1936-03-14 — Page 2

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い

THE COMMERCIAL

DEVELOPMENT. OF TUNGSTEN

Since the time when tungsten replaced tantaqum in the filaments of electric lamps there has been further expansion in appications in other directions The metal it- self, possessing as it does such ex- ceptional physical properties as a melting point of 3,370 deg. C. the highest of any metal), a tensile strength of 220 tons per square " inch, and selercscope hardness value of 40, has naturally attract- ed attention, just as platinum did on account of its inertness. It is, however, in the applications of its alloys, its carbide, and of certain chemical compounds, that the widest development has taken place. This great expansion is duc Ir no small measure to the re- search carried out and stimulated by producers of tungsten and by a number of independent investiga- tors in this fold. About 50 per cent, of the world's production of wolframite is mined in China, he grade.. from this source being superior to that produced in other countries.

إن

per cent.. is yet another metal claimed to give cutting-tool alloys when sintered in hydrogen at 1,301

C. deg.

with tungsten carbide. Tungsten metal has also been alloyed with cobalt for producing hard alloys, and a Brineli nardness "al 660 is claimed for a 60-per cent. cobalt alloy quenched at 1,300 deg. C.

COMPOUNDS NOT NEGLECTED

While tungsten metal is under- going a wide development in Ame- rica in corinection with telegraph (quipment, traffic and railway sig- nals, and other equipment utilising contact discs, the compounds of tungsten have not been neglected. The list of adsorbent" gels' such as those produced from silien and alumina has received an addition in the form of tungstic-oxide, gel. this being used alone or in com- bination with sillea gel. Pigments and lakes containing tungsten compounds have been introduced, while tungstic acid constitutes a special mordant and colouring

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HONG KONG DAILY PRESS SATURDAY, MARCH 14, 1936.

ENGINEERING AND BUILDING

SILENCERS ON HEATING BY ELECTRICAL

PNEUMATIC

DRILLS

sively employed for breaking an concrete in road-repair work, obviously a problem of consider able difficulty. It is hard to man how the noise produced by the piston and chisel can be much re-

THERMAL STORAGE

should not be added harmfully to the peaks. This, in turn, neces- sitates the employment of some system of automatic control. Much ingenious apparatus has been de- signed for this purpose.

The members of the Institution system is dependent on the price Although eminently desirable, of Heating and Ventilating En- charged for the current, though he the effective silencing of the gineers wisely take the view that is also relieved from fuel troubles. pneumatic drills, now so exten- "it is their duty to examine every while it is essential for the under- form of heat energy and to deter taking that the load provided mine its capacity to produce a given effect or set of conditions, so that they can give advice on the best system to Instal for the ful fliment of a specific purpose. In order that such advice may bé ten- dered with certainty that it is good

OBVIOUS IMPORTANCE it is, however, necessary for them "As Mr. Eden points out, a matter to be acquainted with all possible of obvious importance in the de-. methods, including those which sign of such an installation is the are only now beginning to be used. determination of the total daily of have, not yet obtained complete heat demand of the building un- acceptance. For that reason, der the worst possible conditions. paper on "The Warming of Build- as this, in turn, determines the ings by Electrical Thermal size of the electrical heating units. Storage." which was read by Mr. J. It is preferable that the architect Eden before" their meeting ап or consulting engineer who is con-

8. Wednesday, November

1935. cerned with the installation should

duced without materially affecting the efficiency of the tool, and even the complete elimination of the exhaust noise will thus leave much to be desired. The matter is, how. oric of considerable public interest, and any improvemen: that can be effected will be wel- comed. The present position is made clear by some tests carried

agent in the porcelain industry out during the re-paving of Wil. should be welcomed, since it qe ask the supply undertaking to proTM

on-road in the City of Westmin- ter in October Last, the tesis having been made under the direc- Attlor of the Chy Engineer. Nine mokers were each invited to sup- ply a pair of drills fitted with their encers, and these drills were tested for comparison with a pair or unsilenced drills supplied by the contractorS 10T the re-paving

Sodium tungstate is used as a fire- proofing compound, and the tung- state of calcium and of other metals have been applied in pre- paring streens for X-ray work. the Conference of the Internation-

a'

of Society

Leather Trades Chemists, held recently in Brussels. Messrs. V. Casaburi and E. Simon- cini described certain complex derivatives of tungsten which are of value to the leather industry. The compounds bring about the precipitation of albuminoids, and are therefore invaluable as tan- ping agents, as they penetrate the tildes quickly, and eventually yield a heavy grade of leather. Sole, leather, if pickled or mordanted with such compounds, tends show uniform absorption when immersed in water, the leather,

