Patent Publication Number: US-3875016-A

Title: Method and apparatus for controlling the operation of regeneratively heated coke ovens

Description:
-* United States Patent Schmidt-Balve et .al.  
  Filed:  
 METHOD AND APPARATUS FOR CONTROLLING THE orr-mxnox&#39; 0F REG ENERATIVELYHEATED COKE OVENS inventors: lleltnut schmidt-Balvet-Alfred Alhertz. both of Bochum. Germ-any Assignee: Dr. C. &#39;Otto &amp; Comp. (3.xn.h.l-l..-  
 Bochum. Germany Appl. No.: 427.670  
  Related 1.1.5. Application Data Continuation (if Ser. No. 181.532. Sept. 17. 1971.  
 &#39; abandoned.  
  Foreign Application Priority Data Oct. 13. 1970 Germany 2050153 US. Cl 202/151. 201/1. 201/41. 202/141. 202/142. 202/143. 202/144 Int. Cl Cl0b 5/12. Fl6k 11/00 Field of Search 20l/4l. l; 202/141. 142. 202/143. 144. I51  
 A battery of regeneratively heated coke ovens has ap-- 1111 3,875,016 1 1 Apr. 1,1975  
 [56] &#34;References Cited I UNITED STATES PATENTS 3.344.039 9/1967 miner 202/15: 3.494.833 I 211970 Grumrn 201/41 Primary Examiner- M Louis Monacell Assistant Emminer-D. Sanders Attorney. Agent. or Firm-Brown. Murray, Flick 8!. Pecltham ABSTRACT paratus for controlling the introduction of combustion gases to the heating walls and related regenerators and the discharge of burned gases from the regener&#39;ators so that the most heat is produced only during the first regenerative speriod. Control valves in the gas and air inlet to each heating wall and in the flue for burnedgases from the regenerators are operated to control the flow through them in accordance with the heat requirements of the oven chambers during a coking period.  
 11 Claims. 5 Drawing Figures SEEN 2 0f 3 5| 2 s 4 a 0 7 a 9 m F Programming Card J A Fig. 3  
 METHOD AND IAPPARATUSFFORCONTROLLIN&#39; &#39;rna OPERATION-JOEREGENERATIYELYE I ira-a raocoxa-ovaus BACKGROUND or Th s invention it has been known for many years, when supplying gaseous fuels such as rich-gas. e.g.. coal gas,lean gas and air, control devices must be. incorporated in the pipe lines for the gases. Thesecontroldevices are operated at different times so that particular distributions of heat to the individual oven chambers will insure uniform carburization or coking of the coai&#39;in&#39; the chasm bers.  
 During the first few hoursof a coking process, themearswhen,more?wan aib process, becausethe&#39;evaporation&#39; of water from thecoal k &#39;qsa ai ik swi n4= raor a yw a s= amoun &#34;of heat. fhlearythe&#39;z ena .:ar theicokin&#39;g&#34; period, was he iwd irrir a n&#39; ;armada c i he w chamberihave&#39;alrnost attainedi the ii nal colting temperat&#39;ureyitfisfstillnecessary to heattlieIrniddiefportionor master-sea assass ns coal charge .up&#34; to the final {at &#39;thejbeginningjjof. the cokin&#39;gx .process, appreciably tire mass of coal in a newly charged oven chamber at tains only a relatively low temperature, and during this time the water content of thecoal charge must be COB! verted into steam. As discussed herein, the coking process stuns with the loading of wet coal into a coking chamber and ends with a pushing operation. it is essential to the coking process that the coalchargemust necessarily be heated to a certain uniforrnfinaltemperw ture whereby a cellular residue exists as a result of the destructive distillation of coal. At the time when a coke oven chamber is pushed, the chamber walls have a temperature of about l000CL Heating iiues are formed at largerfia mount&#39;s&#39;of heati are&#39;introduced into the coal chargeina coking chamber.  
