US2861304A

US2861304A - Sand cleaning system

Info

Publication number: US2861304A
Application number: US592199A
Authority: US
Inventors: Clifford E Wenninger
Original assignee: American Marietta Co
Current assignee: American Marietta Co
Priority date: 1956-06-18
Filing date: 1956-06-18
Publication date: 1958-11-25
Anticipated expiration: 1975-11-25

Description

Nov. 25, 1958 E, W NN INGER 2,861,304

I SAND CLEANING SYSTEM Filed June 1 8, 1956 2 Sheets-Sheet 1 I I f: j 47 I l 47 #vvavrom- 26 47 2e Br%a/MW% m A T TORNEKS'.

NOV. 25, 1958 c w NNm 2,861,304

. SAND CLEANING SYSTEM Filed June 18. 1956 2 Sheets-Sheet 2 INVENTOR ATTORNBS.

' United States Patent SAND CLEANING SYSTEM Clilford E. Wenninger, River Forest, 111., assignor, by

mesne assignments, to American-Marietta Company, Chicago, 111., a corporation of Illinois This invention relates to a sand cleaning system and more particularly to a system for cleaning sand and similar granular material in dry condition.

It has heretofore been proposed to clean foundry sand and the like by wet cleaning methods according to which the sand is scrubbed in the form of slurry or wet mass, is liquid classified and is then dried for reuse. Such systems produce excellent results, but have as their principal drawback the necessity of drying the sand which is time consuming and requires a considerable amount of power.

It has also been proposed to clean sand in dry condi tion by dry scrubbing or burning. Burning is not entirely satisfactory because of thenecessity of heating a large mass of sand and because it does not remove incombustible particles, such as clay. In dry scrubbing systems, as heretofore proposed, the apparatus is subject to relatively rapid wear requiring frequent replacement of various parts or components which have in general been difiicult and expensive to replace. The systems are furthermore relatively large and complex, requiring a great deal of room and being expensive to install and maintain.

It is one of the objects of the present invention to provide a sand cleaning system in which the sand is cleaned by dry scrubbing and in which wear of the parts is minimized with such parts as are subject to wear being easily and inexpensively replaceable.

Another object is to provide a sand cleaning system in which the sand is moved solely by air and can be retained in the system and recirculated for any desired period necessary to provide adequate cleaning.

According to one feature of the invention, the sand is scrubbed partially in a spinner, partially in a pipe and partially in a deflector, all forming elements of the'system through which sand flows. The pipe and deflector constitute simple and inexpensive elements formed for easy replacement without dismantling the apparatus and the spinner is of simple, inexpensive construction with those parts most subject to wear easily replaceable.

Still another object of the invention is to provide a sand cleaning system which is self-balancing and controlled as to the rate of flow therethrough and retention time of the sand therein solelyby regulating the rate of sand discharged.

According to a feature of the invention, there are a plurality of vertical passages through which sand flows to spinners and to the tops of which sand is returned through the pipes and deflectors. As the channels fill up, sand backs up in the system to regulate the supply thereby maintaining an automatically balanced system. Furthermore, with this system there is no clogging when the system is shut down and operation can bestarted up merely by turning on the supply of air.

A further object is to provide a spinner for a sand cleaning system which is simple and inexpensive to construct, easy to repair, easy to adjust for rate of flow and which will not clog when shut down.

Patented Nov. 25, 1958 The above and other objects and features of the invention will be more readily apparent from the following description when read in connection with the accompanying drawings, in which:

Figure 1 is a front elevation of a sand cleaning system embodying the invention;

Figure 2 is a side elevation;

Figure 3 is a partial section on the line 3-3 of Figure 2;

Figure 4 is a partial section on the line 4-4 of Figure 1;

Figure 5 is a top view of the spinner on the line 5-5 of Figure 2; and

Figures 6 and 7 are sectional views of the spinner on the lines 6-6 and 7-7, respectively of Figure 5.

The sand cleaning system, as shown, comprises a housing indicated generally at 10 which is formed of sheet metal with a closed top, a vertical side 11, a sloping bottom 12 and an elongated reduced lower portion 13. The housing 10 may be supported at any desired elevation by a suitable framework, not shown, and it is one of the features of the invention that regardless of the number of cleaning units employed in a system the housings may all be arranged at the same level so'that the system does not become excessively high.

