Some notes and details of a steam power plant, and results ...

77

SOME NOTES AND DETAILS OF A STEAM POWER PLANT,

And Results of Duty Trial of Same.

BY Mu. W. FYVIE, Nov. 5th, 1902.

The subject I have the pleasure of placing before you con-sists mainly of the results obtained by a trial carried out on a steam power plant, at Messrs. Collins Bros.' woollen mills, Geelong, situated on the Barwon River.

Those mills, I believe, were started over 27 years ago by the late Mr. Henry Collins, the father of present owners.

Those results, together with a few notes and details relating thereto, which I hope may prove interesting to the members of this institute.

Nearly two and a half years ago, Mr. M. E. Collins, a mem-ber of the firm, asked me, as a practical man, to have a look at their Power plant, with a view to advising them, if it would be reasonable and practicable to expect more power from the engine, and if the efficiency could also be improved.

Old Engine.—The engine being of the single column beam type, jet condensing, having a steam cylinder 224,in. dia. x 36in. stroke, running at 45 to 46 revs. per minute, working with a boiler pressure of 50 to 55 lbs. per square inch, (when it could be maintained) ; air pump 14in. dia. x 18in. stroke, operated from the main beam in the ordinary way.

The engine being of very uncertain age, it had been im-ported about 1856, I should say it had not been built within the last 55 to 60 years, it had been at work in Messrs. Collins' woollen mills from the start, about 27 years ago, which in it-self is a pretty good and creditable record ; but I understand it was in use driving a flour mill off and on for nearly 20 years before being erected at the woollen mills.

Old Boilers.—The boilers consisted of two, Cornish type, one pretty old boiler, which I believe had been imported ; it was originally 18ft. long x 5ift. dia., but was lengthened to 26ft. 9in, before being re-erected at the woollen mills about 1874.

At the time I first saw the plant, this boiler was being used for generating steam at about 30 lbs. per square inch, for heating purposes in the drying and scouring rooms, and dvP-house.

78 NOTES ON A STEAM POWER PLANT.

The other boiler being of more modern construction, about 26ift. long by Eft. diameter, also Cornish type, working at a pressure of 50 to 60 lbs. per square inch., having been built and erected to the order of Messrs. Collins Bros., about 13 years ago, this boiler supplied steam for the engine only. The most acute trouble being, the maintaining of sufficient steam pressure to run the engine to speed.

I made an examination of the plant generally, taking a num-ber of indicator cards from the engine cyl. under different conditions. The maximum power developed with all the machinery in motion, and a full head of steam being about 120 T.H.P., making 46 revs. per min., but this could not long be maintained.

I found the slide valve a little out of adjustment, the vacuum very poor; this I found had always been the case, as illustrated by an old indicator card or two which Mr. Collins showed me, and which I afterwards found when the old engine was dismantled (to see into the condenser at all, you had to remove the steam cylinder and all the parallel motion gear), was due to a structural defect in the condenser and air pump, and little help could be expected in that direction, but at a prohibitive cost. The slide valve was re-adjusted, and the air pump improved a little at my suggestion. The engine being loaded beyond its capacity at 120 I.H.P.

The large boiler I found heavily scaled (the Barwon water being rather hard and conducive to the formation of scale in steam generators) the boiler being taxed considerably be-yond its capacity.

•I reported as follows :—"Taking matters all round I would not advise the spending of money on your present plant, as you are now fully up' to the maximum amount of work that can be expected with any reasonable degree of safety from breakdowns. Keep the engine and boiler in good order, at as small cost as you can, nurse the engine carefully ; and make up your mind to 'get a better and more modern plant at as early a date as you can. arrange. The new plant can then be made suitable for whatever additional power you may think necessary."

To tide over the present difficulty and assist the engine boiler somewhat; there being ample power in the smaller boiler for the purpose it was used, but not good enough to •'carry the necessary working pressure. I suggested they should get a good feed water heater, and place between the feed pump and boilers, taking steam at about 301bs pressure, from the small boiler for use in the feed heater ; in this way the small boiler would considerably assist the larger. This suggestion was carried out, with a very pronounced benefit all round ; the assistance amounted to about 11 per cent. on the total work of the large boiler. This,

NOTES ON A STEAM POWER PLANT. 79

together with the adjustment of slide valve, and th.e slight improvement made on the air pump, they now felt they could jog along a good deal better, thus allowing a breathing space to think about a new power plant, no small matter to contemplate for a manufacturer.

