US3261763A - Gun flue coking retort oven - Google Patents

Description

July 19, 1966 e. TUCKER, JR 3,261,763

GUN FLUE COKING RETORT OVEN Filed Aug. 27. 1963 2 Sheets-Sheet l FIG. 1

INVENTOR.

LIA/W000 6. TUCKER, .12.

his

July 19, 1966 1.. G. TUCKER, JR

GUN FLUE COKING RETORT OVEN 2 Sheets-Sheet 2 Filed Aug. 27. 1963 INVENTOR.

L/NWOOD G. THC/(5E, J2.

BY .(ZZinA FIG. 3

ifs

United States Patent 3,261,763 GUN FLUE COKIN G RETORT OVEN Linwood G. Tucker, Jr., Pittsburgh, Pa., assignor to Koppers Company, Inc, a corporation of Delaware Filed Aug. 27, 1963, Ser. No. 304,928 1 Claim. (Cl. 202-141) This invention relates generally to coking retort ovens and more particularly to heating systems for high chambered gun flue ovens of the horizontal type.

It is highly desirable that the coking chambers of a coke oven be increased in capacity in order that the products of the ovens may be correspondingly increased without a proportional increase in the capital cost and the expense of the operation. Within certain limits, the efliciency of the coke oven battery and the return on the investment therein is increased by increasing the capacity of the ovens.

A recent trend has been towards the development or high chambered ovens. The extension of the height of coking chambers of coke oven batteries requires special provisions in order to supply suificient gas and air to the heating flues and to elongate the combustion throughout the length of the flues to such uniform degree as is necessary to effect uniform coking of the coal along a vertical plane.

It has been proposed heretofore to provide additional air or gas at intermediate points of the flues, but such arrangements have been either impractical or attended with serious disadvantages. In such ovens, there has been .an undesirable concentration of the heat of combustion of the fuel gas near the point in the flues at which the gas hasbeen introduced and the combustible mixture is formed. Such concentration produces unequal heating of the walls of the flame flues and unless compensated for, as by varying the thickness of the flue walls, the charge of coke in the adjacent oven chamber is coked at an uneven rate with respect to the vertical height of the charge.

Heretofore it has been possible when using an underjet type of horizontal coke oven to reduce the concentration of the heat of combustion by introducing the gas at two levels; that is, by providing high and low burners in the flue. By utilizing high and low burners, the variation in temperature over the height of the flue is reduced as there are two vertically spaced heat sources. Some variation in temperature continued to exist even with this expedient. The expedient of high and low burners has never been successful in rich gas fed gun flue type horizontal coke ovens because as rich gas is passed to the upper burner it cracks due to the high temperatures imposed by the low burner. The cracking of the rich gas results in carbon and resin deposition in the high burner duct. This deposition of carbon and resins clogs the high burner and the cracking reduces the heating value of the gas.

It is an object of the present invention to provide improved means for heating the coking chambers of rich gas fed gun flue type horizontal coking retort ovens whereby the coking chambers may be of increased height, high and low burners can be used, and there is no resinous or carbon deposition in the high burner. Further, the present invention provides a simple and eflicient means whereby a combustible mixture of rich gas and air may be diluted, with the result that the flame is materially elongated and the rate of combustion throughout the height of the flame flue is substantially uniform. The present invention provides such an arrangement and, in addition, the dilution of the combustible mixture occurs automatically and without the introduction of gaseous media other than that required for combustion purposes.

In accordance with the present invention, I provide a gun flue coke oven battery having coking chambers that are of increased height and that are adequately heated by a system that provides substantially uniform temperatures throughout the length of the flame flues. The heating walls are provided with flame flues in which combustion occurs in two zones and wherein no carbon or resin deposition occurs in the high burner. This is accomplished by the use of a high burner and a low burner. Separate gas guns supply the gas to the high and low burners. Duct means are provided in the partition walls between the flame flues for recirculating at least a portion of the gases of combustion in each of the flame flues of the heating walls. The recirculated waste gases operate todilute the combustible mixture, and the recirculation occurs automatically because of a pressure differential between the ends of the recirculation duct means. The pressure differential is caused by a thermal siphoning eflect which is created by two columns of gas at different densities in combination with an additional decrease in the gravity of the gases caused by the hot fuel gas addition through the gas nozzle.

The above and further objects and novel .features of the invention will appear more fully from the detailed description when the same is read in conjunction with the accompanying drawing. It is to be expressly understood, however, that the drawings are not intended to be a definition of the invention but are for the purpose of illustration only.

In the drawings wherein like parts are marked alike:

FIG. 1 is a transverse vertical cross sectional view through the heating wall of a coke oven battery;

FIG. 2 is an enlarged cross sectional view showing one of the flame fines of the coke oven battery taken on line 2--2 of FIG. 4;

FIG. 3 is a vertical cross sectional view taken on line 3-3 of FIG. 2, and

FIG. 4 is a horizontal cross sectional view taken on lines 44 of FIG. 3.

Referring particularly to FIG. 1, a coke oven battery 10 which comprises side walls 12 that are retained in position by buckstays 14, and a roof 16 through which extend charging openings 20 for charging oven chambers 22 with coal to be coked. Each oven chamber is also provided with a gas off-take opening 24 that is connected by means of an ascension pipe 26 to a collecting main 28. Cross-wise regenerators 30 are located beneath the ovens and their cooperating heating walls, and are separated from the oven by horizontal brickwork 32. The crosswise regenerators 30 extend throughout the width of the battery.

