the discharger while reducing both the temperature of the pulp components and the steam requirements of the system as a whole.
  • the process and apparatus is designed for the continuous discharge of pulp material from a continuous digester.
  • the discharger apparatus in accordance with the invention includes a cylindrical tank mounted vertically for receiving the pressurized cooked pulp or other material as it is continually discharged from the digester or other continuous processing apparatus, and also for receiving a continuous supply of liquid at a substantially lower temperature than exists in the digester.
  • a discharge outlet is provided through which the material is discharged as a result of the centrifugal force imparted thereto by the pressure differential between the interior of the tank and the downstream side of the opening.
  • the liquid level, the temperatures, and the pressures within the discharger are precisely controlled by an automatic system.
  • An upstanding spud may be disposed centrally on the bottom wall of the housing as a finder for assuring that circulation is maintained when liquor is injected tangentially into the housing, and the continuous circulation maintains the discharge opening clear of chips since the rotation of the mass continually wipes across the discharge orifice.
  • the system shown in FIG. 1 generally includes a feed zone A and an intermediate or cooking zone B in which the wood chips are cooked and digested so that the ligneous and other non-cellulosic incrustants or binding materials in the wood are softened or removed to render the wood fibers desirably separable for subsequent preparation of the pulp slurry.
  • the feed zone A comprises a feed hopper 10 for the wood chips or other forms of ligno-cellulose material which conducts it to a screw feeder 11 rotatably driven in tapered neck-like casing 12.
  • Saturated steam is supplied to the casing 14 through valved injector pipe 15 for maintaining a regulated superatmospheric pressure and temperature in both the zone B and the discharge zone C for softening the ligneous fibrebinding incrustants.
  • a chemical may be supplied to zone B through valved injection pipe 16 for use in rendering the ligneous binding material water soluble or for other purposes.
  • a screw conveyor 17 is provided in the casing 14 for the purpose of controlling carefully the rate of progress and the time of transit of the chips through and along the casing 14.
  • a downwardly extending discharge pipe 18 Connected near the downstream end of the casing 14 is a downwardly extending discharge pipe 18 through which wood chips from the conduit freely fall through the opening 19.
  • the digester described above 18 substantially identical to that shown in the above patents.
  • the discharger 20 embodies the present invention and is mounted on the lower end of the down-pipe 18 in communication with the outlet opening 19 of the digester.
  • the discharger 20 includes an elongated tubular tank or housing 21 having a closed base 22 and a radial flange 24 on the upper end thereof which is utilized for interconnection with the similar flange 25 on the down-pipe 18.
  • the inner diameters of the down-pipe 18 and the housing 21 are substantially identical, and the down-pipe can be considered as part of the discharger 20 for operational purposes.
  • the housing including the side walls 26 and bottom wall 22 has inner surfaces which are relatively smooth, and the bottom wall 22 is additionally arcuate or concave and supports the vertical spud 30.
  • This spud is rigidly secured on the center line of the housing 21, and has a cylindrical section 32 with a conical section 33 provided on the upper end thereof, as shown in FIG. 2.
  • Upper and lower tangential inlets 35 and 36 are provided in the housing 21 for connection to the cold liquor conduits 38. These inlets charge the discharger 20 with cold liquid at a preset volume rate and pressure, and this liquid enters substantially tangentially to the inner wall 26 of the housing 21.
  • Each of the conduits 38 is provided with a valve 40 controlled by a suitable control system which includes a temperature sensor 41 mounted on the side wall 26 of the discharger 20 for sensing the temperature of the liquid inside the housing 21.
  • the sensor 41 is electrically connected to a transmitter 42 which supplies a suitable signal to the temperature recorder and 3 controller unit 44 which supplies the necessary control to the valve actuator 45 for opening or closing the valves 40, as will be further described.
  • a discharge valve is provided adjacent the bottom Wall 22 of the discharger 20 for carefully controlling the amount of pulp and liquor discharged under pressure from the discharger into the conduit 52 which leads to the subsequent treatment apparatus 54 (FIG. 1).
  • the discharge valve 50 is shown in FIGS. 46 and includes a housing 55 having the radial flange 56 which is connected by the conventional fasteners 57 to the annular portion 58 of the housing 21 which defines the outlet opening 60 in the side wall 26.
  • a suitable gasket 61 is provided to insure fluid tight engagement therebetween.
  • the housing 55 has the inner tubular sleeve 62 secured thereto to define the outlet passage 63 therethrough.
  • a disk-shaped plate 64 is fixed to the left-hand end of the valve housing 55 and has a discharge opening 66 therein in communication with the passage 63.
  • the fixed shutter member 68 is secured to the plate 64 below the opening 66 for cooperation with the movable shutter 70 to block completely flow through the opening 66 when the adjacent surfaces 71-72 and 73-74 are in contact.
  • the actuator shaft 75 supports the movable shutter 70 which is fixedly mounted on shaft 75 and rocks back and forth with rotation of the shaft to restrict or open the discharge opening 66.
