US1919324A - Control of furnace temperature and furnace wall construction - Google Patents

Description

July 25, 1933. F. G. ELY 1,919,324

CONTROL OF FURNACE TEIPERATURE AND FURNACE WALL CONSTRUCTION Filed April 30, 1931 3 Sheets-Sheet 3 Fig? 1 INVENTOR BYiIS AT%BNZ F. G. ELY

July 25, 1933.

CONTROL OF FURNACE TEMPERATURE AND FURNACE WALL CONSTRUCTION :5 Sheets-Sheet 2 Filed April 50 3 D. Q. 3. L, fl rt l I I I I IIFIIIIIIIIII.

July 25, 1933. F. a. ELY 1,919,324

CONTROL OF FURNACE TEMPERATURE AND FURNACE WALL CONSTRUCTION Filed April 30, 1931 3 Sheets-Sheet 5 Fcederic INVENTOR V vention,

Patented July 25, 1933 UNITED" S ATES 1 FREDERIC G. ELY, or camera, NEW JERSEY, Ass'IGNon rANY, or new 11031:, N. Y., A

CORPORATION OF DELAWARE common or FURNACE TEMPERATUR AND summon WALL cons'iutrrcrron Application filed April so,

My invention relates to the control of furnace temperature, especially by means of the design and construction of the furnace walls. It relates particularly to furnaces,

5 upon the walls of which ash and slag collect.

The invention is useful in connection with furnaces havingwater cooled walls.

One object of the invention is to. control furnace temperature by the design and conlo struction of the furnace walls.

Another object of the, invention is to provide a furnace wallto which .ash and slag will adhere only in limited amounts. A further object is the provision of such a wall in '15 which ash and slag coated thereon will have its surface broken up into sections of small area. Other objects will become apparent upon consideration of the present specification. a

The invention is-shown by way of illustration in the accompanying drawings, in which- Figure 1 is a view of the inside surface of a furnace wall comprising tubes with refractory brlck coverlngthe same Fig. 2 is a II II of Figure 1, a I .7 a

Fig. 3 is anelevation of another furnace wall constructed'in accordance with the in section on the line Fig. 4 is a section on the line IV-IV of Fig. 3, and 4 Fig. 5 is anelevation of a furnace wall showing another form of the invention. 7

An important feature ofmodern furnace operation is the control of temperature within the furnace. The necessity for such tem-' perature control has-become "more marked with the increased utilization offlu'id fuels 40 and the increasing tendency toward more rapid combustion in jthejfurnace. 1

Furnace temperature may be controlled by the construction of the furnace walls, and various constructions of furnace wall have been used for thispurpose. 'I have discovcred that furnace temperature can" be controlled by providing on the insides ofthe furnace walls varyingproportionsof slight-- lv cooled and highly cooled areas. The ratio ofthe highly cooled surfaces to the slightly 1931. Serial no. 533, 73.

ro FULLE LEHIGH ooM-l 7 I have also discovered that a wall so constructed has another 'valuable property, namely, that of, providing a surface whereon ash and slag will adhere only, in limited quantities. 1 v V Where the entire furnace wall is of rough refractory material it has been found that ash and slag in. appreciable quantities will be deposited upon the walls'by the flame and the combustion gases. Thedeposit covering the walls is not mechanically stable and has been known to break away in slabs and fall upon the furnace floor. Where the walls of the furnace are of the usual construction these slabs are frequently too heavy and'too large for safe and proper operation of the furnace. p

According to the present invention, the area ofthe furnace wall is broken'up so that-the ash or slag coming upon the wall I will not deposit continuously over the wall, but will be limited in extent to small slabs. When thesesmall slabs break away from the walls of. the furnace and fall into its botins...

tom they will cause a minimumdisturbance because .of their limited. size, and will not interfere with safe operation of the furnace.

In order to accomplish the above result the character of the wall surface inside of the'furnace is altered-"at intervals,the ratio of'slightly cooledand highly cooledjareas being suchjas to give the desired.tempera-' hire within the furnace in each case.

In the drawings there is shown afurnace wall of the usual type which comprises water cooling tubes 10 and blocks 11 preferably of refractory material covering the tubes on the inside. of the furnace. Thus, the blocks are cooled the water cooled tubes to which they are attached and their life is prolonged l in Well known manner.

" The refractory blocks '11 form the major I elements having a different surface fromthat part of the interior faceof the wall. Other of the refractory blocks interrupt the Verti cal extent of the blocks 11 in the/wall and may interrupt the iextent of these blocks in all directions. These elements may: be

7 means for accelerating heat absorption by the tubes, having a higher rate of heat conductivity than the blocks 11. Thus, in addition to the refractory material carried by the tubes, there is a second class of. material which is of greater heat conducting capacity than the first, and this second class of material may be present in various forms including metal blocks or fins on the tubes, the latter being illustrated in 3 and 4.

