US2188798A

US2188798A - Apparatus for conditioning sand and like materials

Info

Publication number: US2188798A
Application number: US159141A
Authority: US
Inventors: Benjamin A Smith
Original assignee: Co Bartlett & Snow Co
Current assignee: C O Bartlett & Snow Co; Co Bartlett & Snow Co
Priority date: 1937-08-14
Filing date: 1937-08-14
Publication date: 1940-01-30
Anticipated expiration: 1957-01-30

Description

B. A. SMITH Jan. 30, 1940.

APPARATUS FOR CONDITIONING SAND AND LIKE MATERIALS Filed Aug. 14, 1937 INVENTOR. Zfi/i dM/k dfmZf/f BY c9 wi 09 Patented Jan. 30, 1940 UNITED STATES APPARATUS Be A; Smith,

The C. 0. Bartlett 8; Snow Company, Ohio, a corporation of Ohio FOR CONDITIONING SAND LIKE MATERIALS Lakewood, Ohio, assignor. to

Cleveland,

Application August 14, 1937, Serial N 158,141

, 1 Claim. This invention relates as indicated to an improved apparatus for treating and reconditioning materials such as foundry sand and the like.

After foundry sandis shaken out of the molds U at the conclusion of the casting operatio the same mustbe cooled,-aerated, mixed and generally reconditioned before it can be re-used.

It isthe principal object of my invention to provide an apparatus for attaining the above mentioned desirable ends by an improved apparatus characterized in that the process may be carried on continuously, the reconditioning operation carried forth in a relatively small floor area and by virtue of the new principles of my apparatus at a reduced cost as compared with prior,

art processes,

Other objects of my invention will appear as the description proceeds. To the accomplishment of the foregoing and 10 related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claim; the annexed drawing and the following description setting forth in detail certain means and one mode illus- 25 trating, however, but one of the various ways in which the principle of the invention may be used.

In said annexed drawing: Fig. 1 is a side elevational view of an apparatus constructed in accordance with the principles of U my, invention and capable of carrying out';the process of my invention; Fig. 2 is a transverse sectional view of a portion of the apparatus illustrated in Fig. 1 taken on a plane substantially indicated by the line 2-4; Fig. 3 is a transverse a. sectional view of the apparatus illustrated in Fig. 1 taken onv a plane substantially indicated by the line 3-4; and Fig. 4 is a longitudinal sectional view through the rotating shell portion of the apparatus illustrated in Fig. 1.

Broadly stated. my invention comprises the process for reconditioning foundry sand and the like characterized by the fact that the sand to be reconditioned is carried in a continuous stream througha treating chamber such as a horizontal- I ly inclined rotatable cylindrical shell in which the sand is thoroughly mixed and aerated by being subjected to the flow of a stream of air axially through said rotatable chamber and more particularly by the fact that the sand, substan- 50 tially immediately after its introduction intothe treating chamber, is sprayed with water, the quantity of which is the temperature of the treating air stream as it leaves the treating chamber. My invention, furl. tnermore, contemplates the provision of imparatus comprising my automatically regulated by (CL 2H9) proved apparatus for the purpose ofperiorming the above described process.

} and more especially to Fig.

in illustrated as one horizontally 1, the apparatus heremodification of the apinvention consists of a inclined cylindrical shell -I which,

at axially spaced points, is on its outer periphery provided with supporting

rings

2 and 3 which rest on paired supporting rollers 4 and 5 respectively,

said rollers being rotatably supported by suitable supporting bases 6 and the outer periphery of the pinion 9, the latter being able gear reduction unit ID by means of a mover such as electric motor I I.

Positioned adjacent the upper around the opposite end of the shell I5, which, by means 0 1. Likewise mounted on shell I is an annular spur gear 8 which is immeshed with a driving driven through a suitprime or charging end of the shell I is a loading platform generally indiplatform supports a which which is end infiltration of outside air. I5 is provided with a discharge from which the treated sand is discart to be conveyed back to the molding station. During normal operation of the apparatus comprising my invention,

it will be found desirable to maintain a sufllcient quantity of the treated sand in the discharge chute I! at all times so as to prevent infiltration of cold air at this into the treating chamber. Connected with the header or' I5 is an air conduit therewith a fan or blower for example. by a motor 20. provided for the purpose. of controlling th of air flow through the conduit I8, if and desired.

I Projecting into the open forward or end of the shell I is a water pipe 22, the

'point I collecting ring I8 which has associated l9 adapted to be driven, A damper 2| may be e rate when upper inner end of which. as most clearly illustrated in Fig. 4.

is provided with a spaced spray nozzles plurality of longitudinally 23. The spray nozzles 23 will be so constructed and arranged that they 50 are capable of delivering a spray of treating to the hot untreated sand in ing end of the shell I. The water supply p water the feeding or chargipe 22 will be conveniently provided with a pressure reducing valve generally indicated at 23'. Pr

essure reducing valves of this character are so well known to those familiar with the art that a detailed description of its construction and operation is believed unnecessary. Suiiice it to say that the valve 23' is employed for the purpose of adjustably controlling the pressure in the waterpipe 22 to the left of such valve irrespective of the pressure in the water supply pipe.