 &#34; Up I until the&#34;. time of the present invention, coke ovens were operated in a mannersuch that the wall between adjacent oven chambers was heated in a steady and uniform manner. The coke pushing and coal charging operations for these chambers were carried out according &#39;to a sequence whereby one-newly-filled coke chamber was situated on one side of a heating wall while the coke chamber at theother side of that heating wall was approximately midway through the coking ;process.;flhis may be more clearly understood bycon- -sideringa group. of scyen&#39;coke oven chambers within a battery of coke ovenswherein the pushing sequence occurs as oven chambers i, 3, 5, 7, 2, 4&#39;and 6. As a result, the oven&#39;chamber&#39;s lying on the two sides of a&#39;heating wall will be pushed at an interval between them corthe other sides of these walls and attain a correspond-I ingly higher temperature. On the average, the temperature in the heating flues will reach about i200C but can be as high as l400C under a forced coking opera.- tion.  
 As a general rule in a coking process, the shorter the coking time, the higher the temperatures that are needed. After an oven chamber has been loaded with cold wet coal, the surface temperature of the chamber walls drops very sharply. in a given coke oven&#39;installa tion, for example, the temperature will initially drop to about SOOC and after about 2 .56 hours it increases to a temperature of about 700C. The chemical processes which occur within an ovenchamber after the water evaporates from the coal charge are extremely complicated because hydrocarbons are formed which immediately undergo a decomposition and transformation. it is important to bear in mind that a plastic zone or tar seam migrates in a coal charge outwardly from both chamber walls toward the center of the chamber and finally unite with one another.  
  The manner in which a coal charge attains a desired temperature is described in available literature concerning coking processes. The overall temperature of the coal charge does not materially increase after 2 is,  
 5 and even 7 Vs hours in the coke chamber. For example. consider a coke chamber 500 millimeters wide and a given coking time of 30 hours. The coal at the chambcr walls attains a temperature of600&#39;C after 2 A hours. The coal at a distance of millimeters from the chamber walls attains a temperature of IOOG after 2 A hours. After 7 is hours, the coal at l&#39;SOmillimeters from the chamber walls attains a temperature of 200C.- From these relationships. item be seen that the coal charge in the coke oven chamber is capable of absorba, responding to one-half of .the time needed for the coking process.  
 Studies in recent 4 that the heat required for the coking process is greatest immediately after the charging of the oven. Then it decreases rather sharply so as to assume values which, at the end of the coking period, amount to only a fraction of the originally required heat. With the customary uniform introduction of heat to the heating walls of a coke oven battery, the effect is that, toward the end of the coking time, the outer layers of the coke cake assume a temperature that ishigher than is necessary for processing .&#39;of the coke. At any rate, it is higher. than the temperature of.the&#39;coke layers that are in the center plane of the chamber, which aresufficiently processed for thepushing of theoven and which are hardened. Moreover, the chamber walls assume correspondingly higher temperatu&#39;res, and there is the danger that those temperatures&#39;which correspond to the&#39;admis&#39;sible maximum values that the block material can withstand will be&#34; exceeded withia forcedheating. Also, there is heat storage in the walls. Heat discharge corresponds to this 7 storage after the charging of the coal.  
