US2709009A - Cupola charging device - Google Patents

Description

May 24, 1955 H. A. REECE ET AL CUPOLA CHARGING DEVICE Filed March 21 1951 3 Sheets-Sheet 2 us gm 15o 155 1.59

1.60 1.64 1.65 L69 no 114 1.1:? 119 INVENTORS. HERBERT A. Reece: BY CHESTER/X. HARTMAN ATTORNEY.

May 24, 1955 H. A. REECE ET AL CUPOLA CHARGING DEVICE s Sheets-Sheet s Filed March 21. 1951 ATTORNEY.

m m m m HERBERT A. Keege BY CHESTER A.\-\NZTMAN United States Patent CUPOLA CHARGING DEVICE Herbert A. Reece and Chester A. Hartman, Cleveland Heights, Ohio Application March 21, 1951, Serial No. 216,776

Claims. (Cl. 21418) This invention relates, as indicated, to a cupola charging device, but has reference more particularly to a charging device of the type employing a skip bucket.

A typical skip hoist charger, consisting of a hoist or lift close to the cupola in either a vertical or inclined position, is adaptable for small cupolas with restricted clearances, provides rapid loading and is fairly inexpensive to install. Such chargers are shown and described by way of example, on pages 4, 7, 8 and 9 of Bulletin FY-l0l, entitled Whiting Mechanical Charging Systems, published in 1941, by Whiting Corporation, of Harvey, Illi- I'lOlS.

Mechanical charging of a cupola furnace by means of such skip hoists has not proven entirely satisfactory from a control standpoint, although this method of charging is the most economical, from the standpoint of cost, for low tonnages. This dissatisfaction stems primarly from the manner in which the skip bucket discharges and deposits the charge in the cupola. As the metal and coke charges are discharged into the cupola, from the inclined skip bucket, the discharged materials have a tendency to pile up on one side of the cupola, with resultant uneven wear or damage to the cupola side wall refractories as well as varying the charge volume, coke volume and thereby the blast pressure on an operating basis. This uneven charging reflects a changing or variable Belden curve as the melting of iron progresses (see Bulletin 54 U. S. Bureau of Mines, 1913).

Many efforts have been made to avoid this tendency towards uneven charging and damage to the cupola side wall refractories. Some foundries have installed swinging bafiies in the cupola charging opening, while others have installed swinging rails in the cupola in an effort to promote uniform level charging and as a refractory protection. These methods, as well as others, have failed.

The non-uniform distribution or piling up of raw rnaterials charged into the cupola by the skip hoist method of charging also promotes non-uniform melting conditions, which results in (a) lack of uniformity in the composition of the melt, (b) lack of uniformity in the physical properties of the product, (0) variable temperature of the melt, (d) gasified iron, (e) slag entrainm'ent in the metal, (f) lack of uniformity in the cupola promoting hot spots and causing burning through of the shell, (g) high losses in defective castings, additional cost of refractories, and excessive labor costs. In addition of these economic factors, there is a wide variation in the metallurgical and physical properties of the product.

We have discovered, as the result of extensive experiments, that virtually all of the aforesaid disadvantages and shortcomings of skip hoist charging of cupolas can be obviated, and uniform or level charging accomplished, by the use of a novel device which we have developed for use in connection or association with the skip bucket of a conventional skip hoist charger.

The device of our invention is illustrated in the accompanying drawings forming a part of this specifica- 'ice tion, in which like numerals are employed to designate like parts throughout the same, and in which Fig. 1 is a view, partly in section and partly in elevation, showing the bucket of a vertical skip hoist having the device of the present invention incorporated therein, with the bucket at its lowermost or charge-receiving position;

Fig. 2 is a view similar to Fig. 1, but showing the bucket at its uppermost or discharging position, in relation to a cupola furnace, the furnace being shown more i or less diagrammatically;

Fig. 3 is a cross-sectional view, taken on the line 3--3 of Fig. 2, and

Fig. 4 is a fragmentary cross-sectional view, taken on the line 44 of Fig. 3;

Fig. 5 is a diagram showing improved results attained through the use of the present invention;

Fig. 6 is a view similar to Fig. 3, but showing an arrangement wherein the charging device may be projected from the bucket to a varying extent, as may be required, either for experimental purposes to determine the optimum position of the baffie plate for any given bucket load, or to vary the projection of the charging apparatus as the size of scrap, pig iron, steel, etc. becomes larger or smaller;

Fig. 7 is a cross-sectional view, taken on the line 7--7 of Fig. 6;

Fig. 8 is a fragmentary cross-sectional view, taken on the line 8-8 of Fig. 7, and

Fig. 9 is a fragmentary cross-sectional view, taken on the line 9-9 of Fig. 7.

