The Mond Gas-Producer Plant and Its Application.”

190 HUNPHREP OX THE MOND GAS-PRODUCER PLANT. [Minutesof

16 March, 189;. JOHN WOLFE BARRY, C.E., F.R.S., President, in the Chair.

(Paper No. 2956.) ’‘ The Mond Gas-Producer Plant and its Application.”

By HERBERTALFRED HUMPHREI’, ASSOC.M. Inst. C.E. GASEOUSfuel possesses certain well-recognised advantages over solid fuel ; it is easily handled, and its combustion is completely under control, and causes no smoke or dirt. It is also applicable to many cases where solid fuel could not be used, and it is the fuel of internal-combustion engines. For these and other reasons the demand for it is rapidly increasing ; and it is the function of the gas-producers to convertsolid fuel intothe gaseous state. In a Paper read before the Institution in 1886, Mr. F. J. Rowan gave an account of the Wilson, Dowson, Grobe,Sutherland, Siemens, and other gas-producers which had been employed up to that time ; and Papers on the application of the Dowson producer to the generation of gas for motive power hare since been communicated to the Institution by Mr. J. E. Dowson.2 The Author proposes to deal with recentadvances inthis department of industry. Producer gas was used for furnace work many years before its adoption for use in gas-engines ; and its applicationto generating power, which only commenced about 18 years ago, has throughout beenclosely connected with the name of Mr. Dowson. His success, and the great possibilities in this field of work,led to the construction of many other producersfor power gas; those of Wilson, Taylor,Thwaites and Lencauchez having achieved excellentresults. The Dowson producer isadapted to US0

Minutes of Proceedings Inst. C.E., vol. lxsxiv. p. 2. ? Bid, vol. Ixxiii. p. 311 ; and vol. cxii. p. 2.

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] HUMPHRET ON THE MOND GAS-PRODUCER PLANT. 191 anthracite or coke, although gas has been made with steam coal, charcoal, lignite and other fuels. For gas-engine work, however, onlyanthracite or coke are used, and Mr.Dowson’s aim is t.0 replace some of the nitrogen in ordinary producer-gas, as used for furnacework, byan equalvolume of hydrogen. To this end superheated steam is forced with the air through a considerable depth of fuel at a bright-redheat. The resulting gas is cooled and scrubbed, andits composition isthat shown in Table VI, Appendix I. Theprinciple of theother producersmentioned isthe same; but no doubtcertain specialadvantages may be claimed for each. The Lencauchezproducer isperhaps not so well known in England. It is circular in plan, and between its iron casing and the fire-brick lining there is a layer of sand, Fig. 1. The grate is

Scale, 1 inch = 16 feet. LENCAGCHEZGAS-PRODUCER.

closed and the air is forced in near the bottom by a blower driven by the gas-engine. Above the fire-door a small stream of water from the jacket of the engineenters and falIs into a trough. Partial evaporation of this water takes place as it overflows or lies inthe bottom of thegrate, any surpluswater escaping at a U-pipe. The steam thus formed passes with the air through the incandescent fuel, and the gas generated leaves the producer at the top, whence it is conducted to a coke scrubber through which it risesafter bubbling through a hydrauliclute. The gas is washed by a water-spray entering at the topof the scrubber and is then ready for storing in the holder. As the latter becomes full it actuates a chain attached to the air-inlet valve on the producer and so checks the supply of air. The holder cantains enough gas for starting the engine and is also used as a supply during the

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. 192 HUMPHREY ON THE MOND GAS-PRODUCERPLANT. [Minutes Of time the producer is idle for clinkering, a process which becomes necessary every twenty-four hours. With this producer it is found possible to use poor French anthracite or non-bituminous coal, and the success of the plant is yell established in France. Fromthe Papers referred to it may be gatheredthat most producerswere constructed to make gaswithout regard to the by-products, and that attempts to recover the ammonia had been onlypartially successful. No producers had been made togive good results with the cheapest slack coal, and it was only possible to obtain a gas suitable for use in gas-engines by employing an expensive fuel such as anthracite or coke yielding no by-products. The Mond producer and recovery plant, not onlyemploys cheap bituminous fuel, but recovers from it 90 lbs. of sulphate of ammoniaper ton, andyields a gaseminently suitable foruse in gas-engines, and applicable to all classes of furnace work. The difficulties in the use of bituminous slack, which hare been overcome by Dr. Ludwig Mond, F.R.S., in perfecting his produceri have been numerous, involving many years of research and continuous experimental work on a large scale. In addition to the chemical problems of the preservation and recovery of the ammonia and the destruction of all tarry matter, two great troubles arise from the caking of the coal andthe formation of clinker. Holes or channels areformed in the fuel and through them the air steam and flow instead of rising uniformly through thefuel, which burns un- equally and varying temperaturesresult. The fuel also cakes into arches in the producer and the steady downward motion necessary for good work is prevented. The producer becomes blocked and clinkering is difficult ; and, in spite of the bold attempts to break up themass of fuel and clinkerby a mechanical agitator, thesystem becomes unworkable. Evenwhere it wasdesirable to use gas- coke from a neighbouring gasworks in producers of the ordinary type, Nr. Hartley, of the Britannia Engineering Works, found the producers clinker so rapidlythat the working became a matter of serious difficulty, and at the close of the second day theengines had to bestopped andthe fires drawn. Mr. Hartleythen addedmechanical means bywhich the attendant could detach all clinker from the lower portion of the interior of the brickwork and this gear rendered it possible to use the coke for acontinuous run of nine weeks. These difficulties were emphasized by Mr. Dowson in 1893; andstill more recently by Mr. Delamare-Deboutteville, in the report of the trial of a

1 Minutes of Proceedings Inst. C.E., vol. csii. p. 17,ll. 19 et seq.

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. ~roceedings.1 HUMPHREY ox THE MOSD GAS-PRODUCER PLANT. 193 largesingle-cylinder gas-engine,l inwhich he draws particular attention to theLencauchez producers employed. Experiments on gas-producers were begun by Dr. Mond in 1879, and the methods by which he had already achieved success were clearly laid down by him ten years later.2Besides the use of bituminous fuel and the recovery of ammonia, the Mond process is distinguished by the following characteristics : The producer is worked at a much lower temperature than usual, so that the re- sultant ammonia is not decomposed, and the fueldoes not cake and no clinker is made. The low temperatureresults from, and is preserveduniform by, thelarge quantity of superheated steam introduced with the air, amounting tomore than twice the weight of the fuel dealt with. The greater portion of this steam passes out of the producer undecomposed, but during its cmdensation its sensible and latent heat are utilized to produce fresh steam for use in the producer. The gas containing the ammonia is passed through an absorbing apparatus; and, although the quantity of ammonia issmall compared withthe volume of gas, it is so effectually treated that 70 per cent. of the nitrogen in the original fuel is recovered. The fuel is mechanically fed into the producer, and the ashes withdrawnwithout interfering with the regular continuous working. The amount of labour required is small, as no clinkering is necessary;and the fuel is charged in large quantities of 8 cwt. to 10 cwt. at atime. The gas generated is uniform in quality,and, as no taris produced, theplant can be kept clean, and the gas cooled to any desired extent, without blocking the pipesand valves.

