US3282578A

US3282578A - Furnace liner

Info

Publication number: US3282578A
Application number: US335535A
Authority: US
Inventors: Richard W Ulbrich
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-01-03
Filing date: 1964-01-03
Publication date: 1966-11-01
Anticipated expiration: 1983-11-01
Also published as: DE1433806B2; NL6415278A; GB1041550A; DE1433806C3; DE1433806A1; BE657882A

Description

R. W. ULBRICH Nov. 1, 1966 FURNACE LINER Filed Jan. 3, 1964 United States Patent 3,282,578 FURNACE LINER Richard W. Ulbrich, 126 W. Dixon Ave., Dayton, hio Filed Jan. 3, 1964, Ser. No. '335,535 7 Claims. (Cl. 263-40) This invention rel-ates to a liner for a Ifurnace, oven, kiln or the like.

The heating industry in general has long been plagued with the problem of providing adequate furnace line-rs. The problem exists because the present materials used for linens for the most part are bulky and heavy. This, of course, is due to the fact that the primary consideration in providing such a liner is to select a material .that can withstand the high heats which are required to be generated in the ovens in which they are to be used. A comrnon example of such a liner is fire brick or some such refractory and/ or insulation used in most ovens in which heats upward of 1000" F. are produced. The refractory of necessity must Ibe bulky and heavy in order to withstand the required temperatures and repeated exposure to thermal shock. Also, sin-ce the primary consideration of the refractory is to withstand the shock without spalling, additional insulation for the oven is necessary and which makes the outer shell of the furnace very lange -i and expensive in order to support the weight of the refractory and insulation.

The heating device of the type ldescribed above requires in addition to a heavy, bulky wall structure, auxiliary apparatus such as forced air blower or the like to produce heats above approximately 800 F. because the present liners -are not capable of eicient radiation and re-radia tion of the heat produced in the chamber.

The practical effect of the above drawbacks is to .make a furnace, oven, kiln or the like which is required to produce heats above approximately 800 F. very .heavy 'and expensive, and requiring sizable areas on which to locate same.

The present invention overcomes this long standing problem by providing a light in weight, efficient liner for ovens, kiln, or the like which substantially increases the heat producing capacity of the oven in which it is used; yet due to its light weight, does not require a heavy and bulky support wall as do the present liners.

It is therefore an object of the present invention to provide a novel l-iner for a furnace, kiln or the like which is more efficient than those in the prior art.

An additional object of the invention is to provide a novel liner for ovens, kilns or the like which is compact in size and light in Weight. J

Another object of the invention is to provide a novel liner `for furnaces, ovens, kilns or the like which req-uires less supporting structure due to its lighter size and weight.

An additional object of the invention is to provide a liner for =a furnace, oven, kiln or the like which renders the furnace capable of producing 'heats above approximately 800 F. without expensive, bulky auxiliary heating apparatus.

Another object of the invention is to provide la liner comprising 'a plurality of screens in juxtaposition relationship to present greater surface area to the heat produced in the heat chamber so that the heat may be radiated and rie-radiated between the liner and furnace charge.

A further object of the invention is to provide a novel liner for furnaces, oven, kilns or the like which comprises a plurality of screens in juxtaposition relationship wherein the inner layer of screening adjacent the 'heat chamber is of coarser mesh than the layer further removed therefrom to better withstand exposure to the higher temperatures.

3,282,578 Patented Nov. l, 1966 These and other objects will become apparent to one skilled in the art from the following description of the invention taken in conjunction with the drawings in which:

FIGURE 1 is a cross-sectional view of a furnace showin-g the present invention used in conjunction with a typical furnace.

FIGURE 2 is an enlarged cross-sectional view of the wall of the furnace taken substantially along lines 2 2 of FIGURE l showing a particular construction of the liner.

FIGURE 3 is an enlarged cross-sectional view of a furnace wall depicting. a modified liner that could be used in the environment disclosed in FIGURE l.

T-he general furnace combination is disclosed in FIG- URE l and designated by reference numeral 1. The furnace, oven, kiln or the like consists of an outside shell 9, a layer of insulation 8 adjacent to the outside shell 9, and a liner 7, all supported on a base 6. Burners or heating elements 4 are positioned on the base and extend into a heat chamber 10. A grate or support means 3 is provided within chamber 10 to support a charge 2. Fuel or power lines S are provided to deliver lfuel or power to the :burners or heating elements 4. The type or number of heaters used i.e., gas, oil or elect-ric is immaterial so far as the present invention is concerned.

The invention pertains to the construction and use of the liner in a furnace, oven, kiln or the like. The liner comprises multiple layers of screens arranged in juxtaposition relationship. The screen layers nearer to the charge 2 are generally, but not necessarily, of `coarser mesh than the layers more remote from the heat chamber 10 as illustrated in FIGURE 2. The reason for such an arrangement is so the screen nearer to the heat chamber 10 can withstand greater heat with less deterioration, whereas the screens more remote are of finer mesh so that they can present a greater radiation surface per unit of screen area to radiate the heat not radiated by the coarser screens closer to the heat chamber. Obviously, the finer the rnesh o-f wire used, the greater is the radiating surface per unit of screen. The most efficient liner would be where all layers of screens are of fine mesh. This arrangement, shown in FIGURE 3, would be practical where the oven, kiln, furnace or the like is required to produce only ,relatively low 'heats in which the finer mesh wire would be able to withstand the -lo-wer heats with only normal wear. Conversely, where relatively higher heats `are to be produced, the liner will consist of coarser `mesh wire next to the heat cham-ber and becoming progressively liner mesh the more remote the screen layers are positioned from the heat chamber.

