US3440733A

US3440733A - Material drying and conveying apparatus

Info

Publication number: US3440733A
Application number: US688801A
Authority: US
Inventors: Brian R Reuter; Stuart Stern
Original assignee: CONSOLIDATED ENG CO Inc CECO
Current assignee: CONSOLIDATED ENG Co Inc CECO
Priority date: 1967-12-07
Filing date: 1967-12-07
Publication date: 1969-04-29
Anticipated expiration: 1986-04-29

Description

April 29, 1969 REUTER ET AL 3,440,733

MATERIAL DRYING AND CONVEYING APPARATUS Filed Dec. 7', 1967 Sheet of 2' W I40 I it 141 32A BR/AN R REUTER 5 TUA R7 5 TEFPN INVENTORS BY 21/5 6, M

ATTOR/Vf) April 29, 1969 B, R, REUTER ET AL 3,440,733

MATERIAL DRYING AND CONVEYING APPARATUS Filed Dec. 7, 1967 Sheet i of 2 I 4./ 96a? 96 9m 5/a A 4! HL.-l)/

//a 2568/ I/6/ it 1 i 72 &

BR/A/v R R541 75/? STUART STERN [NVENTORS BY 2J5 5,214-

A TTORNE Y United States Patent 3,440,733 MATERIAL DRYING AND CONVEYING APPARATUS Brian R. Renter, Houston, Tex., and Stuart Stern, Fort Lee, N.J., assignors to Consolidated Engineering Comprany, Inc. (CECO), Houston, Tex., a corporation of exas Filed Dec. 7, 1967, Ser. No. 688,801 Int. Cl. F26b 3/08, 17/12 US. C]. 3410 12 Claims ABSTRACT OF THE DISCLOSURE As a primary object the invention sets out to provide a means for automatically controlling the cyclic measured entry, drying while back-filtering, activating, full discharging and purge discharging of a material which enters the processing pump, vessel, or container, the entering material having a moisture content which is removed by drying as the material is rendered fiowable by a pressurized activating and discharging gas.

It is also an object of this invention to provide apparatus of this class which is selectively set to automatically control fill, drying, activation, full discharge and purge discharge, or alternately, when the handled material does not have to be dried, to automatically control, fill, activate, full discharge and purge discharge.

It is still a further object of this invention to provide apparatus of this class which additionally provides a safeguard to close the fill valve in case the regularly provided fill valve closing means should not function, or fail to function timely.

It is also another object of this invention to provide apparatus of this class which may dry the handled material by interspersin-g predetermined filter blast periods between predetermined drying intervals between blasts.

Other and further objects will be apparent when the specification herein is considered in connection with the drawings, in which:

FIG. 1 is an elevational view, part in section, of a container, pump or pressure vessel, partially diagrammatical, which discloses an embodiment of the invention;

FIG. 2 is a sectional bottom view, looking upward along line 22 of FIG. 1;

FIG. 3 is an electrical diagram of the apparatus and circuitry therefor, as employed in actuation of the apparatus disclosed generally in FIG. 1; and

FIG. 4 is an isometric view of safeguarding apparatus indicated in FIG. 1, with a circuit diagram of the circuitry entering into its operation.

Referring now to the drawings in which like reference numerals are applied to like elements in the various views, a material container, housing, pump or activator is shown in FIG. 1 comprised of a shell 11 including a cylindrical main body 11a with upper end closed by a top comprised of a spherical segment or dome 12a and a bottom comprised of a spherical segment or lower closure 12b, the container being constructed after the general 3,440,733 Patented Apr. 29, 1969 ice manner of conventional pressure vessels, and designed with safety factors, to withstand the highest pressures that may be developed therein.

The pressure vessel or container 10 is supported on legs 14 which upstand from a conventional base or grout, not shown. A gas permeable membrane or diaphragm 13, sloped at substantially 13 degrees, as indicated, separates the container into an upper, or material plenum 15, and a lower, or gas plenum 16.

The dome 12a has an inlet flange or neck 17 connected centrally into the top thereof with an inlet gate valve or fill valve 18 being mounted thereon. The top flange 19 of the fill valve 18 is shown connecting the fill valve 18 with a discharge flange 20 from a hopper 21.

A valve operator 23 is shown diagrammatically, as disposed to open and close the gate valve 18, a piston 23a being shown provided in the valve operator 23, with instrument air admissable under the piston 23a through a conduit 23b to open the fill valve, and with instrument air being admissable through a conduit 230 above the piston 23a to close the fill valve. Obviously, the conduits 23b and 230 must be in a closed compressed circuit with a pressurized reservoir, or otherwise selectively supplied with compressed air, to carry out their respective functions.

A hot drying gas conduit 107 is shown connected into the lower end closure 12b of the shell or pressure vessel 11 below the high side of the membrane 13, and such hot drying gas inlet line 107 has a drying gas valve 26 therein, which is shown connected to be opened and closed by a valve operator 27, constructed and equipped in correspondence with the valve operator 23. Also, a discharge outlet pipe 28 extends downwardly through the dome 12a to terminate in a pick-up end 28a disposed slightly above the low side of the gas permeable or air permeable membrane 13. A valve 29 is shown connecting this discharge outlet pipe 28 with a discharge conduit 30. The discharge valve 29 is shown operated by a valve operator 33, which is indicated as being constructed, and as having connections thereto, in correspondence with the fill valve operator 23.

