CA1101021A - Means and method for handling dry bulk materials in a hopper-type container - Google Patents

Abstract

MEANS AND METHOD FOR HANDLING DRY BULK
MATERIALS IN A HOPPER-TYPE CONTAINER

Abstract of the Disclosure Apparatus and method for forming and handling a slurry in a hopper-type container, preferably a hopper railroad car. The product may be unloaded dry using air or the product may be aerated, then liquified while air continues to be forced thereinto, then agitated and mixed to ensure formation of a slurry-or solution having consistent properties. The slurry or solution is aerated during the discharge thereof from the container. The aeration for dry or liquid discharge is preferably performed using aeration devices such as that device disclosed in U.S. Patent No. 3,929,261.

Description

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The present invention relates in general to hopper-type containers, and more particularly, to forming and handling a slurry and solutions in hopper-type railroad cars.
S For certain material~, storage and discharge thereof in slurry form has many advantages over storage and discharge thereof in dry form. For the'sake of convenience, a generic term "liqui~ied mass" will be used to include both a slurry and a solution. However, no limitation on the 10 scope Oæ the in~ention is intended by this terminology, and such is being employed only for the convenience thereof. In some instances, transportation in slurry form'may also be advantageous over transporta~ion in dry form. Thus, it is quite common for many materials to be stored and discharged 15 in slurry form.
'Generally, a slurry is formed in a container by inikially loading material in dry form into a contain r, then liquifying that dry material by pumping a liquid into the container and mixing that liquid with the material while 20 sometimes adding air in ~he la~e stages of agitation~
If the liquid is not thoroughly mixed with the initially dry material, t~e slurry has non-uniform propei ies, such as density, consistency, and the like. Such a non-uni~orm slurry causes many problemc; in handling and discharge 25 of that slurry material. While hiqh pressure liguid introduction into the container may help somewhat in the mixing steps, this method is not entirely satisfactory.
The in~entor is aware of slurry unloading systems, such as that disclosed in U.S. Patent Nos. 3,512,B42 and 30 3,3787387~ In U~S. Patent No. 3,512,842, air is discharged into the bulk material. However, in systems such as that disclosed in the just~mentioned patent, the air discharge apparatus is simply a plurality of pipes extending upwardly into a hopper. There is no device capable of discharging 35 gas at or very near the` ~ottom of the hopper, and in a manner which e~ficiently mixes and fluidizes the matarial.
~erel~ discharging air into the body of such material is not sufficient to adeguately ~luidize that material, or to fluidize the ~aterial near that location on the hopper used ,~

as an inlet for liquid and/or an exit for the slurry or solution. Furthermore, there is no provision in U.S.
Patent 3~512,8~2 for coupling the liquid and air lines to promote efficient fluid handling to and from the hopper.
The device disclosed in U.S. Patent No. 3,512,842 thus is susceptible to compacting of the dry product, which may resuit in product lumps into which liquid will not penetrate. Such lumps are detrimental to a slurry or solution handling method.
Thus, the applicants are not aware of any means or method for transforming into slurry form an initially dry product which is to be stored and handled in slurry form in a hopper-type container, and particularly in a hopper-type railroad car, which is thorouyh enough to completely assure 15 the formation of a slurry which is consistent and thoroughly liquified. The present invention is embodied in a means and method for ènsuring the formation of a consistent and thoroughly liquified slurry or solution.

