US3849061A - Vertical kiln control - Google Patents

Vertical kiln control Download PDF

Info

Publication number
US3849061A
US3849061A US00383484A US38348473A US3849061A US 3849061 A US3849061 A US 3849061A US 00383484 A US00383484 A US 00383484A US 38348473 A US38348473 A US 38348473A US 3849061 A US3849061 A US 3849061A
Authority
US
United States
Prior art keywords
particulate material
burning zone
kiln
outlet
fluid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00383484A
Other languages
English (en)
Inventor
J Summer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ROUND ROCK LIME Co
Original Assignee
ROUND ROCK LIME Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ROUND ROCK LIME Co filed Critical ROUND ROCK LIME Co
Priority to US00383484A priority Critical patent/US3849061A/en
Priority to US467139A priority patent/US3884621A/en
Priority to CA204,903A priority patent/CA1029951A/en
Priority to DE2436527A priority patent/DE2436527A1/de
Priority to JP49086653A priority patent/JPS5071600A/ja
Priority to GB3359074A priority patent/GB1475574A/en
Application granted granted Critical
Publication of US3849061A publication Critical patent/US3849061A/en
Assigned to HOLME ROBERTS AND OWEN, A GENERAL PARTNERSHIP reassignment HOLME ROBERTS AND OWEN, A GENERAL PARTNERSHIP SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: PARAHO DEVELOPMENT CORPORATION
Assigned to NEW PARAHO CORPORATION, THE reassignment NEW PARAHO CORPORATION, THE ASSIGNOR HEREBY RELEASES SECURITY INTEREST IN SAID PATENTS RECORDED ON REEL 4160 FRAME 879. Assignors: Holme Roberts & Owen
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B1/00—Shaft or like vertical or substantially vertical furnaces
    • F27B1/005—Shaft or like vertical or substantially vertical furnaces wherein no smelting of the charge occurs, e.g. calcining or sintering furnaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B1/00—Shaft or like vertical or substantially vertical furnaces
    • F27B1/10—Details, accessories, or equipment peculiar to furnaces of these types
    • F27B1/26—Arrangements of controlling devices

