US2359646A - Means for furnace wall maintenance - Google Patents

Description

Get. 3, 1944. c. s. HULTON MEANS FOR FURNACE WALL MAINTENANCE Filed June 6, 1942 Patented Oct. 3, 1944 UNITED STATES PATENT OFFICE I MEANS FOR FURNACE WALL MAINTENANCE Charles S. Hulton, Cincinnati, Ohio, assignor to The Kirk & Blum Manufacturing Company, Cincinnati, Ohio, acorporation of Ohio Application June 6, 1942, Serial No. 446,152

4 Claims.

Thisapplication is a continuation in part of my co-pending application Serial No. 359,777, filed October 4, 1940, now U. S. Patent. No. 2,310,698 of February 9, 1942.

The present invention relates to means for furnace wall maintenance and has for an object the provision of nozzles for wall cooling systems arranged and adapted for non-wasteful maintenance of furnace walls.

A further object of the invention is to provide a means enabling rapid adjustment of air volume and pressure air applied to a furnace wall under varying conditions of the refractory blocks thereof while the furnace is in operation.

Still another object of the invention is to pro- ;vide means for th purposes stated that may be embodied in existing systems at relatively low cost.

These and other objects are attained by the means described herein and disclosed in the accompanying drawing, in which:

Fig. 1 is a front elevational view of a nozzle embodying an exteriorly disposed adjustment and orifice control means.

Fig. 2 is a cross-sectional view taken on line wall with which the nozzle is operatively associated.

Fig. 3 is a front elevational view of a modified form of the device of Fig. 1.

Fig. 4 is a cross-sectional View taken on line 4-4 of Fig. 3.

Fig. 5 is a cross-sectional view taken on line 55 of Fig. 4.

In th maintenance of furnace walls, such as 22 of Fig. 1 and showing a section of furnace.

refractory block wall structures in glass fur naces, air streams are directed against the outer wall surface to remove the heat radiated through the blocks for the purpose of retarding the destructive action on the blocks which reduces the thickness of the blocks and ultimately requires replacement of the wall. The cost of construction of such walls and the loss involved in shutting down the furnace for the purpose of rebuilding the worn-out walls justifies the installation and operation of air cooling systems that will lengthen the life of the furnace walls. As the wall block thickness decreases during use, increased heat radiation through the block requires more air for its removal. There is a critical limit to the volume and pressure of cooling air for any given block thickness beyond which further surface temperature reduction cannot be obtained by this medium.

In the designing and construction of wall cooling systems provision must be made forair pressure and volume that will be required for the condition existing near the end of the furnace life. Because all of this air is not required during the earlier period of furnace operation, the air source consists desirably of two or more blower units which are connected in parallel and are operable jointly and severally. The nozzles which are positioned closely adjacent the furnace wall have fixed discharge orifice areas, the size being calculated to pass the air volume and pressure in the cooling system when all blower units are in simultaneous operation. It has been a notable disadvantage of cooling systems for refractory wall maintenance that when less than'all of the blower units are in operation, the nozzle discharge velocity is below the desirable point or rate for maximum cooling. The life of the wall is shortened and operating costs are increased due to thi condition.

By the method and means of the present invention greater cooling efficiency is attained throughout the life of the furnace wall and since the increased cooling efficiency effects a corresponding increase in the life of the wall, the operator is not required to choose or compromise on systems using other methods and other types of cooling nozzles.

Referring now to the drawing, the furnace wall comprising refractory blocks Ill and the exterior structural steel supporting members I I, serves to retain a molten charge which is in this instance a mass of molten glass. As will be well understood by those conversant in the art, the substance of blocks I0 deteriorates and erodes under the action of the intense heat and the action. of the charge itself. This condition is most pronounced on that part of the inner wall surface in the changing range of the surface level of the molten charge.

Mountedacljacent the outside surface of the blocks 10 in this critical area are nozzles connected individually to branch pipes l4 which are on straps 3B.