  .On the other hand, the general practice for decades was to select the pushing sequence&#39;during the operation of a coke oven battery so that the two ovens adjacent to an oven to be pushed are approximately at the half-coking stage..As a result, the greater part of the heat produced in a heating wall is available for heating the coke in a just-charged chamber and the heat flow to the other, chambers is less. Aside from the equalization of the heat supply, a sequence of coke pushing, in which the two ovens adjacent to an oven to be pushed are approximately at the half-coking stage, has-the. advantage that the harmful effects that occur with the-use of an-eapanding coal cannot be manifested so strongly asiifthe ovens are possibly pushed in the sequence 1,2, 3, 4, 5 With a the. last-named pushing sequence, ovens with a concoking *ternperat&#39;ure&#39;S-AT- coh&#39;sidjerable 1 reduction to r the ees w-timers: a baking process can be achieved if,  
 years have shownespecially clearly stantly decreasing g H H ovens in whichtheswelling pressureof&#39;the coal-ts-th greatest. With the use of. such a&#39;noperatingsched ulefor ovens in which swellingcoal is beingi ieeess&#39;edg tints.. frequently beenobserved that the&#39; chamber wallsfithatij are located nearthe one batterytop&#39;h&#39;av&#39;e cracks 7 gaping joints, whilethis isnot the&#39;jcasewithiih ijlwalls that are located near the other battery topff Under the assumption that coal which does not has already been suggested that operating schedules be used in which adjacentoven chambersare&#39;inth&#39;e same &#34;r duce any noteworthy swellingpressure -is processed, it  
 coking stage and, moreover, that the&#39;heating wall be tween two oven chambers which are inapproximately the same coking stage be adapted to the heatflrequire ment that exists in the individual phases cfthe coking time. f  
  SUMMARY or This INVENTION s The present invention relates to a control of regenered of heattngg &#34;&#39;prcheatediinfrcgenerators) soasto be variable-{The init dit dfsi nfity i &#39;swb i qn&#39; rrn tbic tq y vg hieextentin order to maintain the&#39;de&#39;sired ratio f of gas andjair-idurin&#39;g th&#39;ejcombustion&#39;processf Because oftheidifferentloading&#39;l of the&#34; individual :he&#39;ating walls,  
 1tohichproyidestheIbasic-featureofsuch&#39;a process, it is not&#39;sufiicient to allow the suction pressure that prevails in the exhaustflue passage to act onfallregenerators.  
  A volumecontrol&#39;must be provided between the regenerator bottom passage&#39;and thejflue passage.  
  The characteristic feature of the new control for the feeding and exhausting of the gaseous fuel with regenerator c&#39;oke oven batteries consists in the fact that control {or} regulating valves &#34;a &#39;re lincorporated in the gas inlet and the air inlet to each heating wall and to the relatedregenerat&#39;ors andin the-eithaustfor the burned gasesfrom the regenerators. By means ofthese valves,  
 atively heated coke oven batteries with a feed of gaseous fuel, which changes constantly or in stages during coking, to the heating walls and the related re&#39;genera tors. it also relates to a changeable discharge of the burned gases from the regenerators. This process has the flows are controlled asfsuite d to the heatrequirement of the adjacent oven chambers in thecourse of a period that corresponds to thecoking time of the ovens. Regenerators that belong to a heating wall are understood tomean-those. which arev exclusively conthe prerequisite that the oven chambers at both sides has a defined prerequisite that the pushing sequence for the coke ovens must be different from the wellknown sequence. According to the present invention, adjacent coke oven chambers must be pushed in the shortest possible time intervals whereby, for example, a battery of 50 coke oven chambers are operated using a pushing sequence for the coke oven chambers Nos. l,2,3,4,5,6,7...49and50.  
  The method and apparatus of the present invention provides control means for operating the control valves to adjust, the flow of gases to bring about the production of the maximum amount of heat during the first regenerative period of the total coking time and then less heat for a plurality of regenerative periods, and finally still less heat for the remainder of the coking time. This manner of introducing heat to a heating wall between adjacent oven chambers necessarily requires that the coal charges in adjacent oven chambers are very closely time related in regard to their status while proceeding through various stages in the coking process and, therefore, there is an inherent heat requirement by these adjacent oven chambers which is achieved by the heat produced during the regenerative periods. This manner of heating adjacent coke oven chambers would be totally unacceptable in regard to instances where a newly-charged coke chamber is situated adjacent a coke chamber which has proceeded midway through the coking process.  