The present invention relates to apparatus and method for thoroughly li~uifying, mixing and agitating a product which is to be stored and/or discharged and~or transported in slurry or solution form from a hopper-type container, and particularly, a hop~per~type railroad car.
In accordance with one aspect of the present invention, there is provided a hopper-type container comprising: a container body having a hopper for con~aining a product to be ormed into and handled as a slurry or solution; a gas induction system or inductii~ ~as into the 30 container body, the gas system including an inlet conduit for connecting a source of gas to the container body, an aeration device mounted on the bottom of the container body hopper, the aeration device having gas discharge means located closely adjacent the hopper bottom for discharging air into 35 the container body adjacent the hopper bottom, and a conduit connecting the aeration device to the inlet conduit, a liquid handling system connected to the bottom of the hopper for 'J
conducting liquid to and from the container body hopper from a 1iquid source and conducting a slurry or a solution from the container to a slurry or solution handling system; and cross-over valves connectiny the gas induction system to the liquid handling system for introducing gas into the container body through the liquid handling system.
A preferred aeration device for use in the container is disclosed in U.S. Patent No. 3,929,261, issued to Keith F.
Solimar on D~cember 30, 1975 (hereinafter re~erred to as the Solimar patent~. Details of the preferred aeration device will not be herein presented, and attention is directed to 10 the referenced Solimar patent for a full description and I discussion of those details.
I For ~he sake of convenience, the invention will ¦ be discussed with particular reference to a railroad car.
I However, other hopper-type containers can be used without 15 departing from the scope of the present invention~ The , sinyle system embodying the present invention which can be ¦ used both for unloading a product dry and in homogeneous slurry form adds considerable flexibility to a hopper-type rail car.
In accordance with another aspect of the invention, 20 there is provided a method of forming and handling a slurry or solution in a hopper-type ~ontainer, including the steps of: placing a quantity o clry material into a container;
forcing gas through the dry mater~.al to agitate the dry material; continuing to agitate the dry material by forcing 25 gas thereinto whilè simultaneously liquifying the dry material by forcing liquid through the material; and agitating and mixing the liqui~ied material to produce a liquified mass having a consistent composition~
~he thorough aeration of the dry product, the 3Qliquified product and the slurry effected in this procedure ensures a slurry which is consistent. The consistency of a slurry handled is much greater than the consistency of the slurries handled accordingto theprior art known to the applicants.
¦ 35 Th~ liquid used to form a slurry can be supplied ! from an external source in any suitable manner, and the liquid ¦ handling system may include other elements, such as, for i example, a standpipe arrangement wherein liquid from a container is withdrawn and handled during ~ormation of the ' ' ' slurry, or elements for circulating liquid through an external pump and back into the car. In the interest of clarity, the exact nature of the liquid circulation system used in conjunction with the liquid of the car will not be discussed.
It is to be emphasized, however, that a suitable liquid supply system is included within the teachings of the present invention.
A plural hopper railroad car embodying the apparatus of the invention can also include means for recirculating slurry from one hopper to another without the use of a standpipe or other similar device. In such an emodiment, the discharge apparatus on the hoppers of the car include valves and hoses which can be configured for fluidly oonnecting t~e hoppers to a main dischargs manifold in a manner such that the aforementioned hopper-to-hopper slurry recirculation can be carried out when desired.
The present invention is described furt-her, by way of illustrations~ ~ith reference to the accompanying ! drawings, in which:
Figure l is a plan view of the bottom of a hopper used in a hopper-type railroad car provided in accordance with one embodiment of the presen1: invention;
E'igure 2 is a view taken along line 2-2 of Figure l;
~lgures 3 to 6 illustrate'the configurations' of the elements associated with a hopper~type railroad car during the various steps involving the formation and handling of`a slurry or a solution following the procedure of the present invention;
~igure 7 shows a plan view of an embodiment of the invention used for discharging bulk material in dry form;
Figure 8 is an elevational view of the e~bodiment of Figure 7;
Figure 9 is an elevational view of a portion of the embodiment of Figure 7i Figure lO is a partial view of the embodIment of Figure 7; and Figure ll is an elevational view of an alternative form of a standpipe.

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Referring to the drawings t shown in Figures 3 to 6 is a hopper-type railroad car 10 having the usual wheel assemblies 12 supporting a chassis 14. The car 10 includes a plurality of hoppers 20 each of which is formed by downwardly 5 converging hopper walls 24 to form generally conical hoppers for storing product P therein. The drawings show three hoppers, however, more or fewer hoppers can be used without departing from the spirit and scope of the present invention. It is also noted that car 10 is shown only schematically as the 10 general and overall makeup of that car does not form part of the present invention. Thus, partitions, and the like, are not shown in figures, but it is to be understood that such general equipment is considered to be part of the car 10~
The car 10 also includes a plurality of normally-closed hatches, 15 or manholes 26, each having the usual manhole covers 30 thereon.
A relief valve 40 is noted on the top 42 of the car body 44.
Referring to Figures 1 and 2, it is seen that the hoppers each have a lower section 5Q which includes a sloped wall 52 and a horizontal bottom 56. The wall 52 has an 20 annular flange 60 which is attached to the hopper wall 24 by a coupling brace~62 and fastening means, such as bolts 66.
An annular gasket 68 is interposed between the brace 62 and the flange 60 to ensure tight sealing of the lower section 50 to the hopper wall 24.
As above-discussed, to facilitate proper stOrage and discharge of product P, gas and liquid flow systems are provided. The gas is preferably air, and the liquid is preferably water, but other fluids can be used without departing from the scope of the present invention. An air 30 system 70 includes a plurality of aeration devices 100 mounted on the lower section wall 52 at a plurality of spaced locations. The aeration device 100 is fully disclosed in the referenced Solimar patent, and attention is directed thereto for a complete discussion thereof. It is here noted that the 35 devices 100 discharge air at or near the bottom of the hopper so that air efficiently fluidizes, and maintains fluidized, the product, In this manner, even that product located immediatley adjacent the ~opper bot~om will be adequately fluidized. Thus, no clumps, or dry volumes will 40 be present in the product.