Definitions

  • ABSTRACT Uniform heat treatment of particulate material of a nonuniform gradation in a vertical kiln or retort is efgl iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii 432/47 432/ fected by regulating either the flow of particulate ma- [58] 17 36 terial from the outlet of the kiln or the heat input to e 0 care the kiln in response to differential pressure changes 7 between fluid, such as combustion-supporting fluid and process gas flowing into and from the burning or [56] References cued calcining zone, to result in a balance between particu- UNlTED STATES PATENTS late mass flow and heat input, and a substantially uni 2,625,386 1/1953 Leone 432/14 formly heat
  • VERTICAL KILN CONTROL This invention relates to vertical kilns. In another aspect, this invention relates to controlled heat treatment of particulate material within a vertical kiln. In still another aspect, this invention relates to a novel calcining process and apparatus.
  • Vertical heat treating vessels which are commonly known as vertical kilns, shaft kilns, shaft furnaces, or shaft generators, retorts or the like, depending upon the type of treatment and the material being treated, comprise process equipment commonly found in diverse kinds of industry.
  • Such devices have been used for burning or calcining lime, coking coal, burning argillaceous and calcareous material in the production of cement clinker, burning magnesite, dolomite, retorting oil shale, and the like.
  • Such kilns commonly include a vertical vessel having an elongated heating shaft therewithin, a means for uniformly feeding a particulate material into the elongated heating shaft, a lower discharge means for removing material from the lower outlet end of the kiln, and a means for introducing a stream of heat treating fluid through the particulate material.
  • the kilns include a means for introducing a combustible fluid such as a fuel-air mixture upwardly through the kiln which establishes a combustion or burning zone in the middle portion of the kiln.
  • Other conventional kilns or retorts utilize a heat supply system which includes an external combustion system and means for directing the hot gases from the combustion systemto the burning zone of the kiln.
  • one object of this invention is to provide a novel method and apparatus for controlling heat treatment of particulate material in a vertical kiln.
  • Another object of this invention is to provide a novel method and means for controlling the residence time of particulate material within the burning zone of a vertical kiln.
  • a further object of this invention is to provide a novel method and means for producing lime from limestone.
  • particulate material of a nonuniform gradation is heat treated in a burning zone of a vertical kiln by regulating the flow rate of particulate material from the outlet of the kiln and/or the heat input to the kiln in response to differential pressure changes between fluid such as combustion supporting fluid and process gas flowing into and from the burning zone, to thereby yield a balance between the particulate mass flow and heat input to produce a uniformly heat treated product.
  • particulate material of nonuniform gradation is heat treated in a burning zone of the vertical kiln having a substantially uniform heat input by continuously passing the material through the burning zone and controlling the flow of the material from the burning zone in response to differential pressure changes between fluid flowing into and from the burning zone to yield a substantially uniformly heat treated product.
  • a method and apparatus are provided for heat treating particulate material of nonuniform gradation in a vertical kiln by supplying a heat input to the burning zone of the vertical kiln sufficient to treat a charge of average particles which have a predetermined mass residence time in the burning zone which is based upon a predetermined bulk density and a predetermined flow rate of particles through the burning zone, and thereafter passing the particulate materials into the burning zone and sensing a quality indicative of bulk density of the particulate materials passing through the burning zone, and comparing the indicated bulk density with said predetermined bulk density and thereafter controlling the flow of the particulate material through the burning zone relative to the compared bulk density to yield a mass residence time substantially equal to the predetermined mass residence time within said burning zone and a substantially uniform heat treatment of the particulate material.
  • the difference in pressure of a fluid passed through the burning zone is measured at a point when the fluid enters the burning zone and a point when the fluid leaves the burning zone and the measured pressure differential is compared to a predetermined pressure differential of a fluid flowing through a mass of average particles having a predetermined mass residence time and a resultant heat treated quality, and, thereafter, the flow of particulate material through the burning zone is adjusted to yield a uniform product having said heat treated qual ity.
  • FIG. 1 is a schematic illustration of a vertical kiln equipped with a control mechanism of the subject invention
  • FIG. 2 is a schematic diagram showing the control mechanism of FIG. 1 in greater detail.
  • FIG. 3 is a partial view ofFlG. 2 showing the fourway valve in its second position.
  • vertical kiln l0 comprises a conventional vertical kiln having an internal hollow shaft within which particulate material is subjected to heat treatment.
  • the inlet to kiln-l receives solid particulate material such as limestone, which is initially delivered from stone storage bin 12 by way of a conveyor 14 through rotary seal 16 into hopper 18.
  • Level controller 180 operates discharge control mechanism 12a of storage bin 12.
  • Vertical'kiln is provided with a fuel and air delivery system adjacent its lower midportion for delivering a combustible mixture tothe burning zone of the kiln.
  • the lower end 20 of the burning zone is schematically depicted by a broken line and the upper end 22 of the burning zone is schematically depicted by a broken line.