  Since the heat requirement of a coke oven has very variable values during the coking time, the heat requirement at the beginning of the coking time being a multiple of that which is needed shortly before the pressing of the oven, it is not sufficient to design only nected to the heating features of the heating wall. Under certain prerequisites,&#34; it is also possible to apply the invention to oven systems with which the regenerators work together several heating walls. I  
  Thetasksjof the controlor regulatingvalves and the reversingyalves that changetheir positionwiththe regenerativeichange in suction be irn&#39;parted to sepa&#39;-- rate organs. in this case,&#34;according tothe invention, the  
  control valves forthefperiodicyolume control of the gas andthccombustion air,viewe din the direction of flowpcan be arranged before&#34; the reversing valves for -&#39;gas and air, and the&#39;controlvalves for the periodic control of the burned gasesc an be&#39;placed behindthe reversing valves for the burned gases. it will be recognized that in this wayonly one control valve at each heating .wall is required for each&#39;individual medium that is to be controlled. .This control valve is active in both half-periods of the regenerative operation.  
  it is also possible to use valves which act both as a control valve and a reversing valve. Such valves allow the passage of volumes which are within a range between finite values in the one regenerative half-period,  
  while they are closed in the other half period. By means of such combination control and reversing valves, it is possible to work with different quantities of fuel in the two suction directions.  
  A variable feed and discharge of the gaseous fuel can also be executed in such a way that a fixed value is maintained for the medium to be introduced or discharged for a longer time period, if necessary for the entire period, but the inlet and outlet in each regenerative half period are completely interrupted during a time segment whose length has variable values in the individual phases of the coking. Thus, flaming, which decreases with a progressive coking, is executed so that no interruption of the feed and discharge takes place in the reversing period at the beginning of the entire time. However, with a progressing coking these time segments are selected so as to be longer and longer. if, for example, the initial flaming is to behave as 4:1 with respect to the flaming at the end of the entire time, the flaming will not be interrupted in the first regenerative .half period, while the time segment during which it is so-calledfstrongigasbr a weakgas that isfirstto be interrupted is gradually increased up to 75% of the half pass a constant value of the gaseousmediums timewise during a half time, but also completely block the&#39;feed&#39; and discharge timewise.  
 Due to the programmed heating, which is the basic pneumatic signal converters. The control and reversing valves are actuated by imeans of the pressure medium. Thebasic elements of such an electro-pneumatic control are, firstya time switch whose periodcorresponds :tothe coking time or totaltime of the ovens. The closing timeof each individual contact of this time switch maynotbe-greater than the shortest time within which feature of the new. control, the coking time can be greatly reduced. However, this is under the assumption to the heating walls in the first hours of the coking time than is the case with the previously standard heating system for coke ovens. Such an introduction of considerably larger gas quantities in the first hours of the coking time also means an increase in the quantities ofgaseous combustion agents which are subjected to the regenerative heat exchange. With the same dimensions for the regenerators, such as are customary with previous heating, the storage capacity will naturally not sufi&#39;ice. The regenerators would have to be greatly enlarged. Thus, a much greater cost would oppose the ad vantage of the new control. Such a cost can be avoided, if a shorter reversing time of, for example, or minutes is used insteadoi&#39; the previously standard reversing time ot&#39;a half hour for the most part. However, that would have to take place during that part of the coking period in which the introduced gas quantity is greater than the average value that is introduced to the heating walls with the previously standard operating process. Thus, the programmed heating can be operated with the new control so that there is a shorter reversing time in the phases of greater heating and a longer reversing time is selected in the phases of lesser heating.  
  lf control valves and reversing valves are separated, as has been suggested above, a programmed heating can be executed with purely mechanical operating devices. Moreover, it is possible to use control valves whose position is changed constantly within the whole time. Specifically, the change is from an initial maximum value, which constantly (flops to a final value. The initial value is much above the average value that is used for the previously standard operation, while the final value represents only a fraction of the previous average value. Cam plates can be arranged for the constant changing of the position of the control valves that are related to each heating wall. Common drives can be provided for their operation for the entire battery or larger oven groups. Care has to be taken that the phase differences that correspond to the coking state of the adjacent oven exist between the actual positions of the individual control valves. With an intermittent operation, such as was given above as a solution (same value for the combustion agent-introduction and discharge over longer time segments; variable times for the interruption of that introduction, i.e., interruptions which become longer and longer with the advancing coking), such a mechanical operation, which only needs to be directed towards switching the gas inlet and discharge on and off. can be executed relatively easily by means of a clockwork mechanism.  
