CA1046461A - Automatic discharge valve in liquid suspension separator for coal - Google Patents
Automatic discharge valve in liquid suspension separator for coalInfo
- Publication number
- CA1046461A CA1046461A CA252,804A CA252804A CA1046461A CA 1046461 A CA1046461 A CA 1046461A CA 252804 A CA252804 A CA 252804A CA 1046461 A CA1046461 A CA 1046461A
- Authority
- CA
- Canada
- Prior art keywords
- float
- stop means
- mean level
- shale
- chain
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
- B03B5/00—Washing granular, powdered or lumpy materials; Wet separating
- B03B5/02—Washing granular, powdered or lumpy materials; Wet separating using shaken, pulsated or stirred beds as the principal means of separation
- B03B5/10—Washing granular, powdered or lumpy materials; Wet separating using shaken, pulsated or stirred beds as the principal means of separation on jigs
- B03B5/12—Washing granular, powdered or lumpy materials; Wet separating using shaken, pulsated or stirred beds as the principal means of separation on jigs using pulses generated mechanically in fluid
- B03B5/14—Plunger jigs
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D9/00—Level control, e.g. controlling quantity of material stored in vessel
- G05D9/04—Level control, e.g. controlling quantity of material stored in vessel with auxiliary non-electric power
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Mechanical Engineering (AREA)
- Feeding Of Articles To Conveyors (AREA)
- Separation Of Solids By Using Liquids Or Pneumatic Power (AREA)
Abstract
ABSTRACT OF DISCLOSURE
A device, for example in a coal washbox, for controlling conditions in the washbox wherein the washing liquid is caused to oscillate vertically therein, the device comprising a float disposed in the liquid thus to oscillate therewith at a mean level determined by the conditions prevailing in the washbox, actuating means responsive to the position of the float and adapted to actuate further means for controlling said conditions, and a reduction gear assembly drivingly connecting the float to said actuating means, the arrangment being such that when the mean level of oscillation of the float rises, the actuating means is simultaneously raised by the float, and when said mean level falls the actuating means is simultaneously lowered by the reduction gear assembly at a predeter-mined reduced rate with respect to the rate of fall of said level.
A device, for example in a coal washbox, for controlling conditions in the washbox wherein the washing liquid is caused to oscillate vertically therein, the device comprising a float disposed in the liquid thus to oscillate therewith at a mean level determined by the conditions prevailing in the washbox, actuating means responsive to the position of the float and adapted to actuate further means for controlling said conditions, and a reduction gear assembly drivingly connecting the float to said actuating means, the arrangment being such that when the mean level of oscillation of the float rises, the actuating means is simultaneously raised by the float, and when said mean level falls the actuating means is simultaneously lowered by the reduction gear assembly at a predeter-mined reduced rate with respect to the rate of fall of said level.
Description
`:
4~1 This invention concerns a devi~e for controlling the discharge of shale from a coal preparation plant con-taining liquid.
'.'' ~ In a coal preparation pklnt untreated coal is - 5 fed into a washbox having an open-top water-filled vessel wherein it passes across a perforated deck. ~he bed of untreated coal separates out so that shale and other relatively dense waste material sinks onto the deck, very ; fine particles passing therethrough whilst the coal - 10 itself, being less dense, remains near the surface.
,-A device is included in the vessel tocreate upwardly directed surges or pulses of current which serve repeatedly to lift the bed of coal and shale. This action assists the separation process.
The denser material is discharged from the ends of the deck where pairs of vertically opposed ad]ustable weir plates are provided and where, at one end, the separated less dense layer flows over a ledge to an outlet passage. An enclosed air chamber is provided at each end above this region and communi-cates with the interior of ., I
:
,, `' '
4~1 This invention concerns a devi~e for controlling the discharge of shale from a coal preparation plant con-taining liquid.
'.'' ~ In a coal preparation pklnt untreated coal is - 5 fed into a washbox having an open-top water-filled vessel wherein it passes across a perforated deck. ~he bed of untreated coal separates out so that shale and other relatively dense waste material sinks onto the deck, very ; fine particles passing therethrough whilst the coal - 10 itself, being less dense, remains near the surface.
,-A device is included in the vessel tocreate upwardly directed surges or pulses of current which serve repeatedly to lift the bed of coal and shale. This action assists the separation process.