  • a vertical kiln equipped with the control mechanism of the subject invention can utilize any heat supply system known in the art, e.g., external or internal combustion chambers.
  • a gaseous fuel such as natural gas is delivered by gas inlet conduit 24 and feeds a manifold 26 from which gas'supply lines 28, and 31 depend.
  • Flow controllers 28a, 30a and 31a operate flow control valves 2b 30b and 31b in gas supply lines 28, 30 and 31, respectively.
  • Air under pressure is supplied from conduit 32 into air manifold 34 from which air lines 36, 38 and 40 emerge.
  • Flow controllers 36a, 38a and 40a operate flow control valves 36b, 38b and 40b in air lines 36, 38 and 40, respectivlely.
  • gas supply line 28 communicates between air supply line 40 and fuel manifold 26
  • gas supply line 30 communicates between air supply line 38 and fuel manifold 26
  • gas supply line 31 communicates between air supply line 36 and fuel manifold 26.
  • the fluid from lines 36, 38 and 40 are passed into fluid distributor systems 42, 44 and 46, respectively, before being introduced as distributed streams as illustrated sche matically by flow arrows 42a, 44a, and 46a, respectively.
  • Suitable such fluid distributor systems are disclosed in US. Pat. No. 3,432,348 or 3,589,611, which systems are herein incorporated by reference into this specification. The preferred such system is disclosed in U.S. Pat. No. 3,589,611.
  • the combustion supporting gas which is delivered by these fluid distributor systems, will provide fuel for the burning zone in the kiln, and allow proper heat treatment of the particulate material passing downwardly therethrough by gravitational force.
  • the off-gases from the kiln are removed via stack 48.
  • Grate 56 can be the linear grate for shaft kilns which is disclosed in US. Pat. No. 3,40l,922 which patent is herein incorporated by reference into this specifica tion. However, any other suitable grate known in the art can be used in the scope of this invention.
  • Grate 56 basically comprises a series of spaced diverter plates 58, having retarder plates 60 positioned a spaced distance below the opening between adjacent diverter plates 58.
  • Pusher bars 61 are reciprocally mounted between diverter plates 58 and retarder plates 60. As illustrated in the embodiment shown in the drawing, half of the pusher bars 61 are interconnected by rods 62 and the other half are interconnected by rods 64. Rods 62 and 64 are connected by rods 65 and are controlled by the action of hydraulic cylinders 66 and 68, respectively. More specifically, rods 62, 64 and 65 move pusher bars 61 in reciprocal motion by the action of hydraulic cylinders 66 and 68, respectively. In essence, the controlled reciprocal movement of pusher bars 61 across retarder plates 60 controls the flow of material passing to the outlet 50 from openings between adjacent diverter plates 58.
  • grate speed controller 70 The relative motion imparted to rods 62 and 64 by hydraulic cylinders 66 and 68, respectively, is regulated by grate speed controller 70. Grate speed controller 70 in turn is operatively connected to differential pressure transmitter 72.
  • Pressure sensor 74 is positioned adjacent the lower end 20 of the burning zone within the kiln and is operatively connected to differential pressure transmitter 72 via line 76.
  • Pressure sensor 78 is positioned at a point adjacent the upper end 22 of the burning zone within the kiln l0 and is operatively connected to differential pressure transmitter 72 via line 80.
  • differential pressure transmitter 72 can comprise any suitable type differential pressure transmitter known in the art having two signal inputs and one signal output.
  • a suitable such device is Honeywell Ap/P transmitter Model 292l2-010l.
  • differential pressure transmitter 72 receives two pressure inputs from pressure sensors 74 and 78, compares these inputs, and transmits a signal representative of the difference of the two to control valve 82.
  • the combination of pressure sensor 78 and line and the combination of pressure sensor 74 and line 76 can each comprise a monometer tube. In this instance, it is desirable to pass a uniform flow of purge gas such as air through the monometer tubes.
  • pressure sensing means 74 and 78 can be positioned at any convenient spaced distance below and above, respectively, the burning zone in the kiln. However, it is generally preferred that pressure sensor 74 be positioned adjacent the lower end of the burning zone and that sensor 78 be positioned adjacent the upper end of the burning zone within kiln 10.
  • the pistons 66a within hydraulic cylinders 66 are coupled to rods 62, and rods 62 carry pusher bars 61.
  • the pistons 68a within hydraulic cylinders 68 are operatively connected to rods 64, and rods 64 carry pusher bars 61.
  • Rods 62 and 64 are interconnected by rods 65.
  • Switch bars 84 and 86 depend from pusher bars 61 and function, as shown, to actuate contacts 88 and 90, respectively.
  • Contacts 88 and 90 actuate a conventional valve control switch 91 which functions to alternately move four-way valve 102 between its first and second positions. 7
  • the hydraulic systemwhich is utilized to operate grate 56 includes a centrifugal pump 92 with an inlet conduit 94 operatively communicating between hydraulic fluid reservoir 96 and the inlet of pump 92.
  • Conduit 98 communicates between the outlet of pump 92 and port 100 of four-way valve 102.
  • Four-way valve 102 can be any conventional four-way valve unit known in the art.
  • a suitable such four-way valve is a Racine Model No. OD4-DNHS-l02S.
  • four-way valve 102 is in its first position, which will thereby allow port 100 to communicate with port 104.
  • Manifold conduit 106 operatively communicates with port 104.
  • Conduits 108 and 110 operatively communicate between manifold conduit 106 and the front faces of the pistons 68a within hydraulic cylinders 68.
  • Conduits 112 and 114 communicate between the rear faces of pistons 68a within hydraulic cylinders 68 and conduit 116.
  • Conduit 116 operatively communicates with outlet manifold conduit 118.