DESCRIPTIONOF THE PLANT. The method of working, diagrammatically illustrated in Fig. 2, Plate 5, will be described in relation to the plant in use at the chemical works of Messrs. Brunner, Nond and Company, North- wich, Cheshire. Cheap bituminous slack, arrivingin railway wagons, isemptied directly into ahopper, from which it is mechanically raised and delivered into a creeper above the row of producers. The creeper has outlets above each of the producer- hoppers, and candeliver into any one as desired. The hopper being thus filled, sufficient slack is by thesimple motions of a sliding neck and two levers, allowed to fall into themeasuring-hopper below to

1 !The Engineer, vol. lxxviii. p. 466. * Presidential Address to the Society of Chemical Industry, 1889. [THE INST. C.E. VOL. CXXIX.] 0

fill it ; and, owing to the closed connection, no dust escapes. The bottom of the measuring-hopper is closed by a hood-valve held in position by a lever and counterweight,so that when the attendant has closed the upper lid he runs the weight towards the valve and allows the measured quantity of slack todrop into the producer. The producer, Fig. 3, consists of an inner and outer wroughb ironcylindrical shell, the latter being lined with fire-brickfor a portion of its height.The top is archedand is also lined with fire-brick, whilethe bottom taperstowards the grate; the whole producer being firmly held in position and supported by cast-iron brackets over a water-lute. For a time the freshly introduced slack is confined in the bell-shaped casting, hung from the top of the producer and surrounded by the hot producer-gas. Herethe slackundergoes a process of distillation,and, as the products formed have of necessity to pass downwards through the hot zone before they can escape, the tar is destroyed and converted into fixed gas, so that the fuel has parted with all its tar before it arrives in the main body of the producer, At the bottom of the producer there is a cast-iron ring round which the upper ends of the sloping fire-bars are hooked. The lower ends of the bars lean against the inside of another ring which holds them atthe proper inclination. As the bars do notreach to the centre, part of the weight of thesuperincumbent fuel rests upon the ashes, which form a reversed cone, filling the centralspace down into the water; and it is from below the water-level that the ashes are withdrawn by a spade. The mixture of steam and air has to pass downwards between the two shells of the producer on its way to the fuel, so that it is thusheated, while the inner shellis cooled. The wrange- ment acts also as an efficient jacket against external radiation. The hot gas leaving the producer flows at once into the regenerator, consisting of a series of vertical double tubes of wrought-iron, SO arranged that while the hot gas is cooled by passing in one direction through the inner tubes, the air-and-steam mixture is heatedby its passage in the opposite directionthrough the annular space between the tubes. Thelong wrought-iron chamber, called a " washer," through which the gas is next forced, 'is fitted with mechanical dashers revolving on shafts' at such a height above the water-level that their blades skim the surface of the water and throwup a great quantity of fine spray, completely fillingthe chamber. Thegas and water-spray intimately mix, with the result that nearly all the heat of the gas is rendered latent by the formation of steam, or water-vapour, at a tempera-

ture of about 90" C. The steam so formed is not sufficient to saturate the gas, so that when it passes through the acid-tower, there is no weakening of the acid-liquor by any deposit of condensed steam. The gas enters the acid-tower at the bottom and in its upwardcourse meets a downwardstream of acid-liquor-a large surface of contact being obtained by means of checker brickwork arrangedin the ordinary way. The acid-liquor containsonly 4 per cent. of free sulphuric acid, the rest being already combined with ammonia and existing as sulphate. The bulk of the liquor is circulatedcontinuously by a gun-metalram pump, andits strength is maintained uniform by draw- ing off a smallstream of thesulphate- TABLE1.-voLUMEPIoFDBY liquorand adding sufficient acidto cor- GASAND WATER-VAPOUB IN 100 VOLUMESOF SATU- respond in value. Thetank at the foot RATED GASAT VARIOUS of the acid-tower, Fig. 2, allows the in- TEMPERATUREB. timate mixing of the sulphuric acid with thecirculating liquor before thelatter DIY Water Gas. Vapour. reaches the pump. emperu-ture. ! The gas, deprived of its ammonia, leaves OC. Per Cent 'er Cent 0 99-40 0.60 at the top of the acid-tower, and is con- 5 99.15 0.85 ducted to the bottom of a large wrought- 10 98.80 1.20 15 98.34 1.66 iron vessel, 12 feet in diameter, filled with 20 97.71 2.29 wood packing of a shape to afford a large 25 9@90 3.10 30 95.85 4.15 surface. The gas, containing its burden 35 94.49 5.51 of steam, hashere tomeet a downward 40 92.77 7'23 current of cold watcr which considerably 45 90.60 9.40 50 87.90 12.10 lowers itstemperature. When entering 55 84.56 15.44 this gas-cooling tower it is nearlysatu- 60 80.45 19.55 65 75.45 24'55 rated with steam, so that as its tempera- 70 69.40 30.60 turebegins tofall, its capacity for 75 62.12 37.88 so 53.44 46.56 carryingsteam rapidly diminishes and 85 43.12 56.88 condensation takes place. Table I shows how considerable the condensation must be, and the resultis, the utilization of the latent heatof the steam condensed, as well as the sensible heat of the steam and gas, in raisingthe temperature of thecirculating water which conse- quently escapes hot. On leaving the gas-cooling tower, pipe mains convey the clean cool gas away for immediate use in furnaces or gas-engines as the case may be, and in the works at Northwich, more than 24,000,000 cubic feet of this gas areused daily. The hot water leaving thegas-cooling tower is pumped into the top of an air-heating tower, where its heat, obtained from the gas as described, is now given back to the cold air passing through 02

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. 196 HUMPHREY OB THE MOND GAS-PRODUCER PLANT. [hrinutes of on its way to feed the producer. To avoid confusion two pumps are shown in the Fig., one pumping the cold water to cool the gas, and the other pumping the hot water to heat the air; but one double-ram pump serves both purposes, and, as the capacity is the same for each of its rams, equal quantities of hot and cold water must be delivered whatever the speed of the pump. Thus the circulating waters are balanced without further regulation. Throughout theprocess the gas hasbeen under pressure, furnished by the blower driving the air into the producer, and it is while on its way from this blower that the air is heated in the tower last mentioned. The chief function of the last tower is, however, to saturate the air with steam at the temperature attained, and by this means alone 1 ton of steam is carried into the producer for each ton of fuel gasified. One producer does not require a set of towers to itself as shown in the Fig., and at Northwich only two sets are requiredfor all theproducers. The surplus sulphate-liquorformed in theacid-tower leaves the delivery of the circulating-pump at a point where the pressure is sufficient to force it over to the sulphate plant, which may be in a separatebuilding. Here, after being neutralized, it enters conical evaporating-pans, each containing two nests of lead coils which carry steam under a pressure of about 35 Ibs. per square inch. Theheat given out to the surrounding liquor causes rapid evaporation and the concentration is continued untilmost of the sulphate has crystallized out. The contents of the evaporator are then dropped on a drainer ; and, after parting with themother- liquor, the solid sulphate is dried in a centrifugal machine and packed in bags for sale. Thefirst circular Mond producer wasstarted to work con- tinuously in September 1893. Up to August 1896 no repairs had been necessary, either to thebrickwork lining or any otherportion of the producer, except the replacement of one faulty tube in the pipe regenerator.