The denser material is discharged from the ends of the deck where pairs of vertically opposed ad]ustable weir plates are provided and where, at one end, the separated less dense layer flows over a ledge to an outlet passage. An enclosed air chamber is provided at each end above this region and communi-cates with the interior of ., I
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the vessel. The chamber includes a valve allowing it to be opened to atmosphere as required. When the chamber is sealed the pulsations in the liquid immediately below the chamber are suppressed as the , water level therein canno~ rise. Thus the material lying on the perforated deck in this region remains stationary. If however, the valve is opened, the pulsations are also effective in the chamber and the material is fluidised and commences to pass over the , second weir plate to be deposited into a chute from which it is removed by a bucket elevator.
.
The valve in the chamber is controlled by a float located in a vertical tube passing into the water in the vessel. As the density o~ the bed of coal and sha1e surrounding the tube increases, so the pulsations in the vessel cause the water in the ~- tube to rise above the normal level of water in the vessel. Therefore the float which is o~cillatbin$
vertically due to the pulsations, oscillates ff~ a higher mean level causing a striker mounted on a vertical rod attached to the float, to engage and lift a stop on a chain drivingly conneoted to said valve, thus to move the valve tQwards the open condition. In this way the shale is discharged from thè deck at a controlled rate determined by the a~ount o~ sha1e on the d and thus the degrse to whioh . .
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the valve is opened.
l~en the bed becomes less d~nse owing to discharge of sha~e the float oscillates about a lower mean level. It is usual for the valve to be continuously urged towards the closed condition by an electric motor connected thereto via a slipping clutch.
The object ofthe present invention is to provide apparatus of this general kind wherein the use of external drive means, for, in this exam~le, returning the valve to the closed position, is obviated~
According to the present invention there is provided a device for controlling the discharge of shale from a coal preparation plant containing liquid, in which the liquid oscillates v~rtically, the device comprising a float disposed in the liquid thus to oscillate therewith about a mean level determined by the density of the bed of shale present, first stop means responsive to an increasing mean level of the float and operatively connected to control means for increasing the rate of shale discharged, and a system comprising second stop means responsive to a reducing mean level of the float, and a reduction drive device drivingly connecting said second stop means to said first stop means, the system being thus arranged to operate such that when the mean level of oscilla-tion of the float rises the first stop means is simultaneously raised by the float to actuate the control means and when said mean level falls the first stop means is simultaneously lowered by the reduction drive device at a reduced rate with respect to the rate of fall of said mean level.
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., An embod.iment of theinvention, given by way of example only, will now be described with reference to the :.
accompanying drawings in w~lich :
. . .
Fig, 1 is a part sectional side elevation of a :coal washbox;
E'ig. 2 is a part sectional end elevation thereof ;
' .
~:~ Fig. 3 is an enlarged part sectional view of i part of the washbox of Fig, 1 embodying the invention;
:
~: and Fig. 4 (sheet 1) is a schematic illustration .` 10of a drive mechanism included within this embodiment.
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~- The washbox comprises a vessel 10 having an input chute 11 and an outlet chute 12 at opposite ~, ends thereof respectively. ~ perforated deck 13 , i ~?
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~ "~ ` ~o~61 extends along the vessel between the input and outlet chute.s.. At each end of` the deck 13 and disposed .' respectively below the chutes 11 and 12 are two pairs of vertically opposed and adjustable welr plates 14 (see Figo 3). The gates 14 serve to limit.the flow ~; of waste materials from the deck 13 into two discharge .. chutes 15 and 16.
~, i Untreated coal is fed into the vessel via . chute 11 whereupon the'consti:tuents separate b~
stratif`ication, and the coal ~loats near the sur~ace whilst the shale and other denser material sinks . . onto the deck 13. The coal ~lows: over a sill 17 with .~. the excess liquid, into.the outlet'chute'l2 whilst the . shale settles on the deck.l3, very fine'particles :~ 15 passing therethrough. Conveying screws 18 are provided in the lower: region of the ves'sel to:direct .~ the fine particles outwardly into the ~ase'of'two ~uck~ t .
. elevators 19. ..
':, . : ' : ~' ~
. A device(not shown~ is provided to cause pulsations o~ current in the ves'sel as generall~
indicated by the arrows 20, which'res'ult in'vertically D oscillating currents3acting on the Oed of material resting on the deck ~. This actlon assists in`the . . separatio'n of` coal and denser material.