A purge line 34 extends between the discharge conduit 30, downstream of the discharge valve 29, to the material plenum or chamber 15 and has a purge valve 35 thereln to control its opening and closing, a valve operator 36 being shown connected to the purge valve 35 for this purpose, such valve operator 36 being constructed, and having connections in correspondence with the fill valve operator 23. However, it may be pointed out, in this regard, that the purge valve 35 should be a normally open valve, whereas the fill valve 18, gas lnlet valve 26, and discharge valve 29 are normally closed valves.

Additionally, the support body 37 for a safeguarding vibratory paddle 38, operative on the tuning fork principle, is shown connected into the cylindrical body 11a of the shell 11, the material sensitive paddle 38 being indicated in dotted lines in FIG. 1 as extending within the housing 10 near the top thereof, such paddle being operative to actuate the valve operator 23 to close the fill valve 18, as will be hereinbelow described.

An insulative cord 39, having therein the electrical conduits to the paddle 38, extends from the paddle support body 37 to a control box 40, to be hereinbelow described, and shown mounted on the exterior of the activator shell body 11a.

A vent valve 31 is shown connected into the dome 12a in FIG. 1 and operated by a valve operator 32 which is constructed, and has connections thereto, in correspondence with the fill vale operator 23. Also a solenoid operated blast air valve 104 is shown connected into the dome 12a oppositely of the vent air valve connection, with blast air, to be hereinbelow described, being supplied to the valve 104 through a blast air conduit 105. Additionally, a solenoid operated, transfer or moving air valve 106 is connected into the shell bottom 12b or gas plenum chamber 16, a conduit 25 being connected to supply moving air to the valve 106. Also, the shell segment 12b is shown having a drain valve 108 connected into the bottom thereof. Also, a conventional manhole 109 is shown provided in the side of the shell cylinder 11a.

The neck or nipple 17 which supports the fill valve 18, and by means of which the valve 18 is connected to communicate through the top of the dome 12a, extends downwardly into the shell or vessel 11 as indicated in FIG. 1. A series of equally angularly spaced apart, radially extending support rods or bars 110 have their inner ends connected to the nipple 17 and are connected at their outer ends to the inner surface of the shell 11a, as best seen in FIG. 2. At a spaced distance below the suspension bars 110 a baffle plate 111 extends across the shell 11a and has a central enlarged opening 12a therein into which is connected the lower end of a central perforated sleeve 112 of frusto-conical shape, the upper end of the sleeve 112 being affixed to the outer periphery of the lower end of the nipple 17.

A ring of round or eliptical holes or openings 113 is provided in the baffle plate 111, the hole being equally angularly spaced apart, and such holes receive therein the lower ends of perforate filter sleeves 114 to be affixed to the battle plate 111. The filter sleeves 114 are of reduced cross-sectional area upwardly and the top of each sleeve 114 is connected upwardly to a respective suspension bar 110 as best indicated in FIG. 1. The filter sleeves 114 may be of woven metal cloth, perforate glass or perforate plastic of such porosity to admit the processing gas or air to pass therethrough while entraining or stopping the passage of the process material. A suitable handhole 115 is shown provided in FIG. 1 for access to the filter sleeves 114 and central sleeve 112. It should also be noted in the bottom view of FIG. 2 that the relative positions of the blast air inlet 104a and the vent air outlet 31a are discernible.

As shown in FIG. 3, a positive line 41 and a negative line 42 extend from a source of electrical power, the positive line 41 having three parallel lines 41a, 41b and 410 branching therefrom with the line 41a serving when manual control is to be used as will be hereinbelow described with the line 41b serving as a neutral third positive conductor and with the line 41c serving as the positive conductor when automatic control is to be employed. A three-way switch, indicated generally by reference numeral 44, is provided to control the selection of automatic or manual control, as desired, and as shown, the switch 44 indicates that automatic control has been selected, the conductors 41b, 410 thus being closed and the conductor 41a being open.

A conductor 45 extends from the conductor 41c, and a push-button switch 45a is shown in FIG. 3 as closing circuit in this conductor, the conductor 41c continuing to a junction with three parallel circuits including the circuit of a variable time delay relay 46, the circuit 47 for a solenoid 48 which operates the fill valve operator 23 shown in FIG. 1, and the circuit of an indicator light 4 9 which may be designated as a green light for illustratwo purposes.

The conductor 45 continues as the conductor 45c and has contacts 51:: therein of a double acting pressure actuated switch 50, such contacts 51a being normally closed at atmospheric pressure and opening upon increase of pressure in the gas plenum 16. The conductor 45c continues from the contacts 51a to a junction with a conductor 45b having therein the normally closed relay contacts 56a of a latching relay 52., the conductor 45b terminating at its connection to the negative power line 42.

A parallel circuit 53 extends from the neutral or central positive conductor 41b, to the junction of the conductors c, 45b, such parallel circuit also including themin the contacts 51b of the aforesaid pressure actuated switch 50, such contacts 51b being normally open at atmospheric pressure and closing upon increase of pressur in the aforesaid gas plenum 16. The circuit 53 also has therein an indicating light 54, designated as a yellow light for indicating purposes, as will be hereinbelow described.

Another parallel circuit 55 from the positive conductor 41b has the switch 46a therein which is closed by the variable delay relay 46 at the end of its preselected cycle, the circuit 55 also having therein the coil 52a of the latching relay 52, and the circuit 55 being continued by the circuit 450, as aforesaid. The circuit 55, as thus closed, energizes the latching relay coil 52a to open the normally closed relay contacts 56a to break the aforesaid

parallel circuits

46, 47, 49 and 55, and upon the solenoid circuit 47 being de-energized, the solenoid 48 retracts and moves the valve operator 23 to close the fill valve 18, both valve operator and fill valve being shown in FIG. 1.

