US2048431A - Oven equipment - Google Patents

Description

July 21 z 1936. w Aj DARRAH 2,048,431

\ ovEN EQUIPMENT Filed No"v. 11, 193s r11/en zfor Patentedv July 21, 1936 UNITED STA-TES ATNT OFFICE 3 Claims.

This invention relates to ovens, furnaces, dryers and similar equipment in which it is desired to maintain a set of conditions in a closed chamber and to keep said chamber from having a full Contact vwith the surrounding. atmosphere. Some of the objects of my invention are to provide a structure which maybe readily loaded or unloaded while maintaining the interior of the structure substantially closed from contact with the surrounding atmosphere.

Further objects of my invention are to provide means for economizing fuel in those cases in which the structure is heated. Other objects of my invention are to provide more endurable conditions for workmen operating the equipment and to prevent the loss of vapor or gases from the interior of my structure. Further objects of my invention provide control of heat distribution within the structure.

Other objects of my invention will be apparent from the drawing, description and claims attached hereto,

In the accompanying drawing:-

Figure l shows a front elevation partly broken away of one form of my device, while Figure 2 shows a side elevation also partly broken away of the same device.

indicates a housing or structure which may be formed of brick, tile or if desired of steel and insulated in order to retain the difference of temperature between the inside and outside of my equipment. The structure is provided with a roof 2 which for ease of construction I have shown arched and two re boxes or combustion chambers 3 and 4. The fire boxes are provided with a burner member 5 which may be adaptable for oil, gas, powdered coal, etc. and cooperates with a combustion block 6. Combustion takes place within the interior of lining 'I which is formed from refractory materials and which is spaced away from the bottom walls 8 of oven member I by an air space 9, allowing circulation of the atmosphere within the oven substantially entirely around combustion lining 1. A flue member I conducts the products of combustion from lining I toward the rear portion of housing I and discharges them through an outlet II into the interior of the oven which is. indicated by I Il.` The structure is provided with an opening I3 which may be used for loading or unloading, etc. A hood I4 is placed adjacent to opening I3 and connects to a stack or exhaust duct I5 at its upper portion. An exhaust duct I6 in the oven structure I provides means by which the products of combustion canleave the structure to make room for the additional new products of combustion. t

Flue or duct I6 is provided with a damper I1 which serves to control the rate of travel of gases through duct I6. I have shown duct I6 connecting into stack member I5, but it will be understood that this is a matter of convenience as the exact arrangement of duct I6 is a matter which may be varied to a considerable extent.

Structure I is provided with a conveyor device I8 which serves to move the material being treated through enclosure I2. For purposes of conveniencev I have shown conveyor member I8 as consisting of a reel in which a. central shaft I 9 carried in bearings 20 and 2| serves to support the moving structure. It should be understood that I do not wish to confine my invention to the particular type of conveyor shown as obviously chain or apron conveyors, and many other types, may be used interchangeably without departing from the principles which I am here disclosing. Shaft I9 is provided with a sprocket 22 which is driven by chain 23 from a motorV 24 or other desired source of power.

Shaft I 9 is provided with a series of arms as 20y illustrated by 25, the arms being supported by a hub member 2E. The arm members such as 25 are grouped in pairs as illustrated in Figure 1 by 25 and 25A. A tray or plate 21 is suspended from the arms by means of a link member 28 which pivots on member 23, so that the tray 21 always remains in a substantially horizontal po-g sition, independently of the position of the arms. It will be understood therefore that as the arms rotate in the direction shown by the arrow in Figure 2, the trays or plates 2'I are loaded, as they come opposite opening I3 and then travel downward around shaft I9 describing an irregular figure which approximates an ellipse. As the trays complete the revolution and return to opening I3 they are in turn unloaded and a new load of raw material placed on them. This type of equipment may obviously be used, for baking, drying, etc. of various materials such as chemicals, blocks, food stuffs, crackers, bread, etc. 1

In order to prevent a rapid circulation of the atmosphere within the oven upward and outward through opening I3, various means are provided. A battle member 30 extends from a point near opening I3 downward toa point beneath the conveyor mechanism I 8 and serves to make the travel of products of combustion out of opening I3 diicult. Inner bale member 3| is mounted upon shaft I9 in such a manner as to remain substantially stationary while the shaft I5 and conveyor mechanism I8 revolves. Baille 3| may be supported in a great variety of ways to accomplish this result but for convenience I have shown baiile 3| carried on a frame indicated by 32 which is supported from saddles or bearings 33 and 34, which rest on shaft I9. I prefer to form the outer contour of ballie 3| in such a shape that it presents at all times a certain minimum 4clearance between the nearest point of tray members 21 and the outer wall of baile 3l. It will be apparent therefore that under these conditions, the combination of the tray member vZI, the baie 3i and the walls of the structure I form a rough sealing arrangement such that products of combustion can only with dlfculty pass outward through opening I3.