METHOD OF PURIFYING

The production

tungsten metal of high purity depends to- day on the methods of purifying the oxide before reduction. The ort- ginal ore is pulverised and fused to yield sodium with soda ash

tungstate containing oxides of Iron and manganese, the latter being almost completely removed by ex- traction of the melt. Tungstic acid

work. then precipitated by adding 1. hydmchloric acid; the powder in this condition being, suitable for the steel trade but requiring fur- ther treatment 1te is to be used for the manufacture of tungsten bars. One method used on a large scale for this purification consists In converting the acid to a tungs- en salt, filtering, and reconverting to tungstic acid. Then follows the reduction to tungsten powder 07 packing the acid in nickel boats or crucibles and heating in electric furnaces in a current of hydrogen, the resulting heavy, black powder being compressed into bars and sintered by means of a heavy cur- rent passed between tungsten

however,

to

subsequently 'drying rapidly. "Moreover, skins mordant- ed with Lungsten derivatives will take up baste colours in a uniform manner.

terminals mounted in water-cooled FRENCH LOCOMO-

cupper blocks. This process causes crystal growth to spread through the metal and yielas vars of 99.95. per cent. purity. While the pars are brittle when cold, they may be, rolled, drawn, and submitted suc- cessfully to the swaging process when heated to redness in hydro-

деп.

For the preparation of contact points for the electrical industry rods are sawn into discs, although some concerns prefer to punch the larger type of disc from tungsten sheet.

!

THE ELEMENTS

TIVES IN 1935

the

Noise measurements were made by the staff of the National Physical Laboratory by means of an objective noise meter, located ai a distance of 24 ft. from the drill in operation. In the case of the unsilenced drills the average cquivalent loudness of the noise measured was 103 phons, and in the case of one pair of silenced drills, the curresponding Agure was 102 phons, showing no appre- clable Improvement. Another pair showed a noise production of 180 phons, and the other seven pairs gave figures ranging from 96 to 98 phone.

scribes in detail the various types of plant available and gives some useful information regarding their installation and operation. Costs are not dealt with, on the grounds that this dimeult phase of the sub- ject has already been gone into in more than one paper, which has recently been read before their in- stitution of ectrical Engineers Perhaps this self-denying ordin ance was wise, for these costs are so important and so fundamental, that they tend to overshadow all other questions once they are al- lowed to crop up. As it was the author's example was followed by the speakers in the discussion, who confined themselves almost entire ly to matters of design and opera- tion, and thus added not a little to the value of their remarks.

THE OBJECTS The objects of electrical thermai storage are two. It gives the elec- tricity supply undertaking a load during the lightly loaded night bours and, in turn, provides the consumer with current at a price much lower than the customary." This current is used for heating water, which is stored in tanks and. clrculated when necessary at" a predetermined temperature for warming buildings or for other purposes. From the consumer's point of view, the use of such d

NOISE REDUCTION From the National Physical Lia- boratory report on the rests, is appears that the best of the sllen- cers gave a noise reduction of about 7 phons, which, it is point ed out, would be about equal to In the summer of 1935.

the effect of doubling the distance principal improvements in Freneu ofine observer from an unsilen- railway services were on the State ced drill in open conditions. This Railways. Some very fast rai-car improvement certainly brings the SCOTTISH SHIPBUILDING services were introduced, the most hole of the drills nearer to the important of which covered the level of the general traffic noises 1414 miles between Paris and Le in a busy street, which are of the " Havre twice daily in either direc-order of 80 phons, but the fact re- do in two. Louis, with one stop mains that even the silenced drills at Rauer. A new steam train was put un to cover the 1481 miles be- tween Parts and Caen in either direction in 2 hr. 44 min, with two stops. For the greater part of the way the gradients of this line are very heavy.

are as loud as the noisiest trame and must still be regarded as ob Jectionable to persons in the vicin- ity. Tests were made by the City Engtheer to see whether any loss of efficiency could be detected in the case of the silenced drills. These The Nord ran one trai

testa, although not entirely con- top from Paris to Brussels (193 clusive, owing to variations in the miles) in 9 hours.

hardness of the concrete broxen ponding Brussels-Par's train was up by the different competitors. civan 3 hr. 4 min. The extra. 4 did not show any marked reduc minutes were intended to allow tion in efficiency in the case of for delays due to works on the up six of the silenced drills, but it is

An alic

The corres-

proposed to give makers of these tools another opportunity of de- monstrating them, and the davis- ability or laying a special area of

concrete, so as to ensure exactly similar conditions for all compeu- tore, is under consideration.