The lower reduced housing part 13 is divided into a series of vertical passages by short partitions 14 and by a longer partition 15, as best seen in Figure 3. In the system as shown there are two cleaning units separated by a central partition 15 each of which includes a parti tion 14 to form two side by side vertical passages. One side Wall of the lower housing part is provided with an inlet opening 16 for sand beneath the level of the tops of the partitions14 and sand may be supplied thereto through an open top casing 17 secured to the side of the housing which is fed from a hopper 18, as indicated in Figure 1. The opposite end wall of the housing is formed with an outlet opening 19 feeding a discharge trough 21 from which the sand may be conducted away in any desired manner. Sincethe outlet opening is at a relatively high elevation above the floor, gravity discharge may be employed. The central partition 15 is formed with an opening 22 therethrough at substantially the same level as the openings 16 and 19.

The sole control of the flow rate through the system,

according to the present invention, is accomplished by controlling the rate of discharge from the outlet opening 19. For this purpose, the size of the outlet opening is made adjustable by a sliding valve plate 23 which can slide vertically over the opening and can be retained in position by a set screw 24. In this way, the rate of flow of material through the system can easily be regulated so that the material will be retained in the system and recycled the required amount of time to produce effective cleaning.

The vertical passages formed by the

partitions

14 and 15 are continued by means of pipes or conduits 25 which connect to the lower ends of the passages and conduct the sand to spinners, indicated generally at 26. As shown, there is one spinner for each cleaning unit and the two passages on the opposite sides of the partition 14 feed into the same spinner. The spinners, as explained hereinafter, are supplied with air to cause the sand to circulate and sand is discharged from the spinners through central discharge openings. The sand discharged from the spinners is received by pipes 27 which may be ordinary iron or steel pipes leading vertically upward from the spinners to discharge through the bottom sloping wall of the housing 10. These pipes are'in use subjected to a certain amount of 'wear and since the installation, as

shown, they are completely external to the housing and other parts of the system, they can easily be removed and replaced. For example, the lower ends of the pipes may fit over spuds 23 on the top of the spinner, as shown In Figures 6 and 7, and the upper ends may extend through openings in the lower sloping wall 12 of the housing so that the pipes are very. easy to replace without emptying the system of sand. i

As seen in Figures 1 and 3, the pipes 27 are horizontally aligned with the partitions 14 and open above the tops of. the partitions. Above each pipe a deflector 29 is mounted to receive sand and air from the pipe and to deflect the sand downwardly toward the vertical passages. Each deflector 29 is supported on a cross beam 31 in the housing by a single fastening such as a bolt 32 so that the deflector can be turning angularly about a vertical axis to direct the sand primarily toward one or the other of the passages on the opposite sides of the partition 14. This provides a further adjustment of the rate of flow through the system and can be utilized to some extent to control the degree of recycling.

The deflectors 29 are designed to produce a minimum of impact on the sand thereby to eliminate breakage. As best seen in Figures '2 and 4, the deflectors are channel shaped in cross section and are curved from end to end so that sand passing upwardly through the pipes 27 will strike one end of a deflector and will be directed smoothly around the deflector and downward from its opposite end toward the vertical passages. The sand discharged from the deflector will cascade downwardly toward the vertical passages while the air in the sand and air mixture discharged through the pipe 27 will flow upwardly around the deflector carrying with it the undesirable fines. The air and fines may be withdrawn from the housing by a suction connection 33 to the upper part. of the housingat the side thereof opposite to the vertical wall 11. By plac ing the exhaust outlet at a right angle to the vertically moving air in the housing, desirable fines are allowed to fall out of the air stream and be returned to the vertical passages while the air and very light, undesirable fines are carried away.

When desired to remove a greater quantity of fines than would normally be removed in. operation of the system, additional, air may be admitted to the system through an opening 34 positioned in the vertical wall 11 of the housing beneath the deflector 29. By utilizing an exhaust blower having a somewhat greater capacity than the amount of air supplied to the system through the spinners, air can be drawn into the opening 34 to pass through the curtain of sand falling from the deflector and to carry fines therefrom.

The spinners 26, as shown in Figures to 7, comprise vertical cylindrical housings 35 closed at the bottom and open at the top. A separate top closure 36 is provided for each housing detachably secured thereto by bolts 37, or the like, and carrying spuds 28 which support the pipes 27. In addition, each cover carries a conical outlet tube 38 having a cylindrical upper end fitting slidably into the spud 28 with its large end opening downward to receive spinning sand and air from the spinner. The taperedoub let tube tends to increase spinning of the sand as it travels upward and being a separate easily replaceable element tends to minimize wear on the pipe 27.

