US1876037A - Method of providing fuel gas for coking retort ovens - Google Patents

Description

J.BECKER Sept. 6, 1932.

METHOD OF PROVIDING FUEL GAS FOR COKING RETORT OVENS Filed Feb. 19. 1929 4 Sheets-Sheet l INVENTOR. ese/0b Sec/heft sept 6 1932 J. BECKER 1,876,037

METHOD OF PROVIDING FUEL GAS FOR COKING RETORT OVENS 4 VSheets-Sheet 2 Filed Feb. 1S. 1929 INVENTOR. Q/Qseyoh Bec/fer BY f y ATTRN ff/ J. BECKER Sept. 6, 1932.

METHOD 0F PROVIDING FUEL GAS FOR COKING RETORT OVENS Filed Feb. 19. 1929 4 Sheets-Sheet 4 Patented Sept. 6. 1932 UNITED STATE s PATENT oFFlcE JOSEPH BECKER, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE KOPPERS CO'M- PANY 0F DELAWARE, A CORPORATIONOF DELAWARE METHOD OF PROVIDNG FUEL? GAS FOR COKING RETORT OVENS- l Application filed February 19, 1929. Serial No.` 341,240.

My invention relates to heating systems for coking retort ovens and particularly to means for utilizing blast-furnace gases for heating the oven chambers of coking retort ovens.

An obj ect of my invention is to provide means whereby blast-furnace gases from one or a plurality of sources may be utilized more effectively. and economically as fuel gas for underiring coke-oven batteries.

Myinvention has also for its further'ob-` jects such other advantages and improvements as may be found to obtain Withrespect to it as hereinafterdescribed or claimed.

In the operation of coke-oven batteries, it is very essential that the B. t. u. value .of the fuel gas be substantially uniform inasmuch as the relative quantity of air that is, in proportion to that of gas, is ordinarily limited by flow conditions that have to be maintained. However, a variation in the B. t. u. value of the gas correspondingly changes the amount of air required for perfect combustion. If the gas exceeds the normal B. t. u. value, the quantity of air is insufficient vand imperfect combustion results. If the gas is too lean,

there is a surplus of air and the result is to cool the ovens by reason ofthe heat required to bring the excess air up to the temperature of the gases of combustion.

The supplying of fuel gas at a definite B. t. u. value insures a uniform application of heat to the coking mass, with the result that a uniform coke is produced from any good coal and uniformity and regularity of coking operations is secured.

In the normal operation of acoke plant in Whichfa part of the coke-oven gas'thatis produced is used as fuel gas to heat the ovens, the coke-roven gas has an average thermal value of 530 B. t. u. The variation in the thermal value of the gas does not exceed more than approximately l5 B. t. u.s, representing ajfluctuation offabout 3%. This `percentage of variationl is so small that from a practical standpoint it is not necessary t o provide means for maintaining the B. t. u. value constant atany predetermined value. The regulation of the B. t. u. value of cokeoven gas might be accomplished by supplying the small amount of air or inert gas needed to maintain the thermal value at the minimum B. t. u. value of the coke-oven gas.

' Lean gas is especially suitable for under- L frinor coke-oven batteries because of the readi y obtained uniform vertical distribution of the heat of combustion, since the combustion of such gas tends to occur throughout substantially ythe entire length of the vflame fiues. When gas of this' character is employed as a fuel, the quality of coke averages very high because of the uniform heating conditions throughout the vertical height of the ovens.

In the operation of blast furnaces in connectionwith steel mills and other similar plants, considerable gas is generated that may be utilized as a fuel gas but which isy of very low B. t. u. value.` By reason of the methods of operation of blast furnaces, the gas varies such` degree of uniformity of B. t. u. value that the coking results are comparable with those of operatlonwithcoke-oven gas, even though coke-oven gas is effectively used without correction of its thermal value. Otherwise, the

coking time required for any given coal is l unduly prolonged and made irregular by the loss in heat when the B. t. u. value of the blastfurnace gas is below its maximum value. l

4 It may be assumed that a coke plant has a coking time of 16 hours when the ovens are heated with coke-oven gas. If, when heated l With blast-furnace gas, there be a variation in It will be readilyseen that'such.

' the B. t. u. value ofthe gas such that there is y a delay of even only 15%, such delay would be"- plant had a defeat the effective or economic use 'of blastfurnace gas in coke ovens.

The manual regulation of very lean gas,

ioo

. B. t. u. blast-furnace gas and thus release thev such as blast-furnace gas, is very difficult since it is not practicable to determine by mere visualv inspection whether the combustion is normal, the combustion occurring substantially without visible ames, and the variations of B. t. u. value in the blast-furnace gas may be too large and frequent.

I havel found, however, that blast-furnace gas from one or more sources and that is even highly variable in yits B. t. u. value may be used with high eiiciency to produce coke of high and uniform quality, by providing means for insuring a constant B. t. u. value of the gas. In general, the B. t. u. value of the gas is regulated ,by means of a calorimeter which controls a valve to admit more or -less `coke-oven gas to correspondingly vary the B. t. u. value of the blast-furnace as, thereby insuring a constant B. t. u'."value or the mixture.