Messrs. Collins Bros. now realised the importance of this step, and concluded that no time should be lost in making arrangements for another plant; and, like far-seeing business men that they are, with Federation near at hand, when it seemed likely that the measure of protection the woollen in-dustry then received in Victoria, would in all probability be re-duced ; and to enable them to successfully meet this, and compete on more favourable terms with their fellow manu-facturers, they decided te put down as good a plant as could be produced for their class of work, and asked my opinion as to what type I would suggest. This largely depended on their present and probable future requirements.

It was agreed that for the present the plant should be cap-able of giving about 50 per cent. greater power • than their present one developed (120 I.H.P.), with a good working effi-ciency at say 120 I.H.P., and up to 180 I.H.P., and if practical so designed that at any future time and at reasonable outlay (without disturbing present arrangements), it could be in-creased in power another 50 per cent., to say 270 I.H.P., with good efficiency, and thus be sufficiently flexible to suit the probable increase of their trade without being much over capitalised in that section, of their plant. They had good prospects, but they had no. wish to have capital sunk in what was not a reproducing factor. Those were roughly the con-ditions agreed upon between us.

At first sight the problem did not appear very easy of solution, . but after as little consideration. I concluded it was quite within the bounds •of practical engineering, and pro posed the following :—

Engine.--A compound tandem jet condensing engine having cylinders 12ín. diameter H.P., and 22in. diameter low pressure, by 36ín. stroke, running at a speed of 65 revs. per minute., with a working steam pressure of 1401bs. per square inch above the atmosphere, both cylinders to be fitted with auto-matic cUt off gear, of the "Corlis" type, regulated by the governor, cylinders jacketed, and a re-heater placed be-tween the cylinders. The engine to be so constructed that it may be easily converted into a triple compound of •about 270 I.H.P., having 12ín. high pressure, 19fin. intermediate pres-sure, and two 22in. low pressure cylinders, by 36in. stroke, 65 revs., with a boiler pressure of 1601ós. per square inch above the atmosphere.

Steam Boilers.-4 proposed a Babcock and Wilcox boiler of their standard type for 1601bs. working pressure, rated at 110

80- NOTES ON A STEAM POWER PLANT.

horse power (at 301ós. water evaporated per horse power), 1265 square feet heating surface, 26i square feet grate area, fitted with their improved steam super-heater, containing about 170 square feet heating surface. With such a plant, well constructed, they should get one indicated horse power for 151bs. of steam per hour, and with fairly economical evapo-ration, the coal consumption should not exceed 14lbs. coal per I.H.P. per hour.

This is roughly the outlines of my proposal, which was accepted by Messrs. Collins Bros. Tenders were called for the engine, and Messrs. Thompson and Co., Castlemaine, were the lowest, and they secured the job. Meantime prices were called for, for the supply of a boiler, and submitted by the Babcock and Wilcox Co. This also was accepted. It is need-less for me to say anything about the boiler, as this type of boiler is now so- well known to members of this Institute.

I might here mention that at this time (as at all others) Messrs. Collins Bros, were very busy with contracts, and had some difficulty in giving their old engine the nursing that was necessary, and which I recommended, and they unfortunately had a good few breakdowns. One of the bearings carrying the main beam gudgeon broke ; next the crank-shaft carried away and had to be welded; next the main, column fractured at the bottom and had to be strengthened. Meantime the new boiler was erected and started to work; and, last of all, within about a fortnight or three weeks of the time fixed for closing

iii the mills to allow Messrs. Thompson and Co. to erect the new engines, when starting one morning, the main beam broke clean through within a few inches of the centre gudgeon, and of course this settled the career of the old engine.

It was a most unfortunate and serious matter for Messrs. Collins Bros., but the new engine was then practically com-pleted ready fog erection, part being already landed at the mills. The work was entered upon at once, but as consider-able alterations and extensions, were to be made in the various main-line shaftings, and it was intended as much as possible of this work would be done before the mills stopped, thererore a good deal of time was inevitably lost which would have been saved if the original arrangements could have been adhered to.