  The control of the introduction anddischarge of the combustion agent and the regenerative reversing of a regeneratively heated coke oven battery, however. can also take place electrically. Electrical impulses are converted into pressure values by means of electroa reversing ora changing of values has to take place.  
 In general&#39;the closing time of all contacts have the same value. The number of contacts corresponds to the maximum valuei&#39;or the reversals and changes which are to be executed within an cntirecoking time. if the total time, for example, is 12 hours and 12 reversals or changes are to be possible within l hour, 12 times l2 or 144 closing contacts must be provided. Each of them is closed for a period of 5 minutes.  
 , Each heating wall is coordinated with a time-matrix plug board. if the heating is to be adjusted in five different stages during an entire coking period, a separate control is used for both direction motions. Thus, five times two or ten vertical conductors are provided in the time-matrix plug board. The provided d.c. voltage, for example 60 volts, is directed to the vertical conductors by the horizontal branches of the plug board by means of diodes during the time in which said voltage is applied to the horizontal branch in question.  
  Moreover, a programming card that has the same number of conductors as the plug board is coordinated with each heating wall. The connection of the conductors of the plug board and the programming card takes place by means of safety circuits. The programming card has as many branches as the reversing organs which are to be actuated. Moreover, it has still other branches so as to be able to adjust the control valves to different stages. The d.c. voltage, likewise by means of diodes, is transferred from the conductors of the programming card to the individual branches of the programming card. From them it reaches the signal converters assigned to the individual valves. The electrical impulses are converted into pressure values in the con verters. The actuation of the control and reversing valves takes place by pneumatic pressure. in order to achieve a stepwise change in the introductionof gas and air and in the discharge of the burned gases within the entire coking period, the electrical impulses pass from the programming card to the electro-pneumatic signal converters through groups of resistances that are connected in parallel in different ways.  
  The connection of the time-matrix plug board with the programming card of a heating wall takes place by means of relays controlled by safety circuits. This monitors the perfect operation of the sequence of processes by the end contact on the regulating unit. Thus,&#39;connections from the matrix plug board to the programming card take place only with a correct execution of the process. it the program for an oven is. to be changed, the program card must also be replaced.  
  When the time switch has returned, if all switches are closed one after another [era short time, opening begins again with the first contact. After the conclusion of a total coking period, the program of the time-matrix plug board also runs out. Hereby, the corresponding phase difference. obviously exists between the plug boards of the individual heating walls. The sum of all phase differences-is equal to the running time of the time switch. It is recommended that a safety program. which is adjusted-to the heating intensity at .the end of the total period, be provided at the end of the program of the time-matrix plug board. A possibility is provided with this safety program for switching over. manually if a disturbance exists and an oven cannot be pushed at the right time.  
  The invention is explained in more detail by means of the attached drawings; specifically FIG. 1 is a vertical section in a battery&#39;s longitudinal direction through several oven chambers and heating walls;  
  FIG. 2 is a schematic representation of the feeding and discharge of the gaseous operation agent to a heating wall that is between two oven chambers;  
  FIG. 3 illustrates the circuits of programmed heating with a time-matrix plug board and programming card;  
  FIG. 4 is a schematic representation of the different stages in the control of heating, and  
  FIG. 5 is a somewhat schematic representation of an electro-pneumatic signal converter.  
  in H6. 1, it is seen that each heating wall 11 is between two oven chambers heated by gaseous fuel. Each heating wall 11 is coordinated with a regenerator 16a and a regenerator 16b. in the one half period, the combustion air is preheated in regenerator 16a and the heat of the burned gases is stored in regenerator 16b. in the next half period, regenerators 16a and 16b change roles.  