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An air manifold system 110 includes an air inlet hose 114 connected to one of the aeration devices for conducting air from a suitable source (not shown) to the aeration devices. The aeration devices each includes a double-5 port inlet chamber 122 and are fluidly interconnected by aplurality of hoses 124 coupled to the inlet chambers of the devices 100 by hose clamps 126, or the like. The inlet chambers have coupling means 130 thereon for receiving the hoses. As discussed in the aforementioned patent, 10 air supply to each of the aeration devices is discharged outwardly thereof into the hopper in a prescribed manner.
As shown in Figure 1, the hopper can include a cleanout 132 if suitable, however, such an element is not an ess~ntial part of the system herein disclosed ~nd is shown 15 i~ Figure:l only for the sake of convenience.
A liquid flow system 14Q includes a conduit 150 connected at one end thereof to the lower sec~ion 50 as shown in Figures 1 and 2 and has a connecting flange 152 on the other end thereof~ As shown in Figure 2, a portion of the 20 lnwer section bottom forms part o an end 156 of the conduit L50. According to the flow directi.on, end 156 is either an inlet end or a discharge end. Su~l positioning increases the efficiency o liquid flow into and out of the conduit 150.
~he usual pipe and hofie hangers ancl other supporting 25 equipment are also included in the fluid systems herein disclosed, but.are not shown for the sake of convenience.
As ~est shown in Figure 3, the air ~low system 110 includes a main air inlet line 160 fluidly connec~ed to a main air inlet hose 162 by suitable couplings, such as 30 coupling 164 and a check valve 166. The air line 160 is preferably a 3 inch line. The control valve i5 used to regulate air flow through the system. A further ~low regulating valve 168 is mounted on the air inlet line 160.
The individual hopper air flow systems are fluidly connected 35 to the main air inlet line 160 by couplings, such.as coupling 172 which can be a tee, or the like~ ~ lock nut, or like fastener, couples air inlet hose 114 of each hopper air flow system to the coupling 172, and thus, regulated air flow from a source through control valve 168 and to the individual hopper systems is permitted Yia air inlet line 160 and the couplings 172.
A main liquid system 180 includes a main liquid line 182 fluidly connected to each hopper conduit 150 and 5 having a plurality of control valves 186 thereon. Each valve 186 is located adjacent a hopper for controlling liquid flow to and from that hopper individually and independently of the flow to other hoppers, as will be discussed below. The main li~uid line 182 is also connected to the air inlet 10 line 160, and a main control valve 187 is located to fluidly isolate and connect the air inlet line 160 and the liquid line 182.
The liquid system includes a main liquid interface coupling 188 having a valve 190 connecting the main liquid 15 line, or, as shown in Yigure 3, branches of the main liquid line, to a suitable liquid system. If suitable, the outlet valve can be manually controlled via handle 192. A pump is schematically illustrated in Figure 3 to indicate a motive means for the li~uid system. In addition, the car has a 20 15 psig pressure capability and can be pressurized to assist in the discharge of the slurry or solution.
As shown in Figure 3, the discharge line 182 forms a wye adjacent the coupling 188, ~lereby the li~uid line from one of the hoppers is fluidly conn~3cted to the liquid lines 25 of the other hoppers. The wye-connection can be placed anywhere on the containers, but is most conveniently located adjacent an endmost hopper.
As shown in Figures 3 and 4, a main water inlet line 194 is fluidly and reI~asably attached at one end 30 thereof to valve 190 and at the other end thereof to a source of liquid (not shown~, and in this case, water A water meter 196 can be attached to the line 1~4 if suitable~
As shown in Figures 5 and 6, a product line 198 is fluidly and releasably attached at one end thereof to the 35 valve 190 and at the other end thereof to a suitable product receptacle (not shown).
Referring to Figures 3 to 6 inclusively, the method of hanaling material in relation to the car 10 will be described ~-in detaii.