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Re~erring now to F'ig. 3 it will be seen thak a chamber 21alongside part o~ the outlet chute 12 . communicates with the interior of the vessel lO. A
., . valve Z2 mounted on a pipe 23 which communicates ,. 5 with the chamber 21 serves, when required~ to open .
, the chamber to atmosphere. If the chamber is ..
P sealed with the valve 22 closed, the pulsations in .
: . the liquid are not effective in the region between ~he weir plates 14 adjacent the chute'l6. However . when the valve 22 is at least partial].y open the , -'. , pulsations in the vessel lift the shale and other ... , dense material lying adjacent the plates 14 and cause them to ~low into the discharge chute 16 ~or . removal.
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,, 15 . The pul.sat,;.ons c~t]se a ~lo?.t ?~ t~
~, - . oscillate vertically in a .tube 25 which in th.is ,'.; . . example extends downwardly through the bed o~
material and the deck 13 into the vessel. If the .
,. bed of material above the perforated deck i~ very .i - 20 ~ dense then the pulsations in the,ve~sel will cau~e water to~low up the tube 25 to a level hlgher , that in the body of the vessel... Thus as the float . rises in the tube 25 whilst still o~cillating due ,:, .~ . . to the pulsations, a striker 26 mounted on a rloat rod extending upl,rdly rrom the ~loet ~4 w~l ' ~ 7 ~ ' , ' ,;, . ', , ., . .,.
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'~0~ 61 , also rise and lift a stop 27 attached to one run o~
, an endles.s chain 28. The'chain 28 wraps a sprocket . 29 mounted on a shaft 30 which carries a cam 31.
The cam 31 acts on the'actuating plunger 32 of an air pressure regulator 33 which forms part of a pneumatic circuit arranged to control the valve 22 and serving any other control device in the washbox. , The circuit is so arranged that as the stop 27 - , is lifted,this movement when transmitted to the ; lO cam 31 serves to adjust the condition of the regulator 33 to comm,ence opening the valve 22, ., and as already explained when the valve 22 is open there is a flow of shale and dense material ~:' into the chute 16. When some Or the waste material has been discharged into chute 15 and the bed there- ' ~ lo~ e~'omes'' i~Ss dense, then the float 24 falls i towards a lower level in the tube 25. It is , therefore necessary to re-adjust the condition of '~ ' , the valve 22 to reduce the flow of waste materi.al ' ,:, `1 20 and in order to move'the valve towards the closed condition it is necessary to rotate shaft 30 . accordingly to adjust the 'condition of the re~ulator ~ ,' .. :i , . . . .,, ~ 33. , ' ' ' , :, .' . . , . ' ,',.~
Referring now to Fig. 4, the 'al)ove actlon is carried out by providing a second endless chain 34 which carriea a ir o~ vert~cally apec~d stops 35 . . . ''.:, ~: . . . ' .
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; and 36 one above and one below the striker arm 26.
:' . ' ., The chain 34 wraps a pair of sprockets 37 and 38. Sprocket 37 is freely mounted on shart 30 while sprocket 38 is a freewheel device which when ~! 5 moving anticlock~ise in Fig. 4 drives a shaft 39 but can rotate clockwise freely thereon. A reduction gear assembly is comprised by sprockets 40, 41, 42 and 43 and chains 44 and 45 as indicated in Fig. 4.
Sprocket 40 is fixidly mounted on shaft 39 and ~ sprockets ~1 and 42.are ~ixidly mounted on an ;i auxiliary shaft 46. Sprocket 43 forms one part o~
or is attached to, a slipping clutch 47 mounted ~ on a rurther auxiliary shaft 48. Mounted fixidly; also on shaft 48 is the lower sprocket 49 o~ the ., 15 pair wrapped by ~he chain 28. ~
.~ . : ~ .' ' .' :. When the striker arm 26 falls due to the ; ~ rloat 24 oscillating ~ a lower mean level the stop , 36 is engaged causing chain 34 to drive the ~procket ,~ ~ 38 anticlockwise. Drive is thus transmitted through :the reduction gear assembly to the sprocket 43 and the ~ slipping clutch 47 thus cau~ing the sprook~t 4~ to " rotate in an anticlockwise direction in Fig. 4 ~hich in turn causes the stop ~T on the chai.n ~8 to fall. The ratio of the reduction gears can ~e ~ ~ arran9ed ns r~q red but is prererabl~ in the regior ', , _ 9 _ ,~
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It will therefore be seen that ~Jhilst the valve 22, via regulator ~3, is opened directly as ~ the float rises, return movement of the float causes .. 5 the valve 22 to be closed by the reduction gear assemb~ Y
.- . more slowly. -: . ' ' , ' .' .