The improvement in the Scottish shipbuilding industry continues. and although the number of con tracts placed since the beginning of this year is not great, several more are likely to be arranged be- fore long. Employment overall is fairly satisfactory and the outlook for this year is generally consider- ed to be very good. The total number of vessels launched last month was eight, with a gross ton nage of 20.141. Of these the Clyde figures were six vessels of 19,291 tons and the Forth, two vessels of 850 tons. The orders for new ton- nage reported last month were

four to be built on the Clyde, and two on the Forth,

SOUND FILMS FOR ADVER.

TISING PURPOSES"

"Thoriated lamp laments and radio-valve elements are furtuvi examples of the application of tungsten metal. The introduction of a small proportion of thorium 1a filaments is in direct contrast to the harmful effects of traces of thorfum in contact points. The thorium oxide in flaments, it is stated, retards crystallisation and prevents embrittlement at high temperatures, while, in radio valine in the Paris area. Yes, the thorium serves to eml

ance of 3 or 4 minutes was giv electrons. In the United States a

to all the important up trains, b ̈* process has been introduced for the the works were not put in hand manufacture of tungsten filaments

Welcome Improvements were possessing an elongated overlap noticeable in the services of t

ing structure which, it is claimed, Est, on which speeds had declined la resistant to sagging and offset-

stace 1932 The improvem--| ing. In this case from 0.75 per were, however, inmufficient to xp', cent, to 1.0 per cent, thorium is them again to the level reached incorporated with the tungsten. A that

year. The employment of great advance has been made in 4-8-2 type steam locomotives to the field of tungsten plating. Fink working the fastest trains has and Jones in America have obtain ceased almost entirely. Some re- ed bright, polished, acid-resisting markable experimental work with deposits by employing an elec- the rebuilt Paris-Oricans 4-8- trolyte consisting of a solution of type engines has been reported, tungstic oxide in aikail at tempera- but the electrification of the 2.0 tures of 80 deg. C.

Midi main he in Central France Tungsten carbide is an example as far as Bave has now deprived of a compound of the metal to these engines of the opportunity which considerable attention has of displaying thel: powers on the been given. Hard alloys for cut- section of fine for. which they from the boller, right through to Bre'distributed by the firm's Road ting tools, for drill bits, and for use best suited.

as special refractory materials

have all been the subject of ex-

tended research, "molybdenum car-

During the present and the three following weeks Messrs. ing of every express locomotive in Western Electric Company, Limit- France is in progress or in con-ed, are giving demonstrations of

modern advertising templation, where it has not al-

propaganda ready been carried out.. This pre- and commercial films in their pri- ramme is proceeding very much vate theatre at Bush House, Alo- on the lines which have met with wych, London, W.C.2 Many, of so much success on the P.O.-Midi these films, which have been pro- Railway, and, comprises measures duced to achieve definitę objects, for increasing the steaming powers display entirely novel technique of the boller, for raising the pres- and exhibit a very high quailty og sure and temperature of the steam, production in which use is made and for facilitating its passage or all the latest innovations. They

the atmosphere by means of lar. Showing Organisation for exhibi-. ger steam pipes, larger valves of tion to selected audiences in clubs, SIX-COUPLED ENGINES

dealers' improved design, and improved institutes, and

'show Nearly all the express trains i blast-pipes. This last point is at rooms. This enables the films to be bide and cobalt being two common France are now worked by six- the present moment, perhaps, re- longer than when the only method constituents of the compositions coupled engines, usually ef ceiving more attention than any of display is an ordinary clisema, produced. In one method for the 4-8-2 four-cylinder compoun other. French engineers have al- and since the audience is invited, preparation of tool alloys these type. Hardly any of these engines ways appreciated the advantages overcomes the objection that ad- three constituents are sintered "in are new." Falling traffic. togethe of a variable blast-pipe. Their lo- vertising should not take the place vácuo" in a high-frequency induce with a certain amount of electrin. comotives are, and have always of entertainment. For the same tion furnace, but a more common cation of main lines, has made been, subject to very strict speed reason, the propaganda can be method consists in pressing the the provision of new engines un- limits, with the result that fast made more direct. We are glad to powders into bars and sintering necessary. On the other hand, old. trains have to run hard uphill and see that in selecting the subject- them under pressure to give com- engines rebullt with radical gently down-hill. In these circum- matter engineering has not been pact products. These are claimed changes in the design of many im- stances A variable blaat-pipe. neglected. The displays are in- to be as hard as Stellite allugs portant parts are giving results so which makes it possible to reduce tended for sales managers and ad-- when prepared from the carbide" much superior to those obtained the draught some distance befors Mert'sing managers of firms, whose slone, while when cobalt is includ- with the same engines before re-the summit of an ascent to reach products demand national advez- ed hard alloys of the Widia series building that it is hardly an ex- ed, prevents great loss of steam tising, and applications for tickets are obtained. Manganese, up to 9 aggeration to any that the rebuild through we safety valves.

should be sent to the company.

vide a definite number of kilowatt-" hours during a given period of time, since, especially with elec- trode heaters, the full output is only obtained gradually when run- ning up from cold. and the unit must therefore be large enough to give this output over the full tem- perature range. The capacity of the storage tank must be deter- mined by the time during which the current has to be switched off, Care must also be taken that the maximum demand contracted for

THE TAIKOO DOCKYARD & ENGINEERING COMPANY OF HONGKONG, LIMITED.