  • This actuator shaft extends through the packing member 77 and has its opposite end 78 pivotally supported in the radial flange 79 on the tubular housing 55.
  • An actuator 80 is provided on the lower portion of the valve housing 55 to extend the actuator lever 83, which is fixed to shaft 75, between the alternate positions shown in FIG. 4 to move the shutter 70 by rotation of the actuator shaft 78.
  • a suitable control unit is provided adjacent the actuator 80 for controlling the operation of this actuator.
  • control unit includes a valve (not shown) whose position is precisely positioned, and the follow-up arm 86 is provided to sense the movement of the yoke 87 on the end of the piston rod 88 of the actuator 80 and terminate movement of the piston rod when the proper position of the shutter 70 is attained.
  • the control system 85 for the discharge valve 50 responds to the liquid level within the discharger housing 21 as determined by the level sensing device 90 mounted on the side wall 26 of the housing and electrically connected through the level transmitter 91 to the level indicator controller 92. The latter is connected to the control unit 85 to supply the necessary signal to open and close the valve 50 so that a preset level of liquid is maintained in the housing 21.
  • the discharger 20 receives treated pulp from the digester through the opening 19.
  • the interior of the discharger is pressurized by the steam present in the digester so that the pulp is at an elevated pressure and temperature as it falls into the discharger.
  • Liquor at a predetermined temperature is continuously supplied to the housing by pumping it through the tangential inlets 35 and 36 so that it creates a rotating mass of liquor about the spud 32 which tends to stabilize the circulation.
  • the liquor then passes through the discharge opening 66 into the conduit 52 which is at a substantially reduced pressure.
  • the level of liquor in the housing 21 is automatically controlled by the level sensor 90 which cooperates with the control system 85 and actuator 80 to vary the size of the discharge opening 66 thereby regulating the rate of flow from the tank.
  • the temperature of the rotating liquor is maintained within prescribed limits by the sensor 41 and control 44 which position the valves 40 to increase or decrease appropriately the liquor being fed into the housing 21.
  • the temperature and level sensing systems thus are interrelated since an increase in temperature would increase the flow through the inlets 35 and 36, and thus the level within the housing 21 would be compensated for by increasing the size of the discharge orifice.
  • the hot treated pulp leaves the digester, it falls freely through the upper portion of the discharger until it contacts the rotating mass of liquor. Centrifugal force tends to move the pulp particles outwardly adjacent the inner surface 26 of the housing 21, and gravity tends to draw them downwardly so that the particles eventually rotate past the discharge opening 66 through which they are expelled. There exists a substantial pressure differential on either side of the opening 66 which causes the pulp particles to be expanded as they pass through the orifice thereby further separating the individual cellulose fibers. Since the liquor is maintained at a temperature substantially less than the temperature of the pulp material as it leaves the digester, the pulp material is cooled to maintain a temperature below that at which serious mechanical damage to the fibers could occur.
  • the housing has an inner diameter of about 27 inches and a vertical height between the flange 24 and the bottom wall 22 of about 5 feet with the spud 32 having a diameter of about 9 inches.
  • the control system is calibrated to maintain the level of liquor within the housing so that there is a free fall from the digester of about 6 to 24 inches.
  • the pulp leaves the digester with a consistency of about 20% solids at about 385 F., and falls into the liquor which is being supplied through the tangential inlets 35 and 36 at 20-30 feet per second at a temperature of about 180 F. and creates a consistency of about 4-10% solids.
  • the discharge valve 50 allows controlled ejection of the pulp particles through the opening 66 and discharges the pulp into the conduit 52 at a temperature of about 240 F., Well below the 385 F. temperature at which it left the digester.
  • spud 32 is shown and described as having a particular configuration, it is within the scope of the invention to use different sizes and configurations thereof to stabilize the circulation. In some instances, it is possible to eliminate the spud completely.
  • the discharger can be used With other types of continuous digesters and processing equipment, and the particular discharge valve shown and described herein can be modified without departing from the scope of the invention.
  • the invention has thus provided a method and apparatus for discharging a material from continuous processing equipment without the use of moving parts within the discharge apparatus except for a discharge control valve. While the apparatus and method are suitiable for the cold blowing of wood pulp from a continuous digester, the invention is not necessarily limited to this application.
  • said tank having a side wall and means defining with said side wall a stationary, substantially annular channel in said tank,
  • said tank side wall is substantially cylindrical
  • said means defining with said side wall an annular channel comprises a substantially cylindrical spud positioned in said tank substantially concentrically with respect to the side wall thereof.
  • a method of discharging the contents of a continuous digester comprising:

Landscapes

  • Paper (AREA)

Description

July 7, 1970 n. a. SUTHERLAND 3 CONTINUQUS DIGESTER DISCHARGER CONTAINING AUTOMATIC TEMPERATURE AND LEVEL SENSING MEANS AND METHOD THEREOF Filed April 1'7, 1967 2 Sheets-Shed 1" i-TG-l A B i 15 l 10 11 12 k1 *1. 54
l/V VE/V TOR DOUGLAS G. SUTHERLAND A TTORNE Y8 July 1970 D. G. SUTHERLAND 3,519,532
CONTINUOUS DIGESTER DISCHARGER CONTAINING AUTOMATIC TEMPERATURE AND LEVEL SENSING MEANS AND METHOD THEREOF Filed April 17, 1967 2 Sheets-Shee t 2 FIG 5 a? as 85 United States Patent O 3,519,532 CONTINUOUS DIGESTER DISCHARGER CONTAIN ING AUTOMATIC TEMPERATURE AND LEVEL SENSING MEANS AND METHOD THEREOF Douglas G. Sutherland, Middletown, Ohio, assignor to The Black Clawson Company, Hamilton, Ohio, a corporation of Ohio Filed Apr. 17, 1967, Ser. No. 631,291 Int. Cl. D21c 7/08 US. Cl. 16252 4 Claims ABSTRACT OF THE DISCLOSURE A cold blow discharger for use with a continuous digester for wood pulp in the manufacture of paper, which receives the treated wood chips from the digester, reduces the temperature thereof, and expands them through an orifice from where they are transferred to the subsequent steps in the manufacturing process. The discharger utilizes no moving parts, and liquor, at a specific temperature and pressure, is admitted tangentially to the discharger establishing a swirling flow pattern in the discharger, thus maintaining circulation in the discharger while reducing both the temperature of the pulp components and the steam requirements of the system as a whole.
BACKGROUND OF THE INVENTION This invention is an improvement over the system disclosed in Keogh et al. No. 2,616,802, issued Nov. 4, 1952, and Surino No. 2,882,967, issued Apr. 21, 1959, both of which are assigned to the assignee of this invention.
In the processing of wood pulp for the manufacture of paper, continuous digesters are widely used, and the blowing operation for removing the cooked pulp material from the digester must also be a continuous process, one form of continuous discharger being shown in the above Keogh and Surino patents, but the loss of steam through the digester is expensive, and the complexity of the discharge apparatus creates maintenance problems. In addition, when the cooked chips or other pulp materials are blown through the orifice at high temperature of the order existing in the digester, damage to the strength properties of the fibers may occur.
SUMMARY OF THE INVENTION In its preferred form, the process and apparatus is designed for the continuous discharge of pulp material from a continuous digester.
The discharger apparatus in accordance with the invention includes a cylindrical tank mounted vertically for receiving the pressurized cooked pulp or other material as it is continually discharged from the digester or other continuous processing apparatus, and also for receiving a continuous supply of liquid at a substantially lower temperature than exists in the digester. At the base of the housing, a discharge outlet is provided through which the material is discharged as a result of the centrifugal force imparted thereto by the pressure differential between the interior of the tank and the downstream side of the opening. The liquid level, the temperatures, and the pressures within the discharger are precisely controlled by an automatic system. An upstanding spud may be disposed centrally on the bottom wall of the housing as a finder for assuring that circulation is maintained when liquor is injected tangentially into the housing, and the continuous circulation maintains the discharge opening clear of chips since the rotation of the mass continually wipes across the discharge orifice.
3,519,532 Patented July 7, 1970 BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT The system shown in FIG. 1 generally includes a feed zone A and an intermediate or cooking zone B in which the wood chips are cooked and digested so that the ligneous and other non-cellulosic incrustants or binding materials in the wood are softened or removed to render the wood fibers desirably separable for subsequent preparation of the pulp slurry. More particularly, the feed zone A comprises a feed hopper 10 for the wood chips or other forms of ligno-cellulose material which conducts it to a screw feeder 11 rotatably driven in tapered neck-like casing 12.
