The Turner-Miesse Generator.

Progress, Volume II, Issue 2, 1 December 1906, Page 54

The Turner-Miesse Generator.

The generator of the Turner-Miesse steam car, which is of the flash type, is built of a number of layers of solid drawn steel tubes, each tube being bent into a special shape. There are sixteen layers in all, laid horizontally one above the other, and each layer being at right angles to the other and each four layers connected together by outside unions. The water enters the bottom layer first and finds its way up through 8 layers, and from the Bth layer it passes to the 13th layer, and up until it reaches the 16th layer. From the 16th layer it drops to the 9 th, and passes up to the 1 2th layer, leaving same as very highly superheated steam and passing to engine. The lowest tubes may thus be considered to act as a feed-water heater, and are therefore not liable to become burnt under ordinary working conditions. The top layers receive less heat from the burner, and may be called the steam raising coils. The intermediate coils may in the same way be looked upon as the superheater portion of the boiler The tubes vary in thickness, although the external diameter throughout is £", those at the bottom have an internal diameter of about 5/16", and the superheated coils of about 7/16". In the 10 h p generator the total length of tube is about 200 feet, and in the 16 h p car, roundly 300 feet The generator is enclosed in a special casing, built up with an inner and outer sheet of steel, held together by channel steel frames top and bottom the space between the metal sheets being filled up with asbestos. The long rectangular holes in it are made to form the bottom of a horizontal flue, a second bent plate being fixed above it This flue runs out through the bonnet in front, and is connected with a vertical flue passing down between the generator casing and dashboard, the burnt gases passing out through it beneath the car. The generator, which is tested to a pressure of 1,200 lbs. per square inch, is fired by a special form of burner which uses ordinary paraffin as fuel. The latter is carried in the air-tight tank, the feed pipe from it is led to a shut-off cock on the left-hand side of the car. A pressure of about 70 to 75 lbs per square inch is main-

tamed m the tank by a mechanically driven air pump, worked directly off the crank shaft of the engine. The delivery pipe from the pump is led to a three-way cock, which is connected with a gauge showing the pressure in the fuel tank, and with a relief valve on the dashboard. The three-way cock has a nozzle to which can be attached an ordinary tyre pump for obtaining the necessary pressure initially. The fuel finds its way into two vaporiser coils which he above the burner, and then to the burner nozzle. The quantity of gas which is fed to the burner is regulated by the amount of air pressure on top of paraffin in paraffin tank. No regulator for the air is provided, the air and gas pass along the pipe into a chamber from which a large number of parallel horizontal tubes project beneath the boiler. The tubes are perforated with rows of fine holes, drilled at an angle, which form the burner jets. The oil enters one end of the vaporiser which rests directly on two of the mam burner tubes, passes through the various spirals and emerges at the other end as vigour The burner is placed in line with hole in the casing, through which the flame of the pilot light is introduced The vaporised oil passes through the pipe to the burner jet. The vaporiser has an internal bore of 5/16" and an external diameter of 9/16". An inspection hole 111 the generator casing allows the operator to see when the coil is sufficiently heated by the pilot light to permit the paraffin cock to be opened The tubes are perforated, the two external tubes having but one row of holes in them and tubes two rows The mixture of gas and air issues out of these holes at an angle of 45 degrees, and the flames from each adjacent tube strike one another and cause the heat gener-

cited to be equally diffused lhe buiaei is held in position by two butterfly nuts at the front of casing, and the central tube of burnei w hich ib somewhat longer than the other, is slid thiough the hole in back of casing and fastened with a wedge-shaped cotter and split pin The mixtuie supply tube lies outside the burner All the tubes are, of course, closed at their real ends. The 10 h p burner has seven tubes and the 1 6 h.p. nine. Even the smaller burner has ovei a thousand small holes in its tubes The hole through the nozzle is extremely small, being about 1/16" in diameter. The burner can be easily taken out when necessary, the pipe connection to the nozzle and the cotter behind the generatoi casing, together with the two butterfly nuts alone require removing, when the burner can at once be dropped. The vaporising coil ol the burner is initially heated up by a pilot lamp and subsequently kept hot by the burner itselt. The vapoiiser coil requires to be thoroughly heated by the

