THE 'CHALLENGE.' MR. A. MORTON'S EJECTOR CONDENSER.

Daily Southern Cross, Volume XXVI, Issue 3960, 2 May 1870, Page 5

THE 'CHALLENGE.' MR. A. MORTON'S EJECTOR CONDENSER.

THEp.s. 'Challenger,' belonging to Messrs. Holmes Brothers, of the North Shore, which made her official trial trip on Friday last, with Mr. J. Stewart, C.E., the Government Inspector of Steamers, on board, was again taken out for a trip on Saturday afternoon, when about 20 guests were on board. On Friday, the little boat had to contend against a very strong N.E. wind, and a considerable tumble of the water ; but on Saturday there was scarcely any wind, and the water was almost smooth. On Friday, she proved herself very steady and a good sea- boat ; and on Saturday she showed that she is capable of running about S£ knots in the hour. She went as far as Brown's Island, where the ' Lalla Eookh,' also belonging to Messrs. Holmes, coming from Coromandel, was met, and the ' Challenger ' was then put about, and there was a race back. The ' Lalla Rookh ' is a smart little steamer ; but the ' Challenger ' headed her so much, that, after running beyond the wharf, she was put round, and she ran back and passed the ' Lalla liookh ' when she was 150 or 200 yards from the wharf. The ' Challenger ' ran the six knots, from the end of the island to the wharf, in 38 minutes. The ' Challenger' was built by Mr. Niccol, of the North Shore, and her boiler and en- i gmes were constructed by Messrs. Fraser and Tinne, of the Phoenix Foundry, Auckland. She is 85ft. long on the keel ; has 12ft. Gin. beam ; and her engine, which is on the diagonal principle, is of 30-horse power nominal. Her boiler is multitubular, with two furnaces j it is circular, and has a length of 9ft., and a diameter of 7ft. The engine is very solidly framed ; it worked in the trial tiips almost without perceptible heating of any of the bearings ; and the boat herself is a pretty model, and most substantially built. Taken merely as a small steamer, locally owned, and meant for a local trade, she is a credit to those who ordered and to those who built and fitted her. But it is because of one peculiarity connected with her engine that the ' Challenger ' and her trial trips deserve special consideration. The engine has added to it a " patent ejector condenser, " invented by Mr. Alexander Morton, of the firm of Neilson Brothers, engineers, Hyde Park Works, Glasgow. This invention was discussed by the members of the Institute of Engineers of Scotland, at a mcc ing held at the close of 186S, when Professor W. J. Macquorn Eankine, C.E., LL.D., F.R.S., &c, read a paper detailing experiments conducted by himself, on the ejector condenser as applied to a pair of 24-horse vertical inverted clirectacting engines, in use at Messrs. Neilson's works. At the meeting, Professor Rankine spoke of the invention as a most valuable one. Mr. J. L. K. Jamieson (as reported in The Aitizan) said, '-it stiuck him that Mr. Morton's invention was one of the greatest improvements of the age in the steamengine ;" and Mr. A. C. Kirk said that the apparatus "\\ as undoubtedly the best addition that had been made to the steam-engine since the days of James Watt." Mr. Kirk added, "He conceived hat to no class of engines would it be more immediately valuable than to river steamers, where reduction of weight was of the utmost importance, besides the obvious convenience of it in all land engines, not to speak of other applications, which will follow by-and-by." Sir William Thomson expiessed his conviction that there would be many very interest ing laboiatory applications of this invention ; and he said, ' ' He had seen four mouths ago, in Professor Bunsen's laboratory at Heidelbeig, a hydiaulic apparatus acting to the same effect as this, but probably not of prior date to Mr. Morton's, The general idea of liquids acting as in the ejector condenser, was (Sir William said) generally known, and had had many applications ; but there were peculiantics connected with the ejector condenser, the effects of which, so far as he knew, had not before been recognised." The practical importance and scientific interest of Mr. Morton's invention were put beyond question by Professor Ilankine's paper, and the discussion which followed it. But, admitting the possibility that both have been over-rated, there are circumstances connected with the constiuction and use of the apparatus on board the ' Challenger, ' -si Inch aie of peculiar interest colomally. Ji the apparatus has up to the present time been applied to any other marine