US1853409A - Regenerative furnace - Google Patents

Description

L. C. EDGAR REGENERATIVE FURNACE April 12, 1932.

2 Sheets-Sheet 1 Filed July 8, 1950 Lou/ S C. EDGAR WWW April 1932- c. EDGAR 1,853,409

REGENEBATIVE FURNACE Filed July 8, 1930 2 Sheets-Sheet 2 Lou/5 C. 50614 R Patented Apr. 12, 1932 LOUIS G. EDGAR, OFQWISSVALEPENNSYLVANIA rmennm'rivn summon hpplieationflled m a, 1930. Serial No. 466,515.

' considerable merit, andvarious methods ofregenerator construction have been advanced with this end inview, among which may be mentioned a bodily .movable regenerator structure by means of which the regenerators,

instead of being permanently connected with the ends of the furnace, are arranged so that theymay beperiodically interchanged. Such structures, however, are impracticable and, so far as known, have neveribeen successfully applied. V

The present invention; contemplates the provision of a particular type of furnace and regenerator structure whereby unidirectional combustion and flow of hot gases and theair to be heated may be obtained from stationary regenerators or checkershaving the inlet and outlet ends thereof permanently connected to the finletand discharge ports of-the furnace. Thus, the inlet anddischarge ports, are

not called upon to do double dutytand'con sequently may be designedwith theirpar-- ticular functions, in View. Likewise, the

checker structure may be givena predetermined arrangement in view of the admission of the hot gases and the air to be heated always at one end of the regenerator chambers, as in the casewhere it isdesired to use checkerwork having the largest openings at the point where the greatest cinderingaction ocours, or adjacent the exhaust and, in fact, the construction of'thefurnace as a Wholemay be given; a predetermined design with a view toward improving its efiiciency and lengthening the life of; the regenerators.

Theinventidn is illustrated as applied to an openihearth steel furnace utilizing a fuel such as natural gas-or tar, which does not re-- quire preheatingin the checkers,the air only beingpreheatedby the latter.v which may be of any conventional design but which are herein shown as of graduated construction. It willv be understood, however, that the i1:-

vention may be found adaptable to other types of furnaces and also that any particular grade of fuel may be utilized, such as producer gas, which may be preheated and mixed with the air from the checkers,any number 65 of which may be employed.

In the drawings Figure lis a view partly in horizontal section and partly in plan of an open hearth furnace and regenerators, the top walls of the latter being broken away in part to show the checkerwork below, t

Fig. 2 is a view in transverse vertical section taken on the line III I, Fig. 1; and

Figs. 3 and 4 are sectional views taken, respectively, .on the lines TIL-III and .IV-IV', Fig. v 1.

The numeral 5; generally designates an open hearthfurnace having the usual hearth 6 for receiving the bath of. molten; metal. A gas, tar or like fuel inlet port or burner 7 is illustrated atone end of the furnace, and below this port is the usual air intake port 8, see Figs. '2 and 3, the heated air passing into this port from'the checkers and up through 7 ports 8 on opposite sides of the fuel inlet port 7, whereit is mixed with the fuel and the flame directed across the open hearth 6.

The products of combustion pass off at the left as here shown and down through port 9 and out through, portv 9 to the checkers, the slag p0cket'10 opening intothe port 9t, note Fig. 4;. 'It will thus be seen thatthe furnace isof the. unidirectional combustion type, the

air andgas beingalways admitted at one end i of the furnace and the products of combustion passing off at the opposite end, the inlet and outlet. ports being designed with their particular functions in view. a

The regenerator arrangement and construction' which permits unidirectional combustion in thefurnace is clearly illustrated in Fig. 1. The regenerators, which are two in number in the presentinstance, are generally indicated at 12 and 13, and comprise the usual brick .checkerwork 14. which isi housed by refractory walls 15 and reinforcingbuckstays 16 and tie rods 17. The. regenerators are shown in the shape of ahorseshoe with eachend connected to the furnace. The outlet m It will be seen that by suitably manipulating the valves 18 and 18*, the waste gases or products of combustion may be alternately directed into the regenerator chambers 12 and 13 as they are exhausted from the furnace.

The waste gases or products of combustion are directed into the upper part of the regenerator chamber and travel down through the checkerwork of the regenerators and into the bottom part of said chamber and then pass out to the stack flue through lower outlet passages or conduits 19 and 19, note Fig. 3 and dotted outlines in Fig. 1, each passage being controlled by reversing valves 20 and 20, the passages 19 and 19 merging into outlet flue 21, which leads to the stack 22.

The air to be heated is alternately admitted into the regenerators at the'same extremity as the hot gases, or the outlet end of the furnace, through inlet ports or conduits 23 and 2- which are controlledby the usual saucer valves or valves of any preferred type as at 24 and 24 which may be controlled either manually or automaticallyand passes into the bottom of the regenerator chamber and upwardly through the checker openings into the dome or top of said chamber and flows along said chamber and passes out of each regenerator through outlet passages 25 and 25*, which are controlled by reversmg valves 26 and 26, and into air intake port 8 and thence into ports 8.to the furnace.

