US2147946A - Furnace construction - Google Patents

Description

O. JAROS FURNACE CONSTRUCTION Filed NOV. 17, 1934 Feb. 21, 1939.

Patented Feb. 2l, 1939 UNITED STATES 2,147,946 FURNAOE CONSTRUCTION Otto Jaros, Cicero, Ill.,

v William J. Gilbert, Chicago, Ill.

assigner of one-half to Application November 17, 1.934, serial N0. 753,423

1 Claim.

This invention relates to furnace structures and more particularly to sectionally supported refractory walls and arches in such structures.

The invention in its -broader aspects may be l applicable to either the air cooled or insulated type of wall.

It is primarily a purpose ofV this invention to provide a wall structure and arch structure by means of which it is possible to use standard shapes of refractories or fire brick and principally standard supporting structures. Heretofore, so far as I am aware, theconventional suspended arch or sectionally supported furnace wall has been made up of specially shaped refractory units andspecial metal supporting units both of which command a high premium in original investmentl and in service replacement. My invention makes it possible to avoid the multiplicity of special shapes of refractories and supporting units thusmaterially reducing the original installation cost and the cost of replacement.

It is also the purpose of this invention to provide a structure for furnace walls and arches of the utmost simplicity which can be readily applied to all sizes of furnaces and likey structures so that the cost of suspended arches and sectionally supported Walls is reduced to .a point where it is practical to apply them in many small installations that the prior expensive specially shaped structures could not be applied to.

My invention contemplates as avmeans for carrying out the aforementioned purposes the provision of a very flexible supporting structure utilizing only a small amount of retainers with standard shape brick as the main part of the wall or arch', the brick being mounted and retained in position by bonding of the retainers to the brick by means of air setting or high temperature setting cements.

Other and more specific objects and advantages will appearas the description proceeds in connection with the accompanying drawing wherein the preferred form of the invention is shown.

It is to be understood, however, that the draw ing and description are illustrative only and are not to be taken as limiting the invention except in so far as it is limited by the claim.

In the drawing- Fig. l is a vertical sectional viewthrough a portion of a furnace structure showing both the furnace wall? and the furnace arch;

Fig. 2 is an enlarged sectional View also taken on the vertical line through the side wall of the furnace;

Fig. 3 is a horizontal sectional View taken on the line 3 3 of Fig. 2; and

Fig. 4 is a sectional View taken on the line 4-4 of Fig. 1. .i

Referring now in detail to the drawing, the 5 supporting structure for the furnace wall consists of the upright beams such as I Il which may be the ordinary I beam. Running horizontally of the beams are the shelf members II which form the base support for the wall refractories. These shelf members are bolted directly to the columns i by means of the bolts I2 through the upright flanges I3 thereof. The members II may be of any suitable length either continuous for the full length of the wall or in shorter sections abutting each other.

Each of the members II has at the upper surface thereof the horizontal groove I4 which may be continuous throughout the length of the base support or in .a series of sections. This groove Ill serves as a supporting socket or retainer for the vertical supports I5 which engage the retainers I6.- The shelf portion I'I of the member Il constitutes the supporting unit for carrying the wall section immediately above each member II. Directly beneath the groove I4, the member Il is also provided with a downwardly directed groove I8 for retaining the upper ends of the members I5.

At the top of the side wall, the members I5 30 may be held by a special member I I which runs horizontally and has only the lower groove I8 formed thereon without any shelf portion such as I1 to project out in the way of the refractories 20 of the arch. These refractories 20 are sup- 35 ported by retainers 2I identical in shape with the retainers I6, and these retainers in turn are carried upon the hanger bars 22 suspended from the rods 23 which hook over the angle irons 24 that run transversely of the furnace .and are carried on top of the cross members I Il which are connected to the column I Il.

I preferably use thin plates for the retainers I Ii and 2l such for example as one-thirty second inch sheet steel so as to maintain as small joints between the bricks as possible. For ad ditional bonding strength between the plate and brick, a hole 30 is provided in plates I6 and 2| in which the cement collects to fortify the strength of the bond. In the case of the insulating lire brick, the natural porosity of their structure permits deeper seepage of the cement thus adding further to the strength of the bond. The retainers may be of other material than metal, such as refractory material of a higher or comparable tensile strength to that of ordinary fire brick.

The refractory units 25 are ordinary re brick or insulating fire brick laid on edge and cut out or sawed out as indicated at 26 to rest upon the ledge or shelf I1. Aside from cutting out the portions at 26, no change is made in the standard fire brick shape throughout the major portion of the refractory lining. the brick at 26 isy to provide protectionforthe horizontal ledge I1 of the supports II from the radiant heat of the furnace.

The method of laying up the brick is to place a thin layer of air setting, or high temperature setting refractory cement on theledge II. The base brick 25 is then laid in place, one end-being supported on the ledge I1 and the other end on a filler block 32 which is carried bythe columnof refractory below. These ller blocksarefonly of a. temporary nature to permit the proper support of the refractorypriorto-thelbonding of the plates I6 to refractory'units 25 and 21 whichl occurs with the setting'of the cement; Thefiller blocks may be of wood which can beleft in place to burn out when the furnace isin operation or can be removed afterA thecement has set, which in case of air setting cement isonly a matter' of a few hours.