I am inclined to think the old engine did not altogether get fair play. When they started the new boiler I warned them to reduce the load on safety valves to blow at 641bs. per square inch in case they might do damage to the old engine. They altered the weights along the lever as far as they would go ; this -still carried 901bs., and I can quite imagine if 901bs. pressure per square inch were turned on to the old engine (and it for the moment only a little off the dead centre), what

NOTES ON A STEAM POWER PLANT. 8I

the effect was likely to be, a general wreck as it proved. When this engine was bAilt they probably never contemplated a greater pressure than 25 to 30 lbs.

As mentioned before, the internal arrangements of the mills relating to main drives were reorganised and brought a little more into line with modern ideas. In the original the power was taken from the engine shaft, on which was secured a bevel wheel of 4ft. 10in. diameter by 4in. pitch ; 47 teeth, fitted with wooden cogs, gearing with this was a bevel pinion secured to a vertical shaft ; this vertical shaft going up to the various floors, the power being transmitted to the various shafting by bevel cog wheels.

A very old system, but nevertheless it had given good satis-faction when it is considered that only one or two of the many cog wheels had to get the wooden cogs renewed during the 27 years they had been at work. I was very much struck with the splendid condition of the woodên cogs in the main wheel on engine shaft ; they looked as if they were good for another 30 years, which speaks well for the designer (who, I believe, is a member of this Instituto) and the millwright who made them. The materials and workmanship must have been good.

The reorganising of the shafting and gearing was carried out by contract, tenders being called for, for this work, Messrs. Thompson and Co. were the lowest and successful in securing this job also.

Ropes being adopted for all the main drives, with a number of friction clutches arranged for cutting out, cor in, any section of the mills, as might be required without stopping the main engine.

Some rather unusual work was necessary in the power trans-mission to the different sections of the mills, a large part of the mills being on the opposite side of the main thoroughfare leading into the mills, practically cutting the factory in two. After due consideration it was decided to cut an underground channel, or rope race, for conveying power to this part of the mills. This meant considerable cost, but the advantage gained has more than repaid the extra outlay. Considerable additions were made to the machinery in the factory, running into about 18 to 20 horse power.

The new engine and gearing started running in the first week of September, 1901, practically without a hitch, and as per contract, was guaranteed for a period of 12 months by Messrs. Thompson and Co., and I am pleased to say the engines,

gearing and all machinery have been running ever since,

giving the utmost satisfaction and great, credit is due to Messrs. Thompson and Co. for the manner in which they have carried out the work entrusted to them. I am also pleased


to say Messrs. Collins have been so busy that from the second week the engines started they have been working night and day ever since.

Just before the twelve months' guarantee expired Messrs. Collins desired to make an efficiency trial of the engine and boiler, and on the 9th September, 1902, the trial was carried out, the results of which I will lay before you.

There was no special preparation of the engine or boiler made for the trial ; it was carried out purely under working conditions ; the steam supply to all other sources was cut off except the engine and boiler feed pump ; all fuel and water being carefully weighed; all, temperatures and pressures were noted every 15 minutes; indicator diagrams were taken every 15 minutes from both cylinders simultaneously, two indicators being used ; revolutions carefully counted at each indication. The speed of the engine right through the trial did not vary more than a of 1 per cent.) .5 per cent. steady running being most necessary for this class of machinery. As a further instance of this the firm within seven months of starting the new engine put in an installation of incandescent electric lighting plant, driving the dynamos direct from main counter shaft, giving complete satisfaction.

The water from hot well was allowed to run to waste, as we found it would complicate matters to attempt to carefully measure this water, being so. hot ; the boiler was therefore supplied with feed water at a temperature of 58 deg. Fah. The soot was blown off the tubes at the commencement of the trial ; the fireman was allowed to use his own discretion in the firing. I fixed the steam pressure at 1401bs., and this allowed a margin of 5lbs. over and under, so that no blowing at the safety valves might occur during the trial, as this would spoil the work. I cautioned the fireman that on no account must he open the furnace door to keep down the steam, as this must be regulated by the damper and ash-pit doors. The feed pump, a single direct-acting "Knowles" double plunger type, 71-in. diameter. steam cylinder, plungers 4iin. diameter by loin. stroke. This was supplied with steam direct from boiler and exhausted into the hot well.

