US1430596A

US1430596A - Heating apparatus

Info

Publication number: US1430596A
Application number: US254382A
Authority: US
Inventors: Wirt S Scott
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1918-09-16
Filing date: 1918-09-16
Publication date: 1922-10-03
Anticipated expiration: 1939-10-03

Description

' Panted Oat. 3., 1922..

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. s. SCOTT.

Patenmd Oct. 3, T922.

HEATING APPARATUS. APPLICATION FILED SEPT. I6, 19.18.

Patented #if 3, 1922.

i f lT D STATES PATENT orric..

WRT S. SCOTT, 0F EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR T WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CQRPORATION OF PENNSYLVANIA.

HEATING APPARATUS.

Application led September 16, 1918.

To all t0/om 'it may concern.'

Be it known that l, VVInr S. SCOTT, a citizen of the United States, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Heating Apparatus, of which the following is a specification.

rlhis invention relates to an apparatus for reducing the heat losses incurred by the ventilation of heating chambers, ovens, drying rooms, furnaces, etc., and particularly to systems of ventilation for electrically heated japanning and enamelling ovens.

In baking japan and enamel on materials, as well as in baking or drying various other con'lpounds, compositions or materials, va-

pors or gases are formed during the dryingout process, and a certain amount of oxygen is required for the hardening of the composition, compound or material. ln order to remove these vapors and gases as rapidly as they are formed, or as rapidly as may be necessary, and to supply the necessary oxygen for completing the oxidation process, a positive circulation must be maintained and fresh air must be supplied to the chamber, oven or drying room.

rlhe present practice is to provide ventilating ducts and pipes for the removal of the vapors and .gases but no provision is made for supplying the necessary fresh air, the supply of fresh air being derived almost entirely from leakage in and around the doors, pipe openings and other crevices. Consequently, either an insufficient amount or an excess amount o-f air is sup lied to the heating chamber, and it is there ore practically impossible to maintain a uniform temperature throughout the interior of the heating` chamber.

.he object of my invention is, therefore, first, to provide a Ventilating system for controlling the circulation of air and gases through the heating chamber that shall maintain substantially uniform temperature throughout the interior of the chamber; secondly, to transfer as much heat as posslble from the discharged volatile and heated gases to the ingoi'ng fresh alr; thlrdly, to

vintroduce the ingoing air and withdraw the Serial No. 254,382.

to support the electric heating means from the ceiling of the chamber adjacent the`fresh air inlets and above the volatile gas zone so that the electric heaters shall be moreeffective.

The above and other objects and the novel features of my invention will be apparent from the following description taken in connection with the drawing in which Figures 1 and 2 are, respectively, a side elevation and an end elevation of a japanning and enamelling oven embodying my invention; Fig. 3 is a longitudinal sectional view of the same on a larger scale and taken on the line Ill-Ulf of Fig. 2, and Figs. 4 and 5 are sideelevational views of other forms of enamelling and japanning ovens, also embodying my invention.

While l have shown my invention as applied to an electrically heated japanning and enamelling oven, it is, of course, to be understood that various features thereof may be utilized equally well in connection with drying rooms, furnaces, etc. Referring to the drawing, the oven 10 may be of the usual or any preferred form, provided with doors" at the ends thereof to introduce into the chamber C and withdraw therefrom, the articles to be treated. The air-inlet duct l1, supported from, or adjacent to, the ceiling of `the chamber C, has a series of openings 12 to distribute the incoming fresh air throughout the upper portion of the .chamber, and suitable electric heating devices 13 may also be supported adjacent the openings 12 to heat the incoming air and the interior of the chamber. The outlet duct 14, extending the length of the chamber C is supported upon. the Hoor of the chamber and has a series of intake openings 15 to conduct away the vapors and gaseous mixtures formed within the chamber. l

In order to utilize some of the heat of the discharged volatile gases, I employ an economizer or preheating apparatus E, which is mounted upon the roof of the oven. The economizer has heat-insulating exterior walls 16, sheet-metal partitions 17, and sheet-metal baille plates 18 to provide two winding or tortuous

parallel passages

19 and 20, constituting, respectively, the freshair inlet passage and the gaseous-mixture outlet passage. The outlet passage 20 contains drip pans 21 which are adapted to collect the condensed vapors and such solid matter as may be carried off with the hotl gases and deposited in the economizer. The fresh-air inlet and

vapor outlet passages

19 and 20, being separated merely by a metal partition 17, provide means whereby heat may be transferred from the outgoing heated gas in the passage 20 to the incoming fresh air in the'passage 19. The passage 19 is connected to the ducts 11 within the chamber C and a header 22 leads the outgoing gaseous mixture from the` duct 14 to the passage 20. l

The other ends of both

passages

19 and 20 communicate with the atmosphere, and, in order to produce a positive circulation through the economizer passages and the heating chamber, I provide a blower 23 which has its outlet connected to the incoming air passages 19. A blower is ordinarily required for forcing the circulation but may, of course, be omitted where natural draft is employed.