  • Outlet manifold conduit 118 communicates between hydraulic fluid reservoir 96 and conduit 120.
  • Conduits 122 and 124 operatively communicate between conduit 120 and the rear faces of pistons 66a within hydraulic cylinders 66.
  • Conduits 126 and 128 communicate between the front faces of pistons 66a within hydraulic cylinders 66 and conduit 130.
  • Conduit 132 commmunicates between valve port 134 of four-way valve 102 and conduit 130. As shown, with four-way valve 102 in its first position, valve port '134 communicates with valve port 136 and valve port 136 operatively communicates with conduit 138, Flow control valve 140 is positioned within conduit 138 and conduit 142 comprises a by-pass loop communicating with conduit 138 on either side of flow control valve 140.
  • Flow control valve 140 can be any conventional such valve known in the art.
  • a suitable such valve is a constant volume, temperature and pressure compensated flow control valve such as a Racine Model F2AHS *-02* valve.
  • Control valve 82 is positioned within conduit 142.
  • control valve 82 is operated by signals from differential pressure transmitter 72 and can comprise any suitable control valve mechanism known in the art.
  • control valve 82 can comprise a Black, Sivalls, and Bryan Valve Operator type 70-13-10 and a Racine Model OF2-CHPW50H hydraulic valve.
  • Conduit 138 communicates fromconduit 142 to hydraulic fluid reservoir 96.
  • a filter 143 and a heat exchanger 144 are operatively positioned within conduit 138.
  • by-pass conduit 146 is positioned around filter 143 with relief valve 148 positioned therein which will allow hydraulic fluid to by pass the filter when a predetermined hydraulic pressure is reached, e.g., in case of pressure surges or in in stances wherein the filter becomes clogged.
  • control apparatus as set forth in the drawing functions to control the heat treatment of particulate materials passing through vertical kiln 10 and assures a predetermined mass residence time within vertical kiln 10.
  • particulate material which is fed to the vertical kiln 10 will vary in particle size and in gradation of the particles and accordingly, will vary in mass density.
  • particulate material such as previousl crushed and sized limestone delivered from storage bin 12 into hopper 18 on kiln 10 will have a mass density which varies from a fixed minimum to a fixed maximum.
  • the particle size graduation will not be constant.
  • the grate speed of controller 70 is calibrated by passing the crushed and sized particulate material, such as limestone, through the kiln having a relative constant heat input to the burning zone, and controlling the grate speed until a product having the desired degree of calcination is obtained, e.g., a product wherein the carbon dioxide content of the calcined limestone falls within the range of from Q weight percent of a control value, such as 3 or 3.5 wt. percent of the product.
  • the calibration of the grate speed and differential pressure is basically linear in nature, and it is found that to obtain a product of cthe desired quality with the material having the nonuniform gradation that a substantially uniform mass residence time will pass through the burning zone.
  • substantially uniform mass residence time is herein meant to include a mass residence time which will yield a product having the predetermined or controlled degree of calcination when passed through the burning zone (a degree of calcination whichfalls within a desired range).
  • a relatively constant heat input is supplied to the burning zone in vertical kiln 10.
  • This constant heat input is based upon an average or predetermined particle gradation and consequently, an average or predetermined mass density of particulate material which is passed through the heating zone to assure that proper heat treatment of the particulate material is effected without resulting in either overburn or underburn of the material as described above.
  • the material of the predetermined mass density will effect a predetermined pressure drop of fluid passing through the burning zone, e.g., the air and fuel mixture and process gases released by calcination and gaseous combustion products of the mixture which is passed upwardly through kiln 10 from fluid distributor systems 42, 44 and 46.
  • valve is set at a predetermined opening and functions in combination with control valve 82 to control the amount of hydraulic fluid passing through conduit 138 and thereby controls the speed of grate 56.
  • control valve 82 When material enters the burning zone which has either higher or lower porosity than the standard mate rial of predetermined particle gradation (i.e., has a higher or lower mass density) differential pressure of the fluid passing upwardly through the burning zone will accordingly be altered and the differential pressure input to control valve 82 will adjustcontrol valve 82 which in turn adjusts flow through conduit 138 and alters the speed of gate 56.
  • valve 82 is calibrated to control the speed of grate 56 in response to variations of differential pressure outputs from differential pressure transmitter 72.
  • differential pressure transmitter 72 will indicate an increase in differential pressure between the lower and upper portion of the burning zone. This will effect a closure of valve 82 and a slowing down of grate 56 which will allow a longer burning time for the higher mass density material entering the zone such that the material will have an equivalent mass residence time to that of the material with the predetermined mass density and thereby yield a substantially uniform calcined product.
  • the differential pressure between the upper and lower portions of the burning zone will be less than that which corresponds to the material ofpredetermined particle size and the differential pressure transmitter will effect an opening of control valve 82, and thereby allow grate 56 to operate at a faster rate so that the resulting mass residence time of the higher porosity lower mass density material is equivalent to that of the material of predetermined particle size and again yield a substantially unifom calcined product.