When blast-furnace gas is used in the manner above stated, the coke-oven battery will operate smoothly and eiiciently. When so used, blast-furnace gas is at least the equal of coke-oven gas as a fuel for heating coke ovens. The coke'produced-is 0f very high quality because ofthe uniform vertical distribution of the combustion of the fuel gas and the short coking time and regular coking schedule/may be maintained by maintaining a uniform inflow of heat into the coking mass in all the ovens of the battery.

Also, if the blast furnaces be supplied with coke from` ovens underired with blast-furnace gas of regulated B) t. u.'value, the operation of the blast furnaces becomes more nearly constant, due to the use of uniform coke, and, consequently, the variations in the B. t. u. value of the blast-furnace gasare materially diminished. When such use of blast-furnace gas and such use of coke from the ovens so fired I is employed, there results a considerable decrease in the fluctuations of the blast-furnace gas, with a resultant decrease in the quantity4 yof coke-oven gas that is required to be utilized bythe regulating.l apparatus.

, An important economygis effected by the use fof blast-furnace gas for fuel purposes in that it `releases valuable coke-oven gas for use as heating gas for commercial or domestic purposes. For example, in the production of a .ton of pig iron, approximately one ton of coke is used, with the production'of about 130,000

cu. ft.of-blastfurnace gas with va thermalv 'mal amount of 530 B. t. u. coke-oven gas re-l' `quired to carbonize coal to produce one ton of value of about-90y B. t. u. per cu.f t. The norcoke is 6400 cu. ft. This carbonization may be effected `by about 40,000 cu. ft. of the 90 6400 cu. ft. ofmuch more valuable coke-oven gat-'z for other purposes for which blast-furnace gas is wholly unsuitable.

Y,When the relatively'lean blast-furnace gas is employed as a fuel, 'the volume Of'th gases of combustion is greater than that when richer ,gas is employed. However, by reason of the regulation of the lblast-furnacev gas to its maximum B. t. u. value, only a sllght 1ncrease in the cross-sectlonal dimensions of certain of the passageways of the view of such battery on the section lines indicated in Fig. 2;

Fig. 4 is a plan View of a mixing-device, parts being broken away; and- Fig. 5 is a view in transverse section taken along the line V--V of Fig. 4.

Referring particularly to Fig. oven plant comprising a battery 1 of coking retort ove-ns is adapted to be supplied with fuel from a source of blast-furnace gas com- 1, a cokeprising a blast furnace'2. The gas from the blast furnace 2 flows through a pipe 3, scrubbers 4 and boosters 5 to a-gas holder 6 of any usual or suitable construction.

Gas from the holder 6 flows through a pipe 7, a mixing device 8 and pipes 9, 10, and 11 to the distributing mains 12 and 13 of the battery- 1. The collecting main 15 of the battery 1 is connected by a pipe 16 to the usual scrubbers 17 and boosters 18 for cleaning the gas and for increasing its pressure for conducting it through a pipe 19 to any suitable storage device (not shown). A branch pipe 20 connects the pipe 19 through a pipe 2l, ameter 22 and a pipe line 23 to the mixing device 8 for a purpose' to be herei inafter described.

A calorimeter 24 of standard construction for measuring the thermal value of gas supplied thereto, and provided with a burner adapted to`serve for blast-furnace gas, is'

connected b-y a pipe 25 to the pipe 9 which supplies fuel gas to the battery 1. An electrical measuring device 26, which is also of standard construction, is connected to the calorimeter 24 and controls the electrical connections of an electric motor 27 that operates Becker regenerative type that are arranged to be` operated either with coke-oven gas or blast-furnace gas for. heating the ovens. The

battery comprisesa ,foundation 30 immedi- 'l Aately above which are located the regenerators 31 and 32 which extend transversely or lcross-Wise of the battery for half lthe Width of the latter.

A AAbove the regenerators 31 and 32 are a series of oven chambers 33 which alternate with heating walls 34, the outer surfaces of `Which constitute the sides of the oven chambers 33. Brickwork 35 constitutes a floor for the oven chambers and a roof for the reizo generators 31 and 32. The battery is provided with a top 36, through which extend 39 are each connected by a duct 44 to a horizontal flue 45 which extends substantially the length of the heating Wall. rlhe horizontal .flues 45 are connected by six crossover lues Each of the oven chambers 33 is provided with an ol-take opening 47 to which is connected an ascension pipe 48 and the collecting main for conducting the gases and other products of distillation from the battery.

" The distributing mains 12 and 13 for supplying blast-furnace gas to the battery are disposed along the respective sides of the battery and are connected to the sole flues 49 and 50, respectively, of the regenerators 31 and 32 by means of valve mechanisms 51 and 52.

The battery 1 is also suppliedwith mains 53 and 54 for supplying coke-oven gas to the dame lues of the heating Walls 34, through the. gas guns 43 that extend through the brickworl 35.