Saturated steam is supplied to the casing 14 through valved injector pipe 15 for maintaining a regulated superatmospheric pressure and temperature in both the zone B and the discharge zone C for softening the ligneous fibrebinding incrustants. A chemical may be supplied to zone B through valved injection pipe 16 for use in rendering the ligneous binding material water soluble or for other purposes.
A screw conveyor 17 is provided in the casing 14 for the purpose of controlling carefully the rate of progress and the time of transit of the chips through and along the casing 14. Connected near the downstream end of the casing 14 is a downwardly extending discharge pipe 18 through which wood chips from the conduit freely fall through the opening 19. The digester described above 18 substantially identical to that shown in the above patents.
The discharger 20 embodies the present invention and is mounted on the lower end of the down-pipe 18 in communication with the outlet opening 19 of the digester. The discharger 20 includes an elongated tubular tank or housing 21 having a closed base 22 and a radial flange 24 on the upper end thereof which is utilized for interconnection with the similar flange 25 on the down-pipe 18. The inner diameters of the down-pipe 18 and the housing 21 are substantially identical, and the down-pipe can be considered as part of the discharger 20 for operational purposes.
The housing including the side walls 26 and bottom wall 22 has inner surfaces which are relatively smooth, and the bottom wall 22 is additionally arcuate or concave and supports the vertical spud 30. This spud is rigidly secured on the center line of the housing 21, and has a cylindrical section 32 with a conical section 33 provided on the upper end thereof, as shown in FIG. 2.
Upper and lower tangential inlets 35 and 36 are provided in the housing 21 for connection to the cold liquor conduits 38. These inlets charge the discharger 20 with cold liquid at a preset volume rate and pressure, and this liquid enters substantially tangentially to the inner wall 26 of the housing 21. Each of the conduits 38 is provided with a valve 40 controlled by a suitable control system which includes a temperature sensor 41 mounted on the side wall 26 of the discharger 20 for sensing the temperature of the liquid inside the housing 21. The sensor 41 is electrically connected to a transmitter 42 which supplies a suitable signal to the temperature recorder and 3 controller unit 44 which supplies the necessary control to the valve actuator 45 for opening or closing the valves 40, as will be further described.
A discharge valve is provided adjacent the bottom Wall 22 of the discharger 20 for carefully controlling the amount of pulp and liquor discharged under pressure from the discharger into the conduit 52 which leads to the subsequent treatment apparatus 54 (FIG. 1). The discharge valve 50 is shown in FIGS. 46 and includes a housing 55 having the radial flange 56 which is connected by the conventional fasteners 57 to the annular portion 58 of the housing 21 which defines the outlet opening 60 in the side wall 26. A suitable gasket 61 is provided to insure fluid tight engagement therebetween.
The housing 55 has the inner tubular sleeve 62 secured thereto to define the outlet passage 63 therethrough. A disk-shaped plate 64 is fixed to the left-hand end of the valve housing 55 and has a discharge opening 66 therein in communication with the passage 63. The fixed shutter member 68 is secured to the plate 64 below the opening 66 for cooperation with the movable shutter 70 to block completely flow through the opening 66 when the adjacent surfaces 71-72 and 73-74 are in contact.
