US1719452A - Soaking pit - Google Patents

Description

July 2, 1929. H. c. RYDlN-G 1.519.452

SOAKING PIT Filed March 3, 1927 3 Sheets-Sheet l July 2, 1929. C, RYDlNG 1,719,452

SOAKING PIT Filed March 3, 1927 3 Sheets-Sheet 2 j?? 062e for @www Patented July 2, 1929.

UNITED STATES HERBERT C. RYDING, OF BIRMINGHAM, ALABAMA.

SOAXING PIT.

Application led March 3, 1927. Serial No. 172,387.

The present invention is related to the invention disclosed in my co-pending application Serial No. 102.443, filed April 16, 1926. The embodiment of the invention described and illustrated in my former application included a recuperator for pre-heating the air used to support combustion. The invention is not limited, however, to the use of such a recuperator. The embodiment of the invention illustrated in the present application is in many respects similaito the apparatus illustrated in my former application, a chief distinction being that in the present case the recuperator is omitted.

Heretofore, it has been practically universal practice to provide soaking pits with checkerwork or regenerative chambers for preheating the air used to support-combustion in the soaking pit and it has sometimes been the practice to also preheat the gas used as fuel. The prior practice has been to periodically reverse the direction of travel of the fuel and waste gases. Therefore, the prior types of soaking pits required usually two sets of regenerative or so-called checker chambers 'and various forms of reversing valves and conduits for reversing the direction of travel of the fuel and waste gases to and from the soaking pit. My invention eliminates the necessity of installing regenerative chambers such as previously used and does away with reversing valves and other necessary operating gear. The economies eiected by my construction, conservatively estimated amounts to about one-third of the cost of prior constructions.

The invention will be apparent from the following specification when read in connection with the accompanying drawings and the features of novelty will be pointed out with particularity in the appended claims. In the drawings- Figure 1 is a plan view with parts shown in section of a four hole soaking pit embodying m invention, the view being intwo parts ivided on the lines a-a.

Figure 2 is a longitudinal section on line 2-2 of Figure 1, this view being in two parts divided on lines [1 -b.

Figure 3 is a transverse section on line 3-3 of Figure 1.

Figure 4 is a section on the staggered line 4 4 of Figure 1.

Referring in detail to the drawings, the soakin pit includes end walls 10 and 12 and si e walls 14 and 16 and division walls 18, 20 and 22, which divide the structure in such way as to form what is termed in the art a four hole soaking pit.

The four holes thus formed are numbered 1 to 4 inclusive, in Figure 1. Each hole is adapted to receive one or more ingots to be reheated as will be hereinafter more fully described. The several holes or pits are of the same construction and arrangement and are provided with the similar devices for supplying gas and air to opposite sides thereof; hence, a description of one will suce for all. 4Each pit is open at the top and a removable cover or roof 24 is supported b a suitable carriage 26 having wheels 28 Whlch are arranged to travel on tracks 30 forming part of a suitable super-structure 32.

Each hole or section of the soaking pit includes an ingot chamber 34 adapted to receive the ingots 36 which are to be reheated for the purpose of properly conditioning them for subsequent rolling.

The structure of refractory material is so arranged that flame chambers 38 and 40 open into each ingot chamber 34.

The lower walls 42 of said flame chambers are preferably inclined so that they serve as a baile against which the llames from burners 44 strike. It is important that the flame chambers 38 and 40 be of considerable length so as to prevent burning the ingot. I have discovered that when using direct gas fired burners in which the air and gas is preheated outside of the soakin pit, as hereinafter described, that the lengt i of the flame chambers must be in excess of two feet as measured in a line from the end of the burner to the nearest wall of the ingot chamber 34, that is to say the distance indi# cated by the dimension line X in Fig. 3 must be two feet or over. The upper wall or roof 46 of each flame chamber is preferably, though not necessarily tapered upwardly as shown.

