US3463459A

US3463459A - Automatically operated door mechanism for a mixer,kneader,reactor or like machine

Info

Publication number: US3463459A
Application number: US704601A
Authority: US
Inventors: Bernard A Loomans; Thomas I Ross; Richard J Balazer; Clarence K Scherping
Original assignee: Baker Perkins Inc
Current assignee: Baker Perkins Inc
Priority date: 1968-02-12
Filing date: 1968-02-12
Publication date: 1969-08-26
Anticipated expiration: 1986-08-26

Description

Aug. 26, 1969 B. A, LooMANs ET Al. 3,463,459 AUTOMAI'ICALLY OPERATED DOOR MECHANISM FOR A MIXER, KNEADEH, REACTOR 0R LIKE MACHINE 3 Sheets-Sheet 2 Filed Feb. l2, 1968 INVENTORS BERNARD A. LOOMANS RICHARD J. BALAZER THOMAS l. ROSS CLARENC K. SCHERPlNG BY 'CAMA'.

l'aa'zman, .fzazman fr culloc/ FIGA.

Aug. 26, 1969 B. A. LOOMANS ET AL 3,463,459

AUTOMATICALLY OPERATED DOOR MECHANISM FOR A MIXER, KNEADER, REACTOR OR LIKE MACHINE Filed Feb. 12, 196e s Sheets-sheet s S G RMR N fm OAESM nu. TMZSR ,.u` NOAOE MRW uw WLBLS llAm .S n @JAH m DM m RROC -m AAHN l N E HT f RC R El A .m TNIL. BR L w HIWHi C m eludlit.. Y x x B United States Patent O M 3,463,459 AUTOMATICALLY OPERATED DOOR MECHA- NISM FOR A MIXER, KNEADER, REACTOR OR LIKE MACHINE Bernard A. Loomans, Thomas I. Ross, Richard J. Balazer, and Clarence K. Scherping, Saginaw, Mich., assignors to Baker Perkins Inc., Saginaw, Mich., a corporation of New York Filed Feb. 12, 1968, Ser. No. 704,601 Int. Cl. B01f 15/02 U.S. Cl. 259-41 15 Claims ABSTRACT OF THE DISCLOSURE A continous mixer having housing means in the configuration of intersecting cylinders and a plurality of parallel shafts extending axially in the housing, radially aligned interwiping mixing paddles on the shafts shaped to also wipe the walls of the housing upon rotation of the shafts, doors for the housing curved to be wiped by the paddles when in closed position, one of the doors being normally maintained in at least partly open position to permit the passage of material out the door while the other is normally maintained in closed position, a control circuit for varying the position of the partly open door according to the power required to drive the shafts in the same direction of rotation and at the same speed, a control for periodically moving the partly open door to closed position to permit a paddle to wipe the door and remove any accumulation of material thereon, and a control for opening the normally closed door when the normally partly open door is substantially fully opened.

One of the prime objects of the invention is to provide a mixer having a discharge door assembly including one normally partly open gate or door configured to be wiped by a mixing element which is controlled in a manner so that it is periodically closed to permit the mixing element to wipe the door.

Another object of the invention is to provide a door of the character disclosed which is retained in a partially open position and regulates the flow of material being discharged from a continuously operating mixer, and which automatically reacts to an emergency situation to open fully toempty the mixer of material.

Still another object of the invention is to provide a door assembly including an upper gate and a lower gate, the bottom gate or door being normally closed and openable automatically in an emergency situation responsive to opening of the upper gate or door to assist the upper door in emptying the mixer.

Other objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawings, in which:

FIGURE 1 is a fragmentary, sectional elevational view through the mixer of the invention, with the midportion of the mixer being broken away and omitted from the view for the sake of convenience;

FIGURE 2 is a transverse sectional view through the discharge end of the mixer, taken on the line 2 2 of FIGURE l;

FIGURE 3 is a similar transverse sectional View taken through the mixer on the line 3 3 of FIGURE 1;

FIGURE `4 is `a fragmentary, sectional top plan view taken on the line 4 4 of FIGURE 2;

FIGURE 5 shows a typical electrohydraulic control system for the door assembly.