  These are double draft ovens with which the evennumbered heating fiues of a heating wall heat up and the odd-numbered flues cool down in a half period. in the next half period, the even-numbered and oddnumbered flues exchange roles. The two pipelines that run through the cellaring, namely lines 210 and 21b, serve to distribute the gas over a heating wall. As shown in FIG. 2, the gas passages that lead to the oddnumbered flues from pipeline 21a are identified as 240. The gas passages 24!: that lead to the even-numbered flues are connected to pipeline 21b. Regenerators 16a and 16b are also shown. The compressed air distribution line 12, another compressed air line 13, the gasdistribution line l4, and the flue passage are also recognizable schematically. The lines or passages 12 to 15 extend over the length of the battery. Lines 22a, which lead to regenerators 16a, and lines 22b, which lead to regenerators 165, are connected with the distribution line 12 for the combustion air that is introduced under pressure. Specifically, these connections are by control and reversing valves RU 32a and RU 32b, respectively. The regenerators are connected at their other side to the flue passage 15 for waste heat; specifically, by means of pipelines 26a, 26b and 25. The valve for switching the waste heat between lines 26a and 26b is identified as U 36; the valve for controlling the waste gas is designated R 35.  
  The two gas pipelines 21a and 21b are connected to the gas distribution pipeline l4; specifically, by means of control and reversing valves RU 310 and RU 31b. Distribution line 13 serves for the introduction of the degraphitization air. From this line, a distribution line 26, to which either gas line 210 or 21b is connected by means of reversing valves U 330, or U 33b, branches to every heating wall.  
  The electric control of the programmed heating with the control and reversing valves that are indicated in FIG. 2, is shown in FIG. 3. Here only one time-matrix plug poard, which is provided for a heating wall, and a corresponding programming card are actually visible.  
 The number 40 identifies the individual contacts; 41  
 &#39; designates the operating mechanism of the time switch.  
 Each time-matrix plug board has ten electrical conductors that are identified as s, to s,,,. They are connected to the corresponding conductors l,, l, r of a programming card by means of a corresponding switch 42 of a safety circuit. Diodes 43vconnect the horizontal electrical branches and the conductors of the timematrix plug board. Diodes 44 connect the conductors and the horizontal electrical branches of the programming card. The branches of the programming card lead to the clectro-pneumatic signal converters 46 by means of so-called X-barriers 45. Here the other pole of the dc. voltage, which is connected to the branches of the time-matrix plug board by means of switch 40, is applied. The electric impulses are converted into pneumatic impulses by means of the signal converters 46. The reversing and control valves that are represented schematically in FIG. 3 are now actuated by the pneumatic impulses.  
  Groups of electrical resistances 47, 48, 49, 50 and 66 are series-connected with the control and reversing valves for the fuel gas and the combustion air and likewise with the valve for the waste gas control. From the positions of the diodes it will be seen that the programming card will switch on different resistance groups (of one to four resistances) with the conduction of the do current into the horizontal branches, depending upon which of the contacts 40 are closed. it also will be seen that all four resistances are parallel-connected with the closing of the first contacts 40 (conductors s,, s, and 1,, t,). Hence, the lowest resistance is present and, therefore, the current strength is the greatest so that the control valves are in their widest open position.  
  The intensity of the heating (that is, the introduced quantity) is illustrated by the stepped line at the lefthand edge of FIG. 3 beside the time-matrix plug board. The entire course of the coking time is represented graphically. Here, the time is represented as the ordinate and the gas quantity introduced in each time unit is represented as the abscissa. it will be seen that the maximum heating strength is used only during the first regenerative period. Diodes 43 connect the first switch 40 to the first pair of plug board conductors s, s, in two half times. From the arrangement of the programming card it will be seen that in the case of its first two conductors r, and r, all four branches are connected by means of diodes 44. Resistances 47, 48, 49, 50 and 66 are then all parallel. Of necessity, this leads to the greatest current value.  