I may here state that I consider and intended the one steam boiler, as specified, amply sufficient to run the engine up to 180 I.H.P., with a good margin for other purposes.

And when it becomes necessary to add the two cylinders as proposed in the specification of triple compound engines up to 270 I.H.P., another boiler exactly the same is proposed to be added, thus forming one battery of two boilers. This would allow an ample margin for other necessary purposes.


COPIES OF INDICATOR DIAGRAMS From Condensing Engine Cyls., 12" dia. H.P., 22" dia. L.P.

x 36" stroke. Revolutions, 64 per min.

Duty Trial of Messrs. Collins Bros. Woollen Mills, Geelong 99/'02.

H.P. Cyl. Scale, l"=1 lb. (No. 1.)

Atmos. Line.

L.P. Cyl. Scale, 116" =1 lb. (No. 1.)

Atmos. Line.

H.P. Cyl. Scale, 61p" = 1 lb. (No. 7.)

Atmos. Line.


L.P. Cyl. Scale, i e" = 1 lb.

(No. 7.)

Atmos. Line

The feed pump was kept going slowly all the time of trial, the combustion very slow, the ash-pit door being nearly closed, and the damper door more than half closed all through the trial. The firing was well and carefully done. The engine had all the load that could be put on, and the run went smoothly along without a single hitch.

Owing to the very low power developed by the engine (less than I expected the minimum would ever likely be), I am satis-fied better results will be obtained with the engine, as the power is increased, up to say 160 I.H.P..

It will be observed the marked improvement obtained with the new engine and driving gear as compared with the old engine and bevel cogs, etc. ; when I took the I.H.P. it gave an average of 118 I.H.P., and on the occasion of trial of new engine and gearing, they were running about 10 horse power of additional machinery (more than with the old engine), and yet the I.H.P. only reached an average through the trial of 100.5 I.H.P., nearly 22 per cent. reduction in the friction load of engine and machinery. Clonsiderable reduction was expected in this direction, but hardly a drop of 22 per cent.

The cylinder jackets and reheater were drained by indepen-dent steam traps, discharging the condensed water into hot well, for boiler feeding, when working under ordinary condi-tions, the "Geipel " steam trap being used in this case, and they worked splendidly right through the trial, kept the jackets and re-heater perfectly free from water, but allowed no steam to escape. This contributed in no small measure to the fairly good results obtained. For as you well know, that any sort of jacketing or reheating by steam, if not well and carefully drained, may be productive of far more harm than good. With some traps I have used for this pur-pose they proved utterly unreliable ; they gave a water jacket one time and a steam jacket the next, accompanied by very considerable risk of serious injury by water hammering; but the Geipel Trap, when once adjusted, gives no further trouble. They are strongly built c.rd take up little space. Messis. Collins have a number of them in use in their various heating and drying apparatuses, of which they speak very highly of


their simplicity of adjustment and satisfactory working. A thoroughly. reliable steam trap is one of the most important, in fact, indispensable adjuncts, of any well-arranged steam plant.

I much regret that my time, and the appliances at my dis-posal, dici not permit my getting more data relating to steam used by jackets, reheater and boiler feed pump, together with other necessary data, from the boiler, such as temperature of flues and nature of flue gases, etc., soy that something like a balance sheet could have been struck of the heat; this is always very interesting and instructive to the steam engineer. But the manufacturer's main object is how much can I get in the nature of energy to do my work from each lb. of my coal' "Such engineering fads," as they are often called, have little interest for them. But I must say Mr. M. E. Collins is a notable exception in this direction, for right through the whole job he took a most intelligent interest, and had a clear grasp of the whole matter, which is much to his credit as a man, and to his profit as a manufacturer, and a pleasure to the engineer, to have to deal with such manufacturers.

I would also like to mention that Mr. M. Collins, Mr. Oliver, their mill. manager, and four more assistants, gave me loyal and satisfactory help ; and I must compliment them on the careful manner in which they carried out the duties entrusted to them.

I may say we had a short rehearsal the afternoon before the trial. I am sure the members of this Institute who have carried out trials of this nature will appreciate the importance of a rehearsal before the actual trial commences, more especi-ally when the assistants have had no previous experience of such work, and can hardly be expected to realise the impor-tance of accuracy in every little detail.