3,463,459 Patented Aug. 26, 1969 ICC Referring now more particularly to the accompanying drawings, wherein a preferred embodiment of the invention only is illustrated, the mixer includes end base members 10 mounting frame portions 11 on which the bed 11a of a horizontally disposed mixer housing generally designated 12 is supported as shown. It is to be understood that the mixer which will be described is a continuous mixer of the character disclosed in Loomans et al., U.S. Patent No. 3,195,868 and in a similar manner inclutdes the figure S-shaped housing 12 which defines communicating upper and lower intersecting, cylindrical chambers 14 and 15. While the `drawings do not indicate it, usually a jacket is provided around the casing 12 to hold a cooling or heating medium in the manner disclosed in the patent mentioned. As FIGURE 1 indicates, the charge end of the barrel or housing 12 is closed by an end plate 16, and a material supply hopper 17 may be provided for moving material into the casing 12 through a material supply opening 18.

Extending axially through each of the chambers 14 and 15 in a concentric manner are upper and

lower mixer shafts

19 and 20, respectively, which may be journaled in suitable bearings 21 at the charge end of the

housing

12, and 22 at the discharge end. Keyed. on the front ends of

shafts

19 and 20 as in the aforementioned patent are

worm sleeves

23 and 24 which serve to advance the material from the charge end of the housing 12 toward the opposite end thereof, and also keyed on the

shafts

19 and 20 are pairs of radially interengaging and interwiping upper and

lower paddles

25 and 26, respectively, which wipe the Walls of the figure 8-shaped housing 12 as well as one another.

As the drawings indicate, each of the

paddles

25 and 26 is of generally lenticular shape and each pair of

mating paddles

25 and 26 is ldisposed with. the major axis of one paddle at right angles with respect to the major axis of the other paddle, as illustrated particularly in FIGURE 3. The

paddles

25 and 26 may be helically pitched in a direction to move the material from the charge end of the mixer housing 12 toward the discharge end and staggered helically so that they collectively also form worms moving the material toward the discharge end of the housing 12. The continuous

spiral feed screws

23 and 24 in cross section have the same configuration as the

paddles

25 and 26 and consequently their respective crests also Wipe the walls of the chambers 14 and 15 clean. The iianks and crests of each spiral feed screw are thus also wiped clean by the flanks and crests of the other spiral feed screw in the same manner as are the flanks and crests of the

paddles

25 and 26. The

feed screw sections

23 and 24 are preferably pitched to provide a more rapid throughput of material than the pairs of

paddles

25 and 26 would provide, and insure the desired rate of throughput. With low viscosity materials supplied under pressure by a metering device, it may be desirable to replace the

worm sections

23 and 24 with pairs of

paddles

25 and 26, and this may also be advisable when certain chemical reactions are occurring in the mixer. The

shafts

19 and 20 are driven in the same direction of rotation and at the same speed Aby a drive shaft 27 mounting a gear 28 in mesh with a gear 29 on the shaft 19, and a gear 30 in mesh with a gear 31 on the mixer shaft 20.

THE DISCHARGE HOUSING At the discharge end of the housing a discharge housing assembly generally indicated by the numeral 32 is connected to an end support wall portion 11' and includes a discharge casing surrounding the discharge end of mixer housing 12 having side walls 33 and 34 (FIGURE 2),

end walls

35 and 36, and stepped

top wall sections

37 and 38 which join to the mixer housing 12, the Wall 37 being 3 joined to the upper portion of mixer housing 12 by a wall 37a. The end wall 36 of discharge housing 32 closes the end of mixer housing 12 as well. As FIGURE 1 indicates, the discharge housing assembly 32 is open at its lower end as at 39 and discharges to any suitable collecting or conveying device, dependent upon the mixing operation or reaction being carried on in the mixer housing 12. A divider plate 32a depends from the end of mixer casing 12.