The water pipe 22 is further provided with a control valve 2d for the purpose of controlling the rate of fiow of water through the pipe 22. The control valve illustrated is a conventional type available in the trade and being concurrently marketed by the Foxboro Instrument Co. This valve 24 is adapted to be actuated and controlled:-

by fluidssuch as air under pressure led thereto by conduit 25. The air for the conduit 25 may be supplied from any suitable source through the conduit 26 and its rate of flow and consequently the pressure in the conduit 28 is controlled by a regulator 27, likewise of conventional construction and generally available on the open market for purposes of this character. The regulator 27!, which is merely diagrammatically illustrated, is likewise available to the trade generally by the Foxboro Instrument 00., so that the description of my invention need not be burdened by a detailed description of the construction and operation of such regulator.

to Mounted in the conduit i 8 so as to be responsive to fluctuations in the temperature of the discharged air stream is a thermosensitive element 28. This element 28 is connected to the regulator 21 by suitable lead 29 so that as the temperature of the discharged air stream varies, the regulator 21 will correspondingly vary the pressure in the conduit 25 and accordingly, the rate of flow of water through the valve 2 into the line 22.

The interior of the cylindrical treater chamber I is more clearly illustrated in Figs. 2, 3 and 4 and from an inspection of these last-named figures, it will be observed that in the feeding end of the cylindrical shell I there are provided helically arranged conveyor flights 30 which carry I the material into the spraying zone generally indicated at 3|; The spraying zone 2| will preferably be provided with a plurality of circumferentially spaced radially inwardly extending flights '32. the form and arrangement of which will be most clearly apparent from an inspection of Fig. 3.

As the shell I rotates, the flights 22 mix the material as it is being sprayed by the nozzles 22. The horizontal inclination of the axisof the cylindrical member I causes the sand to move forwardly and downwardly therein as the same is being rotated. The flights, throughout the remaining axial extent of the cylindrical member I, will preferably be arranged in banks generally indicated at 33, 3| and 36. These diifer from each other primarily in their deflection from the true radial direction to which the flights 32 extend.

terial will become progressively less. Accordingly, the banks of

flights

33, 34 and II will be progressively inclined to a greater degree so that as -'the material passes through the treater shell, a substantial portion thereof will be at all times showered downwardly-"ii the lift flights across the cross-sectional ar .calchamberL, l In the operation of thee-above appaw.

nne summ carrying out the improved process of my inven tion, it will be observed that the hot sand just previously discharged from the molding flasks is first sprayed with water. The actual heat transfer between the hot sand and the cold water will result in a partial cooling of the sand. The amount of water introduced, however, will not be suflicient to completely cool the sand down to the desired temperature. This remaining reduction in temperature is effected as a result of actual heat transfer between the stream of treating air drawn through the treating chamber by the blower is and by an evaporation from the sand of thewater' initially sprayed thereon.

In order to insure that a properbalance will bemaintained at all times between the flow of send, its temperature, the-rate of flow of air, its temperature, and the amount of water introduced to the sand, so that the finally treated sand discharged from the apparatus will have the proper moisture content and be of the proper temperature, the thermostatic regulator 28 in the stream of discharging air is employed for the purpose of regulating the rate of feed of the treating water. By thus regulating the rate at which the cold treating water is fed onto the send, by means functionally responsive to the temperature of the stream of out-going air, I have found that apparatus constructed in accordance with my invention and capable of carrying out the process of my invention may be operated continuously and automatically and with little. if

any actualpersonal attention of the operator or stream proportionally amounts of undesirable finds contained in the sand may be removed from the cool dried sand as it is cascaded across the area confined by the shell I adjacent the discharge end thereof. When the direction of flow of the air is the same as the direction of flow of the sand there is, however, a practical lower limit to which the temperatureof the sand being reconditioned may be reduced. If it should be desired to further reduce the temperature of the reconditioned sand, it is within the contemplation of my invention to carry the treating air through the treating zone in a direction counter to the direction of flow of the sand. This may be conveniently accomplished in' the apparatus illustrated by merely moving the header II and its as-' sociated conduit I 8, blower l9 etc. including the thermosensitive element 2| from the left end to the righthand end of the machine. The lefthand end of the shell I would then be open to the atmosphere to draw in cooled air at room temperature and the heated air would be withdrawn by means of a blower from thegrlghthand end of the treater chamber. It is believed unnecessary to specifically illustrate this modification since from' the. foregoing description and disclosure, those skilled in the art should be able to provide the suggested'changaz 1 Il'rom the foregoing description it will be ob-' served that I have provided an improved process and apparatus for the economical reconditioning of materials such as foundry sand and'such apparatus and process is particularly advantageous for usein that it may be operated-continually areeyree and in that it occupies only a relatively all floor space area as compared to the total ot of sand which it is capable of reconditioning in a given period of time.

Other modes of applying the principle of my invention may be employed instead oi the one explained, change being made as re the means'and the steps hereindiscloeed, provided those stated by the following claim or its equiv m alent be employed.

I, therefore, particularly point out at distinct 1y claim as my invention:

In apparatus for recondltio ffiis'gi? sand.

the combination of a horizontally-inclined cylindrical shell provided on its inner periphery with lifting flights, means for rotating such shell, means for feeding a continuous stream of foundry sand to the feeding end of said shell, means for effecting a flow of air longitudinally through said shell, means for spraying water onto the sand in the feeding end of said shell, and; means functionally responsive to variations in the temperature of the air stream discharged from said shell for varying the quantity of water thus sprayed onto the sand.