TESTSAT WINNINGTONWORKS. In the summer of 1895 the Author was invited to study the producer plant at Winnington, andto obtain all the data relating to its working necessary for a complete statement of its efficiency. With the object of affording the fullest possible particulars Ur. Charles Humfrey, the manager of the plant, organized a set of records, in addition to the ordinary hourly observations of tests, temperatures, and quantities which are regularly recorded, night

and day. Three tests were made, the usual conditions prevailing throughout so far as the.producers were concerned, while the gas from G2 tons, 82 tons and 94 tons of fuel per day respectivelywas driventhrough one set of towers. As mould be expected, the best results were obtained from the first test when the absorbing planthad the least work, but those of the second trial were selected by the Author as more nearly corresponding with the usual conditions. Owing,however, to the very hot weather prevailing at the time, none of the thermal results are equal to those obtained under a more favourable stateof atmospheric temperature. The fuel consisted of Nottingham slacks mixed in theproportion of thecontract quantities and supplied in wagons to the works Fig. 4. at an average cost of 6s. 2d. per l ton. The producers were fed by 90 charges of 8 cwt. to 10 cwt. at a time and the burnt ashes were removed fromthree of thesix lute-holes, alternately, once in eight hours, the lutes untouched during one shift being drawn at the next.Average analyses of the slack and ashes are given in Table I, Appendix I. The den- sity of thesulphate-liquor was kept at 35" Twaddle, equal to 34 per cent. of sulphate of ammonia by weight, so that for every ton of solid sulphatesubsequently made it was necessary to evapo- rate 23 tons of water. By actual measurement of all thecondensed steam from the sulphate plantit was found that 5-6 tons of steam were condensed in performing this work together with the necessary pumping. The resultsof the trial, detailsof which are given in AppendixI, showed that for every ton of fuel fed into the producers, about 23 tons of steam and 3 tons of air are blown through the grate, the mixture being ata temperature of 250' C. Of this steam 1 ton is furnished by the system of regeneration, and 14 ton is added as exhaust steam from various enginesand pumps. More than 3 ton of steam is decomposed in passing through the hot fuel, and nearly 44 tons of gas are formed from l ton of coal, equal to

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. 198 IIUNPHREY ON THE DIOND GAS-PRODUCER PLAXT. [Minutes of about 160,000 cubicfeet at ordinaryatmospheric temperature. This gas has a calorific value of 81 per cent., calculated on the calorificvalue of the original l ton of fuel,and in a Babcock- Wilcox boiler gives an evaporation of somewhat more than 7 tons of water. When used in a gas-engine it is sufficient to give 2,166 LHP. hours, being at the rate of 1*03 lb. of slack per I.HP. hour, the thermalefficiency of the engine being23-8 per cent. ; but better results have since been obtained Fig. 5. by using theCrossley scavenging system. Fron Table 11, Appen- dix I, it will be noticed that for eachton of slack gasified the plantrequires a s11pply of exhaust and direct steam equal to 0 e242 ton of slack, and this is allowed for in the statements of cost and other calculations. The efficiency of the tubular regene- ratoris 81 -9 percent., while theregeneration by circulating watergives an efficiency of 72 * 07 percent. The balance sheet, Table IV, shows the way in whichthe heat quantities enterinto the process, andthe magnitude of the loss; and why in cooler weather better results would be obtained. The changes of temperatureand pressure throughoutthe absorbing plant are illustrated in Figs. 4 and 5, the highestpressure being 310 millimetres of water. The cost of working, Table V, is affected by the market value of sulphate of ammonia, which it will be noticed isextremely low. The position which Mond gas occupies in relation to sevenother typical gases is shown in Table VI. By burning it with a proper amount of air, the gas and air both being cold, the temperature of combustion, as actually observed, is 1,150" C. Thetheoretical temperature calculated from the calorific value and specific heats for a fixed set of conditions is shown in Table 'VI1 to be 1,60G0 C. The temperaturerealized is therefore 71 percent. of the calcu-

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] HUMPHREP ox THE MOXD GAS-PRODUCER PLrlNT. 199 lated value. When regeneration is emploFed to obtain very high temperaturesthe difference between a poor gas and a richgas begins to disappear, and with Mond gas, used in its wet condition, it is easy to reach temperatures beyond the range of any form of pyrometer available. With a Callander pyrometer, a temperature of 1,525" C. has been observed in a flue through which burnt gases from a Mond gas-fired steel furnace were passing.

APPLICATIONSOF PRODUCER-GAS. AS regards the generalproblem of gas-firing it should be stated that where gas has replaced slack firing, 1-1ton to 1 *2ton of coal in the producers isequivalent to 1 ton of good slack carefully burnt by the old method. While, however, it is difficult to burn slack under the best theoretical conditions, it is always easy to regulate the burning of gas with only a slight excess of air above that theoretically required. For this reason, and because of the more regular distribution of heat when using gas, the working results of gas- andhand-firing approachmuch more nearlyto one of equality in weights of slack. The question of decreased labour is also to be considered when comparing the advantages. Many of thefurnaces in the finishing department of Messrs. Brunner, Mond and Company's Works wereoriginally slack- fired, and, since the change tofiring them by Mond gashas been made, a remarkablesaving in repairshas been realized. Thecast-iron pans, underwhich the flames pass and through whichthe heat is transmitted,last four times as long as for- merly, and the output of a furnace during its life is more than quadrupled. The resultsof firing Babcock-Wilcox boilers, by each of the two methods and at various ratesof working, are given in Appendix 11. To adapt the boiler, which was designed to work with the waste heat of furnace gases, to producer-gas firing, the alteration shown in Fig. 6, Plate 5, was made. Part of the inlet-flue was taken out, to allow the introduction of a 15-inch gas-main, and a perforated arch was built over the 4-foot square opening where the fire-bars are ordinarily placed. The gas was regulated by a throttle-valve, and the air entered through the annularspace round the gas-pipe. The space below the archformed the combustion-chamber, and the perforated archserved to shorten the flames and to render the combustion complete. The manufacture of steel in the experimental steel furnace at