THE DISCHARGE GATE ASSEMBLY As FIGURE 1 also illustrates, the portion of mixer casing 12 which extends into the discharge housing 32 houses an end pair of paddle members 25 and 26' and reversely pitched, helical worm or

screw sections

40 and 41 fixed on the

shafts

19 and 20 which are pitched to advance material in a direction toward the charge end of the machine in opposition to the flow of material therein. Provided within the discharge housing 32 are an upper rock shaft 42 and a lower rock shaft 43, di-sposed adjacent and parallel to opposite sides of the mixer casing 12. The

shafts

42 and 43 are journaled in bearings `44 which may be aixed to the casing or barrel 12 and mount discharge doors or

gates

45 and 46, respectively, on arms 47 which are keyed to the

rock shafts

42 and 43 as at 48. As FIGURE 2 particularly indicates, the

gates

45 and 46 have curvilinear inner surfaces as at 45a and 46a to conform to the curvilinear coniiguration of the casing 12 and, when in the closed position in which they are shown in FIGURE 2, eifectively seal the oppositely disposed

side discharge openings

49 and 50 provided in the casing 12. Pivotally mounted as at 51 on a bracket 52 secured to the end frame member 11 is the piston rod 53a of a hydraulic cylinder 53 which carries a cylinder 54 having a piston rod 54a pivotally connected as at 55 to an arm 56 which is keyed to the rock shaft 42 as at 57. Also pivotally mounted as at 58 on a bracket `59 secured on the opposite side of end member 11 is a hydraulic cylinder `60 which has its piston rod 61 pivotally connected as at 62 to an arm 63 keyed to the rock shaft 43 as at 64. As will later become clear, piston rod 53a is normally fully extended to hold cylinder 54 in a position that allows it to open and close gate 45, the piston rod 54a is held in a normally partly extended or open position to provide a gate which is open to the extent e in FIGURE 2, |and the piston rod 61 is normally in the retracted position in which it is shown in FIGURE 3 and holds the gate or door 46 in the closed position in which it is shown in FIGURE 2. Access doors `65 and 66 are releasably secured over

openings

67 and 68 in

walls

34 and 35, respectively, as shown in FIGURE 2, for the sake of convenlence.

THE ELECTROHYDRAULIC CIRCUIT At the left in FIGURE is an electrical circuit and at the right a hydraulic circuit which is controlled by the electrical circuit in a manner to be described. The drive motor for driving `shaft 27, and through it

shafts

19 and 20, is shown at 69 in the electrical circuit connected through a current transformer 70 to an optical meter relay 71 with an indicating pointer contact 71b and separately adjustable high and low contacts 72 and 73, the so-called high contacts 72 being normally open as shown and the contacts 73 being also normally open. The meter relay employed is one which is currently available `on the market and may comprise the type 195 meter relay sold by General Electric Company. Such meters conventionally include the indicating pointer, which is movable relative to a `scale yaccording to the current being drawn and which opens and closes the low and high relay contacts 73 and 72, respectively, at the limits of its travel in the usual manner. Preferably, the so-called high and low contacts 72 and 73 are carried by settable points whose position also can be varied relative to the scale to set different limits.

Also connected in the electrical circuit adjacent the meter relay ygenerally designated 71 is a motor driven timer generally designated IT. Such timers are also currently available on the market and may comprise the series 305B general purpose reset timer manufactured by Automatic Timing & Controls, Inc., King of Prussia, Pa., U.S. The time delay device IT is operative to provide a denite timed period during which the door 45 is normally partly open. A valve IV for controlling the open position of door 45 under normal circumstances has a solenoid 76 which, when energized, operates to further open door 45. The valve IV also has a solenoid 77 which, when energized, operates to pass Huid to cylinder 54 to move the door 45 to a more closed position. At the right end of FIGURE 5 in the hydraulic diagram, hydraulic fluid under pressure is shown as supplied to the valve IV through a hydraulic line 79 by a hydraulic power lunit comprising a pump 80 driven by a motor 81, pump being connected to a reservoir 82. From valve IV a hydraulic fluid supply line 84 leads through a ilow control valve 85 to the gateclosing side 86 of the hydraulic cylinder 54. Similarly, a hydraulic uid line 87 leads from the gate-opening side 88 of the -cylinder 54 through a flow control valve 89 back to control valve IV. Hydra-ulic line 90 connects the valve IV with reservoir 82.

