US2176674A - Regenerative metallurgical furnace - Google Patents

Description

Oct. 17, 1939.,- a.. B. LINDEMUTH REGENERATIVE METALLURGICAL FURNACE Filed Sept. 7, 1938 2 Sheets-Sheet 1 WNN @et E7, g; L. B LINDEMUTH 3769674 REGENERATIVE METALLURGICAL FURNACE INVENTOR //voE/m/TH.

ORNEYSl Patented ocr. 17, 193e UNITED sm'rss )tatami REGENERATIVE METALLURGICAL FUR-NACE Lewis Byron Lindemuth, Port Washington, N. Y.

Application September 7, 1938, Serial No. 228,728

7 Claims.

This invention pertains to regenerative metallurgical furnaces, such as open hearth steel furnaces, and more particularly to novel constructions and arrangements for cleaning the regenerative chambers thereof while the furnace is in operation and without hazard to the workmen. The invention also pertains vto an improved means for determining the temperature of the brick checkerwork in the regenerative chambers while 10 the furnace is in operation.

4Various arrangements have been proposed in the past for cleaning the regenerative chambers of open hearth furnaces during operation,` but such as have come to my attention involve the 16 provision of openings in the side walls or stack end of the chamber, whereby solid matter, dust, etc., accumulating in the bottom of the chamber, may be removed. Such means of removal involve, however, considerable hazard to the Workmen because ofthe gas pressures which may be present at such points in the chamber causing highly heated fumes and inflammable mixtures to be expelled at the openings. If such openings in the chamber walls extend into narrow passage- Ways or tunnels in which the workmen are to operate, as has been proposed,l the men are apt'to be trapped and burned to death. As a feature of my invention I propose to eliminate such hazards by the provision of cleaning.pits adjacent the furnace end of each regenerative chamber and extending therefrom beneath the furnace substantially to the tapping side thereof, whereby a workman may stand some considerable distance away from the end of a chamber while cleaning the same, and in an atmosphere of cool, clean air drawn into the pit through the entering manholes provided therein and thence past the workmen.' and into the regenerative chamber, due to thedraft -or suction effect created at the furnace end of the chamber by the stack or artificial by blowers, during an interval that the chamber is being traversed by exhaust fumes.

The cleaning pit preferably has a height sufficient to permit a workman to stand erect therein to 45 clean the associated regenerative chamber, and a Width equal to that of the regenerative chamber, in order to provide easy access to the entire base thereof.-

As a further feature of the invention I prefer 50 to employ inconjunction with the cleaning pit,

van arrangement of the brick checkerwork in the associated regenerative chamber, such that all matter, dust, etc., accumulatingvon the checkerwork may be easily deposited in the bottom of thel (o1. .ets-15)A cleaning pit, To this end, I assemble the brick in a. series of vertical columns, each preferably vcontaining in cross-section but a single brick), with the columns touching one another only at the corners, whereby a series of smooth-walled, vertical passages are provided between columns.

In consequence of this arrangement, dust and other debris will collect vonly on the tops of the columns, whence such accumulations may Abe forced into the passageways referred to by the action of compressed air jets or by other suitable implements introduced through port holes provided in the chamber walls above the checkerwork, the accumulations falling thence by gravity to the bottom of the chamber for' removal.

In the operation of an open hearth furnace it is important to be able to determine accurately from time to time, the temperature of the brick checkerwork in the regenerative chambers. This cannot be done accurately with recording pyrometers and the like, since at the temperatures in question, the use of thermocouplesjjs imprac' ticable, so that pick-up devices responsive to radiant energy, such as photoelectric tubes, etc.. are required. However, the gas fumes in the regenerative chambers so obscure the checkerwork from such pick-up devices as to introduce substantial error in the temperatures recorded. In Y.

accordance with a further feature of the present invention, this difficulty is overcome by providing the regenerative chambers with one or more sighting' tubes, extending preferably through the top of the chamber, whereby a workman may viewv the checkerwork while the furnace is in operation, and, by selecting an interval when his view of the checkerwork is unobstructed by gas fumes, accurately estimate the temperature of the checkerwork. Such a tube may of course be closed at the sighting end by suitable transparent but refractory material, such as quartz.

In the drawings:

Fig. 1 is a sectional elevation of an open hearth furnace construction incorporating a cleaning pit in accordance with the invention, the section being taken along the line IAv-I of Fig. 4, and extending transversely through the furnace proper and longitudinally through an associated regenerative chamber thereof; v

Fig. 2 is a section at 2-2 of Fig. 1, illustrating in plan view the brick checkerwork of the regenerative chamber;

Fig. 3 is a. plan view of the furnace proper and associated regenerative chambers, shown in partial section`along the line 3-3 of Fig. 4 to i1lus` trate the cleaning pit construction more in detail; while Fig, 4 is a longitudinal sectional elevation through the furnace proper taken at 4-4 of Fig. 1. Referring to the drawings, the furnace proper I has access at one'end'of the charging side thereof through ues I0, ll,.terminating in ports, such as I2. 'I'he regenerative chambers terminate at the ends remote from the furnace extending, inthe usual manner, through reversi ing valves to sources of ,air and gas for' one set of regenerators, and to the stack for the other set, whereby air and gas are admitted to one set pf regenerators and, after being heated up thereyin, pass into the furnace to'burn'there with an intense flame, the products'of combustion passing out of the furnace through the other set of regenerators to the stack. The reversing valves, stack, etc. are not shown because they are of a known construction and form no part of the present invention.