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. 200 HUMPHREP ON THE MOND GAS-PRODUCER PLANT. [IIhutee of Winnington has recentlybeen described by Mr. J. H. Darby,l who has shown that Mond producer-gas has proved a thoroughly suitable and economical fuel for use in the manufacture of the best class of steel. The first experiments in the use of Mond gas for motive power were carried out early in 1894, on a 25-HP. Otto-Crossley engine erected at Winnington. The results of a two-hours’ trial, carried out by theAuthor, are given in Table I, Appendix 111, and, considering that no scavenging arrangements were fitted to the engine, they are among thebest on record. The quantity of cheap bituminous slack at the producers per I.HP. hour was 1*03 lb., and the thermal efficiency is 23.8 per cent. Partly because the engine was not driven at full power, and also owing to the high degree of compression, the mechanical efficiency of the enginewas only 71 -4per cent. in this trial. In analyzing the exhaust-gases, 0.6 per cent. of carbonic monoxide and 1-7 per cent. of hydrogen were found ; but this ischiefly due to faulty governing gear which allowed occasional slipping of the governor lever which rides the ,w-cam. In December, 1895, the engine was removed to another portion of the works, and erected to drive an electric-light in stallation, Figs. 7, Plate 5. It is coupled by a leather link-belt to a dynamo giving 300 amperes at 104 volts, and furnishes every night the current requiredfor lighting the caustic-soda plant. The supply of producer-gas is drawn through either of two sawdust filters, 6 feet in diameter, and containing a layer of 8 inches of loose deal-dust. Since this engine started to run in its new position, it has only been necessary to renew the sawdustonce in one filter ; the other filter still contains the original sawdust, and the valves and cylinder of the engine have not required tobe cleaned. Some figures relating to the ordinary work of this engine during the month of April, 1896, are added in Table 11, Appendix 111. In consequence of the success recorded, Messrs. Brunner, Mond and Company haveinstalled a larger engine, of 150 HP., of the Crossley-Otto two-cylinder end-to-end type. The crank-shaft is connected through aflexible couplingto the armature of a Siemens dynamo, and the whole is designed to give, when working with Mod gas, 750 amperes at 100 volts, whenrunning at 160 revolutionsper minute. It is probably the first instance in Great Britain of a large gas-engine driving a dynamo direct. For purposes of comparison the Author has tabulated a set of figures relating to the use of Dowson gas-producers, Tables 111, IV

1 Journal of the Iron and Steel Institute, vol. xlix. p. 144.

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] HUNPHREY ON THE NOND GAS-PRODUCER PLANT. 201 and V, and, although under special test conditions even slightly better results may have been obtained, yet those given represent a plant working well. With the same object a summary of the trial of the famous " Simplex " gas-engine at PantinMills, working with poor gas generated ina Lencauchez producer, is added in TableVI. When the difficulties of building satisfactory gas-engines of say, 500 HP. and 1,000 HP. have been overcome, they will inevitably replace steam-engines in largecentral electric-light and power stations, even as they are already doingon a smaller scale. To show whatmight then be accomplished inthe supply of cheap power, theAuthor takes as a hypotheticalexample a factoryrequiring a continuous power of 10,000 I.HP., with a Mond producer and recovery plant, erected adjacentto it to supply the necessary gas for the engines. Let the whole of this 10,000 HP. be utilizedto drive dynamos yielding 7,000 E.BP. at the terminals. The cost of thegas-generating and recovery plantis estimated to amount to about ;E20,000, andthe gas- engines, dynamos, exciters,switchboards, cranes, andbuildings would be covered by theadditional sum of 5320,000 exclusive of the price of the land, which is S variable quantity. If thisplant works day and night all the year round, thetotal expenses areestimated to amount to S35,100, whichincludes interest on capital at 8 per cent., givingthe total cost of one kilowatt-houras 0-184d.,or of one E.HP.-hour 0.137d. The case considered is a favourable butnot improbable one, as a factoryworking an electrolytic process mightrequire a continuous power far beyond the 7,000 E.HP. In most cases the mechanical power, without transformation, would be required at various points of the works, and in such cases the gas would be distributed in pipe-mains to the different gas-engine stations. The corresponding total cost would then be reduced to about 0.0865d. per I.HP.-hour. It must not be sverlooked that with theproducer plant inexcess of the power plant any required amount of gas can be furnished for heating boilers, furnaces, drying apparatus, &.C., in the same works, and this at a lower cost than by the burning coal directly. In a largecentral station there arises a greatadrantage in having all the gas-engines near the producer plant, for then the otherwise waste heat of the exhaust-gases and jacket-water can be utilized. Even in the bestgas-engine between 70 per cent. and 72 per cent. of the total heat is lost in these two sources of waste, and sufficient heat can be recovered from the exhaust gases alone to raise all additional steam, at atmospheric pressure, required by

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. 202 HUMPHREY OX THE MOKD GAS-PRODUCER PLANT. [brinUte8 Of theNond producers. A source of economy isthus presented which will reduce the cost per HP.-hour below the figures given, and,by effecting the evaporation of thesulphate-liquors by a direct gas-flame action, fuel would also again be saved. These are sure signs that the bestpossible results are not yetreached. The transmission of power from the South Yorkshire or Mid- land coal-fields to the metropolis, and its subsequent distribution andsupply at a very cheap rate,is undoubtedly to be looked forwardto by metropolitan manufacturers, as well asby the presentusers of electric power. Mr. James Swinburne and Mr. B. H. Thwaite have drawn up a report of this project, and, with the assistance of Mr. Charles Brown, of Messrs. Brown, Boveri and Co., and the Oerlikon Co., Maschinenfabrik Oerlikon, they have found that a selling price to the local distributing companies of aka. per unit would leave a handsome profit after paying 7% per cent. interest on thecapital. In making their calculations the cost of coal, after deducting the value resultingfrom the recovery of residuals, is takenat 4s. 6d. per ton,whereas in the Mond process the recovery of sulphate would be sufficient to cover the cost of coal entirely. The advantages to be derived by consumers, taking power from a largecentral station as indicated, are not measured simply by the reduced cost per unit. Manufacturers can dispense with large and costly engines and foundations; boilers and coal-storage sheds are not required, and greater elasticity in the designof buildings can beallowed when long linesof shafting become unnecessary. In high factories the transmission of power tothe upper storeys becomes simple, and isolatedmachines no longer offer difficulties. Thedirt and nuisance arising from carting of coal and ashes and the troubles from steam-pipes under pressure disappear, together with the anxiety of a possible break- down of the main machinery; while on the other hand an exact knowledge is gained as to the power each piece of plant consumes, and more machinescan be added atwill without multiplying boiler- and engine-power. The cost of repairs, interest on capital, and chargesfor water and lighting all diminish with the new system, but more important still is the actual reduction in the amount of power required. In several well-authenticated cases a saving of 50 per cent. of thetotal power hasresulted after adopting electrical distribution to the individualmachines. There is no doubt that a state of things is rapidly approaching when a central supply for power will eclipse in importance the question of centralstations for electriclighting, and the far- reaching effects of the movement can hardly be over-estimated.