Dependent on the particular setting of relay contacts 72 and 73 with respect to the meter scale 71a, control valve IV will maintain the piston rod 54a of cylinder 54 in a partly raised position and the door `45 in a partly open position so long as the power required to drive

shafts

19 and 20 is normal. When the

mixer shafts

19 and 20 are being driven normally under a normal power load, the pointer 71b of meter 71 will be disposed approximately midway between the relay contacts 72 and 73. When the pointer swings over to the high contacts 72, however, indicating that an undue amount of power is being utilized to drive

shafts

19 and 20, contacts 72 are closed and solenoid 76 is energized to pass fluid through line 87 to move the door 45 to a more open position. At this time, of course, solenoid 77 is deenergized. Conversely, when practically no power is being utilized to drive

shafts

19 and 20, as at a time when the machine is starting up, the low side contacts 73 will be closed, due to the presence of the meter indicator pointer 71b at the contacts 73, and solenoid 77 will be energized to pass hydraulic fluid through line 84 to the cylinder 54 and move the door or gate 45 to a more closed position. At this time solenoid 76 is, of course, deenergized and hydraulic uid is free to exit through hydraulic line 87.

The hydraulic cylinder 54 is actuated to completely open the door or gate 45 in an emergency situation when an abnormally high current is required to drive shaft 27 and, when this occurs, the arm 56 depresses the spring returned operating plunger 92 of a hydraulic valve 3V which 1s operated to move fluid through a line 93 and ilow control valve 94 to operate cylinder 60 and open door 46. Hydraulic fluid is supplied to the control valve 3V through a hydraulic line 95 communicating with line 7 9 and the valve 3V has a reservoir line 96. A similar line 9.7 leads through a ow control valve 98 to the opposite side of the cylinder 60. The valve 3V normally maintains the door 46 closed and it is only when plunger 92 1s depressed that hydraulic lluid is fed by the valve 3V through hydraulic line 93 to raise the piston rod 61 of hydraulic cylinder 60 `and completely open the gate or door 46. This occurs only at a time when the gate or door 45 is already fully opened and serves to permit the extremely fast exit of material from the mixer in an emergency situation. Such a situation might occur, for instance, m a polymerization reaction to empty the machine rap1dly 1f the reaction gets out of control temperaturewlse.

Except when meter contacts 72a are opened (which occurs when pointer 71b closes high limit contacts 72), the timer IT operates to periodically close the top gate 45 so that it may be intermittently wiped by the pair of paddles 25', 26 and

reverse screw sections

40 and 41, it being understood that

reverse worm sections

40 and 41 in cross section have the same configuration as the paddles 25 and 216 to perform the wiping function in the same manner. The timer IT has a motor M driving a spring returned timer pointer p which moves from a preset position 1 governing the time period through a rotary path to a second position 2. to open a switch 98a. The motor M is coupled to the pointer by a clutch C1 which releases when contacts ITRc are opened so that the pointer can return as will later appear. When the motor M of timer IT times out by opening switch 980:, the companion timer switch 98h is closed and the solenoid 99 of spring returned control valve 2V is energized so that hydraulic fluid is fed through a hydraulic line 103 and a flow control valve 105 to the door closing side 104 of cylinder 53. A hydraulic line 100 leads from the opposite, door opening side 102 of cylinder 53 through a ow control valve 101 back to the control valve 2V. Control valve 2V is provided with the usual reservoir line 106 which communicates with the reservoir 82.