After the base brick 25 is placed in position, the vertical metal support I is placed in grooves I4' and I8 for'positive retainment. Before inserting the supports I5 in the grooves, the required number of plates I6 are threaded on the supports I5. The plates I6 arethen slid up to the top extremity of support' I5 where they arev supported by a wedging action which`l develops because of the unbalanced weight of the plates in their mass relation'to the support. The plates are thus kept out of the wayY until theyr are needed'. After the base brick 25 is in position, a thin layer of refractory cement of either the air setting or high temperature setting variety is applied to the top. Then one of the retaining plates I6 is released from the top and placed in position. Then a brick whose underside has been coated with a cement is placed on top of the plate and base brick, thus completing one layer of the unit section. The balance of 'thebrick andplates are then placed in position andinthe series noted in Fig. 1.

I have found in practice that a very thin layer of cement between the brick is all that is necessary for ample bonding of the plates and the brick. This cement is used throughout the length of the bricks and over the fire contact faces as indicated at 28 and 29. Itk can be obtained corn,- mercially with such characteristics that it will resist temperature of 2500* F. and upward, thus assuring a very strong bond between the bricks and the plate.

The bond between the plate and the cement and between the cement andthe brick is so strong that, when force is applied to removefthe plate from the side of a brick, the materialof the brick adjacent the cement breaksroff with the cement thus showing that the bond between the metal and the cement and between the cement and the brick is greater than the tensileI strength of the brick itself.

When the section of brickiscompleted up to the next shelf, a suitable filler 3I" is inserted, this being a composition of resilient and' refractory substances having the property of expansion and contraction as well as being heat resistant, to

The reason; for recessingv compensate for temperature changes in the refractory structure.

Where the insulating fire brick is used, the temperature to which the plates I6 may be subjected is only a few hundred degrees and, therefore, ordinary sheet steel will not be damaged when used for the plates I6. This insulating fire brick is a very porous structure, much lighter than ordinarysre brick and therefore-capable of withstanding a high temperature on onel endwithout being heated very much at the other end. The pores of the insulating brick are lled with the same air setting cement on the faces exposed to the interior of the furnace as indicated by the cement at 29in Fig. 2.

Where ordinary fire bricks are used because of the relatively high heat conductivity, I use a special heat resistant steel for the plates I6 so that they will not be destroyed by the high temperature produced at the back ends of the re brick. Regardless of` the refractory material used, however, the bonding of the plates to the brick is done in the same fashion.

The side walls when laid up have the joints staggered as it is immaterial so far as the plates I6 are concerned whether they bond to two bricks on one side or only to one brick. This also is an advantage over most of the sectional supported wall structures as it permits breaking of' joints where the special tileshapes make it difficult toget this result.

In the arch structure, the ordinary shapes of re brick indicated at 20 are bonded to the retainers with the same cement used in the side walls and with plates 2| identical with plates I6 being used as retainers. Preferably, the plates are interposed in every other jointv between the bricks. The bricks are bonded to the plates before being installed in the arch, and then, after the cement has set, the individual plates with the bricks carried thereby are hung upon the members 22. Since the bonding strength of this cement with the metal plate and with the brick is so great, it will readily carry the weight of the arch so that the plates 2I constitute the load bearing supports for the arch. It is, therefore, unnecessary to provide any holes or notches or slots in the brick and a much greater strength is obtained because of the wide surface contact between the cement and refractory material on the one hand and between the cement and the metal plate on the other hand.

It is a well known fact that re clay or re brick has little tensile strength. Therefore, when it is supported by means of any notch or opening cut into the brick, the entire unit is so weakened as to cause considerable loss due to breakage under its own weight. All of this is avoided in the present structure andl in addition, the special shapes are unnecessary.

The particular supporting structure I have shown is particularly useful in sectionally supported walls because of the great flexibility thereof both in assembly and adjustment for expansion and contraction. It will be noted that the upright supports I5, which in the present instance are shown as simple metal rods, are free to slide horizontally in the grooves I4 and I8 and also free to move up or down a limited amount. Further, the plates I6 can slide up or down upon the rods I 5 to adjust themselves.

The furnace may be repaired either from the inside or outside by removing the rods such as I5 and pulling the brick out from the back or into the furnace. This greatly facilitates the repair of furnace walls and, as no special shapes of refractories are required, the i'lre brick used may be purchased in the open market at the most advantageous price, This structure also avoids the difficulties that furnace operators undergo in obtaining the special shapes of refractory tile and metallic supports as it is not necessary to carry a large stock of different shapes or to Wait until special orders may be lled.

From the above description, it is believed that the construction and advantages of this device will be readily apparent to those skilled in this art.

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

The combination in a furnace structure or the like of a supporting framework, a lining therefor of re brick, certain of said re brick being bonded together by an air setting high temperature resistant cement and retaining members bonded to said brick lining by said cement and having no frictional engagement with the brick and connected With the framework, said retaining members having openings therein, and said framework having vertically and horizontally adjustable members extending through said openings.

OTTO' JAROS.

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