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] HUMPHREY ON THE MOND GAS-PRODUCER PLANT. 203 It cannot be foretold what will be the ultimate degree of economy realized, but it should certainlybe possible to supply every house in London with gas for heatingand ventilating purposes, and electric current for lighting, at such prices that no householder would think of consuming coal in an open grate,or polluting theair of his rooms byburning illu~ninating gas. The atmo- sphere of London would be relieved of the smoke which makes a London fog so objectionable, for factory owners would be supplied with power at a cost which even the Niagara FallsPower Company of America cannot reach. Also theexpenditure of Englandin nitrogenous compounds or fertilizing agents, amounting to about %2,000,000 perannum, would, as the system of gas-producers became general, be changed to an annual income arising frou the sale of the surplus sulphateof ammonia in foreign markets.

The Paper is accompanied by four drawings and seven photo- graphs, from which PIate 5 and the Figs. in the text have been prepared, and by designs and estimates of the cost of a plant to develop 10,000 HP.

APPENDIXES.

Duration of experiment after conditioP8 became Con-} three stant...... Average analysis of fuel (by weight)- Moisture at 100° C...... : ... 7.3 per cent. Nitrogen ...... 1.29 ,, Carbon, total ...... 67.88 ,, Sulphur ...... 1.30 ,, Ash ...... 7.57 ,, Volatile matter (exclusive of carbon) driven off at a temperature over looo C., by difference ...

Analysis of ashes from producer (average)- Ash, on dried sample, by weight ...... Carbon ...... Carbon lost in ashes, on the fuel ...... Carbon available for conversion into gas, on the fuel Calorific value of fuel, per unit weight,kilogram- deereecentigrade - units ...... Kilogram-calories per 1 ton of fuel, kilogram units, . 7,340,600 Averageanalysis of gasduring trial, tested when saturated at15" C.- Carbonicacid (CO,) ...... 16.0 vol. per cent. Carbonic oxide (CO) ...... 10.0 ,, ,, ,, IIgdrogen (H) ...... 26.0 ,, ,, ,, Marshgas (CH,) ...... 2.5 I, >, ,, Watervapour (H,O) ...... 1.7 ,t 3, ,, Nitrogen(N) ...... 43.8 ,, .. ,, Weight of l cubicmetre of gas saturated at 15O C. . 990.8 grams. ,, ,, ,, ,, ,, atdry OOC. ...1,048-5 ,, Weight of carbon in 1 cubicmetre of gassaturated at\ o.1448 kilogram 15OC...... ) Each kilogram of fuel gasified yields- 4.596 mbic metres of gas saturated at 15' C. 4.518 ,, ,, ., dry ,, ,, 4.283 79 7, 19 ,, at Oo C. Volume of dry gas at Oo C. per ton of fuel gasified. . 4361 cubic metres 1,367.3 kilogram OC. Calorific value of 1 cubicmetre of dry gas at Oo C.{ units calorific value of total gas made as a percentage on} 81. o2 per cent. calorific value of total fuel gasified .... Calorific value of 1 cubic foot (Oo C.) ..... 84.57 lb. OC. units

Water circulated through the towers, for 82 tons of fuel per day- Two 12-inch ramsat 32 revolutions per minute. Theoreticalquantity of waterpumped per minute 1.737 cubicmetre. Actual ,, ,, 1.59 ,, Watercirculated per minute per 1 ton of fuel} 19,4 kilograms. gasified ...... *, Total LHP. for blowers, engines, pumps, &c, from actualdiagrams,per 1 ton of fuel gasified perday) *3s Yield of ammonia- NH, as percentage on theweight of fuel gasified . 1.09 per cent. Calculatedas sulphate (of 24-25 percent- NHS) on\ 4.36 ,, fuel gasified ...... J Fuelrequired to produce 1 ton of sulphate. ... 23'0 tons.

TABLEII.-ADDITIOXAL STEAN ACCOUST FOR 1 TONOF FUELGASIFIED. Weight of exhaust steam added to producer blast . 1,583 kilograms. Tons of fuel required to produce this steam (evaporation of eight) ...... 0.195 ton. Kilogram-calories in abovesteam at 85O C., from water at 15O C...... 976,600 Kilogram-caloriesgiven to airby steam in raising temperature of air...... 9,016 Kilogram-calories (total) added in exhaust steam . . 985,616 Steamrequired for all purposes at sulphateplant (equal to 5.6 tons of steam per 1 ton of sulphate)} 0.224 ton. Tons of fuel at sulphate plant equal to above steam . 0.028 ,, Total steamused at producer and absorbing plant,&c. 1.71 ,, (this includes condensation in all pipes, $C.) . .]

ADDITIONALFUEL ACCOUNT FOR 1 TONOF FUELGASIFIED. Totalextra fuel at producersand plant .... 0.214 ton. sulphateplant 0.028 ,, ...... - ,, ,, ,, for combined plant, or 24.2 percont. on thefuel gasified ...... } 0-242 ,,

TABLEI~.-cALCTJLATION OF HEATQUANTITIES FOR MONDPRODUCER AND , RECOVERYPLANT.

(Kilogram O C. units.) PRODUCER:-For 1 ton of fuel gasified :- Temperature of air and steam entering .... 250° C. 9 gas andsteam leaving .... 450' C. Weight of airentering...... 3,165.00 kilograms. ,, steamentering ...... 2,598-00 ,, 673.20 7, ,, decomposed ...... ,, ,, gasleaving (dry) ...... 4,490.00 ,, ,, steamleaving ...... 1,999-00 ,, ,, ,, from moisture slack.in ... 74.16 ,,

Heat of formation of carbon gases :- For thc actual quantity of CO, formed ....3,063,457 I2 ,I .. CO ...... -- 572,592 T otal kilogram-calories Total ....3,636,049-- NoTE.-Tho CH, is regarded as a product of distillation. Equalto per cent. of totalheat of combustion of fuel 49.53 perccnt. Heat accounted for :- In raising 2,598 kilograms of steam from 250° C. ~M,SOO to 450° C...... ) In converting 74 kilograms of water at 15O C. to steam at 450° C...... } 58,238 In the decomposition of 673 kilograms of steam 2,503 ,560 (final temperature 4505 C.)...... I In heatingthe nitrogcn of thcair (250° C. to] 1,8,400 450° C.) ...... __-- Totalheat accounted for in above . . 2,926,995

or, expressed as per cent. on total heat of combus- 39.87 per cent. tion of fuel ...... Heat absorbed by other chemical changes + heat lost at producer equals, asper cent. on total heat 9.66 per cent. of combustion of fuel ...... f TCBELARREGENERATOR :- Temperature of air and steam entering .... S50 c. ,, ieaving .... 250' C. Weight of airentering .. .^ ...... 3,165 kilograms. ,, steamentering ...... 2,598 ,) Temperaturo of gas and steam entering .... 450° C. , .. leaving .... 280° C. Weight of gasentering...... 4,490 kilograms ,, steamentering ...... 1,999 ,I Heat given out :- In cooling gas from 450° C. to 280° C. .... 238,500 ,, steam from ,, .... 161,400 Total heat given out ...... 399,900 or, expressed as per cent. on total heat of combustion of fuel ...... 1 5 448 pcr cent. Heat absorbed :- In heating air from SS0 C. to 250° C...... 124,010 ,, steam from ,, , ..... 203,600 Totalheat absorbed ...... 327,610

or, expresscd as per cent. on total heat of co1nl)us- 4.46 per cent. tion of fuel ...... Efficiency of regenerator ...... 81.90 ,, MECHAXICALWASHER :- Temperature of gas and steam eotering.... 2800 c. 1, ,, leaving . .. 900 c.