  The conductors s; and s, of the second group are connected during three regenerative periods. With the third and fourth pair of conductors, the times are much longer, as is immediately seen. Because voltage is applied to only one of the two conductors of each pair of conductors according to the programming card, the result is that the other is actually without current. The valves 31a and 31b, as well as 32a and 32b, which are switched as control and reversing valves, thus fulfill both a control as well as a reversing function.  
  It is also seen that valves 33a and 33b act as pure reversing valves, since either one or the other is loaded in each half time. insofar as control valve 35 is concerned, a connection 37 between the first and second conductors of each pair sees to it that the diodes 44 which are provided here transmit voltage to the branches, regardless of whether the voltage is. at the f irst or second. conductor.  
  As has already been noted, only the time-matrix plug board and the programming card for the control of a single heating wall, and the control and reversing valves which belong to that wall, are represented in FIG. 3. The horizontal branches of the time-matrix plug board thus are continued to the right. The diodes 43 are displaced to the extent that the phase of the heating is shifted with respect to the preceding one with each of the following heating walls. The vertical conductors lead to another programming card for each heating wail. Their branches feed, likewise by means of additional resistances 47, 48, 49, 50,66, eiectro-pneumatic signal converters which transmit the pneumatic impulses to the control and reversing valves that adjust the introduction and the discharge of the gaseous me&#34;di-&#39; ums for the heating wall in question.  
  The individual parts of the programmed control are indicated schematically in FIG. 4; namely, the timematrix plug board, the safety circuit, and the programming card, all of which are incorporated in the control apparatus. The impulse of the programming card is transmitted to the X-barrier, from which it passes to the adjusting organs. A limit switch releases switch 42 of the safety circuit. The graduation of the heating during the coking time is indicated with five program steps as at the left upper edge of FIG. 3. The operation takes place with the maximum heating strength only for a relatively short time.  
  FIG. represents an clectro-pneumatic signal converter schematically. The number 51 identifies a permanent magnet into whose ring slot a transducer 52 projects. A rod 53, carrying a valve cone 54 at its lower end, is mounted at its center. The cone more or less blocks orifice 55 for the air entering at 56. 57 is an air density control valve by means of which the air entering at 56 is brought to atmospheric pressure. if the transducer 52 is moved downward with rod 53, the throttle cross-section of the valve 54 is also changed and the pressure in chamber 58 increases. The cascade pressure in chamber 58, corresponding to dynamic pressure, is transmitted by an amplifier 59.  
  The operation of a battery of coke ovens is designed on the fundamental concept of a consecutive pushing sequence whereby successive adjacent oven chambers are pushed one after another and at short time intervals between each pushing operation. This has been achieved in a manner that brings about a reduction to the necessary coking time of each oven chamber. These aspects. as well as others set forth herein, are realized by the individual and particular manner of controlled heating of each heating wall between adjacent oven chambers. The control means operate the control valves to adjust the flow of gases to bring about the pro- &#39;duetion ofthc maximum amount of heat during the first regenerative period of the total coking time and then less heat for a plurality of rcgenerative&#39;periods, and tinail y still less heat for the remainder of the coking time. This manner of introducing heat to a heating wall between adjacent oven chambers necessarily requires that the coal charges in adjacent oven chambers are very closely time related in regard to their status while proceeding through various stages in the coking process and, therefore, there is an inherent heat requirement by these adjacent oven chambers which is achieved by the heat produced during the regenerative periods. The inherent heat requirement is unique to the closeiytime related status in the coking process&#39;of adjacent oven chambers.  
  According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the-appended claims, the inventionmay be-practiced otherwise than as specifically illustrated and described.  
 We claim:  
  i. A battery of regeneratively heated coke ove ns having heating walls and regencrators, and an apparatus for controlling the introduction of combustion gases through supply lines to the heating walls and the related regenerators and the discharge of burned gases frbm the regenerators, comprising control valves in the gas and air inlet to each heating wall and in the flue for burned gases from the regenerators, and control means operating said valves to control the flow of said gases to produce the maximum amount of heat during the first regenerative period of the total coking time and then less heat for a plurality of regenerative periods and finally still less heat during the remainder of the coking time. t  
  2. in a battery of regeneratively heated coke ovens according to claim I, said apparatus including means for delivering degraphitization air under pressure to the gas supply lines.  
