FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1920
1920 - 0654.PDF
JUNE 17, 1920 THE "REVERGEN" TOWN-GAS-FIRED FURNACE An Economical System for the Rapid Heating of Draw-Forgings ALTHOUGH the use of town gas for general forge and furnace or that their normal output suffices to raise much higher work has been shown to be advantageous from nearly every temperatures. point of view theoretically, it has hitherto proved uncom-mercial because of the enormous flue losses of heat units. The problem, therefore, has been essentially one of thinkingin terms of heat units, and endeavouring to go very much further toward their conservation than has so far beenachieved. This seems to be the accomplished object in the case ofthe new " Revergen " furnace, lately devised by the Davis Furnace Co.—of the Diamond Foundry, Luton, Beds, and6, Kathbone Place, London, W.—for single or multiple rapid- draw forgings, as well as for annealing. This latest develop-ment has two open slot-like mouths, each provided with a rest-bar, and is designed to work upon the same system ascombined reverberatory and heat-regenerative furnaces : hencs-the name " Rever-gen." Built on the double-hearth system, the method of firingis from a range of faucet-controlled gas jets fed from a common pipe, direct into the furnace. Simultaneous carburationat the jet nozzles is embodied with an air current drawn upward through the spaces between the brickwork of ahearth, built checker-fashion: the resulting flame-current— especially since the nozzles are protected with a baffle lineof brickwork—being naturally reverberatory, provided that the flues run downward. But it is just in this regard that the enormous heat wastageby way of these flues has Ween created ; so that one could not attain anything like high temperatures—such as ij.5000 C.—economically. Hence, in the Revergen, it has been sought to employ the well-known heat-storage capacity of massesof fire-brick, in the first instance—-for which purpose the additionally-exposed surfaces of checker construction aresingularly favourable—and to extend this capacity as far as possible by deepening the mass of each hearth. Thus it willbe evident that the flame-gases, passing downward through the checker-spaces—if acting as flues—would part with theirheat to the mass en route. The checker-spaces in the mass are used in an air-draughtcapacity, instead of merely as flues, and the draught is forced, so that instead of remaining inert, the stored heat units arerapidly extracted and drawn in the one upward direction into the furnace again. The obvious alternative conclusionsare that the flame from the gas jets can be reduced heavily, This alternative function of flues and forced draughthas been effected in the case of the Revergen furnace, first by the use of the double hearth-mass, and, mechanically,by the provision of a huge overhead four-way cock into which the main air-supply pipe runs, as from an electrically-drivenblower-fan, at one angle—-S.W.—while opposite—N.E.— is the main flue-outlet, with the branch-pipes at the otherN.W. and S.E. angles, leading to and from the bottom of the hearth-masses, by way of tapered manifolds, eachbranch acting as a down-take in its air-supply function to its mass, or as the uptake from it—and hence to the flueoutlet through the cock—in the flue function, according to the direction in which the four-way cock is half-turned.The taper of the manifold, of course, slightly increases and regularises the air-draught velocity, and correspondinglyeases the escape of the flue-gases. -Also, each gas supply- pipe has its own cock, so connected with the four-way cock con- ..;-trol as fully to cut-out the burners on the side in flue-function? and heat-storage, and as fully to open up supply to those,*on the other side, which is in air-draught and beat recovery. Thus the final result is—from the full change - overevery six to ten minutes—that while the furnace tempera- ture may be anything up to 1,650° C., that of the gases at the v:flue outlet is never more than about ioo° C. The hearth-floors are, of course, solid, as the air emergesfrom, or the flue gases escape by way of, the perforations behind the burner-baffle line on either side, from or to thechecker-work spaces in the storage-regenerator masses be- neath. But they are built with a slight angle from the -baffles to the longitudinal central line to a slag-plug hole beneath the middle of each mouth of the furnace. Apart,too, from all other advantages, it is claimed—apparently • with good reason—that the strong current action has asingularly cleansing effect on the iron whilst heating. There can be, at any rate, little question about the rapidityof this Revergen furnace for quantity-production of forged pieces, such as axles and other parts used in automobileconstruction ; for when in full action, with four minutes or less to a primrose white heat at the draw, the capacity of each" mouth " would keep half-a-dozen power hammers fully supplied, practically as fast as operators working in turncould handle the pieces. • .. » . .. ,^ - LEGAL INTELLIGENCE The Tarrant Triplane Accident THE Court of Appeal, consisting of Lord Justice Bankes.Warrington and Scrutton, on June 9, dismissed the under- writers' appeal from the judgment of Mr. Justice Roche inthe action brought by the administrator of the estate of Capt. Dunn, who died after an accident at the trial flightof the Tarrant triplane at Farnborough on May 28, 1919. The action was brought to recover ^4,000 on a policy ofinsurance on the life of Capt. Dunn, and it was stated to be the first action which had arisen out of aviation insurance.The original action was reported in FLIGHT of January 29 last. In the course of a lengthy judgment, Lord Justice Bankessaid that a proposal form, made for personal accident in- surance for pilots, contained a clause or note which had beenrelied on as expressly exluding the first flight from the in- surance. The clause or note stated that " the first flight ofa new aeroplane . . . not covered unless specially arranged for." Was the proposal a proposal on the part of the personwho put it forward, with an intimation that he desired that' the first flight of a new machine should be included ? Theproposal read as a whole did seem to convey clearly that what the proposer desired was to cover 12 hours of testflying from the beginning of the first flight. Then the question was whether it was accepted by the underwriters,the acceptance was found in the cover slip. The slip, as originally prepared by the brokers, contained the words :" during 12 hours' flight in the Tarrant machine . . . not exceeding a period of three months from date of first flight."Someone altered the words " during 12 hours' flight" to " during 12 hours' flying " and the words " three monthsfrom date of first flight " to " three months from date and time of first flight." Therefore the appellants failed on the first branch ef thecase, either because the proposer did make the proposal sufficiently plain that he wished to cover the first flight andthat was accepted by the underwriters, or if there was any ambiguity the matter came within the principle of Bradleyand Essex and Suffolk Accident Indemnity Society. The second point taken by the appellant was that Capt.Barber said at the first interview on April 23 that he would not take this insurance except on the condition that themachine should not be flown at all until it had been passed as safe by Col. Bristow. Mr. Justice Roche had come tothe conclusion that, in spite of what took place at the inter- view on April 23, Capt. Barber did ultimately intend tocover the first flight of the machine. The learned judge also came to the conclusion that it was not made sufficiently clearto Capt. Rawlings in the proposal of May 2 that Capt. Barber continued to insist on the condition that the machine shouldnot be flown until it had received Capt. Bristow's approval. It was impossible to take a different view from that arrivedat by the learned Judge on that point. The judgment appealed from must stand, and the appeal must be dismissedwith costs. Lord Justice Warrington and Lord Justice Scrutton concurred. Heavy Fine for Alleged Low Flying AT Bournemouth police court on June 10, ReginaldEdmund Tollerfield, an air pilot, employed by the Bourne- mouth Aviation Co., answered two summonses taken outunder the Air Navigation Regulations, 1919, one for flying over Bournemouth at a dangerously low altitude and theother for trick-flying over Bournemouth on May 9. Two R.A.F. officers gave evidence to the effect that defendantexecuted two Immelmann turns at an altitude of 500 to 600 ft. The defence was that the Immelmann turn was nottrick-flying, but merely a quick way of turning. Defendant also stated that he did two Immelmann turns over the sea,and during his flight he was never under 1,500 It. He could have glided down to the sands or to Meyrick Park had hisengine failed. Mr. Tollerfield was find £25 in each case— £50 in all—and costs. 654
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