The method of wall cooling of the :present invention provides that the discharge orifices of the nozzles have'the areas thereof initially reduced so that the air volume required and supplied by but one of the blowers will issue at a velocity which will most effectively dissipate the surface temperature of blocks lll'when they are new and of full thickness. In the present embodiment this adjustment is made in'the cooling system before putting the newly constructed furnace into'operation and the orifice size selected according to the controlling factors of the furnace, viz., the kind of refractory material, the

size of the blocks, the nature and melting temj perature of thecharge, and therate removal of the molten material with respect to'the extent of melting area in the furnace. By initially providing not only the requisite volume of air but directing it upon the surface at the most eifective velocity, the rate of decrease of the wall thickness is reduced. When the deferred reduction in the wall thickness comes to pass and a greater volume of air is required, another blower is brought into service concurrently with the first. The velocity of the air streams of increased volume is adjusted to optimum cooling efiiciency .by'correctly increasing the size of the discharge orifices. By making the proper adjustment of the size of the discharge orifices, the wasteful practice of expending excessive amounts-of power with less than'maximum efficiency is eliminated. The actual life of the furnace wall is greatly increased because during-no part of the period of its continuous operation does the air volume or velocity deviate from the known optimum efliciency cooling requirements.

Reference is now made to Figs. 1 and 2 which show an end discharge type of nozzle with a simplified and externally applied adjustment and clamping means to simultaneously adjust the orifice areas of a plurality of openings.

The nozzle member 28 is suitably secured on the end of a branch pipe 29 and in this instance is positioned and adapted to discharge velocity air blasts at an angle of about 45 to the normal longitudinal axis of pipe 29. The angle turn is -formed in the pipe so that the same nozzle member 28 may be used in other and different positions as required. The discharge end of the nozzle'has outstanding bosses 30 having orifice slots 3| shaped as hereinbefore mentioned to provide the ribbon-like air streams. The mask or valve member indicated generally as 32 is a curved metallic sheet conforming to and resting on the fronts of the bosses 30 so that by shifting it up and down the top edge 33 will vary the size of the upper orifices 3|, and the top edges 34 of apertures 35 in the mask or valve will correspondingly vary the effective size of the lower orifices= 3|.

Straps 36, which may be fixed to or integral with the mask, extend to the back of the nozzle and are there securely fixed to a block or bar 31 which may slide in a vertical groove 38 2,359,646 I r -i arrange the length of slot 38 that the limits of adjustment of the block 31 therein will also affect the corresponding desired limitsof adjustment of the valve with respect to the discharge orifices. The workman who will occasionally be required to adjust the nozzles need only observe the position of block 31 in its groove to know the relative degree of restriction of the orifices3l.v The orifices are difiicult to see'when the nozzle is in place, as will be understood from an inspection of Fig. 2.

which is formed in a boss or extension 39 on nozzle 28. A hand screw 40 is threadedly passed through block 31, and when the end of said screw is forced against the bottom of slot 38 the block 3'l moves away from the bottom of the slot and exerts the force of the screw in a pulling action The valve or mask is thus easily adjusted over the nozzle orifices. I prefer to so V In the embodiment illustrated in Figs. 3, 4 and 5 there is shown the same general type of nozzle as in Fig. 1, provided with the externally disposed valve or mask and the adjustment means therefor fashioned as described in connection with Figs. 1 and 2. A detailed description need .not'be provided since the only vital distinction to be noted is the change in position of the groove 380 with respect to the longitudinal axis .of the nozzle 40 in order to retain the geneally parallel relation between the mask or valve 4| and the bottom of the groove 38!].

The invention is not to be considered as limited to the exact tructural details shown since they are capable of modification within the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. A nozzle of the class described comprising a hollow body having a group of discharge orifice slots therein and a grooved :portion relatively opposed to said group of slots, a slotted sheet valve movable across said orifice slots for adjusting the effective discharge area thereof and means carried by said valve and operative in .said grooved portion for releasably binding the valve in adjusted positions. 7

2. A nozzle of the class described comprising.

a body provided with a group of bosses having orificestherein, a valve comprising an exteriorty dis-posed sheet conforming to the faces of said bosses, said sheet being apertured to expose the T orifices in the bosses and shiftable to relatively restrict the orifices, a grooved extension on the body relatively'parallel to the direction of shifting of said valve, and means comprising a threaded-member movable with the valve and'in said groove for fixing the valve in adjusted positions.

3. A nozzle comprising a hollow body having spaced orifices in one side thereof, an extension on the opposite side of said body having a groove therein, a slotted mask valve slidable over the "orificed side of the body and having extensions encircling the entire body, a threadedly bored lug fixed on said extensions and seated slidably in the groove in said extension, and a maually operable screw for binding the lug in adjusted positions in said groove.

4. In a nozzle of the class described the combination of a hollow body having a group of discharge orifices therein, a, grooved portion relatively opposed to said group of orifices, a sheet metal mask having apertures therein and r0- viding spaced edges for limiting the effective size of said orifices, and means connected to said mask and guidingly shiftable in said groove for releasably binding the mask in selected positions relative to said orifices.

CHARLES S. HULTON.-

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