. The drive mechanism lllustrated in Fig. 4 . .
~. . enables the steady closure of valve 22 to be effected ::
" . without the use of auxiliary power means, the movementiC
of the float itself being employed to open and close t~ e ; . . valve 22. ~ - ~-'.''. ~. . - ' ,. ' .~.
It will be appreciated.that if the stops J5 ~lnu J~ are adJu~tably rnourlteù on chai,l 34, . . then by adjusting the vertical space therebetween . .
the sensitivity of the mechanism can be adJusted . accordingly. The provision of the slipping clutch :~ .
47 and the free-wheel sprocket 38 serves to prevent : any movement of the reduction gear assem~ly when the : . float rises. . ~ :
.~ , . . ' '. ., ~ .
A further chamber 21 with an associated valve:22 and control mechanism will usually be ~ provi.ded at the input end of the washbox adjacent .. ~he discharge chute 15~ ..
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It may be pre.ferable in some cases to provide a plurality of valves 22 at each discharge . - . point controlled by one pressure regulator 33. In . . this way more even displacement of~air can be ..
, 5. achieved.
,,' ' . I . ' ;: Further adjustabIe devices in the ~ashbox :
. . for controlling, for example, the flow of water into . . the vessel and the flow of untreated coal thereto . can be operated by association with further pressure regulators or similar devi.ces controlled by further : . cams on the shaft or shafts 30. In this way many~
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. . ~ devices for controlling~conditions in the washbox can be operated directly in porportion wikh movements ~ the float or floats 24. .
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It is not intended to limit the invention . : to the above example only many variations such as . might readily occur to one skilled in the art being . possible without departing ~rom khe scope of the .~
" invention. . : :. . '. :,, . For example, the float tube 25 can be .i mounted outside the vessel with passa~e for liquid .:
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the vessel. The chamber includes a valve allowing it to be opened to atmosphere as required. When the chamber is sealed the pulsations in the liquid immediately below the chamber are suppressed as the , water level therein canno~ rise. Thus the material lying on the perforated deck in this region remains stationary. If however, the valve is opened, the pulsations are also effective in the chamber and the material is fluidised and commences to pass over the , second weir plate to be deposited into a chute from which it is removed by a bucket elevator.
.
The valve in the chamber is controlled by a float located in a vertical tube passing into the water in the vessel. As the density o~ the bed of coal and sha1e surrounding the tube increases, so the pulsations in the vessel cause the water in the ~- tube to rise above the normal level of water in the vessel. Therefore the float which is o~cillatbin$
vertically due to the pulsations, oscillates ff~ a higher mean level causing a striker mounted on a vertical rod attached to the float, to engage and lift a stop on a chain drivingly conneoted to said valve, thus to move the valve tQwards the open condition. In this way the shale is discharged from thè deck at a controlled rate determined by the a~ount o~ sha1e on the d and thus the degrse to whioh . .
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the valve is opened.
l~en the bed becomes less d~nse owing to discharge of sha~e the float oscillates about a lower mean level. It is usual for the valve to be continuously urged towards the closed condition by an electric motor connected thereto via a slipping clutch.
The object ofthe present invention is to provide apparatus of this general kind wherein the use of external drive means, for, in this exam~le, returning the valve to the closed position, is obviated~
According to the present invention there is provided a device for controlling the discharge of shale from a coal preparation plant containing liquid, in which the liquid oscillates v~rtically, the device comprising a float disposed in the liquid thus to oscillate therewith about a mean level determined by the density of the bed of shale present, first stop means responsive to an increasing mean level of the float and operatively connected to control means for increasing the rate of shale discharged, and a system comprising second stop means responsive to a reducing mean level of the float, and a reduction drive device drivingly connecting said second stop means to said first stop means, the system being thus arranged to operate such that when the mean level of oscilla-tion of the float rises the first stop means is simultaneously raised by the float to actuate the control means and when said mean level falls the first stop means is simultaneously lowered by the reduction drive device at a reduced rate with respect to the rate of fall of said mean level.