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Product aeration is conducted with the car elemen$s in the configuration shown in Figure 3. In the Figure 3 configuration, one of the manholes 26 is open to permit air to escape from the car, the valves 186 and 187 are closed to 5 preven~ escape-of product P from the hopper, valve 190 is closed to isolate the hopper from a source of water, and the control valve 187 is closed to fluidly isolate the liquid line 182 from the air inlet line 162.
In this configurationl air is pumped from the 10 source, through the hose 162, into line 160 and then into the hoppar air flow systems 70 via inlet hoses 114. The air then passes through the aeration devices 100 upwardly into the product as indicated ~y arrows PA in Figure 3~ The air discharged by devices 100 passes upwardly through the lS product, ~nd then out of the open manhole. Product aeration is conducted as described in the aforementioned patent, and is continued until the product is suitably aerated.
The aeration-devices serve to distribute air into 20 the product in a proper manner which aerates the product in a manner which is much more ef~icient and effective than in prior art systems as discussed` in the referenced patent.
After the product is sufficiently aerated, a product liquification step is performed to convert a dry 25 product into a slurry for convenient storage, discharget or shipment. Product liqui~ication is conducted with the car elemen~s in the con~iguration shown in Figure 4. In the Figure 4 con~iguration, the one manhole is still open, and a water hose is attached to valve 190. It is noted that the 30 water hose is shown in Figure 3 to ha~e been attached in the product aeration step as well, but in that step, the valve 1~0 was closed. The valves 186 are open and water is permitted to flow into and through the water line 182 to the hoppers via conduits 150. The control valve 1~7 remains 35 closed, and-the valves 168 remain open to thus continue the induction of air into the hoppers via the air flow systems 70. Thus, bubbles B are formed and air continues to flow through thë product in the direction indicated by arrows L in Figure 4. After ~lowing through the product, the air ' z~

flows out of the car via the open manhole. In this manner, the product is liquified via ~he liquid system and aerated via the aeration devices 100 simultaneously.
The liquification step is continued until the product 5 is sufficiently liquified.
The aeration devices serve to infuse air into the product in a manner which promotes liquification by keeping the product thoroughly mixed and agitated as the liquid is being forced into the car. Absent such product 10 fluidization, the product may coagulate or coalesce into clumps, thus vitiating the liquification step. The aerakion devices thereby ~romoteliquification so that liquification in the presently disclosed process occurs much more efficiently and thoroughly than in those processes known prior to the 15 present disclosure.
A~ter completion of the liquification step, a product agitation and mixing step is conducted to produce a proper product density and configuration. Product agitation and mixing is conducted with the car elements in the 20 configuration shown in Figure 5. In the Figure 5 configuration, the water hose is changed to a product hose, and the valve 190 is closed to isolate the product hose from the rest of the system and to thus prevent loss of product during this step. The valves 186 are open as is the valve 187. The 25 valve 168 is closed to isolate the air flow systems, and air - is forced from the source through air inlet hose 162 and thus through the liquid line 182 and into the hoppers via conduits 150. In this sequence~ valves 168 and 187 are used as cross-over valves for foxcing air in suitable quantities 3a through the hopper liquid inlet systems ~rom an air supply system. It is here noted that this liquid system is also the product discharge system as is discussed herein. Air flow is indicated in Figure 5 hy arrows A, and flows into the hoppers and forms large bubbles BA due to the large 35 quantities of air infused into the liquified product via conduit passage 156. The air influx quantities in the ~
agitating and mixing step are greater than the other previous steps due to the di~ference`'ih air flow capacity of the liquid system vis-a-vis th- air f1ow system. The valves lB7 and 168 .