In the embodiment of the invention illustrat-ed the ingot chambers are heated by an explosive fuel formed of a mixture of coke oven gas and air, which is mixed in the inspirator portions 48 of the burners, which it is noted are located wholly outside of the refractory structure of the soaking pit. Coke oven gas is supplied to the several burners from a gas manifold 50 having branches 52 and 54 leading to the burners on the opposite side of the pit. Air is supplied to the burners under pressure by means of a blower 56 connecting with an air manifold 58 having branches 6() and 62 leading to the burners on the opposite side of the soaking pit. Because of the fact that the air is supplied under pressure it serves to draw the gas from the gas supply pipes and thoroughly mix it in the inspirator chamber 48, so as to form thorough explosive mixture which ignites instantly and burns with great rapidity within the flame chambers 42. Very low pressure of gas is required as the air pressure will inject suflicient gas when the pressure in the gas manifold amounts to only one or two inches of Water. Valves 53 and 61 control the supply of gas and air to the burners 44.

Located in the opposite walls of the ingot chamber at a point midway between the flame chambers, I provide waste gas outlet ports 64 and 66, which open into flues 68 and leading to tunnel flues 72 which connect with an outlet or stack 7 4. The bottom surfaces of the outlet ports 64 and 66 are on an incline as indicated at 67 so as to prevent the accumulation of dust or other foreign matter thereon. The flues 72 are provided with suitable flue dampers 76 and ghe -stack is provided with a similar damper A suitable cinder bed 80 is formed on the bottom wall 82 of each ingot chamber. A clean-out opening 84 in the bottom wall is provided with a breakable plug 86 which may be knocked out for the purpose of cleaning out the pit at desired intervals. A tunnel 88 extends longitudinally below the several holes of the soaking pit and provides for the entrance of workmen to clean away refuse discharged through the clean-out holes 84.

In operation the in'gots to be treated are lowered into the pit or ingot chamber by the usual form of overhead tackle suspended from a traveling crane. The roof or cover 24 is moved to the position shown in Figure 3. The ingots are then subjected to the heat from the oppositely disposed burners 44 which simultaneously direct the flame in the direction of the ingots. The flames strike the refractory walls of the flame chambers which are designed to absorb and reflect the radiant heat uniformly throughout the entire length of the ingot. The waste gases from both flame chambers simultaneously are ejected or exhausted through the outlet ports 64 and 66 in the opposite walls in the center of the ingot chamber. These outlet ports are of relatively restricted area. Because of this restricted area and also because of the fact the explosive mixture of fuel is supplied under pressure, a super-atmospheric pressure is maintained in the ingot chamber. The amount of air mixed with the gas outside of the pit is proportioned to effect complete combustion within the flame chambers.

cause of this complete combustion and because of the fact that a pressure is maintained inthe ingot chamber, it is apparent that free air or oxygen is excluded from the ingot chamber. This enables me to continuously maintain either a neutral or a reducing atmosphere in the ingot chamber. By maintaining such a reducing or neutral atmosphere in the soaking pit, I am enabled to prevent oxidation or formation of scale on the outside of the ingots. Heretofore such cinder scale losses have amounted to approximately 21/2% to 3%. By my improved method these scale losses will be materially reduced and will amount to not more than 1%. This saving alone in oxidation of ingots will practically pay for the cost of the fuel required to heat the steel in preparation for rolling.

In the old form of soaking pit heretofore used which employed regenerative chambers for preheating combustion air, it was necessary to reverse the direction of the flow of the fuel at regularly stated intervals. Skilled operators were required to operate such pits, the time for reversal of flow of fuel being practically determined by the o erators skill in judging the temperature o the pit by the color of the flame escaping from sight holes in the roof of the pit. If reversal were not made at the proper time, the ingotsl were improperly heated forming cold spots and sometimes even burned. The temperature of the checker chambers were frequently unbalanced by reversal of flow at improper times. All of this has tended to make the operation of heating ingots by former methods very inefiicient. My improved soaking pit employs direct gas fired burners and there is no reversal of flow of fuel required. The design and arrangement of the pit is such that ingots cannot help but be uniformly heated throughout. My improved pit can be operated by relatively unskilled labor. The inclined bottom walls of the flame eh ambers of my improved pit are of such inclina tion and length that said walls function to deflect and break the force of the flame. This prevents direct impingement of the flame against the ingot. The ingot may be said to be bathed uniformly throughout its entire surface by radiant heat, in a neutral or non-oxidizing atmosphere.