Referring more particularly to Figs. 1 to 4 inclusive of the drawings, reference numeral 1 denotes generally the structural steel frame of a skip hoist charger, which is mounted over a concrete pit 2 at one side of the cupola 3, so that the bucket 4 of the charger can be lowered into the pit and filled at floor level. The frame 1 includes laterally-spaced channels 5, in which the pairs of wheels 6 and 7 of the bucket 4 are guided, as the bucket is raised or lowered by means of conventional mechanism, a portion of which is generally indicated by reference numeral 8, but which forms no part of the present invention.

As the bucket 4 is elevated, it remains in the position shown in Fig. 1, until the level indicated at 9 is reached, and at this point, the conformation of the frame is such that the bucket gradually inclines, first forwardly and upwardly, and then forwardly and downwardly, to the discharging position shown in Fig. 2. In this position, the front wheels 6 are stopped by angle abutments 10 on the frame, and the rear wheels 7 are stopped at the position indicated, by reason of the restraining influence of the raising and lowering mechanism of the bucket. The bottom or lower edge of the cupola charging or door opening is indicated by reference numeral 11.

The bucket 4 is of conventional design or construction, except for the addition of the charge distributing device of the present invention, and certain other details, to which reference will be made hereinafter. It consists of a bottom 12 having a semi-circular recess 13 in its forward edge, a rear wall 14 (which assumes the role of the bottom when the bucket is in charge-receiving position), a top wall 15, and side walls 16 and 17, the bottom 12 being considerably longer than the top wall 14 so as to provide a discharge lip which projects into the cupola, as shown, when the bucket is in discharging position.

In the absence of the charge distributing device of the present invention, the charge in the bucket, when the bucket reaches the dumping position shown in Fig. 2, would slide by gravity down the bottom 12, and depending upon the momentum thereof, would descend into the furnace at various distances from the inner walls of the furnace, so that no uniformity in the distribution of the charge would be achieved.

The charge distributing device of the present invention comprises a pair of laterally-spaced metal bars 18 and 19 which are secured, as by flat head cap screws 20, to the inner surfaces of the side walls 16 and 17 of the bucket, the lower edges of the bars being in contiguity with the bottom 12 of the bucket, so that the bars extend at the same inclination as the bottom of the bucket. The bars extend forwardly from the bucket and into the cupola shaft for a substantial distance, as shown in Fig. 2.

The bars 18 and 19 are provided with beveled front ends 21, to which a cross bar 22 is secured, as by welding. The bar 22 has bolted or otherwise secured to the inner face thereof, a battle plate 23, which lies in a plane parallel to the bar 21, and extends to the bars 18 and 59.

As the materials slide down the bottom 12 of the bucket, aportion thereof strikes the bafiie plate 23, and falls down the shaft at one side of the furnace, while the remainder of the materials strike the upper edge of or pass over the baffle plate, and fall down the shaft at the other side of the furnace. The net result is that the charge, as a whole, is distributed by the device in a uniform manner, and does not pile up at any particular spot in the cupola.

The bars 13 and 19 are adjustable relatively to the bucket, and the extent to which these arms extend into the cupola shaft, as well as the angle at which the baffle plate 23 is set with respect to the bars 18 and 19 are determined in advance to produce the uniform distribution of the bucket discharge, which has been described.

In order to counter-balance the weight of the baffle device, a weight 24 is secured to the rear wall 14 of the bucket, and may be adjusted in position to compensate for variations in the length of the bars 18 and 19 and other variables. By the use of such a counterbalancing weight, the hoist cable attachment is prevented from becoming unwound from the cable drum through excessive tilting of the bucket as it discharges its lead into the cupola.

By the use of a battle distributing device, as described, uniformity of cupola charging is assured, and all of the disadvantages which have been referred to, are virtually eliminated.

As an example of improved control which is attained through the use of the distributor of the present invention, reference may be had to the frequency distribution curves in Fig. 5 of the drawings, in which the diagram at the right shows the frequency distribution of silicon before the addition of the device to the bucket, and the diagram at the left shows the frequency distribution of silicon after the addition of the device to the bucket.