The latching relay 52 is of the well known type, which, when its coil 52a is energized, it actuates conventional switching means which opens the normally closed contacts 56a, and pulls closed the normally open contacts 56b in a parallel circuit 57 extending from the negative conductor 42, in manner that the latching relay mechanism latches against any movement except that which may be imparted to the switching means to pull open the normallyopen contacts 56b, which can only be etfectuated by the energization of the latching relay coil 52b, to be hereinbelow described as to operation.

The apparatus for handling a material not requiring drying will be first described, for purposes of clarity, and with its operation understood, the apparatus for interjecting the drying processes will then be described, and the relationship to the activating, full discharging and purge discharging apparatus and steps set forth therewith.

The circuit 57, hereinabove referred to, has the aforesaid latching relay, normally open contacts 56b therein, and adjacent thereto, in direction of the positive conductor 41b, 2. manual throw switch 69 is connected into the circuit '57, so that when the switch 60 is manually or selectively disposed to connect the circuit 57 with a continuation circuit 57a, the apparatus is set to handle a material which does not require a drying process before delivery for subsequent handling. Thus the four circuits:

57b, and then 59, 61 and 62, to be hereinbelow described, are joined to the circuit 57a, the circuit 57b being continued by the circuit 570 to the positive conductor 41b.

From the junction of the circuits 57b, and 570, a circuit 64 a having a switch 64 therein, continues as the circuit 64b to the negative side junction of the aforesaid circuits 59, 61 and 62. A fixed time delay relay 58 of the thermal delay type, in the circuit 57b, operates for its time interval, when the circuit 57a is closed, and closes the switch 64 whereby the solenoid 59a in control box 40 releases air from the tube 127 to open the moving air inlet valve 106 whereby the circuit including the light 61, blue to indicate activation, is closed, and whereby the circuit 62 actuates the solenoid 63 to close the purge valve 35; see FIGS. 1, 2 and 3.

Also, a circuit 57d continues from the junction of the

circuits

57b, 59, 61 and 62 with the circuit 57a, and branches into: a circuit 65 including the coil which operates a solenoid 66 which actuates the valve operator 33, shown in FIG. 1, to open and close the discharge valve 29; a circuit including a light 67 therein, which is designated as a red light, for purposes of illustration; and a circuit having a relay 68 therein; from the positive side junction of the

circuits

65, 67 and 68, there extends a circuit 57e (having a normally open pressure actuated switch 69 therein, to be hereinbelow described), with its positive side connection being completed with the conductor 41c; and there also extends from such junction a circuit 57f having a pair of contacts 70 therein operated by the relay 68, and terminating by connection with the neutral or positive conductor 4112. A push-button switch 71 is shown in FIG. 3 closing the circuit 41c adjacent its connection to the circuit -57e.

Additionally, a circuit 72b, 72a connects the positive or neutral conductor 410 with the negative power line or conductor 42; the circuit 72b having in series therein a pair of contacts 74, (operated by the relay 68 substantially simultaneously with its operation of the contacts 70 in the circuit 57 and a pressure sensitive switch 73 which functions as will be hereinbelow described. Then, the circuit 72a, with which the circuit 721) connects, has therein the latching relay coil 52b which operates to break circuit closed by the hereinabove described relay contacts 56b.

The gas, as compressed air, which activates and transports the material which enters the container, shell, or pressure vessel 11, arrives from its source, as a compressor or pressure header 25h, as shown in FIG. 1, and enters conduit 25 to pass through a strainer 83 and a globe valve 84 on its way to being regulated as to the pressure at which it is to be supplied. Thus the gas is first measured by a high pressure gauge 85 in the top of a gauge pipe 85a which upstands from the main gas line 25 through which the strained gas passes on downstream, and to the transfer gas valve 106.

A smaller sized by-pass line 25a extends between the gauge pipe 85a and the aforesaid pressure regulating valve 86 in the main conduit 25, and has a pilot regulating valve or regulator 87 therein, thus to permit a finer and more responsive control of the pressurized gas on its way to the pressure vessel 11. A by-pass line 87a conveys the reduced pressure gas from the pilot regulator 87, and connects with an upstanding gauge pipe 88 above the main conduit 25, a low pressure gauge 89 being mounted on top of the gauge pipe 88 to indicate the lowered pressure of the gas.

A conduit 90 extends from the lower closure 12b to conduct pressurized gas from the gas plenum 16 to the control box 40, there to bear upon and cause actuation of the pressure sensitive switch 50, operative as hereinabove described, and to bear upon and cause actuation of pressure

sensitive switches

69 and 73, to be further described as to operation hereinbelow.

The switch actuating gas, which must be taken from within the pressure vessel 11, enters the conduit 90 and passes through a strainer 91 therein, and on to the panel box 40, a gauge 92 being provided to indicate the pressure of the actuating gas as it passes downstream of the strainer 91 on its way to the panel box pressure sensitive switches, as aforesaid. The instrument air required by the pressure sensitive switches, as contradistinguished from the actuating air or gas, and any other air or gas required to actuate any of the apparatus, as that required to operate the valve operators shown in FIG. 1, may be brought to the panel box 40 through a conduit 93 for selective distribution.

Also, the

power conductors

41, 42, from a source of electrical power, as a 60 cycle, 115 AC. voltage source. may be brought to the panel box 40 through an insulated conductor cord 95. A conventional fuse 96 is provided in the positive power line 41, indicated as comprising the conventional fuse strip 96a, and in a parallel circuit therewith, the conventional resistance 96b and indicating light 960.