pilot light before attempting to start the burner with its ordinary fuel. The operation of heating up takes something over five minutes to perform, but should not be hastened unduly, as the burner is liable to smoke, if the coil is not sufnently hot. The burner appears to work well and quietly, and to give a very high degree of heat. The water is forced into one end of the generator either by a hand pump, when starting, or by a mechanically driven pump when the car is running ; in the latter case the quantity of water delivered depends upon the speed of the car, but the actual amount which finds its way into the generator is regulated by hand, any surplus being allowed to find its way back to the supply tank. The hand regulator consists of a by-pass, and it primarily enables the driver to regulate the steam pressure. From the water tank the water is led to the feed pumps, its passage to the pump cylinders being regulated by a shut-off cock. A small dome is placed on the top of the tank on the right hand side, and an overflow which passes down through the water and out at the bottom of the tank, terminates at its upper end inside this dome. One of the delivery pipes from the pumps is led to a by-pass valve, which is also connected back again to the suction side of the pump. The by-pass is controlled by a small lever working over a toothed quadrant attached to the steering column under the steering wheel, and the quantity of water delivered to the boiler can thus be regulated The delivery pipe from the pumps to the boiler has an additional non-return valve between it and the pumps. It passes direct to the bottom coil of the generator, and has one branch pipe which leads through a relief valve, which forms a part of the quadrant on the steering pillar. The relief valve is normally kept closed, but m the event of the pressure rising abnormally at any time, it can be opened by the driver, when the water or steam in the delivery pipe will be allowed to pass to the condenser. The feed water pumps are fixed on the right-hand side of the car and are formed in one casting. One of them is operated by the hand lever, and the other by the eccentric on the countershaft. An air pump is fixed to the left of the engine, and is driven by a crank pin on the crank shaft. The other end of the shaft carries a hand brake controlled by a foot pedal; the latter also operates the steam throttle valve, its action being to first cut off the steam supply to the engine, and on further depression to apply the brake. The two water pumps have separate suction and delivery valves. The water passes from the pumps to the hand controlled by-pass, and through an additional delivery valve and pipe fitting m order to go to the generator and to the relief valve. The valve, a non-return valve between the generator and pumps, is thus

piovided which prevents the steam pressure forcing water 01 steam back through the by-pass and the condenser to the water tank.

An inteiesting trial is being conducted under the auspices of the Automobile Club, London, of an invention designed to obviate the use of the differential gear, which, if it fulfils the claims of the inventor, is destined to play a not unimportant part in the development of the motor car. Briefly, Mr Hedgeland, instead of using the ordinary differential, has a solid axle upon which he mounts the wheels on clutches These differ from the ordinary clutch in that as soon as the drive is exerted either forward or backward a coarsecut thread immediately comes into operation and locks the wheel on to the axle, thus taking the strain from the clutch. Ihe effect of this is that on turning corners one wheel is allowed

to revolve freely and the other wheel simply does the driving. The action in this respect is not identical with that of a differential gear, nor, theoretically, can it be contended that it is so good when driving a car round corners. Many claims are made to the effect that the driving is more steady and that the chances of side-slip are minimised. These claims will doubtless be dealt with by the Technical Committee of the Automobile Club at the conclusion of the trial.

Word comes from Melbourne anent the new automatic puncture sealing compound, " Miraculum," which, when injected through the valve into the inner tube of a pneumatic tyre, renders it quite impervious to puncture. A test recently made by Mr. Carty Salmon, M.H.R. gave those present a complete demonstration of its value. An inner tube of a motor tyre had been treated with the preparation as far back as last March, when, after various tests, it had been allowed to lie about the room unused. A few days ago this tube was placed m a cover, and used in a trip to Mormngton, with all its many punctures unrepaired, and went through the journey without attention. This tube, which was used in Mr. A. E. Langford's car, was then detached from the cover, but not before the tyre was pierced through and through, much to the amazement of those present. An inspection of the tube showed very many punctures, through which the compound, a semi-liquid, milk-white substance, slowly oozed. The tube was then replaced, and, after a thick 4" nail had been hammered into the tyre and withdrawn, the chauffeur was ordered to take the car round the streets. On his return the tyre was found to be perfectly hard and firm Ihib test, however, proved more than that the preparation would seal punctures. It showed that the substance did not lose its efficacy, and that it had no deleterious effect on rubber, which, perhaps, is the most important point of all. On the contrary, it is asserted that it acts as a preservative, and it is, to all appearances, similar to rubber in its native state.