As shown more particularly in Fig. 1, the regenerative chambers are disposed in part below the yard level I6,`With the connecting flues 4, 5 and I0, II situated in general above it, as shown. Each regenerative chamber contains a brick checkerwork I1 extending from a height I8 above the bottom I9 of the chamber, to a height below the top 2|. The checkerwork is supported on longitudinally spaced refractory arch members 22, carried by laterally spaced supporting walls 23, extending longitudinally of the regenerative chambers, thereby to provide longitudinally extending pockets 24 between the bottom of the checkerwork V,and the bottom of the regenerative chamber in which the dust, etc. 25 accumulates. To permit of removing the accumulated material 25 while the furnace is in operation, each pair of regenerative chambers is provided, in accordance with the invention, with a cleaning pit 26 or 21, the bottom 28 of which is substantially on a level with the bottom I9 of the associated regenerative chambers. 'Ihese pits extend from the regenerative chambers beneath the ilues 4, 5 and I0, II, respectively, and beneath the furnace proper I, substantially to the tapping side of the furnace as shown. The structure above the cleaning pits is supported on 4I-beams 29 which xrm the vroof of the pit.

The pit, as shown, is preferably of a sulcient height-to provide ample` headroom for a workman, such as 30, to stand erect in the pit while removing the accumulated material 25 from the regenerative chambers by means of an appropriate, long handled implement 3|. 'I'he workman has access to the cleaning pit through one or more man holes such as 32, provided with removable covers 33, situated below the y'ard level I5, and normally covered with suliicient earth to prevent cave-ins.

The cleaning pits are of a sufficient width,

preferably of a width substantially equal to the' combined widths of the pair of regenerative chambers, 2, 3 or 8, 9, as shown more particularly in Fig. 3to permit the workman to have "easy access to all the parts of the longitudinally extending pockets 24 in the chambers `for cleaning vthe same. Although the pits 26, 21 are shown separate in the drawings, they may of in flues I4, I5,

course be joined by a passageway if desired. Normally, the cleaning pits are isolated from the'regenerative chambers, by temporary partitions 34, which are removed when it is desired to clean any particular chamber.

In order to permit of easily cleaning the checkerwork l1 and depositing any accumulations Ithereon into the pockets 24, the brick comprising the checkerwork are assembled, as shown in Figs. 2 and 3, in substantially smoothwalled, perpendicular columns 35, each having preferably the cross-sectional dimensions of but a single brick, with adjacent columns contacting one anotheronly at their corners 3B, thereby to provide unobstructed, smooth-walled passageways 31 extending from top to bottom of the checkerwork. In consequence of this construction no appreciable amount of material can collect on the passageway walls of the checkerwork, but will collect only on the exposed top surface 20 thereof.

In order to remove the material thus accumulating on the top surface 20, and deposit the same in the pockets 24 at the bottom of the chambers, the side Walls 38 of the chambers are provided with a series of normally closed ports 39, through which suitable cleaning implements, such as a compressed air line 40, may be thrust by a workman, such as 4I.

For determining the temperature of the checkerwork as aforesaid, each regenerative chamber is provided with a sighting tube, such as 42, extending preferably through the top 'of the chamber as4 shown, whereby a workman, such as 43,

may view the checkerwork while the furnace L is in operation and, selecting an interval when his View of the checkerwork is unobstructed by gas fumes, estimate the temperature of the checkerwork.

What I claim is:

1. In a metallurgical furnace having a regenerative chamber, a tunnel under the furnace from said chamber, checkerwork' providing smooth-walled vertical passages through said chamber to a height above its base, said base being free from transverse obstructions and said tunnel being of sucient height and width to permit of lcleaning the entire base of said chamber from the tunnel. v

2. In a metallurgical furnace having a regenerative chamber, a tunnel under the furnace from said chamber, checkerwork providing smooth-walled vertical passages through said chamber from a height below its ceiling to a height above its base, said base being free of transverse obstructions and said tunnel. being of sufficient height, depth and width to permit of cleaning the entire base of said chamber therefrom, and meansproviding access to said chamber above the checkerwork for cleaning it.

3. In a metallurgical furnace having a regenerative chamber,V a tunnel under the furnace from said chamber, checkerwork providing smooth-walled vertical passages through said chamber from a height below its ceiling to a height above its base, said base being free of transverse obstructions and said tunnel being of `suicient height, depth and width to permit of cleaning the entire base of said chamber therefrom, means providing access to said `chamber above the checkerwork for cleaning it, and means for observing the temperature o'f said checkerwork 4comprising a sighting tube extending through the roof of said chamber.

4. In a metallurgical furnace having a regenerative chamber, a tunnel under the furnace from said chamber, a removable partition between the tunnel and chamber, means providing access to the tunnel from the opposite side of the furnace, checkerwork providing smoothwalled vertical passages through the chamber from a height below its ceiling to a height above its base, said base being free of transverse obstructions and said tunnel being of sufiicient height, width and depth to permit of cleaning the entire base of said chamber therefrom, and normally closed ports in said chamber above said checkerwork to permit of cleaning it.

5. In combination with a. regenerative chamber for a metallurgical furnace, means for observing the interior temperature thereof comprising a sighting tube providing continuous Y visibility into said chamber.

6. In combination with a regenerative chaming tube extending through the furnace charging' iioor and the roof of said` chamber, said tube4 providing continuous visibility into said chamber.

LEWIS BYRON LINDEMUTH.

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