In Figs. 1 and 2 the other elements to which referenceis made above, are blocks 12 which interrupt the extent of the refractory blocks 11 forming the major part'of the interior face of the wall. These blocks 12 have a different surface from that of the refractory blocks 11, which surface may be that of a "diffe-renttype of refactory or may be ametal surface,'the entire block 12 being constructed of metal. The blocks 12 may i be carried by the tubes as are the refractory blocks 11. In any case the areas provided. by the blocks 12 are highly cooled and tend to cool the inside of the furnace.

Where the above construction is employed, the ash is deposited on the roughrefractory surfaceof the wall, that is to say-on the refractory blocks 11, and large areas of deposited ash are prevented from falling to the furnace floor through the provision at intervals of a surface having a different character; The blocks 12, shown in Figs. .1 and 2, and corresponding elements shown in Figs. 3, 4: and 5, present such surfaces of different character, to which the ash or slag will not adhere and over which the ash or-slag will not bridge in a strong enough section to make a continuous slab which may fall to the furnace floor. As a result of this construction I only small quantities ofv ash .or slag will 7 fall from the furnace Walls at anytime.

are provided by. tubes 14- having longitudie In Figs. 3 and .4 the interruptingsurfaces nal fins thereon-and the major part of the Wallis formed by causing refractory 15 to adhere to spiral fin tubes 13. 'Obviously,

other means might also be employed for this purpose.

Attention is called toqthe fact that it is not necessary to employ the particular design shown in Figure 1, but many variations of this design may be employed with satisfactory effect. As an examplethere is illustrated in Fig. 5 a wall wherein hori zontallines of cleavage only are provided.

The particular description here given and I. the forms illustrated in the-drawings are merely presented by of example. Other constructions varying in detail but not in principle from'the invention. will naturally suggest themselves to those dealing with this problem."

I claimi s 1. In a ,furnace'for burning slag-forming fuel, a wall comprising water tubes, refrac tory material carried by po'rtions of said tubes, and other portions of said tubes arranged to absorb heat more directly than the firstmentioned portions, said portlons belng arranged alternately throughout substantialiythe'entire Wall surface to provide slightly f cooied and highly cooled areas to regulate furnace temperature and prevent accumulation of largqmasses of. slag.

in a, furnace for burnlng slag-forming fuel, a wall comprising water'tubes, refractory materials carried by portions of said tubes, and other portions of'saidtubes arranged to absorb heat more directly than the first mentioned portions, said portions being hrran ged alternately throughout substantially the entire Wall surface in both vertical and horizontal. directions to provide slightly cooledand highly cooled areas to regulate furnace temperature and prevent accumulation of large masses of slag.

8. In a furnace for burning slagforming fuel, a wall comprising water tubes, refractory blocks carried by portions'of said tubes,

and other portions of said tubes arranged to' absorb heat more directly than'the first men-v series of means on other portions of said tubes for more directly absorbing heat, said blocks and said means being disposed and arranged to provide a series of alternate slightly cooled and highly cooled areas throughout substantially the entire wall surface to regulate furnace temperature and prevent accumulat on of large masses of fuel residues such as slag or ash.

5. In a furnace for burning slag-forming fuel, a Wall comprising Water tubes, refractory material carried by portions of some of said tubes, and a second class of material carried by other tubes and tube portions, said second class of material being of greater heat conducting capacity than said refractory material, and said materials being arranged alternately throughout substantially the entire wall surface to provide slightly coolcd and i highly cooled areas to regulate furnace tem perature and prevent accumulation-of large masses of fuel residues such as slag or ash.

'6; "a furnace for burning slag-formingfuel, a wall comprising Water tubes," refractory' material carriedby portions of some of said tubes, and a second class ofmaterial 7 carried by-other tubes and tube portions, said said bare metal being arranged alternately 1 throughout substantially the entire Wall surface to provide slightly'cooled and highly cooled areas to regulate furnace temperature and preventaccumulation of large areas of fuel residues-such as slag 0r ash.

8. In a furnace for burning slag-forming fuel, a Wall comprising Water tubes, refractory material'c-arried by port-ions of some of said tubes, and bare metal on other tubes and tube portions, said refractory material and said bare metal beingarranged alternately throughout substantially the entire Wall surface 1 in both vertical and horizontal directions to provideslightly cooled and highly cooled areas to regulate furnace temperature and preventaccumulation of large areas of fuel residues such as slag brash.

' FREDERIO G. ELY.

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