US2495126A - Oven - Google Patents

Description

J 17, 1959 Q, o, QAKS 2,495,126

OVEN

Filed Sept. 26, 1947 INVENTOR. ORION 0. (Jam Patented Jan. 17, 1950 UNITED STATES PATENT OF Fl CE I Q I 2,495,126

OVEN Orion Ottis Oaks, Summit, N. J., assignor, by mesne assignments, to Thermal Liquids, Inc.,

New York, N. Y., a corporation of Delaware Application September 26, 1947, Seria'lNo. 776,321

This invention relates to ovens and more particularly to ovens suitable for cooking, drying, baking and finishing of ceramics and other materials and foods. More particularly still this invention relates to such ovens in which heat is supplied thereto through the use of a particular classof chemical compounds as the heat transfer medium.

These chemical compounds have been described in the Johnston Patent #2,335,012 dated November 23, 1943, and are the tetra-aryl ortho silicates. These silicates remain fluid at approximately 70 F. and boil in the neighborhood of 725 F. Because of this wide temperature range these compounds are ideal heat transfer media. Since they do not boil at high temperatures no provision need be made in equipment using them as heat transfer media to resist high pressures, and lighter and more economical devices may therefore be used.

Because of these characteristics of the tetraaryl ortho silicates I have been able to devise a novel oven using them as the heat transfer media which gives greatly increased efficiency of operation with greatly'improved temperature control while utilizing the simplest and most economical construction.

It is accordingly an object of the present invention to provide a novel oven using a particular class of chemical compounds as the heat transfer media.

Another object is to provide such an oven using the tetra-aryl ortho silicates as the heat transfer media.

Another object is to provide such an oven which will be of simple and inexpensive construction.

Other and further objects will appear in the following description.

The oven of my invention may have many mechanical forms both stationary and mobile and may be of any desirable size and comprise one or more heating zones of the same temperature or of varying temperatures. I have shown one embodiment of my invention in the accompanying drawing but this embodiment is not to be construed as defining or limiting my invention and reference should be had to the appended claim for this purpose. I

In this embodiment the oven is provided with any suitable casing l0, insulated or not as desired, and, as here shown, is seen to comprise three heating zones ll, [2 and I3 defined by partitions l4 and i5. Casing II) is provided with an entrance door 16 and an exit I! and partitions l4 1 Claim. (Cl. 263-8) and 15 are provided with registering openings at 8 and i9 respectively. Mounted in casing l0 and adjacent doors l6 and I! are rollers 20 and 21 supporting any suitable belt 22 which providesa movable support within-casing [0.

Heat zone l l is heated by hollow heat jackets 23 and 24 arranged above and below the upper run of belt 22. Heat zones l2 and I3 are similarly heated by jackets Z5 and 26 and 21 and 28.

The jackets 23-28 are heated by tetra-aryl ortho silicate heated by any suitable boiler 29 which may burn coal, wood, gas, oil or use electricity as may be most convenient. Heated tetraaryl ortho silicate is taken fromboiler29 by pipes 30 and 3 l, a suitable expansion tank 32 being connected to pipe 36 to allow for any expansion or contraction of the tetra-aryl ortho silicate during heating'and cooling. The heat transfer system of the present invention is a closed system and for safety purposes should be provided with a pressure and vacuum relief valve 33 preset to open only under extreme conditions of pressure or vacuum.

Branch pipes 34, 35 and 36 lead from pipe 3| into each of heat zones ll, I2 and I3. Pipe 34 is connected to heat jacket 23 through thermostatically controlled valve 3'! which is actuated by the conventional bulb 31' arranged in the space below jacket 23 and adjacent belt 22. Pipe 34 is connected to jacket 24 through thermostatically controlled valve 38 which is actuated by the conventional bulb 38 arranged between jacket 24 and the underside of belt 22. Jackets 23 and 24 exhaust through pipes 39 and 40 into return pipe 41. Return pipe 4| is connected to a circulating pump 42 driven by motor 43 through belt 44 and pump 42 is connected to boiler 29 by pipe 45. Motor 43 also drives belt 22 through belt 46 and pulley 41.