  • valve 140 is adjusted so that the flow of fluid therethrough in combination with the flow of fluid through valve 82 will result in a grate speed which is sufficient to yield a predetermined mass residence time of particulate material of predetermined particle size passing through the burning zone of kiln 10.
  • pump 92 is run at a constant speed and constantly withdraws hydraulic fluid from reservoir 96 via conduit 94 and passes the hydraulic fluid to port 100 of four-way valve 102 via conduit 98.
  • the fluid passes through four-way valve 102, port 104, and into conduit 106 and conduits 108 and 110, thereby passing fluid into the front portion of hydraulic cylinders 68 and against the front faces of pistons 68a therewithin.
  • This causes a retraction of pusher rods 64 and a movement of retarder plates 60.
  • pusher rods 64 are interconnected to rods 62 by rods 65, this also causes an extension of rods 62 and results in the front faces of piston 66a of hydraulic cylinder 66 forcing fluid to conduit 130 via conduits 126 and 128.
  • the retraction of pistons 680 causes fluid to pass through conduits 112 and 114 to outlet manifold conduit 118 and into conduits 120, 122, 124 and also into reservoir 96. Fluid from conduit 130 passes to conduit 132 into valve port 134 through four-way valve 102 to valve port 136 and into conduit 138.
  • valve control switch 91 moves four-way valve 102 to its second position as illustrated by the partial view in FIG. 3.
  • the pump output flowing through conduit 98 to valve port 100 passes directly to valve port 134 into conduits 132, 130 and 126 and 128 to the front face of pistons 66a and hydraulic cylinders 66.
  • This action causes pistons 66a to retract, and rods 62, pusher bars 61 and rods 64 to be moved toward hydraulic cylinders 66.
  • EXAMPLE 1 An apparatus such as illustrated in FIGS. l-3 was utilized to calcine limestone.
  • the crushed and sized limestone which was calcined generally had a particle size ranging from about 3 4 inch to about 2% inches.
  • the gradation of the limestone varied substantially but it generally had a mass density in the range of from about 76 to about 86 pounds per cubic foot. Due to the tendency of the smaller particles to gravitate downwardly within storage bin 12 and kiln 10, the gradation of the limestone passing through the burning zone of kiln 10 will vary considerably with time.
  • limestone which had a mass density ranging from about 76 to about 86 pounds per cubic foot and which was delivered from storage bin 12 over a period of 8 days was measured for particle size distribution 2 or 3 times a day and the results are shown in Table l below.
  • Kiln was initially set to operate with natural gas entering conduit 24 and air entering conduit 32 to esto close valve 31a and allow no gas to pass through conduit 31); a total of about 1,305 standard cubic feet per minute of a rich gas-air mixture which consisted of a ratio of about 4.9 standard cubic feet of air to about 3 standard cubic feet of fuel delivered through fluid distributor system 44; and about 2,755 standard cubic feet per minute of a lean fuel-air mixture was passed through fluid distributor system 46 and consisted of a ratio of about 5.8 standard cubic feet of air to about 1 standard cubic foot of fuel.
  • Control valve 82 was calibrated such that the grate speed of grate 56 varied in response to a change in the density of the limestone passing through the burning zone between differential pressure sensors 74 and 78 as determined by changes in the differential pressure of fluid passing therethrough.
  • the grate speed was correlated with each differential pressure increment within this range to yield a product which contained about 3 percent i 1 wt. percent of carbon dioxide and thereby yield a substantially uniform mass flow rate through the burning zone. It was specifically found that for a mass density range'of from about 76 to about 86 pounds per cubic foot, a corresponding differential pressure range of about 7 inches of water would result. This differential pressure range was used to control the valve 82.
  • the average" grate speed setting corresponded to a differential pressure of the fluid passing through the burning zone which would indicate that the mass density of the material therein was about 81 pounds per cubic foot; the fastest grate speed setting corresponded to a'differential pressure which indicated the material had a mass density of about 76 pounds per cubic foot; and the slowest grate speed setting corresponded to a differential pressure which indicated that the mass density of the material passing through the burning zone was about 86 pounds per cubic foot.
  • the differential pressure varied from a low of 16.8 inches of water to a high of 23.7 inches of water with corresponding grate speeds ranging from 62.4 complete strokes of pusher bars 61 (a complete reciprocal motion across kiln 10) to 64.9 complete strokes.
  • the average carbon dioxide content of the calcined limestone removed from outlet 50 was about 3 weight percent, and it ranged from a low of 2.3 wt. percent to a high of 3.3 wt. percent.
  • control mechanism which was utilized in accordance with the subject invention resulted in a substantial uniform product quality.
  • EXAMPLE 2 Particulate limestone such as described in Example 1 and having a mass density which ranges from about 76 to about 86 pounds per cubic foot was delivered to the internal shaft of vertical kiln 10 and subjected to heat treatment within the burning zone thereof operating at a temperature between 1,500" and 2,800 F.
  • the kiln was allowed to automatically operate solely in response to the differential pressure control mechanism' of the subject invention for 4 days at an average feed rate of from 22 to 24 tons of limestone per hour.
  • the exact tons per each day are set forth in Table III below.
  • the calcined product from outlet 50 was peri-. odically analyzed for carbon dioxide in accordance with ASTM 25-69, Ascarite method, and the average weight percent CO in the product was noted.
  • samples were periodically taken from the calcined product and subjected to a standard water reactivity test set forth by the American Waterworks Association and designated AWWA 202-65.