5/11/02. WM. FTVIE.


RESULTS OF TRIAL OF POWER PLANT AT

MESSRS. COLLINS BROS. WOOLLEN MILLS, GEELONG.

ENGINE.—Tandem Compound Condensing. Cylinders, 12" and 22" x 36" stroke, air pump driven through bell cranks from tailrod of Low Press. Cyl.

BOILER.—Babcock and Wilcox standard type for 160 lbs. working pressure, 1265 sq. ft. heating surface, grate area 262 sq. ft., fitted with super-heater having a heating surface of 170 sq. ft.

Date of trial—duration of trial, 4 hours 9/9/02 Class of coal used—South Bulli (see analysis below) Bulli Total coal consumed during the trial (in lbs.)... 672 Coal consumed per sq. ft. of grate per hour ... 6.3 Total quantity of water evaporated during the trial ... 5960 Water evaporated per lb. coal from 58° F. to steam of

140 lbs. and 456° F. 8.87 Equivalent evaporation per lb. coal from and at 212° F. 11.11 Mean steam pressure in lbs. per sq. in. above atmo-

sphere during trial .. 140 Mean vac. in condenser by vac. gauge (in inches mercury) 27" Mean temperature of injection water (injec. condenser) 58° F. Mean temperature of stoke hole ... ... 68° F. Mean temperature of steam at boiler stop valve ... 456° F. Mean temperature of engine room ... ... 73.6° F. Mean number of revolutions per min. during the trial ... 64 Indicated horse power ... ... ... ... 100.5 Net water per I.H.P. per hour, including steam to

jackets, re-heater and boiler feed pump (in lbs.) ... 14.82 Coal consumed per I.H.P. per hour, including steam to

jackets, re-heater and boiler feed pump (in lbs,) ... 1.67 Equivalent coal per I.H.P. per hour, including steam to

jackets, re-heater and boiler feed pump, provided the feed water were taken from hot well aí156° F., which is the usual working conditions (in lbs.) ... 1.534

Efficiency of the boiler and superheater combined . 77.68% Efficiency of the boiler only, assuming it was all dry °

saturated steam that entered the superheater ... 74.87%

PROXIMATE ..--_ — .95 ANALYSIS Volatile hydro carbons — 20.95 OF COAL.

100.00 Efficiency of coal by calorimeter tests 13.810 B.T.U. per lb.

Fixed carboh — 68.40 Ash ... ... — 9.70

NOTES ON A STEAM POWER PLANT.

Discussion.

Mr. Higgins (Chairman) said the Iínstitute had reason to be grateful to Mr. Fyvie for his excellent paper. He thought that as the meeting was a small one it might be as well to do away with the usual form of discussion until members had an opportunity of reading the paper, and indulge in a small conversation on the subject.

Prof. Kernot noticed in the diagrams circulated by Mr. Fyvie that there was a want of compression on the low pres-sure cylinder.

Mr. W. Fyvie thought that in tracing they must have been mutilated. There was a little compression, but scarcely as much as he would like. It was an absolutely sharp corner in the one pointed out, none of them were like that.

Prof. Kernot : The result of an engine of the size was simply splendid.

Mr. W. Fyvie : The engine had been working for over 12 months, practically night and day, and had given no trouble. whatever. Continuing, Mr. Fyvie said that clearance was one of the most important features in engine construction. The clearance in this instance was slightly above what he had stipulated, but as it was only a very little more it did not much matter.

Prof. Kernot, talking about the old engine, he was .aston-ished that it had gone on so well without being entirely broken up. He knew of an engine in his youthful days that had committed suicide ; one day it broke and there was scarce-ly a part that was left intact.

Mr. Geo. Higgins asked whether any special precaution was taken to lubricate the cylinders when using dry steam in that way.

Mr. Fyvie, in reply, said that no special precaution was taken. He thought they used the same oil as had been pre-viously used. The Vacuum Co.'s 600 W. which worked well, and the temperature of the steam under ordinary conditions is often over 560°F.

Mr. Geo. Higgins said that when speaking of improving the old engine, Mr. Fyvie mentioned using the feed heater. Did he understand that there was a gain of 11 per cent by reason of this?