engine, it certainly has not yet been applied to any other marine engine-con-structed in the Southern hemisphere. Mr. Frasei fiisfc knew of the ivA r ention from IJiitish scientific publications, and his knowledge of it has I een mainly gained from The A i than. The description aud a few diagiams published in that journal, have been the only helps which Messrs. Fraser and Tinne had in constructing the apparatus ; and Mr. Fraser was from the first so favourably impressed with the practical value of the ejector condenser, that the fiim took the sole lisk of adding it to the ' Challenger's' engine. If it succeeded, they were to be paid for it ; if it failed, they were to bear all the cost of the work, and al 3 o the cost of removing it, so as to leave j the engine an ordinary high-pressure one. In ordinary condensing engines, the steam, after it has been used to lift the piston rod, is condensed and wasted, save that the condensed steam, and the condensing water which it has heated, go to supply the hob-well, whence the boiler is supplied. But to get the condensed steam and the water to the hot well, an air-pump has to be used ; and the steam power necessary to work a thoroughly well-constructed air-pump is known by experimentto beequal to that which would overcome a back-pressure on the steam-piston of from to |lb. on each square inch of its area. In an ordinary highpressure engine, the steam, once used, is wasted — except it be turned into the smokefunnel to increase the draught ; and there is i a very considerable back-pressure to be overcome, and a consequent non-profitable employment of steam. When a surface-con-denser is used, a cumbersome addition is made to the apparatus, which, both as to weight and to space occupied, is of importance as regards most steamboats. The airpump has still to be used. The indications of the vacuum gauge represent a diminution of back-pressure, and a consequent equivalent profitable use of steam. The ejector condenser of Mr. Moreton dispenses with the I use of the air-pump ; is at least as efficient as an ordinary surface condenser; is, as comparatively with that apparatus, of very little weight and bulk ; and its cost has been estimated at not exceeding one-fourth, as compared with ordinary air-punips and condensers. It is not easy, without diagrams, to describe the ejector condenser and its action ; and we should like to describe it, so that the merits of so important and interesting an invention shouldbe easily understood. A curved iron pipe, rising from the side of the cylinder, and a second pipe with a curve from the side of the boat, are the principal supports, as well as essential parts, of the apparatus. The former is the exhaust steam - pipe ; the latter is the injection water-pipe. The former is arranged so as to communicate with the upper portion of the condenser ; the latter has one opening to the sea-water, and another to the lower side of the condenser. What the pipes support, is a horizontal tube or cylinder ; and it supports at one end a starting and regulating valve, working in a small box. A pipe running from the boiler communicates with the upper side of the ralve box ; and — not in the same line — there is an opening through the valve-box support, into the lower or main horizontal part of the apparatus. This I starting apparatus stands beyond the line of i the injection water-pipe ; which, line is the j boundary of the condenser proper. Into the , condenser there projects a stout copper tube, , with a regulating spindle attached. The tube has an opening which allows steam to enter it, after passing through the regulating 1 valve. The copper tube has a short nozzle ; and up to nearly the point of commencement of that nozzle, the tube is surrounded by a fixed iror tube, which is so madeaa to be in contact only near its termination. Thus, for , nearly its whole length, the copper tube is protected from contact with the water in the

