US2311819A - Blast furnace cooling plate - Google Patents

Description

Feb. 23, 1943.

H. F. DOBSCHA BLAST FURNACE COOLING PLATE I Filed Aug. 1, 1940 IIIIIIIIIA IIIIIIIII/IIYIIIII 4 5 w w p f W M 7 a Patented Feb. 23, 1943 UNITED STATES PATENT OFFICE BLAST FURNACE COOLING PLATE Herman F. Dobscha, North Braddock, Pa. Application August 1 1940, Serial No. 349,260

3 Claims.

This invention relates to cooling elements for blast furnace walls, and more particularly to a novel design of cooling plate having two separate and independent compartments in which the cooling medium is circulated.

Double compartment cooling plates of various designs have long been used for controlling the temperature of blast furnace walls. Usually the double compartment is provided by a front portion and a rear portion. The purpose of such construction is that in the event that the forward end of the plate, which is subjected to the greatest heating effect and to abrasive action by the stock, becomes damaged, some degree of cooling effect may be retained by operation'of the rear portion. To obtain better heat exchange, the cooling plates are usually provided with a system of baffles positioned within the front and v usually employed as a cooling medium can economically be given only a limited amount of conditioning before using it in the cooling system. The hard constituents of the water, to-

gether with silt and other particles which maybe entrained therein, become deposited upon the interior surfaces of the plates and by cumulative action, a heavy layer of such material is rapidly built up. In the prior designs, this deposition is greatest upon the front portion of the double compartment. cooling plates at which points the temperature of the plate surface is much higher. The scale formation accumulates similar to that observed in water tube boiler installations which become encrusted with scale. As the quantity of water required for each cooling plate is usually on the order of to 40 gallons per minute, there is a practical limit to the amount of straining which can be done.

Consequently, when the necessary water is 0btained from a source such as a river, a large quantity of silt and sand is carried by the coolinclude a contiguous channel which extends rearwardly at the side of the plate. Thus, both the.

the major portion of the cooling effect is re-' tained after failure of the front compartment. Another object of my invention is to provide a cooling plate constructed and arranged in the specific manner herein set forth, so that the casting practice is simplified.

These and other objects of my invention will be apparent in the following description, considered in conjunction with the accompanying ing water and deposited in the cooling plate interior.

The front compartments of older designs also drawing, in which:

Figure 1 is a fragmentary sectional view of a blast furnace wall showing the cooling plates installed therein.

Figure 2 is a horizontal section of my improved cooling plate.

Figure 3 is a longitudinal section on line III-,-III of Figure 2.

Figure 4'is a section on line IV-IV of Figure 2.

Referring to the drawing, there is shown in Figure. 1 a furnace wall 2 in which is installed a plurality of cooling plates. Each of the improved plates 3 comprises a one-piece casting usually formed of copper or bronze, having top, bottom, front, rear, side andtintermediate walls. Near the front end of the plate 3, the intermediate wall 5 forms the forward or nose compartment N. Extending. rearwardly from the partition 5 is anintegral vertical rib 6 which, in conjunction with a pair 'of similar ribs 1 extending forwardly from the rear wall 8 of the plate, forms a system of longitudinally extending baflles for the rear compartment R.

The rear wall 8 is provided with two pairs of holes 9 and ill, in spaced relation between the baflies l and the side-walls ll of the plate. The outer pair of holes, 99, is threaded to receive respectively a water supply pipe I! and a water exit pipe, l3. The inner pair of holes, l0lli, are smooth or unthreaded, as shown, and are of the proper size to permit the insertion therethrough of a. water supply pipe I4 and a water exit pipe IS. A pair of holes l6-l6 is provided in the partition eliminate 5 and these holes are threaded to receive the forward ends of the pipes I4 and I5.

The forward or nose compartment N of my improved plate is of comparatively shallow depth and volume in comparison to the similar space in prior designs of plates. While it is unnecessary to maintain any particular ratio between thecross-section of the water supply pipes and the transverse section of the nose compartment, I prefer to use supply and return pipes which have a cross-sectional area of about per cent to per cent of that of the transverse nose section N. By so doing, I have found that using 20 to gallons of water per minute at a pressure of about 20 pounds, I will obtain a sufficient degree of scouring action in the nose compartment to keep the with undiminished force and to move with a turbulent scouringaction to the exit pipe l5.

Heretofore, the provision of battles has complicated the casting of double compartment cooling plates, and it is necessary, in the prior designs, to cast the plates flat, that is to say, with the greater dimensions in a horizontal plane. The result of such prior practice is that frequently the nose portion of the plate is cast in non-uniform thickness. Since it is this portion of the plate which is subjected to abrasive action and directly exposed to the highest temperature, failure of the prior art plate is often attributable to this condition of non-uniform thickness of the nose portion.

In the plate of my invention, the longitudinal disposition of the bafiles 6 and 1 and the overall design of the plate is such that the plate may be cast upright, that is, with its baflles vertically disposed and the nose portion at the bottom of the mold. A solid dense nose portion is thereby obtained, and the use of anchors, required in prior art constructions, is eliminated.

I claim:

1. A cooling element comprising abody having top, bottom, front, rear and intermediate and side walls defining a comparatively small forward compartment and an independent comparatively large rear compartment, a pipe passing through the rear wall and screwed into the intermediate wall for impinging a cooling medium directly against the front wall of said forward compartment and means for circulating a cooling medium in said rear compartment, a plurality of bafiles integral with the top and bottom walls of said body and extending longitudinally in the latter compartment, and being of less length than the longitudinal dimension between said rear wall and said intermediate Wall.

2. A cooling element comprising a cast metal body having a comparatively small forward compartment and a separate compartment of materially larger volume to the rear thereof, respective inlet and outlet pipes communicating with 'the forward compartment for impinging a cooling medium directly against the front wall thereof and for discharging the cooling medium, said pipes passing through the rear wall of said rear compartment and firmly secured in the rear wall of said forward compartment, and respective baffies extending forwardly from the rear wall of said rear compartment and rearwardlyirom the rear wall of said forward compartment.

3. A cooling element of the character described. comprising a shallow metallic body having top and bottom walls, side walls integral therewith, a forward end wall and an intermediate wall integral with said upper and lower and side walls, said forward end wall and said intermediate wall defining with said top, bottom and side walls a forward compartment of comparatively small volume, a rear wall spaced a considerable distance from the intermediate wall and defining with the top, bottom and side walls a rear compartment of considerably larger volume than the forward compartment, respective inlet and outlet pipes communicating with the said rear compartment, other inlet and outlet pipes having smooth unthreaded portions where they extend through said rear compartment, the ends thereof being threaded into said intermediate wall, said pipes being effective to provide for the rapid circulation of a cooling medium through said forward com-

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