It will be apparent that baflle member 3l also contributes greatly to the sealing eiect in the lower portion of the structure I.

In order to still further reduce the volume of gases which can pass through openings I3, I provide a series of pivoted sealing members as indicated by 33A, 34A, 35 and 36. In one practical form, these devices consist of long strips of sheetV metal extending substantially from end to end of chamber I. These devices may be pivotedrasy for example at 3!` and provided with a counter-weight as'38, which is arranged to keep the sealing members pressed into contact with the tray members. It will be apparent that the sizehand arrangement of weight members 38 is chosen such as toprovide a firm, but yielding pressure. Obviously inplace of the weights 38, I may employ a spring or I may use the weight of the sealing member itself to accomplish the desired result. On examining Figure 2, it will be noted that the space within the structure I which communicates with opening I3 is closely sealed on all sides, so that for practical purposes it may be stated that there'is no flow of gases either inward or outward through opening I3.

In this connection it may be pointed out that it is in many cases as desirable to prevent the inward flow of cold air from a room into the oven structure, as it isrto prevent the outward ow of hot products of combustion. Either condition represents a waste of heat and is likely to cause other difficulties. For example, an inward flow of cold air will chill the products being baked and may radically disturb the humidity content of the gases in the oven. In the same manner an outward leakage. of hot gases from within the oven through opening I3 may cause a considerable loss of heat and may make the working conditions about the oven so difficult that loading and unloading becomes slow, Vexpensive and uncertain.

In the case illustrated by the drawing, a floor orplatform 39 is shown at a convenient elevation for the workmen to stand when operating the oven.

From a thermal standpoint, it will be apparent that the heat is produced in the lower forward corner of the structure and a considerable portion radiated upward to the lower front half 'of conveyor member IB. The bulk of the productsof combustion, however, travelrthrough flue II toward the rear portion of structure I then upward over the top and leave by the duct VI6 in the forward portion of the oven. It will be apparent thereforethat the ilow of heat is around substantially the entire circumference of the oven, the heat being removed at a point a considerable distance away from its point of generation. This results in a good distribution of heat and a relatively high thermal efficiency.

I have found that ovens without the features of my invention consume a much greater amount of fuel and give less satisfactory heating conditions. -It is also arwell known fact that ovens of this type are very difficult to operate particularly during warm seasons, owing to the large out flow of heat through the charging opening.

My invention therefore results among other things, in obtaining a materially improved heat economy, a superior heat application and distribution, better working conditions, control of humidity conditions, etc.

It will be understood that many changes in size, shape and arrangement of the mechanical parts of my equipment may be made without departing from the spirit of my invention.

It will be understood that the combustion chamber may be arranged so that the desired amount of radiant heat can be liberated from the surface of said combustion chamber to the exposed portion of the work carrying devices while the products of combustion travel along the flue leading from said combustion chamber and are exhausted into the oven at a Ypoint a considerable distance away from said combustion chamber, the point of exhaust being subject to control by means of damper il which may be moved over a series of openings indicated by i0 in said flue Il. The position of damper II may be controlled by rod 42, which serves to slide damper 4I backward and forward as desired. In a similar manner a shield 43 I and arranged to be rotated by means of rod 44 so as to control the amount of radiant heat leaving the surface of combustion chamber 1 and passing to the material being baked.

This arrangement it will be noted gives control both of the distribution and relative quantity of radiant heat and convected heat from combustion chamber I in different portions of the oven.

It should be understood, that by the term oven, I intend to include such structures as dryers, evaporation furnaces, baking and conditioning equipment which come within the scope of my drawing, specification and claims.

Having now fully described my invention, what I claim as new and wish to secure by Letters Patent in the United States, is as follows:

l. An oven consisting of a housing, a reel member mounted therein, a series of work supports pivotally carried by said reel member, a combustion chamber located below said rotating member and provided with and connected to a ue provided with ports for controlling the heat flow therefrom, a system of bales including a normally stationary centrally located one for directing the travel of hot gases in connection with said rotating member, a working opening and movable sealing members cooperating with said baffles and said work supporting members to prevent passage of gases through said working opening, and means for controlling the distrition of radiant heat to said work supports.

2. In a reel type oven, a housing, a working opening through said housing, a baille system' within said housing, work carrying means arranged to travel through acircular path within said housing and between said baille means, and sealing members adapted to ilexibly maintain Contact between said work supporting members and baffles thereby preventing leakage through said working openings.

3. In an oven, a housing, a working opening therethrough, movable work supports therein, bales directing the flow of heat around said work supports and sealing means arranged to flexibly Contact said work supports and baiiies `to prevent leakage through said work opening.

W. A. DARRAIK-I.

is provided above combustion chamber 2

Images