US2804696A - Mold drying system - Google Patents

Description

sept. 3, 1957 J. M. BYVL MoLD DRYING SYSTEM 2 Sheets-Sheet l Filed April l, 1954 w L M 15 i, A rr. M. A W w w Sept. 3, 1957 J. M. BEYVL 2,30496 MOLD DRYING SYSTEM Filed April l, 1954 2 Sheets-Sheet 2 United States Patent O MOLD DRYING SYSTEM Joseph leyvl, Cleveland Heights, Ohio, assignor .to The Foundry Equipment Company, Cleveland, Ohio, a vcorporation of Ohio Application April 1, 1954, Serial No. 420,273 z claims. (cl. 34-104) This invention relates as indicated to a mold drying system, and more particularly to such a system particularly designed for the drying of molds for large ingot molds and the like.

Molds for ingot molds are open both at the top and bottom and many are of very large size. Means employed for the drying of such molds have been of several different types involving the circulation of heated drying air therethrough, perforated cover platessometimes being placed over the upper ends of the molds to permit the escape of a portion ofV the heated air introduced into the mold at its lower end and lkewise largely withdrawn at the lower end. Since it is usually desired to dry a number of such molds simultaneously with theheated air being withdrawn from the same circulating system, a certain amount of difliculty is encountered when regulating and controlling the amount of air escapingfrom the individual molds through' the perforated cover plates so that each mold will be substantially uniformly dried in the same period of time regardless Vof its -relative position in the circulating system.

It is also important that the interior of each individual mold be substantially uniformly dried, and some dithculty has been encountered in introducing the heated air therein in a manner to obtain the necessary turbulence and circulating flow to achieve this result.

For eificient operation in the foundry, it is highly desirable that control devices be centralized to the extent possible so that a single operator may be responsible for the control and operation of the entire mold drying system.

It is accordingly a principal object of this invention to provide a novel mold drying system particularly adapted to the drying of molds yfor large ingot molds and the like wherein the discharge of a portion vof the air return is adapted to be controlled in a manner ensuring uniform treatment of each ingot mold in the system.

Another object is to provide a mold drying system adapted to ensure uniformly effective circulation of the drying air through the individual molds.

A still further object is to provide such mold drying system which will be rapid in operation, will facilitate placement and removal of the individual molds to be dried, and will be economical in operation.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the prnciple of the invention may be employed.

In said annexed drawing:

Fig. 1 is a top plan view of an arrangement embodying my new mold drying system;

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Fig. 2 is a side elevational view partly in section taken on-the line 2-2 on Fig. 1 and Fig. 3 is a transverse section taken on the line 3-3 on Fig. l.

Referring now more particularly to such drawing, the system there illustrated comprises two heating plants l and 2 'adapted to deliver heated drying air to two series of mold drying benches 3 and 4 respectively. In plant 1 (plant 2 being substantially identical) a gas or oil fired burner Spheats air drawn in through inlet 6 and delivers` the same together with the gaseous products of combustion to the supply fan 7 operative to force such heated gases into main heat supply duct 8 extending downwardly into the pit 9 and along the bottom of the latter in the form of horizontal extension 10. A plurality of upstandng vents or nozzles 11 project upwardly through slabs or covers 12 enclosing the pit and providing a support for the. hollow ingot molds adapted to be rested thereon with such nozzles projecting upwardly therewithin. V i A pair ofl openings vsuch as 13 is provided adjacent each suchV nozzle 11 within an area lkewise adapted to be enclosed within the confines of a superimposed ingot mold. The space 14 between duct 10 and the pit or trench covers 12 serves as a return duct for heated gases which have entered ingot molds from nozzles 11 and have then passed downwardly through openings 13. Recirculating duct 15 communicatestwith the end of such space 14 and extendsupwardl'y to the top of burner 5 so that it will be seen :that a complete recirculating system has been provided.

i Just' before recirculating duct 15 joins heater 5, a small lateralduct 16 is connected there'to for the withdrawal of a controlled amount of the partlycooled and moisture saturatedair by means of exhaust fan 1-7. Such latter fan delivers .the gases thus withdrawn to stack 18 for discharge to the atmosphere. The proportion of the gases thus withdrawn (ordinarily quite small) may, of course, be regulated by appropriate damper means and rate of operation of fan 17. The 'amount thus withdrawn and discharged to the atmosphere will, of course, be compensated for by fresh air drawn in at inlet 6 and also the continuously produced gases of combustion.