The number of screen layers required in a particular lining ydepends on several variables such as the temperatures required to be produced in the furnace, the type and size of the changes which the furnace is required to accommodate, the type of material lfrom which thescreens are constructed, the type of insulation material between the screen liner and the outer wall, and other 'minor considerati-ons obvious to one skilled in the art.

The type of screen material selected for the liner is governed by the heats to be produced. The melting point of the material must exceed the high heat level requirement of the furnace, oven, kiln or the like, in which the liner is to be used. Nichrorne and Inconal are trade names for alloys suitable for screening where the melting point of the screens must be approximately 3,000 F. For higher temperature requirements the screens can be ma-de from other metallic, as well as non-metallic materials.

The principle of operation of the screen liner is that due to the nature of construction of screening, much greater radiating surface is presented than the equivalent area of conventional fiat, continuous surface liners. The greater surface radiates and re-radiatm a greater amount of the heat produced in the heating chamber, thereby, raising the heat of the charge with relatively little heat loss.

The advantages derived rom use of a screen liner are many. An oven or furnace using a conventional fiat, continuous surface type line-r cannot exceed heats -above approximately 800 F. without adding expensive, bulky forced air blower apparatus, or Without heavy power consumption in lan electric furnace. An oven or furnace using a screen liner can produce heats 4of approximately l700 F. Wit-hout adding a forced air blower or by using only a fraction of the power normally required in an electric furnace. Also, a iurnace using the screen line of the pres-ent -invention is more economical to operate due to its greater eiciency and is less expensive initially because of the compactness of the oven design and the lighter weight Wall required to support the screen lliner. These economics of operation resulting :from the saving of uel or electric power are not limited to ovens and furnaces operating at temperatures above 800 F., brut can also be realized in ovens and furnaces operating below 800 F. where the principle of radiation and re-radiation will reduce the ffuel or electric power consumed to maintain a required temperature. Another advantage is a 'greatly reduced time required to reach the desired heat, as Well as to cool d own the furnace.

Various changes and .modcations will become apparent to one skilled in the art in practicing the invention, however, .the invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. An apparatus adapted to produce heat comprising a housing having wall means arranged to define a chamber, said Wall means including a support wall, insulation means disposed intermediate Said .support wall and chamber, and a lining disposed adjacent said insulation means and exposed to said chamber, said lining comprising multiple layers of heat resistant, mesh screens arranged in juxtaposition, and means for :heating said chamber Whereby heat in said chamber is absorbed :by said lining and radiated lback intosaid chamber.

2. The apparatus delined in claim 1 wherein said screens are of diiferent mesh and aire arranged lwith .the coarser mesh screens disposed closer to said chamber than the finer mesh screens.

3. The apparatus defined in claim 1 wherein said screens are of progressively liner mesh and are arranged with the screen having the coarsest mesh disposed closest to said cham-her and the succeeding layers of screens are of progressively finer meshV with the iinest mesh screen disposed most remote from said chamber.

4. The apparatus dened in claim 1 wherein said screens have substantially the saline mesh.

5. In lan apparatus adapted to produce heat land which includes walls arranged to delinea heat chamber in which the heat is `adapted to be produced, a liner for the chamber comprising multiple layers of lheat resistant, mesh screens arranged in juxtaposition 'and positioned relative to said chamber to receive heat therefrom and radiate it back into said chamber.

6. The apparatus as defined in claim 5 wherein said screens are of progressively finer mesh iand are arranged with the screen having the ooarsest mesh closest to said chamber andthe succeeding layers of screens are of progressively finer mesh with the screen hav-ing the finest mesh disposed `niost remote from said chamber.

7. The apparatus as defined in claim 5 wherein said screens have substantially -the same mesh.

References Cited by the Examiner UNITED STATES PATENTS 2,542,029 2/ 1951 Hoffert 158-112 X 2,543,708 2/ 1951 Rice et tal. 263-40 X 2,607,663 8/1952 Perry et al. 2,641,456 6/ 1953 Sohmertz 263-50 X 3,122,197 2/1964 Saponara et ral.

FOREIGN PATENTS 727,174 3/ 1955 Great Britain. 852,457 10/1960 Great Britain.

FREDERICK L. MATTESON, JR., Primary Examiner. JOHN J. CAMBY, Examiner.

Claims

5. IN AN APPARATUS ADAPTED TO PRODUCE HEAT AND WHICH INCLUDES WALLS ARRANGED TO DEFINE A HEAT CHAMBER IN WHICH THE HEAT IS ADAPTED TO BE PRODUCED, A LINER FOR THE CHAMBER COMPRISING MULTIPLE LAYERS OF THEAT RESISTANT, MESH SCREENS ARRANGED IN JUXTAPOSITION AND POSITIONED RELATIVE TO SAID CHAMBER TO RECEIVE HEAT THEREFROM AND RADIATE IT BACK INTO SAID CHAMBER.