When the'coke-oven battery is especially adapted for blast-furnace gas operation, the horizontal ues 45, crosover flues 38 and certain of the ducts 44 are slightly enlarged as compared with the dimensions for producer gas operation, other ducts 44 being enlarged to a greater extent. rllhe ducts and 41 are gas is equally well adapted for producer gas j since the latter is of somewhat higher thermal value and accordingly the volume of combustion products is smaller. The cokeoven battery shown and described herein is therefore adapted for operation With either blast-furnace gas, producer gas or coke-oven gas 'I-he details of the mixing device 8 are shown in Figs. 4 and 5. The pipe 7, for introducing blast-furnace gas. from the holder 6 to the battery 1, is ,surrounded by an annular header 55, to which is connected the pipe line 23 and by means of Which the header is .sup-

plied with coke-oven gas from the main .19. The header 55 is connected to the interior of the pipe 7 by means of a series of radially-extending pipes 56 and 57 that are of different lengths and Which, accordingly, extend into the pipe 7 different distances, Accordingly.I

when y'gas enters the pipe 7 from the mixing' device 8, it is thoroughly distributed with the blast-furnace gas traversing the latter to pro. duce a substantially uniform mixture.

In the operation of the heating 'system describedV above, the blast-furnace gas from the blast furnace 2 may vvary in thermal value from approximately to 110 B. t. u.s. The i 4holder 6 may be and is in practice of relatively small capacity. A small holder is possible` because correction of the blast furnace rend-A ers it unnecessary to employ a large holder to at least partially equalize the inequalities of the supply of gas from the blast furnace 2 lor other'blast furnaces before it is supplied to the battery 1. A

As the gas flows through the pipe 7 and the various pipes andv distributing mains to the battery, a relatively small amount flows through the pipe 25 to the calorimeter 24 Which measures the thermal value of the gas as it is delivered to the battery. The calorimeter translates the B. t. u. value thus measured to the electrical unit 26, a movable member of which operates in accordance with the measurement thus obtained to control the electric motor 27 and the latter adjusts the butterfly valve 28 to admit more or less-cokeoven gas to the pipe line 23.

This gas passes through the mixing device 8 and the quality of the blast-furnace gas' is thus varied 0r corrected to the predetermined value for'which the calorimeter 24 is adjusted.' rllhis predetermined value' is preferably.

the maximum value of the blast-furnace gas when it is not corrected. A higher predetermined value may be selected but it is obvious that such value requires more. coke-oven gas to maintain the higher thermal value of the corrected gas. The result is to supply the battery 1 with blast-furnace gas that has been corrected to a substantially constant value of approximately B. t. u.s.

.A pipe 58, having a valve 59, is provided for' use in case it is necessary or desirable to by-passthe gas holder 6. ,Valves 60 and 61 controlthe connect-ions to the holder 6 and pipe 58 is used.

` control the amount of coke-oven gas so mixed A pipe 62 may be employed when necessary or desirable to by-pass the meter 22, suitable valves being provided for the respective conne'ctions.

While my invention has been described in connection with a single blast furnace as a source of supply of blast-furnace gas, it is obvious that any desired number of blast furnaces\ may be so employed. Also, While the heating system has been shown and described in connection with a single coke-oven battery, the arrangement may be extended by similar connections from the pipe 9 to other batteries ofthe plant, one of such batteries 63 being indicated by dot-and-dash lines.

My invention has for its advantages the 'employment of a relatively cheap fuel gas of very low thermal value that is unsuitable for the many purposes for which coke-oven gas may be utilized. Inasmuch as the blast furnaces and coke ovens are often adjacent to each other particularly in steel plants, the utilization of the-'blast-furnace gas in accordance with my invention constitutes an extremely convenient and economical arrangement.

While I have shown and described my invention in its preferred form, it is obvious that modificati ons may occur to those skilled in the art relating tothe operation of cokeoven plants. Accordingly, the scope of my invention is not limited to the particular embodiment shown herein except as expressed in the claims.' l

I claim as my invention:

1. The method of providing fuel gas for coking retort ovens which comprises supplying blast-furnace. gas of variable thermal value, mixing a` relatively small amount of coke-oven gas with said blast-furnace gasto correct the thermal value of the latter when it falls below a predetermined value, measuring the thermal value of the gases so mixed, and then regulating the amount of coke-oven gas added to said blast-furnace gas in according retort ovens having flame ues which comprises supplying blast-furnace gas that is variable between minimum and maximum thermal values, mixing a relatively `small amount of coke-oven gas with said blast-furnace gas, measurin the thermal value of the gases so mixed, emp oying the measured value JOSEPH BECKER.

ance with the measurement thus obtained to l maintain the thermal value of the mixed gas substantially constant at approximately the maximum thermal value of the blast-furnace gas.

2. The method of providing fuel gas for coking retort ovens Which comprises supplying blastfurnace gas of variable thermal value, mixing a relatively small amount of cokef Iwith the blast-furnacegas to maintain said 'measured value substantially constant, and then supplying the mixed gas to said ovens for combustion therein.

J3. The method of providingfuelgas for col(-

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