USRE3017E - Improvement in driers - Google Patents

Description

. UNITED STATES PATENT OEEICE.

FRANCIS H. SMITH, OF BALTIMORE, MARYLAND.

l `IMPROVEMENT IN DRIERS.

Specification forming part of Letters Patent No. 562, dated February 26, 1861; Reissue No. 3,017, dated i June 30, 1868.

To all whom't 'may concern.-

Be it known that I, FRANCIS II. SMITH, of

' the city of Baltimore, county of Baltimore, and State of Maryland, have invented a useful Improvement in Drying-Tunnels; and I do hereby declare that the following is a full, clear, and exact description of the same, ref- Aerence being had to the accompanying drawdescribed; Fig. 5, a top plate of furnace;

Fig. 6, vertical section Fig. 7, bottom plate; Fig. 8, plan of bottom box; and Fig. 9, same as Fig. 4, for fruit.

Similar letters of reference in each of the several figures indicate corresponding parts- The nature of my invention consists in a tunnel having a furnace, or its equivalent, at the rear end, and a chimney at the front end, in' combination with gates cars, trays, and rails, constructed substantially as and for the purposes hereinafter described. The rails may either be arranged on aleve'l plane or slightly inclined.

"My invention also consists yin arranging at one end 'of the tunnel an improved style of furnace.

Furnaces constructed with straight air-chambers are found by experience to be more or less objectionable, from the fact that the current of fresh air which is constantly being introduced rushesthrough the chamber and is discharged into the tunnel without being properly heated.

By my arrangement of air-chamber this difficulty is entirely obviated, andvr at the same time the free entrance and exit of the air are in no manner interfered with. I wind spirally around the furnace-column a metal sheet sufficiently wide to iill the entire chamber. This causes the air, when it enters the chamber, vto

trayerse, as it'were, through a spiral flue, by which means 1t is brought in contact with a much greater extent of heating-surface, and,

' Dowing to the form of the iue, the air is sufficiently retarded in its circutous passage to in,v

' sureO of its being thoroughly heated.

. The whole apparatus is intended for drying brick, fruit, &c., by means of cars loaded with trays, upon which the articles to be dried-are pilled, the cars traveling through a heated tunne The apparatus is so arranged that the drying-tunnel and loading of the cars can go on uninterruptedly for any length of time.

To enable others skilled to make and use my invention, I will proceed to describe its construction and operation.

A B C represent a tunnel of considerabla length-say, one hundred feetmade of brickwork, or yother suitable material. The rear and front end of the tunnel are provided with gates H and F, which can be closed or opened, as may be necessary in the course of the operation.' Y

The front portion A of the tunnel may be cut off from the main part of the tunnel by `means of a gate, G, which is represented halfopen in Fig. 1. The section A-communicates with a chimney,L, while the rear end C of the tunnel communicates through an opening, D, with a furnace, R, provided with a suitable grate, O.

A railway is composed vof rails E E, and is laid on the fioor of the tunnel. The plane on which the rails are laid may be level, or, if preferred, slightly inclined from the front toward the rear of the tunnel.

A number of cars, enough to fill the whole length of the tunnel, are provided and are to be loaded, one after the other, with trays I,

upon which the articles to be dried are placed.

The said trays are constructed as clearly shown in Fig. 4, having each four legs, 13, fitting in cavities i in the upper corners of the tray below. l

This 'construction is needful in order tofenable the trays to stand securely in four separate stacks, as represented at I I, Fig. 1, with a space between ,their edges to facilitate handling.

' When the tunnel is used for the purpose of drying fruits and vegetables, the style of tray used is shown in Fig. 9. ,Instead of the fiat table-top a ledge, i t', is attached, which, for

fruits, should be about two inches in height,

and for vegetables, such as sweet potatoes, about four inches high. The first ear having been freighted in this manner while in se@ ,tionfA of the tunnel, the gate F is shut and gate G isy opened,.as seen in Fig. 1, and the car is pushed into the main part B of the tunnel, so that the gate Gr can be shut behind it. The gate F is then opened, the next car is entered into section A, and, after having been freighted in the same manner as the preceding car, the gate G is again opened and the car is moved forward into section B, pushingthe iirst car forward. The gate G is then again shut, gate F is opened, and the third car is 'entered and freighted, and so forth, each car pushing forward the preceding seriesof cars as it enters the main part B of the tunnel until the car which had been entered first arrives at the end C of the tunnel. The gate H is then opened as often as a car is entered,

in order to allow the last car of the series to pass out of the tunnel. The heated gases arising from the combustion of fuel infurnace R enter through opening D and pass` through Y the whole length of the tunnel, and finally out at the chimney L.

From this it will be seen that the substances to be dried enter the tunnel at the end where the temperature is lowest, and are gradually subjected to an increasing heat as they ap preach the other end of the tunnel, where they finally come in' contact with the .intense heat arising directly from the furnace.

It is intended that about twenty-four hours shall elapse from the entrance to the exit of each particular car, thereby giving ample time for drying thearticles with which the cars are freighted thoroughly while they pass through the entire length o f the tunnel.

The rails E E .may be level or slightly inclined, as shown in Fig. 1, sokthat the whole series of cars can be pushed along easily by the operator or operators attending the rear car.

The draft caused from the furnace B through the whole length of tunnel toward and out of the chimney L serves to carry the moisture of the drying articles away as fast as it is liberated; by, which means the drying process is considerably facilitated.

Figs. 3 and 6 represent, at Q,R, D', S', P, N, M,.and K, a modification or substitute for the furnace R to suit the apparatus for drying fruit, vegetables, and'similar articles'. For thispurpose 'the opening D, connecting the tunnel with the furnace R, is closed by means of a'suitable valve 'or damper, S, and the valve or damper S is opened, so as to effect a communication between the real wirt lie tunnel and a hot-air chamber, R', through open- 'lhe air in this chamber is heated by means of a suitable hot-air furnace, which cont `sists of a drum, k, spiral hot-air passage N,

ing D.

central fire-place m, and smoke-stack Q. The hot-air passes from the drum through P into chamber R', and thence through opening D into the tunnel, obeying the draft created by the chimney-L at the front end, and thereby drying the articles upon the shelves and cars passing through the tunnel in the same manner as already set forth.

Figs. 5, 7 and 8 show 'modified forms of the furnace and air-chamber. The fresh air enters through openings c of plate V, and is discharged through openings 'v' of plate V. The' whole furnace is supported on brick-work W.

vl t will be understood that this apparatus in its original or in its modified form will answer for drying various articles, such as, for instance, bricks, tile, pottery, cores for castings, and other manufactures of clay and sand, grain, fruit, vegetables, lumber, glue, starch, Whiting, sugar, bagasse, guano, leather, hides, fish, meat, saltpeter, alum, and other chemicals.

Having thus fully described my invention, what I claim therein as new, and desire to secure by Letters Patent, is-

1. The tunnel A B C, furnace It, and chimney L, when the former is so constructed and l arranged that the current of warm air is supplied to the same at the opposite point from which the articles to be dried enter, which causes the article to be subjected to the action of a varying temperature, substantially as described, and for the purpose specified.

2. The tunnel A B G, furnace R, and chimney L, and gates F, G, and H, when the same are so combined and arranged as to operate substantially as described, and for the purpose 3. The tunnel A B C, furnace R, chimney j L, and gates F G H, when' the same is in com-- bination with the rails E E and car J, and the whole operates substantially as and for the purpose specified.

In testimony whereof I have signed myname to this specification before two subscribing witnesses.-

FRSQH. sMrrH.

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