These curves or diagrams are based on an analysis of 200 consecutive tons (87 determinations). The frequency of silicon is indicated by the ordinate percentage figures. The silicon specification which is aimed at are those indicated by the bracket and unshaded areas, while those determinations outside the desired specification are indicated by the shaded areas. The desired specification, in this case, was 1.60% to 1.86% silicon.

It is apparent from these curves or diagrams that the control improved 100% in silicon. There was a like improvement in other elements. The cost of repairs and maintenance, etc., were reduced.

In Figs. 6, 7, 8 and 9, we have illustrated a bucket and charging device which we have used, in which the charging device may be projected from the bucket to a varying extent, as may be required, either for experimental purposes to determine the optimum position of the baffle plate for any given bucket load, or to vary the projection of the charging apparatus as the size of scrap, pig iron, steel, etc., becomes larger or smaller.

Referring to Figs. 6, 7, 8 and 9, there are secured to the sides 16 and 17 and bottom 12 of the bucket, as by welds 25, housings 27 consisting of angle plates.

The arms 18' and 19' of the charge distributing device are mounted for reciprocal sliding movement in these housings, and for this purpose, the bars are provided with portions 30 and 31 of reduced height, which are guided in guide bars 32 and 33 respectively, rigidly secured within the housings. The portions 30 of the arms provide recesses 34, the rear ends of which form shoulders or abutments 35.

A pair of pins 23 are provided, one above and one below the portions 39 of the arms, these pins extending through the housings 27, recesses 34 and into the sides of the bucket, as clearly shown in Fig. 8. The ends of these pins are cut flush with the outer surfaces of the bucket sides and spot welded to the bucket sides at these poi; s to prcvent their displacement.

iwith the pins 28 in the position shown, the arms 18 and 19 will slide downwardly to the position indicated by the broken lines in Figs. 6 and 7, at which position, further movement of these arms will be stopped by virtue of the abutment of the pins 28 with the shoulders 35.

If it is desired to shorten the stroke of the arms 18 and 19, the pins 28 may be removed, and new holes for pins provided in the housings 27 and sides of the bucket, at points spaced the desired distance from the location of the old holes, and pins inserted in the new holes and secured in position in the same manner as previously.

It will be apparent from the foregoing, that by setting the pins 28 at different selected positions along the housings 27, the extent to which the arms 18 and 19 Will fall from the housings can be varied, as determined by the abutment of the shoulders 35 against the pins 28. In this way, the optimum position of the bafile plate 23 with respect to the cupola shaft for any given bucket load may be determined, or varied in accordance with changes in the size of scrap, pig iron, steel, etc.

Moreover, by the use of wedges, bolts and groups of openings in connection with the bars 22, baffie plates 23 and forward ends of the arms 18 and 1?, the optimum angle at which the baffle plate should be set with respect to the vertical axis of the cupola shaft, may also be determined or varied in accordance with requirements.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention, or the scope of the subjoined claims.

Having thus described our invention, we claim:

1. in a cupola charging device, the combination of a skip bucket, charge distributing means secured to said skip bucket for movement therewith, said means having charge distributing surfaces movable into the discharge path of the charge in the cupola charging section in response to tilting discharge movement of said bucket.

2. in a cupola charging device, the combination of a tiltable skip bucket, charge distributing means secured to said skip bucket for concurrent movement therewith, and angular charge distributing surfaces provided on said means, said surfaces being movable into the discharge path of the charge in the cupola charging section in response to tilting movement of said bucket to its discharge position.

3. A combination, as defined in claim 2, wherein said distributing means comprises a deflector element and support means secured to said bucket and said deflector element to project said deflector element forwardly from the discharge end of said bucket.

4. A combination, as defined in claim 3, including adjustable securing means provided on said bucket and engageable with said support means for selectively securing said deflector element in predetermined spaced relationship to the discharge end of said bucket.

5. A combination, as defined in claim 3, wherein said 5 support means comprises spaced arms extending forwardly from the discharge end of said bucket, and said deflector element comprising a plate secured to said arms transversely thereof in a position angular to the common plane 840,575 thereof. 1,534,891 1,772,884 2,025,702

UNITED STATES PATENTS Messiter Jan Beaumont Apr Beetham Aug. Anderson Dec.

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