The actuator shaft 75 supports the movable shutter 70 which is fixedly mounted on shaft 75 and rocks back and forth with rotation of the shaft to restrict or open the discharge opening 66. This actuator shaft extends through the packing member 77 and has its opposite end 78 pivotally supported in the radial flange 79 on the tubular housing 55. An actuator 80 is provided on the lower portion of the valve housing 55 to extend the actuator lever 83, which is fixed to shaft 75, between the alternate positions shown in FIG. 4 to move the shutter 70 by rotation of the actuator shaft 78. A suitable control unit is provided adjacent the actuator 80 for controlling the operation of this actuator. Specifically, the control unit includes a valve (not shown) whose position is precisely positioned, and the follow-up arm 86 is provided to sense the movement of the yoke 87 on the end of the piston rod 88 of the actuator 80 and terminate movement of the piston rod when the proper position of the shutter 70 is attained.
The control system 85 for the discharge valve 50 responds to the liquid level within the discharger housing 21 as determined by the level sensing device 90 mounted on the side wall 26 of the housing and electrically connected through the level transmitter 91 to the level indicator controller 92. The latter is connected to the control unit 85 to supply the necessary signal to open and close the valve 50 so that a preset level of liquid is maintained in the housing 21.
In operation, the discharger 20 receives treated pulp from the digester through the opening 19. The interior of the discharger is pressurized by the steam present in the digester so that the pulp is at an elevated pressure and temperature as it falls into the discharger. Liquor at a predetermined temperature is continuously supplied to the housing by pumping it through the tangential inlets 35 and 36 so that it creates a rotating mass of liquor about the spud 32 which tends to stabilize the circulation. The liquor then passes through the discharge opening 66 into the conduit 52 which is at a substantially reduced pressure. The level of liquor in the housing 21 is automatically controlled by the level sensor 90 which cooperates with the control system 85 and actuator 80 to vary the size of the discharge opening 66 thereby regulating the rate of flow from the tank.
Similarly, the temperature of the rotating liquor is maintained within prescribed limits by the sensor 41 and control 44 which position the valves 40 to increase or decrease appropriately the liquor being fed into the housing 21. The temperature and level sensing systems thus are interrelated since an increase in temperature would increase the flow through the inlets 35 and 36, and thus the level within the housing 21 would be compensated for by increasing the size of the discharge orifice.
As the hot treated pulp leaves the digester, it falls freely through the upper portion of the discharger until it contacts the rotating mass of liquor. Centrifugal force tends to move the pulp particles outwardly adjacent the inner surface 26 of the housing 21, and gravity tends to draw them downwardly so that the particles eventually rotate past the discharge opening 66 through which they are expelled. There exists a substantial pressure differential on either side of the opening 66 which causes the pulp particles to be expanded as they pass through the orifice thereby further separating the individual cellulose fibers. Since the liquor is maintained at a temperature substantially less than the temperature of the pulp material as it leaves the digester, the pulp material is cooled to maintain a temperature below that at which serious mechanical damage to the fibers could occur.
In the preferred embodiment of the discharger 20, the housing has an inner diameter of about 27 inches and a vertical height between the flange 24 and the bottom wall 22 of about 5 feet with the spud 32 having a diameter of about 9 inches. The control system is calibrated to maintain the level of liquor within the housing so that there is a free fall from the digester of about 6 to 24 inches. The pulp leaves the digester with a consistency of about 20% solids at about 385 F., and falls into the liquor which is being supplied through the tangential inlets 35 and 36 at 20-30 feet per second at a temperature of about 180 F. and creates a consistency of about 4-10% solids. This effects a whirling motion which is stabilized by the vertical spud 30 and the centrifugal force in the swirling mass forcing the heavier particles outwardly against the inner wall 21 of the housing 20. The discharge valve 50 allows controlled ejection of the pulp particles through the opening 66 and discharges the pulp into the conduit 52 at a temperature of about 240 F., Well below the 385 F. temperature at which it left the digester.