, . .
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,`" ' .. ~
.~ .. .
., An embod.iment of theinvention, given by way of example only, will now be described with reference to the :.
accompanying drawings in w~lich :
. . .
Fig, 1 is a part sectional side elevation of a :coal washbox;
E'ig. 2 is a part sectional end elevation thereof ;
' .
~:~ Fig. 3 is an enlarged part sectional view of i part of the washbox of Fig, 1 embodying the invention;
:
~: and Fig. 4 (sheet 1) is a schematic illustration .` 10of a drive mechanism included within this embodiment.
..~
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~ . .
~- The washbox comprises a vessel 10 having an input chute 11 and an outlet chute 12 at opposite ~, ends thereof respectively. ~ perforated deck 13 , i ~?
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~ "~ ` ~o~61 extends along the vessel between the input and outlet chute.s.. At each end of` the deck 13 and disposed .' respectively below the chutes 11 and 12 are two pairs of vertically opposed and adjustable welr plates 14 (see Figo 3). The gates 14 serve to limit.the flow ~; of waste materials from the deck 13 into two discharge .. chutes 15 and 16.
~, i Untreated coal is fed into the vessel via . chute 11 whereupon the'consti:tuents separate b~
stratif`ication, and the coal ~loats near the sur~ace whilst the shale and other denser material sinks . . onto the deck 13. The coal ~lows: over a sill 17 with .~. the excess liquid, into.the outlet'chute'l2 whilst the . shale settles on the deck.l3, very fine'particles :~ 15 passing therethrough. Conveying screws 18 are provided in the lower: region of the ves'sel to:direct .~ the fine particles outwardly into the ~ase'of'two ~uck~ t .
. elevators 19. ..
':, . : ' : ~' ~
. A device(not shown~ is provided to cause pulsations o~ current in the ves'sel as generall~
indicated by the arrows 20, which'res'ult in'vertically D oscillating currents3acting on the Oed of material resting on the deck ~. This actlon assists in`the . . separatio'n of` coal and denser material.
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Re~erring now to F'ig. 3 it will be seen thak a chamber 21alongside part o~ the outlet chute 12 . communicates with the interior of the vessel lO. A
., . valve Z2 mounted on a pipe 23 which communicates ,. 5 with the chamber 21 serves, when required~ to open .
, the chamber to atmosphere. If the chamber is ..
P sealed with the valve 22 closed, the pulsations in .
: . the liquid are not effective in the region between ~he weir plates 14 adjacent the chute'l6. However . when the valve 22 is at least partial].y open the , -'. , pulsations in the vessel lift the shale and other ... , dense material lying adjacent the plates 14 and cause them to ~low into the discharge chute 16 ~or . removal.
,,''' . ., ' ~ "' ' - ,' ;" , .
,, 15 . The pul.sat,;.ons c~t]se a ~lo?.t ?~ t~
~, - . oscillate vertically in a .tube 25 which in th.is ,'.; . . example extends downwardly through the bed o~
material and the deck 13 into the vessel. If the .
,. bed of material above the perforated deck i~ very .i - 20 ~ dense then the pulsations in the,ve~sel will cau~e water to~low up the tube 25 to a level hlgher , that in the body of the vessel... Thus as the float . rises in the tube 25 whilst still o~cillating due ,:, .~ . . to the pulsations, a striker 26 mounted on a rloat rod extending upl,rdly rrom the ~loet ~4 w~l ' ~ 7 ~ ' , ' ,;, . ', , ., . .,.
'~ 214-041 ' '::- ' :
'~0~ 61 , also rise and lift a stop 27 attached to one run o~
, an endles.s chain 28. The'chain 28 wraps a sprocket . 29 mounted on a shaft 30 which carries a cam 31.
