Process And Apparatus For Controlling The Heating Of A Horizontal By-product Coke Oven

Abstract

The coke oven battery has heating walls with pairs of heating flues separated from each other by a wall with an upper opening therein to permit combustion gases flowing upwardly in one flue to flow through the opening and downwardly through the adjacent flue. An opening is also provided in the separating wall adjacent the bottom of the flues to permit recirculation of a portion of the downwardly flowing waste gas. Each of the flues have inlet openings adjacent the base of the flues for combustion gas and air. There are also provided jet nozzles adjacent the base of each flue and jet nozzles adjacent the top portion of each flue to supply through one or more of the nozzles streams of high velocity propellant gas into the preselected flues in the same direction as the flow of gases therein. The streams of high velocity gas control and intensify the recirculation of gases within the adjacent flues to thus provide a more uniform vertical distribution of temperature in the flues and the adjacent coke charge.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process and apparatus for controlling the heating of horizontal by-product coke ovens with a stream of high velocity gas and more particularly to a process and apparatus for controlling the heating of the horizontal regenerative coke oven with a stream of high velocity gas in which a portion of the downwardly flowing waste gas is recirculated into the heating flue.

2. Description of the Prior Art

U.S. Pat. No. 2,207,573 discloses a regenerative coke oven battery in which separate gas flow devices are provided to supply either secondary combustion air or secondary fuel into the upper and lower parts of the vertical heating flues to permit the operator to control the uniformity of the heat supplied to the coke oven chambers.

U.S. Pat. No. 3,373,087 discloses a regenerative coke oven battery in which combustion gas is supplied to elevated burners through supply conduits extending along the roof of the coke oven battery with downwardly extending branch conduits.

U.S. Pat. No. 3,494,834 discloses a regenerative coke oven battery in which combustion fuels are supplied at different elevations in the vertical heating flues through separate conduits. It is also known to provide openings in the dividing wall between the "on" and "off" vertical flues to permit recirculation of controlled amounts of waste gas from the "off" flue to the "on" flue. With the above known methods and apparatus for heating coke oven chambers the velocity of flow of the combustion gases both in the "on" flue and the "off" flue is controlled by the velocity of the gases that are admixed and burned in the "on" flues and recirculated as waste combustion gas to the "off" flue. The velocity of the gases is in turn controlled by the volume of gas supplied to the "on" flue for combustion and the volume of the waste gas recirculated from the "off" flue to the "on" flue. There is a need for a process and apparatus to control the heating of horizontal coke ovens at various elevations within the respective flues by controlling the velocity of the hot combustion gases in either the "on" and "off" flue of both the flues.

SUMMARY OF THE INVENTION

This invention relates to a process for controlling the heating of a horizontal by-product coke oven having a pair of flues separated from each other by a separating means such as a separating wall that has an opening adjacent the top of the flues for circulating a heating gas therebetween. Combustible gas and air are introduced into one of the flues adjacent the base of the flue at a first velocity and the combustible gas is ignited at the base of the flue to form a waste gas. The waste gas is circulated upwardly through the first flue and downwardly through the adjacent other flue. A jet stream of gas at a velocity greater than the velocity of the combustible gas and air is introduced into at least one of the flues in the direction of flow of gas in that flue to accelerate the flow of the gas in the flue.

The apparatus for controlling the heating of the horizontal by-product coke oven includes nozzle means positioned in each flue preferably at the base of the flue and adjacent the top portion of the flue to introduce gas at a high velocity into the flues to accelerate the flow of gas in the flues.

The invention thus solves the problem of uniform heating by making the recirculated stream of gas more intense than is possible in known coke ovens to thereby obtain better vertical equalization of temperature in the heating flues. The present invention proposes an acceleration and intensification of the recirculation by one or more propellant jets and one or more gaseous media, as for example combustible gas, air or waste gas. The propellant jets have an essentially higher velocity of flow than the combustion media introduced into the heating flues in a conventional manner.

The use of waste gas refers to recirculated waste gas or also to a gas produced expressly for this purpose by combustion. In the latter case, for example, it is recommended to use high velocity burners which preferably introduce their jets of waste gas directly into each flue co-ordinated with the burners. When several propellant jets are provided, they can consist of similar or different gaseous media.

Accordingly, the principal object of this invention is to provide a method and apparatus for accelerating and intensifying the recirculation of the gases in adjacent flues.

Another object of this invention is to provide a process and apparatus for secondary combustion in the "off" flue.

These and other objects of this invention will be more completely disclosed and described in the following specification, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a twin heating flue with propellant jet nozzles for discharging a gaseous media at high velocity into the heating flues.

FIGS. 2 and 2a illustrate one arrangement of the propellant jet nozzles at the burner level and at the location for gas reversal from one heating flue to the other.