BUILDERS OF ALL CLASSES OF SHIPS. BUILDERS OF RECIPROCATING STEAM ENGINES." BUILDERS OF MARINE AND LAND BOILERS. BUILDERS OF TURBINE MACHINERY

Under License From Messrs Parsons. BUILDERS OF DIESEL ENGINES

Under Special License

From Messrs. Sulzer Bros., Winterthur. Licensed To Manufacture Lanz Perlit Iron. Specially Suitable For Internal Combustion Engine Working Parts.

DOCK & SLIPWAYS.

FOR DOCKING VERY LARGE, AS WELL AS SMALLER VESSELS,

ON ANY TIDE.

ALL CLASSES OF SHIP, ENGINE AND BOILER

REPAIRS AND EXTENSIVE

WELDING, BOTH ELECTRICAL AND, OXY- ACETYLENE SKILFULLY AND PROMPTLY CARRIED OUT.

BUTTERFIELD & SWIRE, Agenta,

HONG KONG, CHỈNA & JAPAN.

TIL. Address: "Tarxoodock,“ HONG KONG.". TELEPHONE: 90211,

CALL FLAGE" Numaral One" Üvƒr " Pinnant ANB,"

is not exceeded and in this connec tion Mr. Eden makes the useful point that in most cases the es- timated heat demand is consider- ably in excess of the actual con sumption. This excess naturally means unnecessary capital ex- penditure and is probably due to a too generous allowance being made for depreciation. There are now

Consider

this.

The real cost of any installation never lies in its original price. but in its upkeep throughout its normal period of service. During 1935 the following major contracts DODWILL & CO., LTD.

INDUSTRIAL SCHOOL, ABERDEEN.

ITALIAN CONVENT,

were awarded

to

suelent installations in operation to enable the relationship between the actual heat demand and the economic size of the plant to Be determined with accuracy and it would be well if the information could be made public for future 'use. At present there is a certain amount of reluctance to publish the necessary data.

OIL FIRED HOT WATER SYSTEM. OIL FIRED RICE & VEGETAR LE BOILERS. FIRE FIGHTING EQUIPMENT.

OIL FIRED HOT WATER SYSTEM. OIL FIRED COOKING RANGES, FIRE FIGHTING EQUIPMENT

KOWLOON HOSPITAL, O. P. DEPT. OIL FIRED HOT WATER SYSTEM.

MAGISTRACY, KOWLOON.

SHUM CHUN HOTEL.

OIL FIRED CENTRAL HEATING BYSTEM,

OIL FIRED CENTRAL HEATING SYSTEM.

UIL FIRED HOT WATER SYSTEM. OIL FIRED CENTRAL HEATING SYSTEM.

BRITISH CIGARETTE CO'S FACTORY,” SANITARY INSTALLATION,

KNIGE HYDRO-THERAPEUTIC INST. HYDRO-THERAPEUTIC INSTALLATION.

MARINA HOUSE.

HONGKONG CLUB.

STEAM HOT WATER SYSTEM. STEAM BOXES, ETC.

SANITARY INSTALLATION. FIRE FIGHTING EQUIPMENT

OLL FIRED COOKING RANGES & HEATING SYSTEM.

J

There are sound reasons for the widespread acceptance that has been accorded "Dodwell IDetaliations by Architects, Engineers and Building Owners. Among these reasons the following are noteworthy ---

1. On definite specifications our prices are competitive. 2. We do not sublet work or pay our staf piece-work rates. The danger of scamped work is therefore eliminated.

8. All jobs are supervised by European Craftsmen.

4. In the absence of a specification, all systems are designed with a view to giving trouble free service and low upkeep cost.

5. We do not undersize a job, with the view of

submitting the lowest tender."

#

FOR YOUR NEXT JOB. ASK FOR OUR TENDER. READ OUR SPECIFICATION." THEN DECIDE.

DODWELL & Co.,

Ltd.

SANITARY, HEATING & VENTILATING DEPT.

Manager:

A. W. Balter, MRSL, MIEVE. Supervising Engineer H. E. Mandy

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