The operation of the apparatus shown in FIGS. 1, 2 and 3 may be set forth in a sequence, and partially by way of reiteration, with the composite switch contacts 51a and the latching relay contacts 56a closed, the switch 45a may be manually closed whereby the solenoid 48 actuates its associated valve operator to open the fill valve, as the variable time delay relay 46 starts its cycle and times out as it closes the switch 46a at which time the relay 52a of the latching relay is energized to break the latching relay contacts 56a and close the latching relay is energized to break the latching relay contacts 56a and close the latching relay contacts 56b, the fill valve 18 thus being closed. The switch arm 60 closes circuit with the circuit 57a, and the fixed time delay relay 58 is energized so that the switch 64 is closed and the solenoid 59a actuates its associated valve operator to open the activating air or gas valve 106 to let gas, such as compressed air, into the gas plenum 16 to pass through the membrane 13 and into the material plenum 15 to start pressurizing the vessel or activating the material to be transferred. Also, as this occurs, the circuit 62, having therein the switches 62a, 6217 on either side of the solenoid windings 62, in circuit closed position, the energized solenoid windings 62 actuate the solenoid 63 to actuate the valve operator 36 to close the purge valve 35. This pressurizes the vessel 10 and activates the material until that pressure is attained which will close the normally open pressure actuated switch 69 whereby the solenoid 65 is actuated to move its associated valve operator 33 to open the discharge valve 29. Also the relay 68 is energized to close the normally open switch 70 and the normally open switch 74.

Discharge then continues until the pressure drops to open the pressure sensitive switch 69, then to close the pressure sensitive switch 73, thus completing circuit to the latching relay coil 52b which is energized to open the latching relay contacts 56a, thereby to close the latching relay contacts 56b whereby the windings of the discharge control solenoid 66, of the activating air control solenoid 59a, and of the purge control solenoid 63 are de-energized, so that discharge valve 29 and air supply valve 26 are closed and the purge valve 35 is opened. The vessel then purges itself until the pressure falls substantially to atmospheric to close switch contacts 51a and open switch contacts 51b, thus returning the apparatus to initial status.

Also, a fail-safe or safeguarding, material sensitive, frequency change actuated, control assembly 37 is provided to insure the closing of the fill valve 18 in case the variable time delay relay 46 may not function to close the time-out switch 46a at the end of the time cycle period selected, as indicated diagrammatically in FIG. 3, and as shown partially diagrammatically and in greater detail in FIG. 4.

The fail-safe circuit is shown extending from a point on the conductor 55 between the time-out switch 46a and the latching relay coil 52a, and is continued to a solids state relay housing 98, there to be connected to the junction between a conduit 75a to the normally open side of a relay switch 97, and a circuit 76 which extends to the positive conductor power line 41a, the circuit 76 having the push-button switch 77 therein, to be hereinbelow described. Normally, the relay switch 97 closes contact between a grounded conductor 97a (and thus the negative power line side 42) and a conductor means 99 between the relay switch 97 and the negative terminal of a coil 82 in the control housing 37.

The coil 82, within the housing 37, is indicated externally thereof by its

connections

82a, 82b which terminate within the plug 98. Within the housing 37 the coil 81 energizes a plunger or armature, not shown, in manner that it normally vibrates cycles per second to impart vibration at this frequency to the lower tuning fork tine 38av which is shown connected in FIG. 4 to the paddle or vibrator 38. Thus normally the tine 38b also vibrates with the paddle 38 at 120 cycles per second. The vibrations of the tine 38b are imparted to an armature, not shown, which normally actuate a second coil 81, at an imparted voltage, 60 cycles per second frequency. Such coil 81, also not shown within the housing 37, is indicated externally thereof in FIG. 4 by its connections 81a, 81b, which terminate within the plug 98.

An induction coil, not shown, is imposed across the terminals of the coil 81 within the plug so disposed with relation to the switch 97 that this switch may be shifted when the differential between the line voltage and the imparted voltage achieves a certain value, as is the case when material entering the container or activator 10 extends at such an angle of repose to interfere with, reduce, or stop the vibrations of the paddle 38.

When the aforesaid induction coil across the terminals of the coil 81 thus shifts the switch 97 to close circuit from the neutral or positive side conductor 41b, by way of the conductor 78, the coil 82, and the conductor 99, through the switch 97, as thus shifted, and by way of the conductors 75a, 75, 55 (including the latching relay coil 52a), and on through the conductor c, the closed switch contacts 51a, and the circuit 45b (including the latching relay closed contacts 56a), to the negative power line 42. The energization of the latching relay coil 52a in the circuit results in the latching relay breaking the circuit 45b by shifting open the contacts 56a, whereby the solenoid winding 47 is de-energized to actuate the solenoid 48 to operate the valve operator 23 to close the fill valve 18.

Obviously the quicker the fail-safe switch 97 is operated after a failure of the variable time delay relay 46 to close the time-out switch 46a, the less the material from the hopper 21 can over fill the container 10, and the closer the delivered batches of material may be controlled to deliver a desired lesser volume per batch.

Also, it is obvious that the variable time delay relay 46 may be omitted entirely, together with its time-out switch 46a, and in this case the frequency control device 37 alone can be relied upon to actuate the valve operator 23 to close the fill valve 18.