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] HUMPHREY ox THE NOND GAS-PRODUCER PLANT. 207 Weight of gasentering ...... 4,490 kilograms. .. steamentering ...... 1,999 1, ,I .. leaving ...... 2,741 ., ,, addedin washer ..... 742 ,, Heat given out- In cooling gas from 280" C. to 90° C. .... 266,700 ,, ,, steam ,, .... 180,400 Totalheat given out ... 447,100 v, expressed as per cent. on total heat of combustion of fuel ...... 6-09 per cent. NOTE.-If all the heat given outwas utilized, the weight of steam added in the washer would be 829.4 kilograms instead of 742 kilograms. ACIDTONER- Temperature of gasand steam entering. ... 8Go C. ,l .. leaving .... 820 c. The acid liquor is heated from 79O to 82" C. Heat given out- By cooling gas ...... 5,616 .. ,, steam ...... 5,208 Totalheat given out(Fasted) ... 10,824 NoTE.-The gas is never saturated in the acid tower. GAS-COOLINGTOTTER- Temperature of gas and steam entering .... , 9, .. leaving .... Weight of gas entering ...... ,, steamentering ...... leaving ...... ,, .. condensed ...... NoTE.-In cooler weather this last n-ould be increased. Temperature of water entering ...... 500 c. ,, ,, ,, leaving ...... 800 c. Heat given out- In cooling gas from 82O to 66" C...... 22,450 In cooling steam ,, ...... 20,830 In condensing 1,546 kilograms of steam at 66O to water at 66O...... I 833,300 Total heat given out ... 876,580 or, expressed as percent. on totalheat of combustion} 11.94 per cent. of fuel ...... NoTE.-Owing to thc hot weather which pre- vailedduring the trial, the gas could not be cooled to the usual extent; but supposing it had been cooled to 15O C., 767,655 more heat-units would have been obtained,equal to 10.46 per cent. on the total heat of combustion of fuel.

Heat accounted for by rise in temperature of circulating water ...... 838,080 or, expressed as pcr cent. of heat givcn out ...I 95'6 per cent. AIR-HEATISGTOWER :- Temperature of air entering ...... 330 c. ,, andsteam leaving .... 73O C. waterentering ...... 80' C. I, ,, leaving...... 550 c. Weight of air, in andout ...... 3,165 kilograms. ,, steam(natural moisture in sir) a I ,. mate ...... ' plrosi-l 11 Weight of steam leaving ...... 1,015 ,, Heat absorbed :- In heating air from 33O C. to 73O C...... 30,040 ,, formation of steam at 73O C...... 601,895 -- Total heat absorbed ...... 631,935

or, espressed as per ccnt. on total hest of combus- 8.61 per cent. tion of fucl ...... 1 Heat given out by circulating water (SOo C. to 55O C.) 698,400 Efficiency of air-heating tower ...... 90.40 per cent. Total efficiency of regeneration by circulating water 72-07' ,,

.TABLEIV.-BALANCE SHEET OB HEATQUANTITIEB FOB MOND PRODUCER PLAXT.

Total hest of 1 ton of fuel . 100.00 Heat of combustion of gas) 81 .02 Heat added in exhauststeam 13.43 ma,dc ...... Hnat = work done in engines, Heat recovered inpipe re-} 5.45 &c...... ] 0.29 generator ..... Heat = steam condensed, &c. 1.37 Heat recovered in air-tower 8.61 Heat remainingin gas(above) lo. 46 15' C.) ...... Heatlost ...... 9.55 115.09 115.09

TABLEV.--STATEMEXT OF COSTOF WORKIXG OF MOXD PRODIJCEBAND RECOVEBY PLANT. (At Winnington, Cheshire.) E S. a. Price of fuel pcr ton at works :-Weight average for contract quantities ...... )062 Sellingprice of sulphate :-Price in August, 1896. Net' nakedat works ...... per tou} 1 ton of sulphate is obtained from 23 tons of fuel gasified, but adding fuel for steam required the total is 28.56 tons.

Cost per ton of sulphate of ammonia made :- E 8. a. Total cost of all fuel (28.56 tons at 6s. 2d.) . . ... 816 1 Wages at producers (23 tons at 6.4d.) ...... 012 3 Manufacturing wages, administration ...... 019 > ,, labour ...... 019 8 Repair wages and materials, including renewals ... 018 3 Gas for lighting purposes ...... 0 311 Lubricants ...... 018 Sulphuricacid, 0.95 ton at 145' Twaddle . . ... 144 Total for above ...... 12 1711 Sellingprice of sulphate,naked at works ..... 74 6 Final works cost of 23 tons of fuel gasified ..... 513 5

Or, final cost of gas from 1 ton fuel gasified ..... 0 4 11 -1 Or, the cost of 1,000 cubicfeet of gas(at 15' C.) is . . 0 0 0.351 The gas for 1 I.HP.-hour will cost ...... 0 0 0.02685 Or, gas for 1 LHP. for twenty-four hours a day for a year. 0 19 7.2

[THE mm. C.E. VOL. CXXIX.] P

TABLEVI.-ASALYSIS AND CALORIFICVAL~E OF VARIOUSGASES. (Products coolcd to lSo C.)

T701ume per cent.

Hydrogen(H) .... 24.8 8.6 Marshgas (CH,) ... 2 .3 2.4 CnHBngases . .. nil nil Carbonicoxide (bOj . . 13.2 24.4 Nitrogen (N) .. 46.8 59 *4 Carbonicacid (CO,) . . 12.9 i 5.2 Total volume ....-00.0 100.0 Totalcombustible gases . 40.3 , 35.4 Theoretical. Air required forcombustion .12.4101.4 Calorific valueper cubic) 85.9 74.7 foot in lb. O C. units . .J Calorific value per litre in) gram O C. units ...j

Nom.-Wh&e the volume per cent. does not add uq to 100 the slight difference is due to thepresence of oxygen.