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are used to adjust the amount of air flowing into the appropriate system. Thus, during the various steps, valve 168 is opened so that the air flows through aeration devices 100 in the Figures 3 and 4 steps with the valve 187 closed, 5 and valve 168 is closed and valve 187 is opened to direct all of the air into hoppers through open valves 186 in the Figure 5 stepO The quantity of air is also indicated by the size of the bubbles in Figure 5 as compared to the bubble sizes shown in Figure 4. It is noted that, for some products, 10 the aeration using the devices 100 prior to this step may sufficiently aerate the product so that continued aeration is not necessary~
The large bu~bles in Figure 5 produce an agitation `and mixing actio~ of the liquiied product, as indicated by 15 the broken product surface line S in Fisure 5. Air flows from the car via the open manhole, and moves upwardly through the car in the direction indicated by arrows AM in Figure 5.
It is noted that, while a hose is shown in Figure 5 as being connected to valve 190, such connection is not 20necessary as the valve 190 is closed. Thus, if the product is to be stored, or moved aft~r the agitating and mixing step, the valve 190 may just be closed of~ and free of any connection downstream thereof.
It is also noted that either the aeration and/or 25the agitating and mixing steps can be conducted during storage of the liquified pxoduct t:o prote~t a~ainst settlin~
or other similar phenomena which m~ght occur ~uring long periodsof quiescence of the liquified product. Periodic aeration and/or agitating and mixing will keep that slurry

3~"stirred up" sufficiently to prevent such settling.
After the agitating and mixing step, the product can be suitably stored, transportedl or the liXe with the manholes 26 closed. The product is discharged in a dischargè
step with the car in the configuration shown in Figure 6.
35 The manhole 26 is closed so that air introduced into the car pressurizes the car. The car has a pressure capacity of 15 psig, and can therefore be pressurized to assist in the discharge step. This pressure serves to assist in the .

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product unloading~ and in a preferred embodiment is 15 psig 5maximum). In the Figure 6 configuration, air is conducted to the car from a sui~able source ~not shown~ via an air inlet hose 162', and valve 168 is open so that air is conducted to the air flow systems 70 of the hoppers. It is noted that the prime notation is used to indicate a movement of the car from a loading area to a discharge area, but such areas may be the same if desired. The valve 187 is closed so that all of the air supplied via hose 162' is forced through the aeration devices into the product to maintàin the product thoroughly agitated without interfering with product discharge in any way. The valves 186 are open as is valve 190, thereby fluidly connecting the hoppers to a discharge line 198 via conduits 150 and line 182.
Air flows into the product in the direction of arrows D in Figure 6. It is also noted that use of air pressure to unload is optional, and a pump (not shown~
may be used with or without air pressuxe.
While specific elements of a liquid circulation 20 means, such as pumps, and the like, have not bee~ illustrated in the Figures as being associated with the car, it is to be understood that such circulation means can be used. For example, the discharge side of a pump can be connected either to discharge hose 198 in Figure 6, or to water line 25 194 in Fiyure 3, and the inlet side of the pump can be connected to a sepaxate fitting (not shown) in the hopper bottom to circulate liquid from and back to car 10~ A
liquid handling system which includes standpipes, such as that system disclosed in U. S. Patent No. 3,338,63S, can 30 also be associated with the herein disclosed li~uid handling system without departing from the teachings of the present disclosure. If a standpipe is used, liquid in the container can be circulated out of the rontainer during the formation of the slurry. Thus, the liquid circulation can occur 35 during the liquifying step, or the agitating or mixing step, or at any other suitable time. A liquid withdrawn from the container via the standpipe can be used, stored, ~r circulated back into the container, as desired.

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' The aeration provided via the aeration devices keeps the product thoroughly mixed and agitated to ensure smooth flow of product into the discharge system via conduits 150. Absent such aeration, product may become clogged in 5 the discharge lines due to a coagulation thereof during storaga and/or transport. Such clogging may slow the discharge step, or even stop that step in extreme cases.
Therefore, the aeration provided by the aeration devices during the discharge step serve to expedite that discharge 10 step.
It is thus evident that in each step requiring the U5e thereof, the aeration devices promote the efficiency and thoroughness of such step to a level beyond those levels attainable-using those methods known prior to the 15 present disclosure. Thus,-the process comprising the above-described steps loads, mixes, stores and discharges product in a manner which is much more efficient than heretofore known processes.
An arrangement for handling dry product is sho~n 20 in Figures 7 to ll~inclusively. As shown in Figure 7, the hopper bottoms 50 are arranged as disclosed above to inlcude an air inlet hose 114 connected to an air manifold system 110 which includes a plurality of aeration devices 100. The devices 100 in the Figurq 7 emobodiment are the same as in 25 the Figure 1 embodiment, and thus are fully disclosed in the referenced Solimar patent. The air flow from the devices 100 is indicated by the arrows 101 in Figure 10. A conduit 150 is connected to the hopper bottom and serves as a product discharge line.
As shown in Figure 7~ the air inlet system includes the main air inlet hose 162' connected to the check valve 166' which controls the flow of air from an air source (not shown) to the hoppers. A tee coupling 172' connects a - control valve 187' and a control valve 168' connects air 35 ~upply line 160' to the tee coupling 172' and hence to the air supply. A hopper close-off valve 300 connects each hopper inlet hose 114 to the air supply line 160' and can be used to selectively connect and disconnect each hopper to the air supply line. The valves 300 are optional and enable the -., .