On occasion it may be desirable to operate the filling and evacuation of the container 10 by manual control of the sequence of steps, rather than automatically, as hereinabove described. For such occasion, it may be considered that the variable time delay relay 46 and its timing out switch 46a are immobilized. Then a circuit 101 is provided, parallel with the circuit 45, to extend from the positive conductor 41a and to connect with the circuit 45 between the pushbutton 45a and the

circuit junction

46, 47, 49. Also in this case, there also serves the aforesaid circuit 76 from the circuit 41a to the junction of circuits 75, 75a, and having the pushbutton 77 therein; also, the circuit 102, parallel with the circuit 57c and connected thereinto between the pushbutton 71 and the normally open pressure sensitive switch 69; also, the positive power circuit 41a is extended to connect with the junction of the circuits 72a, 72b, and to have the pushbutton 103 therein.

Thus, with the three-way switch controlling the parallel conductor lines 41a, 41b and 41c turned from the position shown in FIG. 3, in manner that the conductors 41a, 41b are closed, the conductor 410 thus being left open. Beginning with the container 10 empty and at atmospheric pressure, the pushbutton 45a may be pushed downwardly and held to close the circuit 101. The circuit 47 is thus energized so that the solenoid 48 actuates the valve operator 23 to open the fill valve 18. Then, the pushbutton 45a may be released from closing the circuit 101, thus breaking circuit through the solenoid coil 47 so that the solenoid 48 actuates the valve operator 23 to close the fill valve 18.

With a batch of material delivered into the container 10 in amount determined by the length of time the pushbutton 45a has closed the circuit 101, activation of the material may be started, after the pushbutton 45a has been released, by manipulating the pushbutton 77 to close the circuit 76. Circuit is thus closed through the circuit 75, the circuit 55 including the latching relay coil 52a, and to the negative power line side 42, by way of circuit 450, closed contacts 51a of the pressure sensitive switch 50, and the circuit 45b, including the latching relay closed contacts 56a therein. This energizes the latching relay coil 52a to operate the latching relay 52 to break the contacts 56a and close the contacts 56!).

Circuit is thus closed to the fixed time delay relay 58,

which actuates the time out switch 64 to close the solenoid coil circuit 59, thus to actuate the valve operator 27 to open the compressed air valve 26; also the solenoid coil circuit 62 is closed whereby the solenoid 66 actuates the valve operator 36 to close the purge valve 35.

Then, the operator of the apparatus may observe the gauge 92, and when the pressure indicates that the vessel is ready to discharge, or when the operator appreciates that a proper time interval after the opening of the gas inlet or compressed air valve 26 has taken place, the pushbutton 71 may be pushed to close the circuit 102,

the normally open pressure sensitive switch 69 being closed by the pressure that has built up in the vessel.

Thus, as aforesaid, the armature may move to set in operation the opening of the discharge valve 29, while circuit is closed to operate the second relay 68 so that it closes the circuit 57], and closes the contacts 74 to partially close the circuit 72b. Discharge may thus continue as long as the pushbutton 71 is held closing circuit 102, or even if the operator may now release the pushbutton 71, since in this case the circuit continues completed through the contacts 70 in the circuit 57], even after the pressure has fallen enough to cause the pressure sensitive switch 69 to open.

Thus to purge the vessel 10 after the pushbutton 71 has been released, or thereafter, or at any time, with the threeway switch 44 turned to manual operation, (41a, 41b closed), it is only necessary to push pushbutton 103 to close circuit with the circuit 72a to energize the latching relay coil 52b, which, when energized, operates, as aforesaid, to close the circuit 45b and to break the circuit 57, whereby the purge valve 35 is opened and the compressed air valve 106 and discharge valve 29 are closed. Then, as the purge pressure diminishes the normally closed pressure sensitive switch 73 opens, and as the pressure falls further to substantially atmospheric pressure, the contacts 51a of the pressure sensitive switch 50 close, and the pushbutton 45a may again be pushed to close the circuit 101 to admit material into the container 10.

Respective conduits 23b, 33b, 36b, 27b and 32b connect into the respective fill, materials delivery, purge, hot drying gas and vent

valve operator cylinders

23, 33, 36, 27 and 32, under respective piston heads 23a, 33a, 36a, 27a and 32a, and respective conduits 23c, 33c, 36c, 27c and 320 connect into such cylinders above the respective piston heads therein. Thus, as shown in FIG. 1, conductor cords or

sleeves

23d, 33d, 36d, 27d and 32d for the respective conduits for the respective valve operator cylinders aforesaid, are provided to extend from the control or panel box 40, where conventional instrument air, as from the instrument air conduit 93, may pass through respective conventional solenoid actuated valves, not shown, as operated by the

aforesaid solenoids

48, 66 and 63, and sOlenoids 126 and 138, shown in FIG. 3, and to be hereinbelow described, these five solenoids admitting operative air, gas or fluid, respectively into the conduits 23b or 230; into the conduits 27b or 270; and into the con- 36c; into the conduits 27b or 270; and into the conduits 32b or 320; selectively to open or close the aforesaid fill valve 18, materials delivery valve 29, purge valve 35, hot drying gas valve 26 and vent valve 32.

As shown in FIG. 3, a light 49 is in circuit parallel with the solenoid circuit 47 and the variable time delay relay circuit 46, and thus the light 49 is on when the fill valve 18 is open; also a light 61 is in a circuit parallel with the solenoid circuit 59 which actuates the valve 106 which admits the material activating gas, and with the solenoid circuit 62 which closes the purge valve; and also a light 67 is in a circuit parallel with the solenoid circuit 65 which actuates the opening of the materials delivery valve 29. Additionally, a light 54 is shown in a circuit 53 which is completed when the latching relay 52 is actuated to close the contacts 56a while the pressure within the container is still high enough to maintain closed the contacts 51b of the pressure senstive switch 50.