FIGS. 3 and 3a illustrate another arrangement of the propellant jet nozzles at the burner level.

FIG. 4 is a section taken along the line IV--IV of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, there is schematically illustrated heating flues 1 and 2 that form a pair of twin flues with a wall 3 therebetween. The wall 3 separates the flues 1 and 2 and has an upper opening 4 that permits the combustion gases flowing upwardly in the "on" heating flue 1 to reverse direction and flow downwardly in the "off" heating flue 2. There is also provided an opening 5 in the base of the wall 3 to permit recirculation of a selected amount of the waste gases flowing downwardly in the "off" heating flue 2 into the "on" heating flue 1.

The combustible gas and air for combustion are applied to the heating flue 1 through openings 6 and 7 in the base of the heating flue 1. The waste gas is withdrawan from the "off" heating flue 2 through similar openings 8 and 9 in the base of the "off" flue 2. When the direction of flow is reversed, i.e., flue 2 is the "on" flue, the gases of combustion flow upwardly through the openings 8 and 9 in the base of the flue 2 and the waste gas is withdrawn from flue 1 through the openings 6 and 7.

Jet nozzles 10 and 11 are provided in the base of flues 1 and 2 and other jet nozzles 12 and 13 are provided adjacent the top of the heating flues 1 and 2. A high velocity gaseous medium propellant can be introduced into the heating flues 1 and 2 through the respective jet nozzles 10, 11, 12 and 13 to accelerate and intensify the recirculated stream of heating medium, as indicated by the arrows in FIG. 1. For example, as illustrated in FIG. 1, a gaseous medium can be supplied through the jet nozzles 10 in the base of the heating flue 1 to accelerate the upward flow of combustible gases in the "on" flue 1. Another source of high velocity gaseous medium may be introduced through the jet nozzle 13 located adjacent the upper portion of the "off" flue 2 to accelerate the downward flow of the heating gases entering the upper portion of the "off" flue 2 through the opening 4. After reversal of the direction of heating, wherein the flue 2 is the "on" flue in which the combustion of the gases initially takes place, the high velocity propellant gaseous medium is ejected through nozzles 11 and 12 to thus accelerate the upward flow of the gases in the flue 2 and the downward flow of the gases in flue 1. Where described, the jet nozzles can be provided solely in the base of the flue in the region of the burner level or at a location adjacent the top of the respective flues.

FIGS. 2 and 2a illustrate the propellant jet nozzles in a flue having a so called bus duct 14 provided in the upper region of the heating chamber to adjustably control the heat adjacent that location. Similar numerals are intended to designate similar components in all of the drawings. With the arrangement illustrated in FIG. 2, there is provided an opening 4 between the adjacent flues 1 and 2 below the bus duct 14 for recirculation of a portion of the combustion gases therethrough. Openings 15 and 16 are provided between the respective flues 1 and 2 and the bus duct 14 thereabove. Control bricks 17 and 18 are provided to control the size of the openings 15 and 16 to thus control the volume of combustible gases flowing upwardly from the "on" flue into the bus duct 14 and downwardly therefrom into the adjacent "off" flue. As illustrated in FIG. 4, a pair of horizontal conduits 19 and 20 extend along the roof 21 of the coke oven battery. Branch conduits 22 and 23 are connected to the respective horizontal conduits 19 and 20 and extend downwardly into the respective flues 1 and 2. The horizontal conduits 19 and 20 carry the propellant gas which then flows downwardly through the branch conduits 22 and 23 into the top of the flues 1 and 2. Thus, if, as previously described, flue 1 is the "on" flue then propellant gas would flow through the horizontal conduit 20 and down through the branch conduit 23 into the top portion of flue 2.

As illustrated in FIG. 2a , openings 24 and 25 are provided in the base of the flue at burner level to supply gas and air for combustion in the flue. A rich gas nozzle 26 is provided to supply rich gas only when the ovens are being heated with rich gas in the heating flues. The numeral 5, as previously described, indicates the openings in the wall 3 for recirculation of the waste gases flowing downwardly in the "off" flue. In FIG. 2a pairs of jet nozzles 27 are provided in the base of each flue on opposite sides of the rich gas nozzle 26 through which a propellant gas supplied from suitably positioned feed lines (not illustrated) is ejected at high velocity to the preselected flue at the burner level.

Referring to FIGS. 3 and 3a, a modification is illustrated in which there is a single propellant jet nozzle 28 in each of the heating flues at the level of the burner. The propellant jet nozzle 28 is positioned between the openings 24 and 25 for the lean gas and air. It is also possible when the oven is being operated on lean gas to use the rich gas nozzle 26 as a propellant jet nozzle.