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system ~o operate with limited air supplies, and/or with difficult product. The ~alves 300 permit operation o one hopper at a time. A close-off valve is shown in Figure 10 in the open configuration.
A standpipe 310 is connected to the air line 160' by a feed line 312 and a tee coupling 314. A standpipe control valve 318 is located in the feed line 312 to control the flow of air from the supply line 160' to the standpipe 310.
A product discharge system includes a pipe section 10 320 connecting the control valve 187' to an elbow 324 which is connected to a second pipe section 326. As in the abovet disclosed embodiment, the valve 187i is a balancing valve and balances the air flowing into each of the pipes 160' and 182' to proper and desired levels. A control valve 330 15 controls the flow of air from the supply into product discharge line 182l. Each hopper conduit 150 is connected to a product discharge valve 334 which is connected by a Y-coupling 338 to the product discharge line 182'.
The product discharge valves 334 control the flow 20 of dry product out of each hopper and can be used to ~hut off each hopper either temporarily (to, for example, loosen a plug of product lodged in the hopper discharge line 150, or the like), or permanently (e.g., after the hopper is completely empty).
~s shown in Figures 8 and 9, the standpipe 310 includes a vertical section 340 having an exit section 342 located near the top o~ the container 344 to discharge -pressurizing air 346 into that container, and a blow~down section 348 located near the hopper bottom 50. The section 30 348 includes a blow-down valve 350 and a vent pipe 352 which is open to the atmosphere to discharge pressurizing air 346 9 thereinto. Various flanges, such as flange 354, connect pipe sections together to form a standpipe having a proper length. The blow-down section 348 is used to relieve 35 air pressure within the container.
~ pair of pressure relief valves 360 and 362 are positioned in the standpipe feed line r as is a vacuum relief valve 364. A remote control system (not shown~ can ~e used to operate these valves, and a lead wire 366 is shown , .

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in Figure 9 to indicate connection to such control system.
A standpipe control valve 370 is connected to the feed line 312 to further control the amount of air flowing into the standpipe.
An alternative embodiment of t~e standpipe is shown in Figure 11 and is indicated by the numeral 310'.
The standpipe 310' includes a tilted section 340' and pressure relief valves 360' and 362' located in the blow-down section 348'. The blow-down section 348'is open to atmosphere, 10 as is blow-down section 348 to vent air thereto. Otherwise, the standpipe 310' is similar to the standpipe 310.
Suitable pipe hangers 380 r and other such elements are also included to properly mount the pipes on the container.
Suitable baffles can also be included to isolate each hopper 15 from the others, if so desired.
The operation of the system shown in Figures 7 to 11 will now be discussed. Normally, only one hopper is unloaded at a time, and the hoppers are unloaded sequentially.
To initiate unloading, valves 166', 187' and 330 are opened 20 with control valve 168' closed to force air through the discharge line 182'. The air is initially forced through the product discharge line into the product collection means, such as a silo, or the like~ to permit the air moving de~ices, such as blowers or the like, to come up to working 25 levels. Once these working levels are attained, control valve 187' is closed and valve l68' is positioned to f1Ow air through the air supply line 160' and into the hopper air systems as previously described. Air also flows through the standpipe in~o the container.
All of the air is forced through the aeratio~
devices 100 to fluidize the productn Once the product is sufficiently fluidized, control valve 187' is opened slightly to permit air to flow into the product discharge line. It is noted that container pressure is generally 35 maintained in the range of 10 to 12 psig, and can be controlled via the standpipe system.
Once the proper air.flow is established through both the aeration systems and the product discharge line, 2~L