Mr. Fyvie: No; he had made the small boiler help the larger one, and thus obtained that advantage.


Mr. Stone congratulated Mr. Fyvie on the, very successful result he had obtained from his design of the engine. Mr. Fyvie had got a high efficiency from the boilers, and under conditions from which the best results could not be expected. It seemed, however, that the short duration of the test (4 hours) and the small consumption of coal, no matter how care-fully made, was open to question. He thought Mr. Fyvie might give some particulars as to the method he adopted in this case. It was not an important point. Comparisons could then be made with previous or subsequent tests. The boiler question is one that had taken some prominence lately. People were beginning to take more care with the coal.

Mr. Fyvie was well aware of the possibility of error in such a short test. It was a trial under actual working conditions. The test was carried out as carefully as possible under the circumstances and the time at disposal. He was quite in agreement with Mr. Stone when he said the result was open to question. He was pleased the question had been raised so that he might explain. Give him a week for a trial, then he could get something almost accurate. He did not believe in tests of short duration, but could not make it longer in this case.

Mr. Stone said that his remark was not calling in question the accuracy of the test, but simply to find out how the test had been conducted. He thought Mr. Fyvie had managed very well. The method of starting with a thin fire and finish-ing with a thin fire allowed the amount of coal in the furnace to be judged. With regard to the calorific value of the fuel, he would like to know whether it was obtained by calcu-lation or by calorimeter.

Mr. Fyvie said that the' result was obtained by calorimeter. Continuing, he said that the firing was done remarkably well, and he had paid special attention to it himself. He had par-ticularly instructed the fireman not to allow a hole in the fire. He had been very careful, and the temperature in the waste gases must have been very low. There was a great deal in the firing, and a fireman could put away 25 per cent. of the heat value and you would scarcely know it. The thing was to keep the heat there.

Mr. Rowe congratulated Mr. Fyvie on his paper. He said that often the indicator was wrong. He had a very unpleasant experience recently with a well-known indicator. In fact, it had been so bad that he had to return it to the maker. As regards lubrication he had found that a small quantity of flake plumbago added to the Cylinder oil was very effective. It must be used in small quantities, otherwise it would give trouble in other directions.


Mr. Fyvie said that as regards the springs of the indicator every precaution had been taken. Altogether five indicators were in use at one time or other, and the results were pretty close in all cases.

Prof. Kernot said his favourite indicator was Elliott's, which had a spring entirely outside, and was a long way from the heat, and it was always just about the temperature of the engine room. With other indicators it seemed that the temperature affects the spring to an unknown degree.

Mr. Fyvie said that there was too much oil used in the cylinders generally. There were a lot of boilers absolutely ruined from gorging the cylinders with oil when the condensed steam had again to be put back to the boilers.

Dec. 3, 19,92.

Mr. Fyvie said Professor Kernot was justified in his remarks re the want of compression in the low pressure' cylinder as shown on the diagrams. The cards exhibited by him were traced by a junior, and they were mutilated'. The one the Professor pointed out had in absolutely sharp corner. The compression in the low pressure cylinder was not very great.

Mr. J. H. Smith said in connection with lubrication, if he remembered rightly, Mr. Fyvie had said that there was no lubrication except what was carried in by the piston rod. Was that correct?

Mr. Fyvie : No ; there was a sight feed lubricator in the ordinary way.

Mr. Thompson said there was a compound engine in Sydney driving the tramway. There was no lubrication' at all in either cylinder.

Professor Kernot asked if the engine was not fairly lightly loaded.

Mr. Thompson said it was. Mr. Adamson said the results under review were very good,

and he thought great credit was due to the fireman. There was great danger unless the fireman was careful of getting holes in the fire. The coal by the analysis appeared to be better than was obtained in the average sample. The pre-sence of water in coal, he thought was more detrimental than was usually admitted.

Mr. Rowe observed that in the question of compression there had been a. good deal of difference of opinion. He thought the subject was worthy of more consideration.

Professor Kerfot said that in locomotives the compression was enormous.

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Author/s:

Fyvie, William

Title:

Some notes and details of a steam power plant, and results of duty trial of same (Paper &

Discussion)

Date:

1905

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Some notes and details of a steam power plant, and results of duty trial of same (Paper &

Discussion)

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