Further, the conical outlet tube 38 is adjustable vertically to adjust the rate of sand fed through the spinner. For this purpose, the conical tube carries a pair of diametrically extending brackets 39 which are enlarged at their ends to receive hooks on the ends of supporting rods 41. The upper ends of the supporting rods 41 are threaded and pass through openings in the cover 36 to.

receive nuts 42 which can be adjusted to adjust the vertical height of the conical outlet tube easily and quickly.

The lower inner surface of the spinner body is lined by an annular ring 43 formed of a good wearing material such as steel, cast iron, or the like. The ring 43 fits closelyin the slots 45 and rests on the bottom thereof.

Above the ring there is an annular. partition 44v which is;

supported above the bottom of the spinner housing by the ring 43 and whose open center liesbeneath and in register with the lower end of the conical outlet tube 38. The partition 44, as best seen in Figure 5, is formed near its periphery with slots 45 through which sand can flow from the upper part of the spinner body into the space beneath the partition. Sand can also flow through the annular space between the lower end of the conical outlet tube 38 and the partition, this space being adjustable by adjusting the vertical position of the vertical conical outlet tube 38. Sand entering the spinner from the conduits 2S flows through spuds 46 formed on the cover 36 near the outside thereof so that the sand enters the upper part of the spinner housing around the conical outlet tube 33. To cause movement of the sand in the spinner and through the system, air is supplied to the lower part of the spinner beneath the partition 44. For this purpose, air inlet pipes 47 are connected to the spinner body and lie substantially tangent thereto. The ring 43 is formed with openings therein, as shown at 48 in Figure 6, which register with the discharge ends of'the pipes 47 so that air can enter the spinner.

In operation of the spinner with sand being supplied through the inlet spuds 46, the space around the conical discharge tube 38 will be filled with sand and sand will flow through the slots 45 and through the annular space between the conical outlet tube and the partition 44 unitl it reaches its natural angle of repose. At this time, sand flow will stop so that the spinner will not becompletely filled withsand and will not clog. When compressed air is supplied through the pipes 47, the air and saind will be caused to swirl around in the space beneath the partition 44 and within the ring 43 and will passupward through the conical discharge tube 38 into the pipe 27. The sand will be scrubbed as it swirls around in the spinner and the scrubbing action will continue as the sand enters the conical outlet tube 38 and passes through the pipe 27. The major part of the scrubbing occurs at this time although there is additional scrubbing in the deflector, as described hereinafter.

It will be seen that the rate of flow of sand through the spinner can easily be adjusted by adjusting the conical outlet 38 vertically and by adjusting the air supply. The parts principally subject to wear in the spinner, namely the ring 43, partition 43 and conical outlet tube 38, are all simple inexpensive elements which are easy to replace. In fact, by including shut ofl valves in the vertical passages, which can be in the form of simple slide valves; the spinner can be disconnected and repaired without the necessity of emptying all of the sand from the system.

In operation'of the system, as a whole, when the hopper is filled sand will tend to flow through the inlet opening 16 until the adjacent vertical passage is filled to the point Where the sand covers the inlet opening. Due to the fact that the inlet opening is in a vertical wall, no further sand will flow into the system when the opening is covered so that the system cannot clog and so that the sand feed is self-regulating. With the spinners running, sand will flow from the vertical passages into the spinners and will be returned in a sand and air mixture through the pipes 27 into the housing. The sand striking the deflectors 29 will be deflected downwardly toward the vertical'passages, a part of the sand falling on each side of the partition 14. At the final vertical passage adjacent the outlet opening sand will flow through the outlet opening by gravity whenever the sand level in the passage is above the opening, the rate of flow being determinedby the adjusted size of the outlet opening.

In normal operation all of the vertical passages are substantially filled with sand up to approximately the tops of the partitions 14 and the sand will fiow'through to opening: 22 in the center partition 15 from the unit' adjacent the inlet opening to the unit adjacent the outlet opening. In the event the system fills up the sand in the passage to the left of the partition 15 will block the opening 22 so that no further sand can flow therethrough. This will retain sand in the right-hand unit until it accumulates to the point where it blocks the opening 16 at which time no further sand will be admitted. In this way, the system is completely self balancing with each vertical passage holding the proper amount of sand and with no possibility of clogging. It will also be seen that a certain amount of the sand discharged from each pipe 27 goes into the vertical passage nearest the inlet with respect to the pipe 27 and is recycled. Therefore, simply by adjusting the size of the outlet, the retention time in the system and the number of recycles can be adjusted so that the sand can be properly cleaned regardless of its character.