  3. in a battery of regeneratively heated coke ovens according to claim 1, said apparatus including reversing valves for gas and air and reversing valves for burned gases, said control valves for gas and air being located upstream from the reversing valves for gas and air, and the control valves for burned gases are located downstream from the reversing valves for burned gases.  
  4. in a battery of regeneratively heated coke ovens according to claim 1, in which said control valves are adjustable to vary flow in a regenerative half period and can be closed in the other regenerative half period, whereby the control valves also act as reversing valves.  
  5. in a battery of regeneratively heated coke ovens according to claim 1, said apparatus including a timematrix plug board for each heating wall, a programming card for each heating wall, a plurality of electrical conductors on each card, electropncumatic signal converters for operating said valves, a time switch whose period corresponds to the coking time of the ovens for transmitting a direct current voltage to the branches of said plug boards, means including diodes for conducting said current from said branches to said cards, and means including diodes for conducting said current from the cards to said signal converters to actuate them.  
  6. in a battery of regeneratively heated coke ovens according to claim 5, including groups of resistances for transmitting electrical impulses from the programming cards to said signal converters, and means for connecting said resistances in parallel in different predetermined ways to achieve a stepwise change in gas and air feed and discharge of burned gases within a total coking time.  
  7. in a battery of regeneratively heated coke ovens according to claim 1, said apparatus including cams arranged for the continuous changing of the control Valve assigned to each heating wail within a coking period. and common driving means for the cams for the entire .11 x v pp v V v 1? battery, whereby phase differ-&#39;- 10. A method according to Claim ences that correspond to the 8; in Which said heat is produced coking state of the adJacent by burning a mixture of gas and ovens occur between the actual air, and said heat is reduced by p sitions of the individual 5 reducing delivery of gas and air control valves to the heating walls and simultan- 8. A method of operating eously reducing the size of the regeneratively heated coke flues from the regenerators. ovens having heating walls 11. The method according to and regenerators, comprising 1G Claim 8 wherein the oven chambers using the maximum amount of at both sides of the heating walls neat only during the first receive amounts of heat correspondregenerative period of the ing to different stages of the cok total coking time, then using process, and said stages are ing less heat for a pluralcharacterized by a small time diffity of regenerative periods, erence in relation to the total co1 and then using still less ing time of an oven. heat for still more regenerative periods whereby to limit, the production of heat to the requirements of the ovens during the coking period.  
  9. A method according to Claim 8, in which said plurality of regenerative periods are three.  
 Patent No. 3,875,016 Dated April 1, 1975 Helmut Schmidt-Balms and Alfred Albertz Inventor(s It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:  
 Col. 10, line 67, after &#34;entire&#34; insert battery, whereby phase differences that correspond to the coking state of the adjacent ovens occur between the actual positions of the individual control valves.  
  8. A method of operating regeneratively heated coke ovens having heating walls and regenerators, comprising using the maximum amount of heat only during the first regenerative period of the total coking time, then using less heat for a plurality of regenerative periods, and then using still less heat for still more regenerative periods, whereby to limit the production of heat to the requirements of the ovens during the coking period.  
 9. A method according to claim 8, in which said plurality of regenerative periods are three,  
  10. A method according to claim 8, in which said heat is produced by burning a mixture of gas and air, and said heat is reduced by reducing delivery of gas and air to the heating walls and simultaneously reducing the size of the flues from the regenerators. I  
  11. The method according to claim 8 wherein the oven chambers at both sides of the heating walls receive amounts of heat corresponding to different stages of the coking process, and said stages are characterized by a small time difference in relation to the total coking time of an oven.  
 &#39; &#39;s&#39;i gned and sealed this 15th day ofJuly- 1975.  
 (SEAL) Attest:  
 RUTH C MASON Commissioner of Patents Attesting Officer and Trademarks