The coking chambers 22 are formed between spaced heating walls 34 (FIG. 4) that extend transversely of the battery. Each of the heating walls 34 is provided with a series of vertical flame flues 36 that extend throughout the height of the wall and each flame flue is divided into a lower section 38 and an upper section 40. Each flame flue includes a high burner and a low burner whereby combustion occurs in each of the sections 38 and 40. The lower section 38 of each of the flame flues 36 is connected at the bottom portion thereof through ducts 42 in brickwork 32 to the regenerator 30 that is beneath the respective heating wall. The duct 42 is employed for supplying the flame flue with or for conveying prodnets of combustion in accordance with the direction of gases in the heating system.

The lower section 38 of each of the flame flues 36 is further provided at its lower end with a nozzle 44 which is connected through duct means 46 to a gas gun 48 for supplying rich gas to the lower section 38 of the flame flue. As shown in FIGS. 1 and 4, the gas gun 48 extends horizontally through the brickwork 32. The gas gun 48 is supplied with rich gas from a rich gas main 50 which supplies rich gas to all of the gas guns for the low burners 44 along the coke oven battery.

The upper section 40 of each flame flue 36 is connected to a second rich gas nozzle 52 by means of a vertical duct 54 which directs the rich gas from the rich gas nozzle 52 to the lower end of the upper section 40. The vertical duct 54 extends through the lower section 38 of the flame flue 36 and the vertical duct 54 is positioned within a stepped portion 56 of the dividing wall 58 between the flame flues 36.

Rich gas is supplied to burner 52 through duct 60 from gas gun 62 which receives the rich gas from rich gas main 64. The gas gun 62 supplies rich gas to each of the high burners 52 and the rich gas is directed from the burner nozzle 52 through vertical duct 54 to the upper section 40 of the flame flue 36.

In contrast to coke ovens built heretofore the buckstays 14 can be straight I-beams without alterations. This is possible because of the use of the two gas guns 48, 62 which pass through the walls 12 of the oven to the sides of the buckstays 14. The rich gas mains t), 64 can be positioned at opposite sides of the coke oven as shown in FIG. 1, or in the alternative the rich gas mains can each be disposed on the same side of the oven.

A waste gas recirculation duct 66 is provided within each of the dividing walls 58. The waste gas recirculation duct 66 has an upper opening 63 into the flame flue near the top of the upper section 40 thereof. At the lower end of the waste gas recirculation duct 66 the duct communicates by means of a passage 70 with the vertical duct 54 described hereinabove.

The heating flues of each heating wall are operatively divided into flue groups. Each group of flues communicates by means of a crossover duct '72 with a corresponding group of heating flues in an adjacent heating wall and the so connected flue groups alternate periodically as flame flues and combustion product flues.

Combustion occurs upon the entrance of the heated gas and air to each of the flame flues and the gas burns upwardly therein as two distinct flames, a first flame emanating from the burner nozzle 44 in the lower section 38 of the flame flue 36 and a second flame emanating from the vertical duct 54 and burning in the upper section 40 of the flame flue. The gases of combustion pass upwardly, a first portion passing out through crossover duct 72 and a second portion being drawn into the waste gas recirculation ducts 66 at the upper entrance 68 of the latter. The waste gases flowing downwardly through the waste gas recirculation duct 66, through the connecting passage 70, and upwards in vertical duct 54 and back into the flame flue 36 at the lower end of the upper section 40 thereof.

The recirculation of the waste gases is caused by the thermal syphoning effect which is created by two columns of gases at different densities. The waste gas in recirculation duct 66 is at a lower temperature and thus higher gravity than the combustion gases in the adjacent burning flue 36. This difference in densities will cause the waste gas in recirculation duct 66 to flow vertically downward. The hot fuel gas addition through the nozzle 62 at the base of vertical duct 54 will additionally decrease the gravity of gases in recirculation duct 66 which will further increase the rate of recirculation. The combination of these two forces will create sufficient recirculation to en able the coke oven gas to travel upwardly through vertical duct 54 without any carbon formation. The specific construction of the duct system thereby combines a pressure differential with the aspirating effect induced by the flow of rich gas through nozzle 52.

The return of waste gases to the flame flue 36 results in a dilution of the combustible mixture formed by the gas and air and thereby elongates the flame of combustion. The elongation of the flame equalizes the distribution of heat throughout the height of the flame flue thus providing an evenly heated heating wall 34- which results in evenly coked coal in the coking chamber.

What is claimed:

In a coking retort oven having a plurality of flame flues in the wall separating adjacent coking chambers and a plurality of dividing walls separating adjacent flame flues, the improvement comprising:

(a) a first low burner nozzle at the bottom of said flame (b) a second high burner nozzle in the bottom of said flame flue and spaced apart from said first burner nozzle;

(c) a vertical first duct in a stepped portion of a fluedividing wall communicating with said second burner nozzle, said first vertical duct terminating in a high burner port intermediate the bottom and the top of said flame flue; and

(d) a vertical second duct in said dividing wall communicating with the region of said flame flue that is above said high burner port and the region of said first duct adjacent said second nozzle burner whereby the gaseous products of combustion in the region of said flame flue above said high burner port circulate downward in said second duct and mix with and dilute the gaseous products of combustion formed at said second nozzle burner.

References Cited by the Examiner UNITED STATES PATENTS 3,123,540 2/1964 Van Ackeren 202141 FOREIGN PATENTS 577,126 6/ 1959 Canada. 407,664 1934 Great Britain.

MORRIS O. WOLK, Primary Examiner.

JAMES H. TAYMAN, JR., Examiner.

Images