If a larger system is desired for greater flow with long retention time, two or more double units of the type shown may be mounted in side by side relationship with the outlet opening 19 of one unit registering with the inlet opening 16 of the next succeeding unit. In this way, a system of any desired size can easily be built up by connecting several units in cascade relationship. It will be noted that in this type of installation, all of the units are at the same level so that excessive height for an installation is not required. Furthermore, the units are all relatively light so that they do not have an extremely high load weight and can be installed without expensive foundations and expensive supporting framework.

While one embodiment of the invention has been shown and described herein, it will be understood that it is illustrative only and not to be taken as a definition of the scope of the invention, reference being bad for this purpose to the appended claims.

What is claimed is:

1. A sand cleaning system comprising a housing having a sloping bottom at one side, means defining a plurality of side by side vertical passages extending downwardly from the other side of the housing,'spinne'r units connected to the lower ends of said passages to receive sand to be cleaned therefrom, means to supply air to the spinner units to force a mixture of sand and air therefrom, a pipe detachably connected at its lower end to each spinner unit and at its top to the sloping bottom of the housing spaced horizontally from the passages and lying wholly outside of the housing and passages, and means forming inlet and outlet openings for th housing.

2. A sand cleaning system comprising a housing having a sloping bottom at one side, means defining a plurality of side by side vertical passages extending downwardly from the other side of the housing, spinner units connected to the lower ends of said passages to receive sand to be cleaned therefrom, a means to supply air to the spinner units to force a mixture of sand and air therefrom, a pipe connecting each spinner unit to the lower part of the housing spaced horizontally from the passages with its discharge end lying horizontally between adjacent passages, a deflector in the housing above each pipe to deflect sand discharged from the pipe downward toward the passages part into one and the remainder into the other of the passages between which the pipe lies, and means defining sand inlet and outlet openings for the housing opening respectively into the opposite end passages of the series.

3. The system of claim 2 in which the deflector is mounted for angular adjustment about a vertical axis for adjusting the proportions of sand discharged into the respective passages.

4. A sand cleaning system comprising a housing having a sloping bottom at one side, means defining a plurality of side by side vertical passages extending downwardly from the other side of the housing, spinner units connected to the lower ends of said passages to receive sand to be cleaned therefrom, means to supply air to the spinner units to force a mixture of sand and air therefrom, a pipe connecting each spinner unit to the lower part of the housing spaced horizontally from the passages with its discharge end connected to the sloping bottom of'the housing horizontally between adjacent passages, a deflector in the lower part of the housing above each-pipe to deflect sand discharged from the pipe downward toward the passages part into one and the remainder into the other of the passages between which the pipe lies, an exhaust connection to the upper part of the housing above the deflector to withdraw air and'fines therefrom, and sand inlet and outlet opening communicating with the housing opening respectively into the opposite end passages of the series.

5. A sand cleaning system comprising a housing having a sloping bottom at one side, means defining a plurality of side by side vertical passages extending downwardly from the other side of the housing, spinner units connected. to .the lower ends of said passages to receive sand to be cleaned therefrom, means to supply air to the spinner units to force a mixture of sand and air therefrom, a pipe connecting each spinner unit to the lower part of the housing spaced horizontally from the passages with its discharge end connected to the sloping bottom of the housing horizontally between adjacent passages, a deflector in the lower part of the housing above each pipe to deflect sand discharged from the pipe downward toward the passages part into one and the remander into the other of the passages between which the pipe lies, an exhaust connection to the upper part of the housing above the deflector to withdraw air and fines therefrom, an air bleed opening in one side of the housing below the deflector, and sand inlet and outlet openings communicating with the housing opening respectively into the opposite end passages of the series.

6. A sand cleaning system comprising a housing having an enlarged upper portion and a narrow elongated bottom portion joined to the upper portion by at least one sloping wall, partitions spaced longitudinally of the bottom portion at the same horizontal level dividing it into a plurality of relatively narrow passages, spinners beneath the housing, conduits connecting two of said passages to each spinner to supply sand thereto, means to supply air to the spinners to force a mixture of sand and air therefrom, a pipe connected to each spinner to receive sand and air therefrom and discharging through said sloping wall, one of the partitions being horizontally aligned with each pipe, a deflector in the housing above each pipe to deflect sand rising through the pipe downward part into one and the remainder into the other of the passages on opposite sides of said one of the partitions, the walls of the passages on opposite sides of said one partition and opposite thereto being formed with openings below the top of said one partition and inlet and outlet openings for the housing opening respectively into the opposite end passages of the series.