______~~.___

TABLEVII.--THEORETICAL TEMPERATUREOF COMBUSTION OF MONDPRODKXER- GAS. Analysis of Gas, Volumetric. Products of hbustion. Per cent. l H ...... 27.5 With theoreticalquantity of air. CH,...... 2.0 Per 1 volume of gas burnt. C,H, ...... trace. 1 Water vapour ....0.315 CO ...... 11.0 CO, ...... 0.295 CO,...... 16.5 N ...... 1'303 N ...... 43.0 Conditim.-Gas to be taken a8 saturated at 15OC. ; air to be taken as half saturated at 15O C. Cubic feet of moisture for 1 cubic foot dry gas at 15OC. 0.0168 ,, airrequired for 1 cubic foot produccr-gas . 1.105 Moisture in the air ...... 0.00924 cubic foot. Totalmoisture for mixedgas and air ...... 0.0260 ,, ,, Weight of 0.315 cubic foot of steam formed bycombustion 0.0158 lb. 7, 0.0269, 9, ,, presentvapour.as . 0.00131 ,, Average specific heat of products of combustion ...0.2616 Heat-units required to raise products l0C...... 0'04002 Gross heat-units from burning 1 cubic foot of gas ...85'1 If X = temperature of combustion above 15O C. 0.04002 X = 85*1-{0.0158 (536 + 0.475 ~))-0.00131 (0.475 Z) which gives the temperature of combustion 1,606O C. -

TABLEWIT.-EFFICIEN~IES OF GAS-PRODUCERS. (Tabulated from examples given by Mr. C. P. Jenkin.’)

l Mond circular producer ... 1,367 8,627 0.810 Author. 894 6,210 0.562 C. F. Jenkin.

1,311 7,750 0.712 9, 1,549 8,110 0.754 ...... 1 ,154 7,060 0.565 1,044 7,060 0.468 anthracite ...... 1,321 7,540 .. Dowson; using anthracite 1,272 6,590 0.689 . . l ” Wilson producer, using slack 1,261 7,730 .. coal ,, using Durhamj ...... 1,238 7,140 .. l :: Wilson producer,another example I 1,314 7,420 0.702 l ”

’ Minutes of Proceedings Inst. C.E., vol. cxxiii. p. 328. * The “figure of merit ” is the heat of combustion of the gas per kilogram of carbon contained in it. Units-kilogram and Centigrade degees.

APPEN

HASD-FIREDASD GAS-FIREDSTEAX-BOILER TRIALS. (Communicated by

Esperirnenta at

With Ordinary Fuel (1896). ___ l Babcock- Wilcox Boilers. Uaber's estimate of HP...... 123 I 123 I 123 23 feet long by 36 inches) l lize of drum ...... in diameter i Number of tubes ...... 63 ] 63 I 63 18 feet long by 4 inches '1 Diameter and length of tubes ...... in diameter 1 Grate-area in square feet ...... I 26.5' Totalheating-surface ..... squarefeet .-l' --,411-0 Fuel. Kind of fuel ...... slack slack slack Quality ...... good good good 't::-):{Bostou Boston7 Colliery ...... Main pit Pit J Weight in tons per twenty-four hours .... 6.9 ,, Ibs. perhour ...... 4r$:i81 437.0 4.6:644.0 Lbs. per square foot of fire-grate per hour ... 16.5 24.4 Method of firing ...... hand hand hand -- -- Water.

Temperature of feed-water ...... O C. 50.0 Water evaporated in tone per twenty-four hours . 44.0 ,, ,, lbs. per hour ..... C,106.0 I.HP. at 30 Ibs. per I.HP. per hour ..... 137.0 Steam pressure ...... lbs. per sq. inch Evaporatiou. Lbs. of water per lb. of fuel (actual) ..... ll Equivalentevaporation from and at looo C. .. Lbs. per square footof heating-surface . per hour

Flue Gases.

Temperatureleaving boiler ..... O C. 315.0 370.0 Analysis by volumewith fires in g% per cent. 15.0 14-8 average condition anddoors shut 0.8 0.8 I :: 3.0 5.0

DIX 11.

EXPERIXENTIWITH I~ABCOCK-WILCOX BOILERSAT WISNIXGTOS. Nr. C. Humfrey.)

Winnington Works. Nunchester Stenm Users' Report, 1895. With Xond Producer-Gas (1896). , 159 l 159 I 159 l1 159 (given for comparison) 20 feet long bp 42 inches 23 feet long by 48 inches in diameter 1 in diameter 81 1 81 I 81 1 81 54 I 54 18 feet long by 4 inches l8 feet long by 4 inches in diameter { diameter in 33.5 if bars mere in 1.827.0 I 1,827.0 I 1,827.0 l 1,827'0 ______-,__..___ i I-- 1 Mond producer gas. Bnrgy 1 Burgy rhe weights givenarc those of slack fed into producerclean 1 wet clean dry .. I I 5.3 5.5 6.1 494.0 812.0 ...... 23.8 -- see Fig 6, Plate 5.

44.0 40.0 42.0 55.0 6.0 32 5 35.7 44.445.3 53.2 3,034.0 3,337.0 4,144.0 4,969.0 4,232.0 1 3,642.0 101.0 ___-111.0 -__138.0 166.0 141.0 125.0 84.0 84.0 80.0 85.0 78.0

6.13 6.50 6.43 6.12 6-11 ' 6.49

7.00 7.46 7.36 ~ 7.52 1.66 1.82 3.26 2.72 2.32 : -_ 1 6.83 1 7.41

209.0 15.4 3.6 0

APPENDIX 111.

TABLEI.-TRIAL OF A 25-NOMINAL-HP. GAS-ENGINE(CROSSLEY BROTHERS) WORKINGWITH MONDPRODCCER-GAS. Date, 5th July, 1894. Conditions:-The trial was conducted by the Author with the assistance of Mr. Bradley (Messrs.Crossley Brothers’ representative). The engine drove 8 200-ampre dynamo (100 volts),and the power wasabsorbed by iron wire resistance-coils. An hour’s preliminaryrun was madeto get all conditions steady. Some of the indicator diagrams (taken at five-minute intervals) were obtained with a Richards indicator, the others with a new Crosby gas-engine indicator purchased for the occasion. Duration of trial (3.30 P.M. to 5.30 P.M.), two hours.

Average Analysis of Gas during Trial-Nond Producer-&s. CO, ...... 12.9 volume per cent. 0...... 0.0 1, CO ...... 13.2 .. H ...... 24.8 ,, CH, ...... 2.3 .. N ...... 46.8 ,, , NoTE.-some gasescaped into the exhaust due to occasional dipping of governor lever.

Calorific value of 1 cubic foot of gas (lb. O C. units, see] 85,9 Table) ...... Meanspeed of engine,revolutions per minute ... 191.4 Number of explosionsper minute ...... 47.8 Pressure of explosion ...... 226.1 average Ibs. ,, at end of compression ...... 107.4 .... ,, at opening of exhaust ...... 38‘4 .. ,, working pressureMean effective working ...... 67.3 Indicated HP. calculated from diagrams .... 38.71 Gas used per hour, as measured by meter, saturated at 26.P C. and 764.5 millimetres ...... Gas perI.HP. (dry at Oo C. and 760 millimetres) per’) 69,70 hour ...... Slack used atproducer per I.HP. hour ..... 1.03 lb. Heat-units developed by actual quantityof gas used per) 3,861 minute (lb. O C. units-products cooled to 18O C.) . Heat-unitsaccounted for by indicatordiagram per minute ...... ] 919 Thermal efficiency ...... 23.8 per cent.