In Fig. 4 the arrows indicate the'course of the hot gases or products of combustion and the air to be heated as they pass into the regenerators. It will be noted that the flames or hot gases are directed from the exhaust into the upper part of the regenerator chamber and travel. down through the checkerwork, while the air to be heated is admitted into the lower part of the regenerator chamber and flows upwardly through the checkerwork. When the air to be heated is passed through the regenerator chamber. the heat previously absorbed by the checkers from the hot gases is partly expended in heating the air and in view of the fact that the relatively cold air when admitted into the regenerator chamber first contacts with the lower portion of the checkers, and also in view of the tendency of warm or hot air to 4 rise, the upper part of the checkers and regenerator chamber will be much warmer than the lower part of the checkers and regenerator chamber during the portion of the cycle when the hot gases are directed into the regenerator. In other words, there isi'diiferential temperature headpressure set up in the regenerators which will cause the hot gases to flow down through the checkers, or from the relatively warm to the relatively cool portion of the regenerator chambers, and conversely, this difference in temperature will cause the incomipg cold air to flow upwardly through the checkers, or from the relatively cool to the relatively warm portion of the regenerator chambers, and this action is augmented by the exhaust pressure and fine draft. While it is preferred to build the checkerw'ork with graduated checker openings, as heretofore stated, and such construction is herein shown, yet due to the foregoing action, the'regenerators will function in an efficient manner with any suitable arrangement of eheckerwork, as in any event'the hot gases and air to be heated will be equally and proportionally distributed throughout the checker passages.

The operation of the furnace will be readily understood by those having a knowledge of the art. The reversing valves may be antomatically operated in proper order to alternately direct the waste gases or products of combustion into the regenerators 12 and 13. Assume that the instant order of the cycle is to direct the hot gases through the regenerator 12 and the air to be heated through regenerator 13. The valves 18, 24a, 26a and 20 would then be closed and valves 18a, 24, 26 and 20a opened, and the. gases from the furnace would thus be directed into the regenerator 12 andclosed off from 13 while the air would be admitted into regenerator 13 and closed off from 12. As heretofore stated, the hotgases pass into the dome or top part of the regenerator chamber and down through the checker work into' the bottom part of the regenerator chamber and out through the port 19a and flue 21 to the stack. The air would be admitted through inlet port 23 into the bottom part of the chamber of the regenerator 1'3-and passes up through the checkers and into the top part of the chamber of regenerator 13, thus becoming heated, and flows along said chamber and finally passes out through outlet passage 25 and into air intake 8 and upwardly through passage 8 to be mixed with the fuel and the flame directed onto the bath. 8

While both the hot ases and air to be heated could be admitte into the lower part of the regenerator chambers as commonly I practiced, yet it is preferred to have the air flow through the checkers in a direction counter to the flow of the gases or products of combustion, so that it passes from the cold est to the hottest portion of the checkers and thence to the furnace, and thereby improve the efficiency of the regenerators. The arrangement of the checkers as shown in the drawings is an example of a construction which has proved advantageous in regenerators, the larger openlngs belng provided at the inlet extremity, or where the hot gases are directed into the regenerators from the exhaust.

IVhat is claimed as new is:

1. The combination with a furnace having unidirectional combustion, of a stationary horse shoe shaped regenerator structure having inlet and discharge ports permanently connected to the exhaust and intake ports of the furnace, and means for alternately (lirecting the products of combustionand the air to be heated through the regenerator in the same direction.

2. The combination with an open hearth furnace provided with inlet and discharge ports, respectively, for fuel and products of combustion of a stationary horse-shoe shaped regenerator provided with a plurality of regenerator chambers in permanent communication at opposite extremities, with said inlet and discharge ports, and means for alternately directing the products of combustion from the furnace through the chambers of the regenerator.

3. In combination, an open hearth furnace having unidirectional combustion, of a plurality ofstationary horse-shoe shaped regenerator chambers having inlet ports for waste gases permanently connected to the exhaust ports of the furnace, and means for alternately diverting the said gases into said chambers.

4. In cc mbination, an open hearth furnace having inlet and exhaust ports, of a plural ity of horse-shoe shaped stationary regenerator chambers having inlet ports for waste gases at one extremity in alternate communication with the exhaust port of the furnace and additional ports at the same extremity hand. LOUIS C. EDGAR.

for alternate intake of air or both air and fuel.

' 5. In combination, an open hearth furnace having unidirectional combustion, of a plurality of horse-shoe shaped stationary regenerator chambers having inlet ports for the products of combustion and the air to be heated at one extremity and outlet ports leading to the discharge flues and air intake ports of the furnace at the other extremity, and means for controlling alternate flow of the products of combustion and the air to be heated through said chambers.

6. The combination with an open hearth furnace provided with an inlet port at one end and a discharge port at the opposite end, said ports being, respectively, for fuel and products of combustion, of a stationary horse-shoe shaped regenerator provided with a pluralityof regenerator chambers in permanent communication at opposite extremities with said inlet and discharge ports, said inlet and discharge ports communicating with said regenerator chambers .adjacentuthe top thereof, said regenerator chambers being provided with air inlet ports adjacent the

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