  • pressure transmitter 72 can actuate the fuel-air control system to thereby supply a predetermined heat increase to the heat treating zone to thereby compensate for the greater mass density material.
  • the fuel-air system can be proportionally cut back.
  • the average C content in the product is relatively constant. This indicates a uniform degree of calcination of the product. Furthermore, the reactivity of the lime produced over the 4-day period as indicated by the reactivity test also indicates a uniformly active lime product.
  • the subject invention can be utilized for control of any vertical kiln, furnace, retort, or the like, which is conventionally utilized to heat treat any particulate material.
  • the subject invention can be used not only for the calcining of lime but for the coking of coal, for burning argillaceous and calcareous material in the production of cement clinker, burning magnacite, dolomite, but also for retorting oil shale.
  • the differential pressure control system of the subject invention can be utilized to not' l.
  • a process for heat treating particulate material of nonuniform gradation in a vertical kiln having a particulate material inlet at the upper end thereof and a particulate material outlet at the lower end thereof comprising:
  • step (b) controlling the rate of said particulate material passing through said burning zone in step (b) relative to a comparison of said quality with a quality indicative of said predetermined bulk density to yield a mass residence time equivalent to said predetermined mass residence time within said burning zone and substantially uniformly heat treated particulate materials.
  • a process of calcining particulate material of nonuniform gradation in a vertical kiln comprising:
  • a process for calcining particulate material of nonuniform gradation in a vertical kiln comprising:
  • a vertical kiln having means to feed particulate material to its upper inlet end thereof; means to pass a fuel-air mixture upwardly through said vertical kiln and establish a burning zone within the midportion thereof; and an outlet grate means to remove heat-treated particulate material from the lower outlet end thereof at a controlled rate; the improvement comprising:
  • a vertical kiln for heat treating particulate material comprising:
  • an elongated heating chamber having an upper inlet end, a lower outlet end, and a burning zone therebetween;
  • grate means positioned in the outlet of said kiln for removing heat treated particulate material therefrom at a controlled rate
  • said means for supplying fluid comprises a means for supplying a fuel-air combustion supporting fluid to the interior of said elongated heating chamber.
  • the vertical kiln of claim 14 further comprising means to supply particulate material to the inlet of said elongated vertical heating chamber to maintain a constant level of particulate material within said chamber.
  • said grate means comprises a series of spaced-apart generally parallel positioned deflector plates extending across the outlet of said elongated heating chamber and providing at least one opening therebetween in said outlet, retainer plate means positioned below and spaced from each said opening and having its edges extending under the edge of each deflector plate to prevent a space therebetween along vertical lines; pusher means reciprocally mounted in the space between said deflector plates and said retainer plates, and means for reciprocally moving said pusher means across each said retainer plate.
  • said means for reciprocally moving said pusher means comprises first and second opposed hydraulic cylinder means each comprising internal piston means having a front and back face and a piston rod attached to each front face and extending outwardly therefrom and positioned in an opposed manner through opposite walls of said elongated vertical heating chamber and being operatively connected to said pusher means.
  • said means to control the outlet rate of said grate in response to fluctuations in said differential pressure comprises a hydraulic fluid flow control means operatively connected to said first and second opposed hydraulic cylinder means.
  • hydraulic fluid flow control means comprises:
  • hydraulic pump means for delivering hydraulic fluid and hydraulic reservoir means for delivering hydraulic fluid to said hydraulic pump means;
  • a four-way valve means having first and second ports which alternately communicate with third and fourth valve ports, such that when in its first position, the first valve port communicates with the fourth valve port and the second valve port communicates with the third valve port, and when in its second position, the first valve port communicates with the fourth valve port and the second valve port communicates with the third valve port;
  • first conduit means communicating with the outlet of said hydraulic pump and said first valve port of said fourway valve means
  • third conduit means communicating between said third valve port and the space adjacent said front face of said piston means within said second hydraulic cylinder means;
  • fifth conduit means communicating between said second valve port of said four-way valve means and said hydraulic reservoir means, and having a flow control valve means positioned therewithin which regulates the flow therethrough in response to said differential pressure.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Incineration Of Waste (AREA)
  • Furnace Details (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)
US00383484A 1973-07-30 1973-07-30 Vertical kiln control Expired - Lifetime US3849061A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US00383484A US3849061A (en) 1973-07-30 1973-07-30 Vertical kiln control
US467139A US3884621A (en) 1973-07-30 1974-05-06 Control of vertical heat treating vessels
CA204,903A CA1029951A (en) 1973-07-30 1974-07-16 Vertical kiln control
DE2436527A DE2436527A1 (de) 1973-07-30 1974-07-29 Schachtofensteuerung
JP49086653A JPS5071600A (de) 1973-07-30 1974-07-30
GB3359074A GB1475574A (en) 1973-07-30 1974-07-30 Vertical kiln control