TABLE11.-STATEMENT OF COSTFOB ELECTRICLIGHT AT THE CAUSTIC-SODA PLANTOF THE WINNINGTONWORKS. This installation consists of incandescent-lamps and arc-lamps, the latter in pairs, all on a 100-voltcircuit. The dynamo is driven by a 25-nominal-HP. Otto gas-engine usingMond producer-gas. Timerun during month of April, 1896 ...... 320 hours. Total Mond gas used, measured by meter, April, 1896 . 920,033 cubic feet. Equivalent weight of slack into producers ..... 5.75 tons. Power- Averagepressure atswitchboard ...... 100.0 volts. ,, current ,, , ...... 184'0 amperea ,, work...... 24.5 E.HP. ,, including power for drivingfan ... 37-7 I.HP. Gas- Cubic feet of Mond gas (wet at 15O C.) per electrical 117.2 HP.-hour (calculated) ...... D itto Ditto per I.HP.-hourperDitto (calculated) I 76.1s

cost- € S. d. Slack at producers (without deduction for ammonia) . 203 Gas-engine oil, renewal of carbonsand lamps . , . P10 6 Labour at engine, one-thirdof man at 4s. per eight hours 213 0 -- Total cost ... 939-- Number of Board of Trade units at switchboard ... 5,888 Cost per unit (1,000 Watt-hours) ...... 0'394d. Cost as campaled with illuminating gas- To furnish thesame amount of light, 17,040 candle-power with illuminating gas at 2s. per 1,000 cubic feet, and 1,192,c40 cubic feet. allowing 35 cubic feet per 16 candle-power-hour, total illuminating gas required ...... l Costfor illuminating gas ...... X119 NOTE.-The engine-driver in charge had two other engines to attend, less than one-third of his time being taken by this installation. Seven, and some- timeseight, pairs of arc-lamps were incircuit. Half the cost of theoil is charged, as this oilwas used over again on other engines.

TABLEIII.-Dowsox-GAs PLANT. FIGURESFOB A PLAXT OF NOT LESS THAN 100 BRAKE-HP.UNDER ORDINARY WO~IKGCONDITIONS. Per Brake IIP. First cost of Dowson plant, including ash-pit for generator, foundations and erection- For 80 brake HP. size ...... $4 fd 1) 500 39 ,, ......

Downloaded by [ University of Saskatchewan] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. 216 HUMPHREY ON THE MOND GAS-PBODUCEB PLANT. [Minutes Of Fuel used- Anthracitein producer ...... 1.O lb. Coke in steam boiler (17 per cent. on total) ..... 0.2 lb. c Total fuel ... -1.2 lb. Fuel lost per hour when plant stands idle ...... 0.2 lb. Gas-cubic feet of gasrequired ...... 80-95 Waterused in boiler perhour ...... 1.O lb. ,, ,, for washinggas per hour ...... 1.4 ,, ,, ,, forcooling ...... 60.0 ,, Cost-Total cost of fuel ...... 0.M. Total cost, including fuel, water, cd, wages, repairs at 3 per cent.and depreciation at 10per cent. on prices erected 0.37d. (estimatedby Mr. Dowson) ...... I (Gas made per ton of anthracite, about 190,000 cubic feet.) Pe’~~~~~~~~efcet Fuel required- Anthracite ...... 10 Ibs. Coke 2 ,, ...... - Total ... 12 99 c Total water for gas-making ...... 32 lbs. Steamaccounted for in gas ...... 8 ,, Volume of air required to mix with gas ...... 1,400 cubic feet. Cost of producinggas ...... 2aa.

TABLEIV.-DOWSON-GAS PLANT. Clerk of Works Report on Dmson-Gas Plant at Gloucester County Asylum. (This plaut hasbeen in use twelve years.) Estimated cost of production during the year ending the31st of Xarch, 1895. e S. d. Anthracite,tons125 at 218. 2d. per ton ...... 132 4 10 One year’s repairs at 6d. per day...... 92 6 Gasman’s wages at 21s. per week ...... 54 12 0 --- 19519 4 Total gas made, 25,496,700 cubic feet. Cost per 1,000 cubic feet, exclusive of slack used at boilers, Isd. The above figures were kindly given by Mr. Dowsou tothe Author in August, 1895.

TABLEV.-~OJIFARATITE COST OF MOXD PRODUCER-GAS(WITHOX-T RECOTEBYPLANT) AND DOWSONGAS. If a Mond producer is worked without any plaut for the recovery of ammonia, then for 1 ton of fuel gasified the0.20 ton. extra fuelfor steam is ......

S. d. Total cost of fuel (1.20 ton at 6s. 2d.) ...... 7 4.5 Wages at producer ...... 0 6.4 - Total cost of gas from 1 ton of fuel ... 7 11.2 Quantity of gas from 1 ton (measured through wet meter} 165,994 cubic at 15O C.)...... Cost of fueland labour for 1,000 cubicfeet .... 0.507~2. Corresponding cost of Dowson gasper 1,000 cubicfeet . 1.Sd.

TABLEVI.-TRIAL OF A 320-I.HP. SINGLE-CYLINDERU SIMPLEX” GAS- ENGINEWORKED WITH LENCACCHEZPRODUCER-GAS, AT THE PANTINFLOUR MILLS, FRANCE. Quantity of fuel used during trial ...... 10,000 kilograms. Duration of trial ...... 194 hours. Kind of fuel used-dry coal of the Anjou mines. Cost of fuel per ton (estimated at Brussels) .....20 francs. Engine- Diameter of cylinder, 0.57 metre, equal to .....34.5 inches. Length of stroke, 1 metre, equalto ...... 39.37 ,, Maximum I.HP. (French) during trial ...... 280 Maximum brake HP. (French), calculated .....220 The engine was run on a steady load, driving mill machinery. Producers.-Two Lencauchezproducers coupled together, but arranged to work independently during the clinkeringof fires. Conditions.-The producers were filled before starting the experiment and left full at the end of the trial, the fuel used being taken from a separate weighedquantity of 10,000 kilo,pmsand used until exhausted, when the length of run was found to be 194 hours. Consumption of fuel-grams perFrench I.HP. hour . . 3GS equal to 0.803 lb. per British I.HP. hour, or to 1.043 lb. per British brake-HP. (calculated). Jacket cooling water ...... G,100 litres per hour. Water for washers and producers ...... 3,000 ,, ,I Total water consumption per British brake HP. hour . 55 ‘3lbs. Estimated cost of fuel ,, ...... 0 067d.