Fig. ltshows an oven equipped with a stack S for producing a positive circulation naturally.y In this arrangement, the fresh-V air passage 19 is connected to an annular passage 25 that is open to the atmosphere at the top under the hood 26 and surrounds the pipe 27. The pipe 27 is connected to, and carrles olf the'volatile gases from, the passage 20, and is open at its upper end be neath the hood 28. Otherwise, the structure shown in Fig. 4; is similar to the one disclosed in Figs. 1, 2 and 3, and has the added advantage that additional heat is transferred from the outgoing gas to the incoming air through the metal wall of the Fpipe 27.

`ing gases in the pipe 271 to the incoming fresh air flowing through the pipe 251 provides suiicient preheating of the ingoing air. In other respects, the oven structure shownin Fig. 5 is similar to the one shown in Figs. 1 to 3.

An oven constructed according to my invention requires much less power for ventilation and operation than those in use at the present time. By the utilization of the exhaust gases `for lheating the incoming fresh air, the costof operation is materially reduced, and a uniform temperature may also be more easily maintained. Heretofore,

the temperature in the upper part of the oven has been anywhere from 75 to 200 F. hotter than the lower part. With my Ventilating system, the volatile and heated gases that naturally tend to rise to the upper portion of the chamber are forced down by or baking. A circulation through the oven and a uniform temperature therein also eliminates the danger from tires and explosions.

By locating electric heaters in the upper part of the heating chamber adjacent to the air inlets they will be out of the volatile Zone and will occupy what is otherwise waste space inthe oven. The volatile gases, being heavier than air, settle to the bottom of the oven and heaters which are placed on the floor or side walls are constantly bathed in these frases and do not operate at their highest ehciency. The heaters suspended from the 4ceiling are out of the way of the worlo men and are in a most advantageous posi- A l'the heaters. With the heaters located on the ceiling, the radiant heat is distributed uniformly over a larger area, thereby reducing the time required for baking and providing al substantially uniformy temperature, as a result of which the product will be of a much more uniform and durable quality.

While I have shown and described, in detail, the features of the heating chamber or oven embodying my invention, itis to be understood that various modifications may be made therein without departing from the spirit and scope of the invention, as expressed in the appended claims.

I claim as my invention:

1. The combination with a heating cha ber having an outlet in the lower part thereof for heated gas and an inlet in the upper part thereof for cooler gas, electric heating means in the upper part of said chamber only adjacent said inlet for heating said incoming cooler gas, whereby the heatedgas travels downwardly and a substantially uniform temperature is maintained within the chamber, and means whereby heat is transferred from the heated gas after it is discharged to the cooler gas before the latter enters the chamber.

2. The combination with a j apanningl and ena-maling oven, of electric mean`s located-at the top only of said oven, meansfor leading a heated gaseous mixture from the lower part of said oven, meansfor leading cooler gas into theupper part of said oven past masones derived from said heated gaseous mixture after the latter discharges from the oven, said means comprising a plurality of connected passageways for said heated gaseous mixture, and a plurality of connected passageways for the cooler gas, said passageways being located in opposed intertting side-by-side relation and means in the passageways for the heated gaseous mixture for collecting substances deposited from the gaseous mixture flowing therethrough.

3. The combination with an oven struc-- ture comprising a chamber havingl an air inlet adjacent the top thereof and a gaseousmixture outlet adjacent the bottom thereof, of electricheatng means adjacent to said air inlet at the top of said chamber for heating said incoming air, means for pre-heating the air before it enters said chamber by heat derived from the gaseous mixture discharged from said outlet, and means for positively causing circulation through said air-heating means into said chamber and out of the latter through said outlet.

ft. lin a japanning and enanielling apparatus, the combination with an oven having a series of air inlets adjacent the upper wall thereof and a series of volatile-gas outlets adjacent the lower wall thereof, of .electric heating means ladjacentsaid air inlets and above the volatile-gas zone, meanswhereby the air is preheated, and means for producing a positive circulation through said oven from said inlets to said outlets, the arrangement being such that a substantially uniform temperature is produced throughout the interior of the oven.

5. The combination with a heatingchamber having an inlet and an outlet, of an economizer or preheating apparatus comprising parallel elongated passages .connected to said inlet and said outlet, respectively, and arranged in side-by--side relation,

whereby the ingoing gas may derive neat from the outgoing gas, and means in the outlet passage for collecting the substances deposited from the gases passing therethrough.

ln, testimony whereof, l have hereunto subscribed my name this th day of Aug., 1918.

RT S.' SCGTT.