The cam 31 acts on the'actuating plunger 32 of an air pressure regulator 33 which forms part of a pneumatic circuit arranged to control the valve 22 and serving any other control device in the washbox. , The circuit is so arranged that as the stop 27 - , is lifted,this movement when transmitted to the ; lO cam 31 serves to adjust the condition of the regulator 33 to comm,ence opening the valve 22, ., and as already explained when the valve 22 is open there is a flow of shale and dense material ~:' into the chute 16. When some Or the waste material has been discharged into chute 15 and the bed there- ' ~ lo~ e~'omes'' i~Ss dense, then the float 24 falls i towards a lower level in the tube 25. It is , therefore necessary to re-adjust the condition of '~ ' , the valve 22 to reduce the flow of waste materi.al ' ,:, `1 20 and in order to move'the valve towards the closed condition it is necessary to rotate shaft 30 . accordingly to adjust the 'condition of the re~ulator ~ ,' .. :i , . . . .,, ~ 33. , ' ' ' , :, .' . . , . ' ,',.~
Referring now to Fig. 4, the 'al)ove actlon is carried out by providing a second endless chain 34 which carriea a ir o~ vert~cally apec~d stops 35 . . . ''.:, ~: . . . ' .
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~ 1 1 )~64~
; and 36 one above and one below the striker arm 26.
:' . ' ., The chain 34 wraps a pair of sprockets 37 and 38. Sprocket 37 is freely mounted on shart 30 while sprocket 38 is a freewheel device which when ~! 5 moving anticlock~ise in Fig. 4 drives a shaft 39 but can rotate clockwise freely thereon. A reduction gear assembly is comprised by sprockets 40, 41, 42 and 43 and chains 44 and 45 as indicated in Fig. 4.
Sprocket 40 is fixidly mounted on shaft 39 and ~ sprockets ~1 and 42.are ~ixidly mounted on an ;i auxiliary shaft 46. Sprocket 43 forms one part o~
or is attached to, a slipping clutch 47 mounted ~ on a rurther auxiliary shaft 48. Mounted fixidly; also on shaft 48 is the lower sprocket 49 o~ the ., 15 pair wrapped by ~he chain 28. ~
.~ . : ~ .' ' .' :. When the striker arm 26 falls due to the ; ~ rloat 24 oscillating ~ a lower mean level the stop , 36 is engaged causing chain 34 to drive the ~procket ,~ ~ 38 anticlockwise. Drive is thus transmitted through :the reduction gear assembly to the sprocket 43 and the ~ slipping clutch 47 thus cau~ing the sprook~t 4~ to " rotate in an anticlockwise direction in Fig. 4 ~hich in turn causes the stop ~T on the chai.n ~8 to fall. The ratio of the reduction gears can ~e ~ ~ arran9ed ns r~q red but is prererabl~ in the regior ', , _ 9 _ ,~
Y , .
,,~,,,,,~,, . ,' ~
,.-: 214-0'~1 ., ::
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,': -' ' , , ' . :, ..
.. . ..
,. , '~ , : ., ' ' :' ' :
lOg64~1 . of five to one.
,.~' . ' .
It will therefore be seen that ~Jhilst the valve 22, via regulator ~3, is opened directly as ~ the float rises, return movement of the float causes .. 5 the valve 22 to be closed by the reduction gear assemb~ Y
.- . more slowly. -: . ' ' , ' .' .
. The drive mechanism lllustrated in Fig. 4 . .
~. . enables the steady closure of valve 22 to be effected ::
" . without the use of auxiliary power means, the movementiC
of the float itself being employed to open and close t~ e ; . . valve 22. ~ - ~-'.''. ~. . - ' ,. ' .~.
It will be appreciated.that if the stops J5 ~lnu J~ are adJu~tably rnourlteù on chai,l 34, . . then by adjusting the vertical space therebetween . .
the sensitivity of the mechanism can be adJusted . accordingly. The provision of the slipping clutch :~ .
47 and the free-wheel sprocket 38 serves to prevent : any movement of the reduction gear assem~ly when the : . float rises. . ~ :
.~ , . . ' '. ., ~ .
A further chamber 21 with an associated valve:22 and control mechanism will usually be ~ provi.ded at the input end of the washbox adjacent .. ~he discharge chute 15~ ..
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' , . ',', 214- 0'11 , . . ' .
`: .. . . . . : . , -` ~ 1~ 461 ,. . ':
It may be pre.ferable in some cases to provide a plurality of valves 22 at each discharge . - . point controlled by one pressure regulator 33. In . . this way more even displacement of~air can be ..
, 5. achieved.