While the spud 32 is shown and described as having a particular configuration, it is within the scope of the invention to use different sizes and configurations thereof to stabilize the circulation. In some instances, it is possible to eliminate the spud completely. Moreover, the discharger can be used With other types of continuous digesters and processing equipment, and the particular discharge valve shown and described herein can be modified without departing from the scope of the invention.
The invention has thus provided a method and apparatus for discharging a material from continuous processing equipment without the use of moving parts within the discharge apparatus except for a discharge control valve. While the apparatus and method are suitiable for the cold blowing of wood pulp from a continuous digester, the invention is not necessarily limited to this application.
While the method and form of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.
What is claimed is:
1. In combination with a digester discharging paper making pulp on a substantially continuous basis and a substantially vertically extending discharge pipe extending from the downstream end of said digester the improvement comprising:
(a) a tank mounted on the downstream end of said discharge pipe to receive said pulp from said digester,
(b) said tank having a side wall and means defining with said side wall a stationary, substantially annular channel in said tank,
(c) means for introducing a cooling liquid into said tank substantially tangentially with respect to said channel to establish a swirling flow pattern in said tank through said tangential introduction of liquid to intermix said pulp and liquid and maintain the discharge opening from said tank unobstructed by the contents thereof,
((1) means for sensing the temperature of the contents of said tank,
(e) means responsive to said temperature sensing means for controlling the flow rate of said cooling liquid into said tank,
(f) an adjustable valve mounted in said tank adjacent the base thereof,
(g) means for sensing the level of the contents of said tank, and
(h) means responsive to said level sensing means for controlling the adjustment of said valve.
2. The improvement of claim 1 wherein:
(a) said tank side wall is substantially cylindrical, and
(b) said means defining with said side wall an annular channel comprises a substantially cylindrical spud positioned in said tank substantially concentrically with respect to the side wall thereof.
3. A method of discharging the contents of a continuous digester comprising:
(a) discharging pulp at a first temperature from said digester into a discharge tank having a substantially cylindrical side wall,
(b) introducing liquid into said tank,
(i) at a temperature substantially lower than said first temperature, and
(ii) substantially tangentially with respect to said side wall to establish a swirling flow pattern in said tank through said tangential introduction of liquid to intermix said pulp and liquid and maintain the discharge opening from said tank unobstructed by the contents thereof,
(c) monitoring the temperature of the mixed pulp and liquid,
(d) controlling the flow rate of said liquid into said tank in response to said temperature of said mixed pulp and liquid, and
(e) discharging said mixed pulp and liquid from said tank.
4. The method of claim 3 further comprising:
(a) monitoring the total amount of pulp and liquid in said tank, and
(b) controlling the rate of discharge of said mixed pulp and liquid from said tank in response to the amount of pulp and liquid in said tank.
References Cited UNITED STATES PATENTS 1,776,761 9/1930 Morterud 16252 X 2,882,967 4/1959 Surino 162246 2,938,824 5/1960 Richter 162-246 X 3,041,233 6/1962 Richter 16252 X 3,206,356 9/1965 Carlsmith 162237 S. LEON BASHORE, Primary Examiner A. L. CORBIN, Assistant Examiner US. Cl. X.R.
US631291A 1967-04-17 1967-04-17 Continuous digester discharger containing automatic temperature and level sensing means and method thereof Expired - Lifetime US3519532A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US63129167A 1967-04-17 1967-04-17