The No. 2 plant is of the same general construction and is adapted to deliver heated gases through main heat supply duct 19 to nozzles 20 and to return the same through recirculating duct 21.

Now referring more particularly to Fig. 3 of the drawing, I there show a large mold 22 resting on the cover 12 of the pitof bench 3 and enclosnig an upstanding nozzle 11 and the two adjacent orifices 13. An imperforate cover plate 23 is placed over the top of the mold 22 so that heated gases entering through nozzle 11 are directed thereagainst and deflected downwardly along the mold lining to the bottom of the latter where they escape through openings 13 into the space 14 above duct 10 and are then withdrawn into recirculating duct 15. It will thus be seen that no consequental portion of the heated gases escapes to the atmosphere from the molds and that the escape or release of a portion of the recirculated gases is Controlled directly by means of exhaust fan 17. As a result of this arrangement, the molds form parts of what is in effect a closed system, and no heated gases which are still at a relatively high temperature and unsaturated are released to the atmosphere as in the past when they have been permtted to escape from the tops of the molds with such tops left open or only parti-ally closed by means of a perforate cover plate. Apart from being more economical in operation and ensuring that all of the molds of each system are substantially unifonnly dried, there is a further advantage in that objectionable gases and fumes are not released at a working level where they may be obnoxious and injurious, but

only from stack 18. A single operator may control each plant and the molds -are adapted to be conveniently raised and placedin position by means of an 'overhead crane. The nozzles 11 or 20 desirably projectupwardly within the molds approximately; at least one-third the height of the latter and the heated gases are .forced through the system under suflicient pressure and Velocity to cause the same when exiting from the respective nozzles to`impinge against the cover plates 23 to achieve the desired turbulence with reflected downward flow along the inner sides of the molds to the withdrawal openings 13.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following clams or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention: i

l. In a mold drying system comprisingra heater, a duct leading from such heater and extending longitudinally along the bottom of a trench, a blower associated with said heater adapted to blow heated g-ases'therefrom through said duct, a plurality of nozzles extending Vertically from said duct and protruding upwardly through said cover, said cover having apertures therein closely adjacent each said nozzle, a recirculating duct leading from said trench back to said heater; a diversion duct leading from said recirculating duct, a Stack, an exhaust fan arranged and disposed to withd'r'aw a portion of the gases returning through .said recirculating duct into said diversion duct and to discharge the same to said Stack, molds having open tops and bottoms resting on said trench cover, each enclosing one of said upwardly protruding nozzles and associated apertures with such nozzles extending upwardly therein at least about one-third the Vertical extent of said molds, and imperforate covers on said molds whereby said molds become parts of a wholly enclosed gas circulating system with heated gases discharged from said nozzles being directed against said imperforate covers on said molds and then flowing down- Wardly with turbulence against the sides of the molds to the apertures in the trench cover for return to said recirculating duct.

2. In a mold drying system comprising a heater, a duet leading from such heater and extending longitudinally along the bottom of a trench, a blower associated with said heater adapted to blow heated gases therefrom through said duct, a plurality of nozzles extending vertically from said duct and protruding upwardly through said cover, said cover having apertures therein closely adjacent each said nozzle, a recirculating duct leading from said trench back to said heater; a diversion duct,

leading from said recirculating duct, a Stack, an exhaust fan arranged and disposed to withdraw a portion of the gases returning through said recirculating duct into said diversion duct and to discharge the same to said stack, molds having open tops and bottoms testing on said trench cover, each enclosing one of said upwardly protruding nozzles and associated apertures, the thus enclosed nozzles projecting appreciably into the molds, and imperforate covers on said molds whereby said molds become parts of a wholly enclosed gas circulating system wherein substantially all the gases discharged from said nozzles are withdrawn from said molds through said apertures in the trench cover.

References Cited in the file of this patent UNITED STATES PATENTS 1,525,131 Hitchcock Feb. 3,'1925 2,453,400 Barnett et al. Nov. 9, 1948 2,509,396 Mayer May 30, 1950 2,653,392 Von Hofen et al Sept. 29, 1953

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