7. A sand cleaning system comprising a housing, means defining pairs of vertically elongated passages extending downward from the lower part of the housing with their upper ends at the same level, a spinner connected to the lower end of each pair of passages to receive sand therefrom, means to supply air to the spinner to force a mixture of sand and air therefrom, a pipe connecting the spinner to the housing to discharge sand and air into the housing, said pipe lying horizontally between the passages of said pair to discharge a portion of the sand into one of the passages of the pair and the remainder of the sand into the other passage of the air, an exhaust connection to the upper part of the housing to exhaust air and fines therefrom, there being an inlet opening for sand into a vertical wall of an outer one of the passages adjacent to the upper end of the passage and an outlet opening for sand through a vertical wall sponsor '7 of the outermost passage at the opposite end of the series adjacent 'to the upper end of the passage.

8. A sand cleaning system comprising a housing, means defining a pair of vertically elongated passages extending downward from the housing, a spinner including a casing having substantially vertical side walls and top and bottom closures, the passages discharging into the upper part of the casing, air nozzles discharging substantially tangentially into the lower part of the =casing to create a swirl of air and sand therein, a discharge conduit extending vertically centrally downward in the casing and opening between the top and bottom thereof, means in the casing to restrict the flow of sand from the upper to the lower part of the casing, and a pipe connecting the discharge conduit to the housing.

9. A sand cleaning system comprising a housing, means defining a pair of vertically elongated passages extending downward from the housing, a spinner includ ing a casing having substantially vertical side walls and top and bottom closures, the passages discharging into the upper part of the casing, a horizontal partition in the casing spaced above the bottom closure and having a central opening therein and at least one opening adjacent the side wall of the casing, an air nozzle discharging substantially tangentially into the casing beneath the partition, a discharge conduit extending, vertically down ward into the casing and terminating adjacent to and in registry with the central opening in the partition, and a pipe connecting the discharge conduit to the housing;

10. In a sand cleaning system, a spinner comprising a casing having vertical side walls and. top and bottom closures, an annular horizontal partition in the casing intermediate the top and bottom closures formed'with an open center and with openings adjacent the side walls for flow of sand therethrough, a connection to supply sand to the casing above the partition, an air nozzle discharging substantially tangentially into the casing beneath the partition, and a discharge conduit extending axially downward into the casing and opening above the open center of the partition.

11. The construction of claim in which the discharge conduit is conical with its large end down.

12. In a sand cleaning system, a spinner comprising a casing having vertical side walls and top and bottom closures, an annular horizontal partition in the casing intermediate the top and bottom closures formed with an open center and with openings adjacent the side walls for flow of sand therethrough, a connection to supply sand to the casing above the partition, an air nozzle discharging substantially tangentially into the casing beneath the partition, the top closure having a vertical central tubular stub thereon, a discharge conduit slidable in the stub and opening above the open center of the partition, and means to adjust the discharge conduit vertically.

. 1.3. .In a sand cleaning system, 'a spinner comprising a vertical cylindrical casing having top and bottom closures, an annularring fitting in the bottom of the casing and terminating below the top, an annular horizontal partition resting on top of the ring and having an open center and openings therethrough adjacent to the inner surface of the ring, an air nozzle discharging substantially tangentially into the ring, and a discharge conduit extending axially downward into the casing and terminating adjacent to and in registry with the open center of the, partition.

14. Sand cleaning apparatus comprising a housing, partitions in the lower part of the housing separating it into a series of side 'by side vertical passages, spinner units connected to the passages to receive sand therefrom, means to supply air to the spinner units to force a mixture of sand and air therefrom, a pipe receiving the mixture of sand and air from each spinner unit and discharging it into the housing above the partitions, each pipe having its discharge end horizontally aligned with one of the partitions, a deflector in the housing opposite to the discharge end of each pipe to receive the mixture therefrom and deflect it downward toward the passages part on one side and the remainder on the other side of the partition, with which the pipe is horizontally aligned, andlmeans defining sand inlet and outlet openings for the housing opening respectively into the opposite end passages of the series.

References Cited in the file of this patent UNITED STATES PATENTS 1,393,092 Davis Oct. 11, 1921 1,700,713 Campion et al J an. 29, 1929 FOREIGN PATENTS 469,068 Great Britain July 19, 1937 1,108,806 France Sept. 14, 1955 OTHER REFERENCES Foundry, July 1953, page 247. Modern Castings, February 1956, vol. 29, No. 2, pages 24-27.