Thus, this occurs after the purge valve 35 has been reopened by opening of the latching relay contacts 56b, to permit the purging of the container by the residual pressure therein until such pressure drops to substantially atmospheric so that the pressure sensitive switch 50 is actuated to open the contacts 51b and close the contacts 51a, thereby breaking the circuit 53 which contains the light 54 therein.

The

lights

49, 61, 67 and 54 may have selectively differently colored bulbs, as, respectively, green, blue, red and amber, thus to indicate, respectively, that filling, activating, discharging and purging are taking place.

The

respective valve operators

23, 27, 33, 32 and 36 may be used to operate the respective fill valve 18, hot drying gas delivery valve 26, material delivery valve 29, vent valve 32 and purge valve 35, as shown, but it is often not necessary, in the case of light duty installations, and/ or in the case of the

valves

26, 29, 31, 35, that special valve operators be required for their operation. In such cases the

solenoids

60, 66 and 63, and the vent valve solenoid, to be hereinbelow described, may thus be connected directly to the

respective valves

26, 29, 35 and 31 to elfectuate their operation.

Also, as to the fail-safe feature of the vibrating paddle 38, the sensitivity of this feature is such that it can be regulated to operate almost instantaneously as a container first starts to overfill, so that the relay 52a is energized to operate the latching relay 52 immediately the variable time delay relay 46 fails to function.

Additionally, as set forth hereinabove, the vibratory paddle 38 may be used instead of the variable time delay relay 46, as the primary functional element to actuate the closure of the fill valve 18. In such case the sensitivity of the paddle 38 to adjustment, can determine the promptness of sensitivity to material to close the relay switch 97.

In order to carry out a preliminary drying of material preparatory to activating it and pressurizing it for discharge, as this invention entails, additional apparatus and circuitry is provided for use with the apparatus and circuitry hereinabove described. Such additional inventive circuitry and apparatus supports and controls the admission and cut off of drying air through the drying air valve 26, the venting of the container during selective cycles through the vent valve 31, and the admission of cut off of filter cleaning blast air through the air blast valve 104, the

valves

26, 31 and 104 being shown in relation to the container 10 in FIG. 1.

Thus the double pole, single throw switch 60, shown in FIG. 3, may be manually switched from closing circuit between the

conductors

57 and 57a, as shown in FIG. 3, to the dotted line position to close circuit between the aforesaid conductor 57, and a conductor 116 from which a series or succession of parallel circuits extend to a conductor 118. The conduit or conductor 118 in turn connects with a conductor 640 which connects with the junction of the conductors 64a, 64b, hereinabove described, the conductor 640 in turn being connected to the neutral or positive side conductor 41b, as aforesaid. The circuit or conductor 64c has a double pole, single throw switch 119 therein which is mechanically closed by the closing of the fill valve 18, this operation being indicated diagrammatically in FIG. 3 by a heavy dotted line connecting the switch 119 and the solenoid 48 which operates the fill valve operator 23 shown in FIG. 1.

A timer 120 of the well known Eagle type is provided in a circuit between the

conductors

116, 118, which is adjusted to run for a predetermined time, at the end of which time it closes a normally open switch 117 across the

conductors

57a, 116, and opens a normally closed switch 121 in the conductor 118.

A motor 122, which actuates the timer 120, is in cir cuit parallel therewith, as shown in FIG. 3. Thus the motor 122 can be connected to run the timer 120 for the predetermined duration of the whole drying period. A

light 123, which may be designated as a White light, is in circuit parallel with the timer circuit and its motor circuit 122 to indicate that the drying process is in progress.

A solenoid winding circuit 124, in parallel with the circuits 120, 122, 123 has a normally closed switch 125 therein; the solenoid winding 124 actuating the aforesaid solenoid 126 which actuates the valve operator 27 to open the hot drying gas valve 26. Also a solenoid winding circuit 128, extends from the conductor 116 and includes a normally closed switch 135 therein, the circuit 128 terminating at a contact 130, to be hereinbelow described. The solenoid winding 128 when energized, actuates a solenoid 129, to release air in a tube 142 to permit the filter blast air valve 104 to open.

Also, a timer circuit 131 extends from the conductor 116 parallel to the circuit 128 and terminates at the contact 130, the timer 131 serving the purpose of timing the brief opening of theair blast valve 104 between intervals of drying, as will be hereinbelow described.

Additionally a timer circuit 132 from the conductor 116 includes the timer 132 therein and a normally closed switch 133 therein adjacent its connection to the conductor 118. Between the timer 132 and the normally closed switch 133, the pivot of a normally open switch 134 is connected into the circuit 132, which in closed position completes circuit to the contact or junction of the circuits 128 and 131. The timer 132 serves the purpose of timing the drying interval between successive opening of the blast air valve 104, the drying air entering continuously through the valve 106 between those brief instances when the blast air valve 104 opens.

Also, the additional circuitry and apparatus comprised by the invention includes a solenoid winding circuit 136 between the

conductors

116, 118, and also a relay circuit 137, parallel thereto. The circuit 136 actuates a solenoid 138 which in turn actuates the valve operator 32 which controls the opening and closing of the vent valve 31, shown in FIG. 1.

The Eagle timer 120 is set, as aforesaid, to run for the duration of the preselected and preset drying cycle and then times out to close the normally open switch 117 and to open the normally closed switch 121. The Eagle timer cycle is divided into a number of sub-cycles, during each of which the drying air is delivered for an interval and then for an instant the drying air is shut off and blast air enters the top 12a of the shell to blow reversely through the filters 114 and through the central filter 112 to blow any material grains or particles impinged on the inner surfaces thereof back into the material plenum 15. Thus, in each sub-cycle the drying air timer 132 times out to open the normally open switch 125 to break the solenoid circuit 124, whereby the solenoid 126 closes the drying air valve 26, the timer 132 at the same time closing the normally open switch 134 to start the blast air timer 131 and to close the blast air solenoid circuit 128, whereby the solenoid 129 opens the blast air valve 104.