It should be understood that the gaseous medium propellant may be one or more gaseous media as, for example, combustible gas, air or waste gas. The propellant jet nozzles are arranged to have an essentially higher velocity of flow than the combustion media introduced into the heating flues in a conventional manner. The advantages attained with the invention are exemplified in a comparison with known apparatus in that a more uniform vertical distribution of temperature in the charge of the coking coal is now made possible by the improved vertical equalization of the temperature in the heating flues. Local overheatings or hot spots can be avoided thereby in high velocity ovens which can now be operated safely at the maximum limit of productivity. With the herein described invention there is a more intense and complete participation of the waste heat flue in transferring heat to the charge resulting from the intensified recirculation of the gases. This results in a shortening of the coking time and an increase in the limit of productivity.

Further, the recirculated streams are adjustable in the twin heating flues because of the additional propellant jet nozzles provided. A complete adaptation of the evolved heat to the variable requirement from the pusher side to the coke side of the oven can be obtained not only in the horizontal direction but also in the vertical direction. For example, adjustment devices can be provided which coordinate one control to one or also to several propellant jet nozzles or correspondingly calibrating the feed lines and/or the propellant jet nozzles to the desired conditions of flow.

Where the gaseous propellant is introduced adjacent the top of the "off" flue, the invention further includes the feature of selecting a gaseous medium so that this gaseous medium effects a reaction evolving additional heat in the waste gas flue in addition to the effect of flow. For example, it is possible to provide at the burner level of the "on" heating flue a greater excess of air, which is destroyed to a great extent by the combustible gas introduced as a propellant stream in the region adjacent the upper portion of the "off" flue.

According to the provisions of the patent statutes, the principle, preferred construction and mode of operation of the invention have been explained and what is considered to represent its best embodiments have been illustrated and described. However, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

Claims

1. A process for controlling the heating of a horizontal by-product coke oven having a pair of flues separated from each other by separating means and an opening in the separating means adjacent the top of the flues for circulation of a gas between the flues comprising,

introducing a stream of combustible gas and a stream of air into one of the flues adjacent the base of the flue at a first velocity,

igniting the combustible gas at the base of the flue to form a waste gas,

circulating the waste gas upwardly through said one of the flues and downwardly through the adjacent other flue, and

introducing a separate jet stream of gas at a velocity greater than the velocity of said stream of combustible gas and stream of air into at least one of said flues in the direction of the flow of gas in the flue to

2. A process for controlling the heating of a horizontal by-product coke oven as set forth in claim 1 which includes,

introducing said separate jet stream of gas into said one of the flues

3. A process for controlling the heating of a horizontal by-product coke oven as set forth in claim 1 which includes,

introducing said separate jet stream of gas into said other flue adjacent

4. A process for controlling the heating of a horizontal by-product coke oven as set forth in claim 1 which includes,

introducing said separate jet stream of gas into said one of the flues adjacent the base of said flue, and

introducing a second separate jet stream of gas into said other flue

5. A process for controlling the heating of a horizontal by-product coke oven as set forth in claim 1 which includes,

introducing an excess of one of said gases introduced into one of the flues so that partial combustion of said combustible gas takes place in said one of said flues, and

introducing a jet stream of a gas to support combustion in said second flue so that secondary combustion of said excess gas takes place in said

6. A process for controlling the heating of a horizontal by-product coke oven as set forth in claim 1 which includes,

recirculating a portion of the gas from said adjacent other flue into said

7. In a horizontal coke oven battery having heating walls with vertical heating flues therein the combination comprising,

a first flue having a base portion and a top portion,

a second flue having a base portion and a top portion,

means separating said first flue from said second flue,

said means having a gas flow opening therein adjacent the top portions of said first and second flues to circulate gas from one of said flues to the other of said flues,

said flues each having pairs of openings therein adjacent the base of said flues to introduce combustible gas and air into a preselected one of said flues, and

separate nozzle means positioned in each flue to introduce gas at high

8. In a horizontal coke oven battery having heating walls with vertical heating flues as set forth in claim 7 in which said jet nozzle means includes,

a jet nozzle positioned in the base of at least one of said flues to inject high velocity propellant gas into a preselected one of said flues adjacent

9. In a horizontal coke oven battery having heating walls with vertical heating flues as set forth in claim 7 in which said jet nozzle means includes,

a jet nozzle positioned in the top of at least one of said flues to eject high velocity propellant gas into a preselected one of said flues adjacent

10. In a horizontal coke oven battery having heating walls with vertical heating flues as set forth in claim 7 in which said jet nozzle means includes,

a jet nozzle positioned in the base of at least one of said flues to inject high velocity propellant gas into a preselected one of said flues adjacent the base of said preselected flue, and

a jet nozzle positioned in the top of at least one of the other of said flues to eject high velocity propellant gas into a preselected other one of said flues adjacent the top of said other preselected flue.