As FIGURE 5 indicates, a switch actuator 107 provided on the arm 56 moves into engagement with the actuator arm of a switch ILS when arm 56 on which it is mounted is pivoted downwardly to dispose door 45 in closed position. Thus, when the gate or door 45 is moved to fully closed position by the cylinder 53, the movement is sensed by limit switch ILS. Connected in circuit with the limit switch ILS is a timing relay ITR which has relay contacts ITRa with associated timing contacts IT Rb and contacts ITRc, as shown. When the contacts ITRc are opened by relay ITR, the pointer p of timer IT is freed so that it may return (reset) to original position. Simultaneously, the contacts ITRa close to hold solenoid 99 energized after timer IT contacts 98b reset to their open position. The pneumatic timing contacts ITRb hold solenoid 99 energized for a time period of approximately one second or whatever time is required to insure that the interior'surface 45a of door 45 is cleaned. When the timing contacts ITRb of relay ITR open, solenoid 99 is deenergized and valve 2V is free to return to original position. Cylinder 53 is thereby returned to original position, the gate 45 is opened to a position again governed by the control valve IV, limit switch ILS is released, and timer ITR is reset by the opening of limit switch contacts ILS. When the pointer p of timer IT is returned to its original position, contacts 98a and 98b close and open, respectively, contacts ITRc reclose when timer ITR resets, and the clutch solenoid C of timer IT is energized at this time to recoupled the timer pointer p to motor M so that the cycle repeats.

It is to be noted that when the timer IT times out and the door 45 is closed for cleaning, the complete cylinder 54 is carried along downwardly with its piston position unchanged. Later, when cylinder 53 reopens the gate 45, the gate or door 45 will return to the same control position. The

ow control valves

101 and 105 for cylinder 53 are set to provide relatively fast movement so that the closing of gate 45 will not last long enough to raise the motor load and upset the control position of cylinder 54.

As the control circuit indicates, both manual and automatic control of the upper gate or door 45 is provided. With the control selector switch C at hand (the position x of the bridge members shown in solid lines), the top door v45 is controlled by watching the motor load indicator pointer of meter 72 and pressing the open or close push button 107 or 108, respectively, to position the door 45 as desired. Manual gate operation will be used during start-up to position the gate 45 to a predetermined amount of material is present in the machine. When quick-close button 109 can be used to close the top gate 45 quickly for cleaning. When the button 109 is released, the gate 45 will return to its previously positioned opening. The olf position of the control bridge members is indicated at y and the automatic position at z.

In operation, both

gates

45 and 46 are initially closed, of course, until the machine is charged and a predetermined amount of material present in the machine. When this occurs the amount of current required to rotate

shafts

19 and 20 will increase and control valve IV will be operated through energization of solenoid 76 to open the gate 45 to a predetermined open position in which it is normally maintained, as shown in FIGURE 2. Thereafter, as long as normal flow conditions are maintained in the mixer and normal current is required to operate

shafts

19 and 20, valve 45 will be retained in this normally open position except that it will periodically be closed by the timer IT operating through valve 2V. The gate 45 is closed under these conditions for a sufficient period of time for the top gate 45 inner surface to be wiped clean. Only in an emergency situation will door 45 be completely opened, and at this time the bottom door 46 will also be completely opened for the period of time during which the unusually high current is required to revolve

shafts

19 and 20. When the high current situation is relieved by emptying of the material rapidly through both

gates

45 and 46, the Igate 45 will return to a partially open position while gate 46 returns to closed position.

We claim:

1. In a mixer, kneader, reactor or like machine: housing means in the configuration of intersecting sylinders; a plurality of parallel shafts extending axially in said housing means and having interwiping material agitating means thereon shaped to also wipe the walls of said housing means upon rotation of said shafts; means for driving said shafts in the same direction of rotation and at the same speed; door means in said housing means configured to be wiped by said agitating means when in closed position; means normally holding said door means in a position removed from closed position to permit the passage of material through said door means; and means for periodically moving said door means to closed position to permit said agitating means to wipe said door means and remove any accumulation of material therefrom.