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00383484A US3849061A (en) 1973-07-30 1973-07-30 Vertical kiln control

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US467139A Continuation-In-Part US3884621A (en) 1973-07-30 1974-05-06 Control of vertical heat treating vessels

Publications (1)

Publication Number Publication Date
US3849061A true US3849061A (en) 1974-11-19

Family

ID=23513375

Family Applications (1)

Application Number Title Priority Date Filing Date
US00383484A Expired - Lifetime US3849061A (en) 1973-07-30 1973-07-30 Vertical kiln control

Country Status (5)

Country Link
US (1) US3849061A (de)
JP (1) JPS5071600A (de)
CA (1) CA1029951A (de)
DE (1) DE2436527A1 (de)
GB (1) GB1475574A (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3957422A (en) * 1974-01-24 1976-05-18 Georg Bernhard Kohn Method and device for the peripheral heating of mineral substances in shaft furnaces with fluid fuels and air
US4212706A (en) * 1977-07-08 1980-07-15 Nippon Kokan Kabushiki Kaisha Method of controlling pressure of gas circulating in the coke dry quenching apparatus
US5040972A (en) * 1990-02-07 1991-08-20 Systech Environmental Corporation Pyrolyzer-kiln system
US20120028203A1 (en) * 2010-07-27 2012-02-02 Flsmidth A/S High capacity shaft kiln
WO2014047284A1 (en) * 2012-09-21 2014-03-27 Rosemount Inc. Flame instability monitoring with draft pressure and process variable
CN111039581A (zh) * 2020-01-03 2020-04-21 中冶长天国际工程有限责任公司 一种琴键式石灰立窑布料系统及布料方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2625386A (en) * 1947-05-20 1953-01-13 David P Leone Method and apparatus for controlling blast furnaces
US2626141A (en) * 1948-04-24 1953-01-20 Babcock & Wilcox Co Fluid heating apparatus
US2774572A (en) * 1951-11-05 1956-12-18 Phillips Petroleum Co Improved pebble heater
US2814479A (en) * 1953-01-12 1957-11-26 Otto J Leone Blast furnace control system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2625386A (en) * 1947-05-20 1953-01-13 David P Leone Method and apparatus for controlling blast furnaces
US2626141A (en) * 1948-04-24 1953-01-20 Babcock & Wilcox Co Fluid heating apparatus
US2774572A (en) * 1951-11-05 1956-12-18 Phillips Petroleum Co Improved pebble heater
US2814479A (en) * 1953-01-12 1957-11-26 Otto J Leone Blast furnace control system