Thermostatic valves 31 and 38 are provided with by-pass connections 48 and 49 connecting with pipe 4| respectively to by-pass heated tetraaryl ortho silicates around jackets 23 and 24 under certain conditions of operation as will appear hereafter.

Jackets 25 and 26 are provided with similar thermostatic valves 50 and 5| actuated by bulbs 50' and 5| respectively :and with similar bypass connections 52 and 53 and exhaust pipes 54 and 55, the by-pass connections and exhaust lines all dis-charging into pipe 4|.

An identical system is provided for jackets 21 and 28 and the thermostatic valves are identified at 56 and 51, the actuating bulbs at 56 and 51', the by-pass connections at 58 and 59 and the exhaust pipes at 60 and 6|.

Because of the heat transfer characteristics of tetra-aryl ortho silicate the several jackets can be made both of small volume and light construction, the several valves may be of the simplest and lightest construction, and the piping and connections of light weight.

With the embodiment of my invention set up as above described when it is desired to use the ovens for cooking, drying, baking or any other suitable purpose boiler 29 is fired and motor 43 started. Pump 42 and belt 22 are then actuated and pump 43 circulates heated tetra-aryl ortho silicate through the several heating jackets to heat the several heating zones. When the several heating zones have reached desired temperatures the articles to be heated are introduced through door l6 onto belt 22 and are progressively moved by belt 22 through the heating zones at a predetermined rate to effect the desired degree of heat treatment.

It is to be understood that the several thermostatic valves may be preset to provide any desired temperature in the heating zones or may be so regulated that a progressively increasing or decreasing temperature may be had from zone to zone as may best suit the article being heat treated.

Since all of the thermostatic valves operate in the same way a description of the operation of one will suffice for all. In the case of valve 31 and heat jacket 23, when th heated tetra-aryl ortho silicate passing through jacket 23 has brought the temperature at bulb 31' to more than the temperature for which valve 31 is preset valve 31 will close shutting ofi the supply of heated tetra-aryl ortho silicate to jacket 23 and by-passing the same to return line 4| through connection 48. Valve 31 remains closed and heated tetra-aryl ortho silicate continues to by-pass jacket 23 until the temperature at bulb 31 drops below that for which valve 31 is preset. Valve 31 then opens and heated tetra-aryl ortho silicate again passes through jacket 23 to heat jacket 23 and the space about bulb 31'. An accurate and simple control of the temperatures in the several heating zones is thus obtained.

It will now be apparent that by the present in- 4 vention I have provided a novel oven for all types of heat treating which utilizes the tetra-aryl ortho silicates as the heat transfer medium, which is economical in operation with improved control of oven temperatures, and which is of simple and inexpensive construction.

To those skilled in this art changes to or modifications of this illustrative embodiment may now be suggested without departing from my inventive concept. To determine the scope of this invention reference should be had to the appended claim.

What is claimed is:

In an oven using an organic silicate as the heat transfer medium, one or more heating zones, heating jackets in said heating zones, means for moving the articles to be heated progressively through said zones, means for heating the heat transfer medium, supply piping connecting one side of said jackets to said heating means, return piping connecting the other side of said jackets to the return side of said heating means, by-pass piping at each of said jackets between said supply piping and said return piping, a thermostatic valve controlling the flow of the heat transfer medium through each of said by-pass piping and responsive to temperatures adjacent its respective jacket, said piping for circulating the heat transfer medium constituting a closed system, an expansion tank connected into said closed system and normally closed pressure and vacuum responsive relief means connected into said expansion tank, said expansion tank being connected into said supply piping adjacent and above said heating means.

ORION OTTIS OAKS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,437,187 MacDonald Nov. 28, 1922 1,440,926 MacDonald Jan. 2, 1928 2,205,182 Whitten June 18, 1940 2,222,809 Curran Nov. 26, 1940 2,335,012 Johnson Nov. 23, 1943

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