Publications (1)

Publication Number Publication Date
US3519532A true US3519532A (en) 1970-07-07

Family

ID=24530578

Family Applications (1)

Application Number Title Priority Date Filing Date
US631291A Expired - Lifetime US3519532A (en) 1967-04-17 1967-04-17 Continuous digester discharger containing automatic temperature and level sensing means and method thereof

Country Status (1)

Country Link
US (1) US3519532A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3622441A (en) * 1969-10-07 1971-11-23 Improved Machinery Inc Multiple discharge stock treatment apparatus and method
FR2337225A1 (en) * 1975-12-31 1977-07-29 American Defibrator DEVICE AND METHOD FOR STATIC DISCHARGE OF A FIBROUS COMPOSITION FROM A PRESSURIZED LAUNCHER
US4085002A (en) * 1973-01-05 1978-04-18 Sunds Aktiebolag Bleaching tower for gas phase bleaching
US4105494A (en) * 1973-01-05 1978-08-08 Sunds Aktiebolag Process of gas-phase bleaching high consistency finely disintegrated pulp
US4324820A (en) * 1980-07-18 1982-04-13 St. Regis Paper Company Method and apparatus for coating a paper web
EP0420791A2 (en) * 1989-09-25 1991-04-03 Beloit Corporation Process and mechanism to empty pulping digester
US5711600A (en) * 1994-06-09 1998-01-27 Ahlstrom Machinery Corporation High consistency pulp tower with a parting member and the introduction of dilution liquid
US20210404116A1 (en) * 2018-10-31 2021-12-30 Valmet Ab Reactor discharge screw

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1776761A (en) * 1928-04-02 1930-09-23 Morterud Einar Method for blowing out pulp digesters
US2882967A (en) * 1954-10-06 1959-04-21 Pandia Inc Digesting apparatus discharge valve assembly
US2938824A (en) * 1957-01-22 1960-05-31 Kamyr Ab Digestion apparatus and method
US3041233A (en) * 1957-12-17 1962-06-26 Kamyr Ab Method of introducing high density pulp into a pressure vessel
US3206356A (en) * 1964-06-05 1965-09-14 Improved Machinery Inc Continuous upflow digester

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1776761A (en) * 1928-04-02 1930-09-23 Morterud Einar Method for blowing out pulp digesters
US2882967A (en) * 1954-10-06 1959-04-21 Pandia Inc Digesting apparatus discharge valve assembly
US2938824A (en) * 1957-01-22 1960-05-31 Kamyr Ab Digestion apparatus and method
US3041233A (en) * 1957-12-17 1962-06-26 Kamyr Ab Method of introducing high density pulp into a pressure vessel
US3206356A (en) * 1964-06-05 1965-09-14 Improved Machinery Inc Continuous upflow digester