2. The combination defined in claim 1 in which electrically controlled motor means drives said shafts; said door means is mounted to move to various positions in which it varies the amount of material passed; and control means is provided for varying the position of said door means according to the power required to drive said shafts.

3. The combination defined in claim 2 in which said door means is moved away from said housing means upon an increase in the power required.

4. The combination defined in claim 1 in which said agitating means comprises radially aligned, generally lenticular paddles on said shafts, the interwiping paddles being angularly displaced 5. The combination defined in claim 4 in which said paddles are helically disposed to feed material toward one end of said housing means; and reverse-hand worm means on said shafts at said end feed material in an opposite direction; there being discharge casing means leading from said housing means at the juncture of said worm means and paddle means and housing said door means.

6. The combination defined in claim 1 in which said door means is provided in the upper part of said housing means and a second door means is provided in the lower part of said housing means; said second door means being normally in closed position; and control means for opening said second door means when said first door means reaches a fully open position.

7. The combination defined in claim 6 in which electrically controlled hydraulic rams separately move said door means and second door means to open and closed positions.

8. The combination of claim 7 in which said housing means is in the configuration of an upright figure 8 and the door means and second door means are on opposite sides of the housing means.

9. In a mixer, kneader, reactor or like machine: housing means; shaft means extending axially in said housing means and having material agitating means thereon; means for driving said shaft means; door means in said housing means configured to be wiped by said agitating means when in closed position; means normally holding said door means in a position removed from closed position to permit the passage of material through said door means; and means for periodically moving said door means to closed position to permit said agitating means to wipe said door means and remove an accumulation of material therefrom.

10. In a mixer, kneader, reactor or like machine: housing means; shaft means extending axially in said housing means and having material agitating means thereon; means for driving said shaft means; gate means for said housing means for controlling the discharge of material therefrom; means for sensing the amount of current required to operate the shaft means; and means for moving the gate means away from the housing means to increase the outflow therefrom when said sensing means senses that the current requirement is greater than a predetermined requirement.

11. The combination defined in claim 10 in which the sensing means includes contacts set at high and low power requirement limits.

12. In a mixer, kneader, reactor or like machine: longitudinally extending housing means; shaft means extending axially in said housing means and having mixing element means thereon; means for driving said shaft means; upper gate means in one end of said housing means; means normally holding said upper gate means in a position removed frorn closed position to permit the passage of material through said upper gate means; lower gate means for said end of the housing means; and control means operable in response to said upper gate means reaching a predetermined position removed from closed position to open said lower gate means.

13. In a mixer, kneader, reactor or like machine, housing means; shaft means extending axially in said housing means and having material agitating means thereon; means for driving said shaft means; discharge door means in said housing means; means normally holding said door means in a position removed from closed position to permit the passage of material through said door means; means for sensing the amount of power required to drive said shaft means; and means for holding said door means in an open position when said power requirement increases.

14. In a mixer, kneader, reactor or like machine: housing means; shaft means extending axially in said housing means incorporating mixing element means thereon; means for driving said shaft means; door means in said housing means configured to be wiped by said agitating means when in closed position; and means for automatically periodically moving said door means from an open to closed position, and returning said door means, to permit said agitating means to wipe said door means and remove any accumulation of material therefrom.

15. The combination defined in claim 14 in which a first fiuid pressure operated cylinder moves said door means to more open or more closed positions dependent on the power required to drive said shaft means; and said means for automatically periodically moving said door means includes a second fiuid pressure operated cylinder means carrying said first fluid pressure operated cylinder means.

References Cited UNITED STATES PATENTS 2,994,100 8/1961 Comes 259-41 X 3,099,040 7/1963 Matsuoka 259-41 X 3,195,868 7/1965 Loomans 259-104 ROBERT W. JENKINS, Primary Examiner U.S. Cl. X.R. 259-6