The timer 131 then runs to time out to open the normally closed switch to the solenoid winding 128 whereby the solenoid 129 opens the blast air valve 104 and opens the double pole, single throw or relay switch 133, thus breaking the circuit to both timers. Both the timer 131 and the timer 132 may now reset, the timer 131 taking power off the normally closed switch 135 to permit the solenoid circuit 128 to be restored and taking power off the relay switch 133, allowing it to open. Also, the timer 132 takes power off the normally open switch 134, permitting it to open, and takes power off the normally closed switch 125 in the solenoid winding circuit 124, allowing this normally closed switch 125 to close, whereby the solenoid 126 may open the drying air valve 26. With the timers 131 and 132 both reset, the drying air valve 26 is opened for its sub-cycle of drying air delivery, followed by discontinuation for filter air back blast, as aforesaid.

When the drying air-blast air sub-cycles have been repeated *for a total amount of time equal to the time for which the Eagle or control timer 120 has been set, this timer times out, opneing the switch 121 and closing the switch 117, as aforesaid. During the drying process the relay 137 has been energized to move the respective switches 62a, 62b in contact with the repsective contacts 64d, 64s, thus keeping the winding 62 of the solenoid 63 energized whereby the solenoid 63 has held the valve operator 36 in purge valve closing position. At the end of the drying process the relay 137 is de-energized to switch the switches 62a, 62b into the position shown in FIG. 3, thus to complete the purge solenoid winding circuit 62 to the switch 64, which is closed to begin the activation and transfer of material steps, as hereinabove described, the purge valve 35 thereby remaining closed after the switch 64 is closed, until it opens to start the purge step.

The closing of the switch 117 throws the apparatus directly into the activation and transfer step, while the opening of the switch 121 breaks circuit to the apparatus functioning in the drying cycles, and this apparatus and circuitry remains inactive until the next closing of the fill valve 18 mechanically closes the shift switch 119. Then, with the switch 117 closed, the apparatus immediately embarks into the steps of activating the material, discharging it, purges the vessel, and returning to initial conditions, as hereinabove described.

By a skillful combination of circuitry and apparatus the processing may be carried out with both uniformity and alacrity, and within the fineness of detail permitted by the many features through which adjustment may be made. The materials processed, for instance, may cover a wide range of pharmaceutical components, plastics, foods, and the like, which enter with various proportions of moisture therein. The physical form of the material handled may be granular, crystalline, or powdered, as examples, in micron size particles up to from to 20 mesh. The diaphragm separating the gas and material plenums should best be of 200 mesh woven, stainless steel, or of porous ceramic. Fineness of the membrane may be controlled by employing successive layers thereof. As to the angle at which the membrane may be installed, this may be varied by virtue of the type of material used, and by the moisture content, and the slope may range from 5 degrees to say degrees. Also, the filter requirements may vary, it having been found that filters which provide a total filtering area in 15 to 1 ratio to the bed area of material is a satisfactory ratio, but this ratio may vary, as say from to 1 to 10 to 1.

The apparatus and methods disclosed hereinabove, and hereinbelow claimed, are not all inclusive, as set forth, including as portrayed in the drawings, and other combinations of structure, circuitry and methods of employing the invention may be considered as falling within the four corners of the herein invention, as long as such also fall within the broad spirit of the invention, and Within the broad scope of interpretation claimed for and merited by the appended claims.

What is claimed is:

1. Material drying and transporting apparatus comprising a pressure vessel, a gas permeable membrane across said vessel separating a lowermost gas plenum from a central, material plenum thereabove, a fill valve to admit material batches into said material plenum to be dried and transported, a valve controlled drying gas delivery conduit into said gas plenum, a vent valve from said material plenum, a valve controlled, pressurized gas conduit into said gas plenum, a pressure sensitive valve controlled discharge conduit from said material plenum, and automatically operable circuitry sequently functional to open said full valve, to close said fill valve and to open said drying gas valve and said vent valve, to close said drying gas valve and said vent valve and to open said pressurized gas valve to activate the dried material into a flowable state and to build up a pressure in said vessel to open said discharge valve whereby said materials are discharged through said discharge conduit, said discharge valve opening responsive to pressure drop, and upon further ressure drop said apparatus being restored to initial status automatically to repeat the handling of a succeeding batch of material.

2. Material drying and transporting apparatus as claimed in claim 1 which additionally includes a pressure sensitive valve controlled, purge by-pass conduit from said material plenum to said discharge conduit downstream of said discharge valve, said purge valve being opened by said circuitry responsive to the pressure drop which closes said discharge valve whereby said material is purge discharged by residual pressure in said vessel until said apparatus is restored to initial status, as aforesaid.

3. Material drying and transporting apparatus as claimed in claim 1 which additionally includes a filter means around the fill valve inlet and-between the fill valve inlet and the interior of said vessel and above the material, whereby to filter the drying gas on its way to said vent.

4. Material drying and transporting apparatus as claimed in claim 1 which additionally includes a baffle across the vessel below the vent and above the material, in which said fill valve includes an inlet spout with lower end comprising a filter opening centrally through said bafile, in which a plurality of filters opening downwardly through said bafile are provided around said central filter, said apparatus additionally including a valve controlled filter blast gas conduit into said vessel above said filters, and in which said circuitry is operable intermittently to interrupt drying gas delivery to admit filter blast gas to back clean said filters.