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3622441A (en) * 1969-10-07 1971-11-23 Improved Machinery Inc Multiple discharge stock treatment apparatus and method
US4085002A (en) * 1973-01-05 1978-04-18 Sunds Aktiebolag Bleaching tower for gas phase bleaching
US4105494A (en) * 1973-01-05 1978-08-08 Sunds Aktiebolag Process of gas-phase bleaching high consistency finely disintegrated pulp
FR2337225A1 (en) * 1975-12-31 1977-07-29 American Defibrator DEVICE AND METHOD FOR STATIC DISCHARGE OF A FIBROUS COMPOSITION FROM A PRESSURIZED LAUNCHER
US4039373A (en) * 1975-12-31 1977-08-02 American Defibrator, Inc. Static discharge device and method for fiber discharge from a pressurized digester
US4324820A (en) * 1980-07-18 1982-04-13 St. Regis Paper Company Method and apparatus for coating a paper web
EP0420791A2 (en) * 1989-09-25 1991-04-03 Beloit Corporation Process and mechanism to empty pulping digester
EP0420791A3 (en) * 1989-09-25 1991-10-23 Beloit Corporation Process and mechanism to empty pulping digester
US5711600A (en) * 1994-06-09 1998-01-27 Ahlstrom Machinery Corporation High consistency pulp tower with a parting member and the introduction of dilution liquid
US20210404116A1 (en) * 2018-10-31 2021-12-30 Valmet Ab Reactor discharge screw
US12091817B2 (en) * 2018-10-31 2024-09-17 Valmet Ab Reactor discharge screw

Similar Documents

Publication Publication Date Title
US1922313A (en) Process and apparatus for disintegration of material
US2803540A (en) Wood chip digestion
US4082233A (en) Disc refiner having means for removing gaseous media from pulp stock
US4023982A (en) Apparatus for the production of sugars from hemi-cellulose-containing raw materials
US3950147A (en) Process for feeding coal to a fluidized bed or suspended particle pressurized processing chamber and apparatus for carrying out the same
US3519532A (en) Continuous digester discharger containing automatic temperature and level sensing means and method thereof
US6436233B1 (en) Feeding cellulose material to a treatment vessel
US2474862A (en) Process and apparatus for continuous digestion of fibrous materials
US7658820B2 (en) Digester wash extraction by individual screen flow control
US5034095A (en) Apparatus and process for the delignification of cellulose pulp
US3586600A (en) Continuous digesting apparatus
US3041232A (en) Method of continuous cellulose digestion and digester apparatus for practicing said method
US2938824A (en) Digestion apparatus and method
US2685937A (en) Deaerating a susp ension of cellulosic fibers
US2614656A (en) Deaerating a suspension of papermaking stock
US2858211A (en) Apparatus for wood chip digestion
JPH10158986A (en) Supply of cellulose fiber to plural pulping cooker and system therefor
US4239590A (en) Method of maintaining uniformity of fibrous material fed to a continuous digester
US4057461A (en) Method and apparatus for impregnation of fiber material by pressure pulsation
US2870009A (en) Method and apparatus for the separation of liquids from cellulosic pulp
US4104113A (en) Two-stage digestion with between vessel heating
NO145592B (en) A sealing head.
EP2467533B1 (en) Method and arrangement for adding treatment liquors to cellulose raw material in a continuous process using down flow vessels
GB892277A (en) Continuous digester
US4432836A (en) Vessel false bottoming

Legal Events

Date Code Title Description
AS Assignment

Owner name: WALTER E. HELLER & COMPANY, INC., 101 PARK AVE., N

Free format text: SECURITY INTEREST;ASSIGNOR:BLACK CLAWSON COMPANY, THE;REEL/FRAME:004250/0792

Effective date: 19840130

AS Assignment

Owner name: BLACK CLAWSON COMPANY THE

Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:HELLER FINANCIAL, INC. F/K/A/ WALTER E. HELLER & COMPANY INC.;REEL/FRAME:004628/0875

Effective date: 19861015