Though I have described quite specificallyv the embodiment of the invention herein illustrated. it is not to be construed that I am limited thereto since various changes may be made by those skilled in the art without departure from the invention as defined in the appended claims.

What I claim is 1. In the heating of ingots to prepare them for rolling, the method which consists in placing them in a pit and supplying exx plosive gaseous fuel to the pit so as to 130 maintain therein a pressure above atmosphere and thus exclude air from the pit which would oxidize the surface of the inotf.

2. In the treatment of ingots, the method which consists in simultaneously directing explosive gaseous fuel toward opposite sides of the ingot and withdrawing the waste gases from a point substantially midway between the points at which the fuel is introduced so as to uniformly heat the ingot, and maintaining a pressure above that of atmosphere while heating the ingots.

3. A soaking pit comprising a structure of refractory material having a chamber formed therein adapted to receive an ingot, means located wholly outside the pit structure for mixing fuel and air, means for discharging the explosive mixture thus formed into said chamber and an outlet port of restricted area adapted to assist in maintaining a pressure in said chamber above that of atmosphere. f y

4. A soaking pit comprising a structure of refractory material having a chamber formed therein adapted to receive an ingot, means located outside said structure for mixing fuel and air and discharging said mixture under pressure into said chamber so as to prevent entrance of any free air into the chamber, and outlet ports for the waste gases. f

5. 'A soaking pit comprising a structure of refractory material having a substantially rectangulai` chamber formed therein adapted to receive an ingot, separate means located outside said structure on opposite sides of said chamber for mixing fuel and air, means for simultaneously discharging said mixtures at o posite sides of the pit, and outlet ports ormed in the walls of said chamber at right angles to the walls through which the fuel is introduced.

6. A soaking pit for heating ingots comprising a' structure of refractory material having a substantially rectangular ingot chamber formed therein, flame chambers opening into the opposite ends of said ingot chamber and having outwardly converging top and bottom walls, burners located outside of said structure, means for Supplying `gas and air to said burners arranged to deliver an explosive mixture under pressure to said flame chambers and outlet ports formed in the side walls of said ingot chamber at right angles to said end walls.

7. A soaking pit for heating ingots comprising a structure of refractory material having a substantially rectangular ingot chamber formed therein, flame chambers opening into the opposite ends of said ingot chamber, the bottom wall of said flame chamber being inclined downwardly toward said 'ingot chamber, burners outside said structure for supplying an explosive fuel mixture under pressure to said flame chambers and outlet ports located' in opposite Walls of said ingot chamber at points midway between said flame chambers.

8. A soaking pit for heating ingots comprising a structure of refractory material having an ingot chamber formed therein, in combination with flame chambers opening into the opposite ends of said ingot chamber, burners for discharging a fuel mixture to said flame chambers, the length of each said flame chambers being greater than two feet in length, measured from the outlet of the corresponding burner to the nearest wall of the ingot chamber.

9. A soaking pit for heating ingots comprising a structure of refractory material aving an ingot chamber formed therein, in

combination with flame chambers opening into the opposite ends of said ingot chamber, burners supplying a fuel mixture to said flame chambers, and outlet ports formed in the opposite walls of the ingot chamber at right angles to said ame chambers, said ports being at an elevation above the floor of said ingot chamber and thebottom surfaces of said ports sloping downward to# ward said ingot chamber t0 prevent accumulation of soot or scale thereon.

l0. A soaking pit for heating ingots comprising a structure of refractory materials having a substantially rectangular ingot chamber formed therein, flame chambers opening into the opposite ends of saidingot chamber and having top and bottom walls 100 which converge outwardly, burners located outside of said structure, means for supplying` gas and air to said burners arranged to de iver an explosive mixture under pressure to said flame chambers and outlet ports 105 formed substantially or approximately in the center of the side walls of said ingot chamber.