5. Material drying and transporting apparatus comprising a pressure vessel, a gas permeable diaphragm across said vessel separating a lowermost gas plenum from a central material plenum thereabove, a bafile across said vessel separating said material plenum from a filter blast and drying gas uppermost plenum, a fill valve to admit material into the top of said vessel including a delivery spout with lower part comprising a central filter and opening downwardly through said bafiie, a plurality of filters spaced about said central filter and opening downwardly through said bafiie, a valve controlled drying gas delivery conduit into said gas plenum, a valve controlled filter blast gas conduit into said uppermost plenum, a vent valve from said uppermost plenum, a valve controlled pressurized gas conduit into said gas plenum, a pressure sensitive valve controlled discharge conduit from said material plenum, a pressure sensitive valve controlled purge by-pass conduit from said material plenum to said discharge conduit downstream of said discharge valve, and automatically operable circuitry sequentially functional to open said fill valve, to close said fill valve and said purge valve and to open said vent valve, and in sub-cycles, successively to open and close said drying gas valve to dry said material, and said filter blast valve to back-clean said filters, and then to close said vent valve, said drying gas valve, said filter blast gas valve and said purge and to open said pressurized gas valve to activate said dried material to a pressure to open said discharge valve to discharge said dried materials until the vessel pressure drops to close said discharge valve and open said purge valve whereby said material is purged by diminishing residual pressure until the vessel pressure drops to substantially atmospheric to start a succeeding cycle, as aforesaid.

6. Material drying and transporting apparatus as claimed in claim 1, which additionally includes compressor means to supply drying gas, filter blast gas, and pressurized activating gas as compressed air.

7. The method of automatically drying and transporting material comprising the steps of admitting the material as a predetermined batch into a defined space providing a gas plenum below a material plenum, passing drying gas into the gas plenum to pass through a perforate diaphragm supporting the material and through the material to be vented from the material plenum, discontinuing the drying gas admission and closing the vent and admitting pressurized gas into the gas plenum to pass through the membrane to activate the dried material and to achieve a predetermined pressure in the vessel thereby to open the material plenum to discharge, and full discharging the material responsive to the pressure built up in the space until the pressure falls to a predetermined value to actuate the discontinuation of pressurizing gas admission, and restoring initial conditions for the receipt of a succeeding batch of material into the defined space.

8. The method as claimed in claim 7 which includes the additional step of using the residual pressure in the defined space immediately after discontinuation of full discharge to purge the material plenum as the pressure falls to substantially atmospheric prior to restoration of initial conditions as aforesaid.

9. The method as claimed in claim 7 which includes the additional step of filtering the drying gas between the material and the vent.

10. The method as claimed in claim 7 which includes the additional steps of filtering the drying gas of material particles on its Way to the vent while repeatedly interrupting the drying gas supply by injecting gas blasts above the filter means to back-clean the filter means.

11. The method as claimed in claim 7 which includes the additional step of filtering the drying gas of material particles on its way to the vent while repeatedly interrupting the drying gas supply by injecting gas blasts above the filter means to back-clean the filter means, the blast gas supply being discontinued when the drying gas supply is discontinued, the further additional step being included of using residual pressure in the defined space immediately after discontinuation of full discharge to purge the material plenum as the pressure falls to substantially atmospheric prior to restoration of initial conditions, as aforesaid, the drying gas and the blast gas being pre-heated, and the drying gas, blast gas, and pressurized gas for activation each comprising compressed air.

12. Material drying and transporting apparatus comprising a pressure vessel including a gas permeable membrane bridging the lower part of said vessel above the bottom thereof and dividing it into a material plenum thereabove and a gas plenum therebelow, a fill valve to admit flowable material through the top of said vessel into said material plenum to upstand from said membrane, a compressed gas inlet valve into said gas plenum, a discharge valve controlled discharge conduit with discharge valve disposed in the upper part of said material plenum, a purge valve controlled by-pass conduit with purge valve disposed in the upper part of said material plenum adjacent said discharge valve, a pressure sensitive control means, and circuitry including said control means and automatically operable sequentially to open said fill valve, to close said fill valve, then to close said purge valve while opening said gas inlet valve to admit pressurized gas substantially uniformly through said membrane and to activate said material to a high state as the pressure rises in excess of a pressure sensitive means high control pressure fully to open said discharge valve for said material to pass upwardly and onward through said discharge valve and outwardly through said discharge conduit, as the pressure falls below a pressure sensitive means lower control pressure fully to close said discharge valve and said gas inlet valve and to open said purge valve, the residual compressed gas purging upwardly through said purge valve and said by-pass conduit and on outwardly through said discharge conduit, the pressure falling to approximately atmospheric whereby to open said fill valve, as aforesaid, said pressure vessel also including a valve controlled drying gas delivery conduit into said gas plenum and a vent valve from said material plenum, said circuitry also including means operable, along with the closing of said fill valve and of said purge valve, to open said drying gas valve and said vent valve, then to close said drying gas valve and said vent valve prior to the closing of said purge valve and the opening of said gas inlet valve, as aforesaid.

References Cited UNITED STATES PATENTS 2,799,947 7/1957 Elwess 3415 2,916,831 12/1959 McCash 34-57 3,186,102 6/1965 Brociner et al 34-56 XR 3,392,456 7/1968 Rainville 3456 KENNETH W. SPRAGUE, Primary Examiner.

' US. Cl. X.R. 34-15, 57