,,' ' . I . ' ;: Further adjustabIe devices in the ~ashbox :
. . for controlling, for example, the flow of water into . . the vessel and the flow of untreated coal thereto . can be operated by association with further pressure regulators or similar devi.ces controlled by further : . cams on the shaft or shafts 30. In this way many~
~, : 2'-` ~h~ ..
. . ~ devices for controlling~conditions in the washbox can be operated directly in porportion wikh movements ~ the float or floats 24. .
;~, ' . . ' ' . . ,.
It is not intended to limit the invention . : to the above example only many variations such as . might readily occur to one skilled in the art being . possible without departing ~rom khe scope of the .~
" invention. . : :. . '. :,, . For example, the float tube 25 can be .i mounted outside the vessel with passa~e for liquid .:
thereto, - 11 -~' " . '' ' '. ~
,., ~ ' '. :' ..
'' . .;.
,' 214- 041 .-:; , ,` ` . " ' ~' ' : - ` ' .
.
Claims (8)
1. A device for controlling the discharge of shale from a coal preparation plant containing liquid, in which the liquid oscillates vertically, the device comprising a float disposed in the liquid thus to oscillate therewith about a mean level determined by the density of the bed of shale present, first stop means responsive to an increasing mean level of the float and operatively connected to control means for increasing the rate of shale discharged, and a system comprising second stop means responsive to a reducing mean level of the float, and a reduction drive device drivingly connecting said second stop means to said first stop means, the system being thus arranged to operate such that when the mean level of oscillation of the float rises the first stop means is simultaneously raised by the float to actuate the control means and when said mean level falls the first stop means is simultaneously lowered by the reduction drive device at a reduced rate with respect to the rate of fall of said mean level.
2. A device according to claim 1, wherein the float has a member extending upwardly therefrom to engage the first stop means when said mean level rises, and the second stop means when said mean level falls.
3. A device according to claim 1, wherein said control means comprises a pressure regulator included within a fluid pressure control circuit.
4. A device according to claim 1, wherein said first stop means comprises a single stop fixed to an endless chain, above said float to be contacted thereby when the float rises, said second stop means comprising a pair of stops fixed to a second endless chain one above and one below a member attached to the float, said second chain being drivingly connected to a reduction gear assembly the output of which is drivingly connected to said first chain, the first chain being drivingly connected to said control means for controlling said shale discharge.
5. A device according to claim 4, wherein said pair of stops are spaced apart on said second chain by a predetermined distance which determines the sensitivity of the device.
6. A device according to claim 4, wherein said reduction gear assembly includes a slipping clutch so arranged as to prevent drive to the gears upon elevation of said first stop means.
7. A device according to claim 4, wherein said reduction gear assembly includes a free-wheel device adapted to prevent drive to said gears upon elevation of said pair of stops.
8. A device according to claim 1, wherein said control means for controlling the shale discharge comprises a pressure regulator included within a fluid pressure control circuit operating a valve for venting a chamber in the plant such that the amount by which said valve is opened determines the rate of discharge of said shale.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB26897/75A GB1532234A (en) | 1975-06-25 | 1975-06-25 | Coal preparation plant |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1046461A true CA1046461A (en) | 1979-01-16 |
Family
ID=10250926
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA252,804A Expired CA1046461A (en) | 1975-06-25 | 1976-05-18 | Automatic discharge valve in liquid suspension separator for coal |
Country Status (4)
| Country | Link |
|---|---|
| AU (1) | AU499143B2 (en) |
| CA (1) | CA1046461A (en) |
| GB (1) | GB1532234A (en) |
| ZA (1) | ZA762969B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4710214A (en) * | 1986-12-19 | 1987-12-01 | The M. W. Kellogg Company | Process for separation of hydrocarbon gases |
| CN103246295B (en) * | 2013-05-02 | 2015-08-19 | 福建金东矿业股份有限公司 | Discharge opeing formula ore dressing doser |
-
1975
- 1975-06-25 GB GB26897/75A patent/GB1532234A/en not_active Expired
-
1976
- 1976-05-18 CA CA252,804A patent/CA1046461A/en not_active Expired
- 1976-05-18 ZA ZA762969A patent/ZA762969B/en unknown
- 1976-05-25 AU AU14256/76A patent/AU499143B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB1532234A (en) | 1978-11-15 |
| AU499143B2 (en) | 1979-04-05 |
| ZA762969B (en) | 1977-05-25 |
| AU1425676A (en) | 1977-12-01 |
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