11. A soaking pit for ingots comprising a. structure yof refractory material having an 11o ingot chamber in combination with oppositely extending flame chambers, burners outside the structure arranged to deliver an explosive mixture of gas and air under pressure to said flame chambers, outlet ports 115 formed in opposite walls of the ingot chambers at right angles to said flame chambers and flues communicating with said ports for continuously carrying off the waste gases in a uni-directional path. 120

12. A soaking pit for heating ingots including non-reversible means located wholly outside the pit for mixing gas and air outside the pit and burning it in the pit, and means for exhausting the waste gases from 125 thehcenter of the pit in a uni-directional pat 13. A soaking pit for ingots having continuously operated direct gas-fired burners on opposite sides thereof and means for con- 130 vburners located at opposite ends of said pit and ports and flues for continuously exhausting the waste gases/from the cent-er of the pit. A'

15. A soaking pit for heating ingots having direct fired 'burners at opposite ends thereof, gas and air mains connected to said burners, means for continuously forcing air required for combustion to said burners and ducts for continuously exhausting the waste gases from the center of the pit.

16. A soaking pit for heating ingots having a series of direct gas fired burners connected with the gas supply pipe located outside the pit, anair main and means for continuously forcing air through said main to said burners and ports and iues for continuously exhausting the waste gases 'from the center of the pit.

17. An apparatus for reheating ingots prior to rolling comprising a masonry structure shaped to form a rectangular pit furnace, exterior burners ext-ending into the opposite end walls of the furnace, gas and air mains outside the furnace connected with said burners, outlet ports located substantially at the center of the side walls of said pit and flues connected with said ports for carrying off the waste gases in a uni-directional path.

18. A soaking pit furnace having a removable top to permit insertion and removal of ingots, burners projecting into opposite end walls of the furnace, gas headers and air headers connected outside the furnace to said burners, means for carrying oft' the Waste gases including an outlet port located in a side wall at a point between said burners.A

In witness whereof, I have hereunto signed my name.

HERBERT o. RYDING.

tinuously exhausting the waste gases from opposite sides of the center of said soakingIr pit in a uni-directional path.

14. A soaking pit for heating ingots,

burners located at opposite ends of said pit and ports and flues for continuously exhausting the waste gases from the center of the pit.

15. A soaking: pit for heating ingots having direct fired burners at opposite ends thereof, gas and air mains connected to said burners, means for continuously forcing air required for combustion to said burners and ducts for continuously exhausting the Waste gases from the center of the pit.

16. A soaking pit for heating ingots havingr a series of direct gas fired burners connected with the gas supply pipe located outside the pit, an air main and means for continuously forcing air through said main to said burners and ports and flues for continuously exhausting the waste gases from the center of the pit.

17. An apparatus for reheating ingots prior to rolling comprising a masonry structure shaped to form a rectangular pit furnace, exterior burners extending into the opposite end walls of the furnace, gas and air mains outside the furnace connected with said burners, outlet ports located substantially at the center of the side walls of said pit and fines connected with said ports for carrying off the Waste gases in a uni-directional path.

18. A soaking pit furnace having a Iemovable top to permit insertion and removal of ingots, burners projecting into opposite end walls of the furnace, gas headers and air headers connected outside the furnace to said burners, means for carrying off the Waste gases including an outlet port located in a side wall at a point between said burners.

In witness whereof, I have hereunto signed my name.

HERBERT C. RYDING.

D so L Ai M E. R Lhasa-Herben o. Rydmg, Birmingham, lua. SOAKING PIT. Patent dated July Disclaimer filed April 16, 1932, by the patentee.

Hereby enters this disclaimer to said claim 13 of said Letters Patent.

[Qjcial Gazette Moy 10, 1932.]

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