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3957422A (en) * 1974-01-24 1976-05-18 Georg Bernhard Kohn Method and device for the peripheral heating of mineral substances in shaft furnaces with fluid fuels and air
US4212706A (en) * 1977-07-08 1980-07-15 Nippon Kokan Kabushiki Kaisha Method of controlling pressure of gas circulating in the coke dry quenching apparatus
US5040972A (en) * 1990-02-07 1991-08-20 Systech Environmental Corporation Pyrolyzer-kiln system
US20120028203A1 (en) * 2010-07-27 2012-02-02 Flsmidth A/S High capacity shaft kiln
WO2012018406A1 (en) * 2010-07-27 2012-02-09 Flsmidth A/S High capacity shaft kiln
WO2014047284A1 (en) * 2012-09-21 2014-03-27 Rosemount Inc. Flame instability monitoring with draft pressure and process variable
CN104487771A (zh) * 2012-09-21 2015-04-01 罗斯蒙特公司 通过气流压力和过程参数进行火焰稳定性监控
RU2601021C1 (ru) * 2012-09-21 2016-10-27 Роузмаунт Инк. Контроль за неустойчивостью пламени посредством давления тяги и переменной процесса
US10558731B2 (en) 2012-09-21 2020-02-11 Rosemount Inc. Flame instability monitoring with draft pressure and process variable
CN111039581A (zh) * 2020-01-03 2020-04-21 中冶长天国际工程有限责任公司 一种琴键式石灰立窑布料系统及布料方法
CN111039581B (zh) * 2020-01-03 2023-06-23 中冶长天国际工程有限责任公司 一种琴键式石灰立窑布料系统及布料方法

Also Published As

Publication number Publication date
CA1029951A (en) 1978-04-25
GB1475574A (en) 1977-06-01
JPS5071600A (de) 1975-06-13
DE2436527A1 (de) 1975-02-20

Similar Documents

Publication Publication Date Title
AU2009215632B2 (en) Method and apparatus for pressurized calcination of gypsum
US2451024A (en) Method of calcining and calcining apparatus
US2498710A (en) Process for burning lime
US4113836A (en) Continuous gypsum calcination process and kettle therefor
US3849061A (en) Vertical kiln control
US4002421A (en) Control of vertical heat treating vessels
US3884621A (en) Control of vertical heat treating vessels
US2527488A (en) Apparatus for conveying materials
US3307840A (en) Continuous calcination of gypsum
CA1047765A (en) Control of vertical heat treating vessels
US3832128A (en) Process and apparatus for preheating solid particulate materials
GB1508721A (en) Method of burning pulverous alkali-containing raw materials
RU96122789A (ru) Способ контроля температуры в обжиговой печи и устройство для производства цементного клинкера
US4090945A (en) Method of operating an oil shale kiln
GB1451374A (en) Device for the thermal treatment of granular and/or lumpy materials
CA1079065A (en) Cement calcining apparatus
US3743697A (en) Process of calcination
US2587379A (en) Apparatus for treating bulk material
SU1089071A1 (ru) Способ регулировани процесса обжига клинкера
GB1447349A (en) Planetary coolers
SU775578A1 (ru) Загрузочно-распределительное устройство шахтной печи
SU935129A1 (ru) Способ управлени процессом измельчени материала после обжига
SU797748A1 (ru) Способ автоматического регу-лиРОВАНи пРОцЕССОМ пРигОТОВлЕНи СуСпЕНзий
SU361989A1 (ru) УСТРОЙСТВО дл УПРАВЛЕНИЯ ТЕПЛОВЫМ РЕЖИМОМ ОБЖИГА СЫРЬЕВОЙ СМЕСИ ВО ВРАЩАЮЩЕЙСЯ ПЕЧИ
SU948936A1 (ru) Способ регулировани расхода топлива при обжиге карбонатсодержащей сырьевой смеси

Legal Events

Date Code Title Description
AS Assignment

Owner name: HOLME ROBERTS AND OWEN, 1700 BROADWAY, SUITE 1800

Free format text: SECURITY INTEREST;ASSIGNOR:PARAHO DEVELOPMENT CORPORATION;REEL/FRAME:004160/0879

Effective date: 19830726

Owner name: HOLME ROBERTS AND OWEN, A GENERAL PARTNERSHIP,COLO

Free format text: SECURITY INTEREST;ASSIGNOR:PARAHO DEVELOPMENT CORPORATION;REEL/FRAME:004160/0879

Effective date: 19830726

AS Assignment

Owner name: NEW PARAHO CORPORATION, THE

Free format text: ASSIGNOR HEREBY RELEASES SECURITY INTEREST IN SAID PATENTS RECORDED ON REEL 4160 FRAME 879.;ASSIGNOR:HOLME ROBERTS & OWEN;REEL/FRAME:004613/0388

Effective date: 19860811