condenser. There is formed from a point inside the line of the injection pipe, another tube of iron, also nozzle-ended, and with, its end extending beyond the nozzle of the copper tube. The copper tube ia kept from contact with the water, to avoid a condensation of steam within that tube j and the iron tube just mentioned prevents the exhaust-steam coming near the copper tube, or mixing with the water except at a point between the nozzle of that tube and i the point of ejection. The casing, as it maybe called, of the condenser is, at something more than Ift. in advance of the nozzle of the iron tube described, moulded into a conoidal nozzle, with a continuation which opens out to a trumpet-month tube, and then ends in a common pipe which passes through the ship's side on a level with the condenser. So much for the apparatus. When steam is allowed to pass through the regulating valve, and through the copper tube, it drives the water out of the condenser through the trumpet-mouth tube, so as to form a vacuum. This it does so satisfactorily, that Sir W. Thomson, at the meeting of the Institute of Engineers, said, "the effect of the trumpet-mouth tube in producing a vacuum of 131b. was most wonderful." It has been found that the vacuum and flow of water caused by this initial jet of steam is maintained by the action of the exhaust steam drawn from the cylinder. But should this not be perfectly done — or should the opening of a cock, by accident or otherwise, impair the vacuum — the regulating valve at once a#ts, and restores the vacuum. Without going into details, the valve is so constructed that the vacuum, acting against a helical spring, causes the valve to shut off steam from the boiler ; but the instant the vacuum is impaired, the spring acts, allows steam from the boiler to pass into the copper tube, and so retores the vacuum. As constructed by Messrs. Fraser and Tinnp, the ejector condenser raises the injection water 3ft. The ejection, as has been stated, is on the level of the condenser. The hot-well is affixed to the lower side of the ejection-pipe, and the discharge being above the line of the well, the latter remains constantly full. During the trial-trip of the 'Challenger,' on Satm-day, with a pressure averaging about 401b. in the boiler, and the engine making 30 revolutions a minute, the vacuum was tolerably steady at 111b., and the temperatuie of the water in the hot-well was from 120" to 140°. The gain in point of economy, from the adoption of the ejector-condenser, as represented by these results, will be understood by all practical men ; and, as we understand, the apparatus can easily be applied to any existing engine. The results would certainly not bo less satisfactory in the ease of a pair of engines than they have been in that of the single engine of the c Challenger. ' We have no doubt that the engineer of the boat will continue for a uime to observe and record the working of the engine. During the run down to Brown's Island on Saturday afternoon, the Aisitors on board the ' Challenger' assembled in her small, but neatly fitted and comfortable, cabin, where refreshments had been spread. The health of Messrs. Holmes Brothers, especially in connection with their enterprise as» affording accommodation to the residents at the North Shore, was proposed by Mr. T. S. Hall, the names of Messrs. Fraser and Tinne being coupled with the toast. — Mr. James Holmes, in acknowl edging the compliment, said that he and hi*> bi other were poifectly satisfied with the boat, bha had turned out to be first class, m evciy way. He believed that Iheboilei, especially, was better than they would have got anywhere else — aye, even had they sent Home for one. The firm would ne\er again send out of the colony for engines or boilers. The work might requii c a little more true in the doing here ; but there was satisfaction when it was done. The boat was intended for the ferry trade, eventually ; and so her engine had to be somewhat more powerful than would otherwise have been necessary. — Mr. Fraser said that if this was not the first time the ejector condenser had been applied to any steamer, it was certainly the first time it had been done south of the equator. It was only seven or eight months ago that he learned anything of the invention. He at once determined to give it a trial on the first opportunity; and from the success of the last few days he ventured to say that this ejector condenser would supplant the old condensing arangenients — that it would do away with the use of the air-pump and the large condenser, which were cumbersome, taken at the best. Mr, Morton's inventions enabled more power to be got, while much less room would be occupied by the apparatus. He and his partner had to thank Messrs. Holmes for the kindness with vhich they had waited for the boat while the experiments that were inseparable from the first introduction of such an apparatus had been carried on The excuisionis f s were landed at the breakwater at a quarter after five o'clock. We hope that what has been written will justify the statement, that special interest, for Auckland in particular, attaches to the ' Challenger' and her trial trips.