the hopper product discharge valve 334 on the first hopper is opened. Product from -that first hopper then flows into the product discharge line and then to the product collection means.
Product is discharged until line pressure and container pressure both drop theréby signifying an empty tank~ or in the case of a hopper-type railcar, an empty hopper.
At this time, the valve 334 of the first hopper is closed, and the valve 334 of the next hopper is opened, that hopper 10 pressurized and emptied in the manner just described. The process is continued until all of the hoppers are emptied, There may be some residual product remaining in each of the hoppers after the completion of the just-described process. Each hopper is individually opened to 15 the product line via valves 33~ and each hopper is pressurized to a fairly high value. Such procedure discharges t~e residual product from each hopper into the discharge line.
It is noted that on a three hopper car, it is ; preferable to empty the center hopper first, then emptying 20 the end hoppers. In a four hopper car, baffles may be present to limit product shift, and thus it is preferable to empty an endmost hopper first, then proceed to the next adjacent hopper, and so on.
It is noted that air is forced into the product 25 through the aeration devices at all times during the discharge process. In this manner, the product is thoroughly fluidized and is therefore efficiently unloaded. The blow-down sections of the standpipes can-be used to further control the pressure inside the container. The pressure 30 relief ~alves and the vacuum relief valves in the standpipe feed line are optional and can be used to direct some, or all, of the air supply into the container. An operator thus has extra control valves which can be adjusted to optimize settings for a particular combination of product and air 35 supply. The air flow established in the product line keeps the product therein fluidized and moving ef~iciently there-through. rr The product discharge valves 334 can also be used to discharge any product clogged in the hopper discharge ' ' ~ ' , . . .

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lines 150. Closingthe valve 334 and pressurizing a hopper, then popping the valve 334 open will unplug the discharge line.
The system shown in Figures 7 to 11 can be used in 5 conjunction with either a railroad car or a road vehicle.
As shown in Figure 10, a railroad car will have a hopper wall inclination angle of about 30 whereas a hopper-type trailer will have hopper walls inclined at about 45 with respect to -the vertical. The difference in wall angle results from 10 clearance differences between rail cars and trailers as well as considerations of container center of gravity~

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Claims (15)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A hopper-type container comprising:
a container body having a hopper for containing a product to be formed into and handled as a slurry or solution;-a gas induction system for inducting gas into said container body, said gas system including an inlet conduit for connecting a source of gas to said container body, an aeration device mounted on the bottom of said container body hopper, said aeration device having gas discharge means located closely adjacent the hopper bottom for discharging air into said container body adjacent the hopper bottom, and a conduit connecting said aeration device to said inlet conduit;
a liquid handling system connected to the bottom of said hopper for conducting liquid to and from said container body hopper from a liquid source and conducting a slurry or a solution from said container to a slurry or solution handling system; and cross over valves connecting said gas induction system to said liquid handling system for introducing gas into said container body through said liquid handling system.

2. The container of Claim 1 further including control valves in said gas induction and liquid handling systems for controlling the flow of fluid through said systems.

3. The container of Claim 1 further including a plurality of aeration devices and conduits interconnecting said aeration devices.

4. The container of Claim 1 wherein said container body includes a plurality of hoppers.

5. The container of Claim 1 wherein said container is a railroad car.

6. A method of forming and handling a slurry or solution in a hopper type container, including the steps of:
placing a quantity of dry material into a container;
forcing gas through said dry material to agitate said dry material;

continuing to agitate said dry material by forcing gas thereinto while simultaneously liquifying said dry material by forcing liquid through said material; and agitating and mixing said liquified material to produce a liquified mass having a consistent composition.

7. The method of Claim 6 further including a step of discharging said slurry from said container.

8. The method of Claim 7 wherein said agitating and mixing step includes forcing gas into said material through the system used to force liquid into said material.

9. The method of Claim 7 further including a step of forcing gas into said material during said discharge step.

10. The method of Claim 6 wherein said gas is air.

11. The method of Claim 9 wherein said gas is air.

12. The method of Claim 9 further including a step of using said gas to pressurize said container during said discharge step to assist in said discharge of said slurry from said container.

13. The method of Claim 6 wherein an external pump is used to circulate liquid into said container.

14. The method of Claim 6 wherein said container includes a plurality of hoppers.

15. The method of Claim 6 wherein said container is a railroad car.