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HONG KONG DAILY PRESS, SATURDAY,
JANUARY 16, 1932.
THE EXPRESS LIFT CO., LTD.
WITH WHICH IS INCORPORATED THE BUSINESS OF
SMITH, MAJOR & STEVENS, LTD, EXPRESS SMS
LIFTS
MODERN LIFTS
FOR MODERN BUILDINGS
SPEEDY RELIABLE SERVICE
FOR DETAILS APPLY TO
THE G.E.C., QUEEN'S BUILDING, Chater Road.
EVERYTHING (9.8.C.) ELECTRICAL
wour guarantee
ROCKGLOSS
WHITE ENAMEL
FOR BOTH INTERIOR AND EXTERIOR USE.
STOCKS CARRIED
W. R. LOXLEY & CO.
"Desyriads
a &
Berger Product
YORK-BUILDING, CHATER ROAD.
Radultre Licenszzo'
Members of the C.M.5,
ENGINEERING AND BUILDING
The Problem of Boiler Ash Removal
APPLICATION OF HIGH-PRESSURE WATER JETS.
GENERAL CONDITIONS OF OPERATION.”“
Time Was when boiler-hours subsequently be dropped inte ruil operation was both"dirty and up- way waggons or lorries. Yet again plonsant The handling of dirty the ashes may be removed by pump [coal and still dirtier nah mands the ing to an adjoining lowlying area conditions of steam-raising very over which they are evenly distri uncongenial work. Even when-im-buted" and, after draining, leave a provements in the firing of the compact foundation, the area, of fuel were effected, there sill re- mnined the problem of the removal
of the ashes.
14
charge pipe.
support, without fixing, refractory bricks, In these hoppers the ashes
ATO.
clonyaneus are kept filled with clear thoroughly mixed with the ejector - flowing water, and not abrasivo water; and, then discharged liquid This alona" water controls either into the suiceway or direct the electric or steam supply for the into the samp. Dust in dry and drive, and makes it impossible for hot state is extremely abrasive and. the pump to be in operation unless the use of an elector in this way this clear water is available. completely obviates all the troubles. consequent on the use of fans for inducing the suction.
Orst quenched. Now, such
This may be taken as hut one qufhching water after contact with
illustration of the many "details ashes beccaves corrosive, altogethor 100 deleterious for steel construe which have had' to receive attention
As in the care of the sluicing for officient operation, and in every tion. An unmachined cast-iron
detail of the system at first unfore Byster arrangements are made to surface provides the greatest re- sistance to this corrosion, and this diffignition have received suc-ford the dust in proportion to the
cessful attention. material is therefore of extensive
carrying capacity of the ejector, no- application in the system.
To avoid the corrosive action of that there is no possibility of block- Normally, eight to twenty-four the ash water, the ash bin recpiring hours storage capacity is aimed the pumped material is again con- at, and when the hoppers are full, structed of, unmachined cast-iron the ash is fed out into a high-plates. Intertilly, overflow louvres velocity duiceway running beneath are provided, and the oponinga at thom. It is essential to feed the the bottom through which the ash nah out under control, and in pro- is dumped are provided with water portion to the carrying capacity of collecting gates. These arrange-effective handling of dust in a dry
4
age; moreover, the system is totally enclosed and therefore completely dustloss.
Until the dust enters the ejector it has no contact with water, and this is an emential feature in the
state.
the sluice.
ments ensure that after brief atand- which may from time to time be
This is accomplished by the coming the ash can be removed in
Bigh-pressure water jets are also extended by lengthening the disbination of a high-prauo feed relatively dry but nevertheless
serviconble in the removal of chim- nozzle and a sloping feed plate. The dustless condition.
ney dust, and the system, with ite: The scheme is one which mustash rests on the food plate, which To-day, by means modern me
DUST ACCUMULATIONS.
numerous advantages, would appone, thods of ash-handling, the lean make an instant appeal to those forms the bottom of the hopper,
to have applications widely IB" At other points in the staam- lincos and generally good endi who have recognised the diandvan-and the jet from the feed nozzle |
moved froin boiler-house work. tions of the boiler house have been lages of the older method of nah impinges against the face of the raising plant,, such as below the There, however, the transformation extended to the floor below, and removed.
ash pile, undercuts it, and agitatos economizors and air pre-heaters, which has been effected from the the modern ash basement provides
it, and the backwash brings the and, as previously mentioned, below earlier conditions provides another. A FLEXIBLE SYSTEM. a. pleasing contrast with those.)
ash down to the lip of the foed the special dust-handling apparatus example of the marked advances from which the ash-wheeler, for It is not too much suggest, plate, from which it drops. inte.if fitted, considerable quantities of which have bem made in power- however, that while the principle the sluier. By arranging the feed dust from the gases of combustion raising from solid fuel, which seems is extraordinarily simpla the mne nozzle to swing acres
the feed will accumulate. This material destined in this and many other thod of application to
plate hay extra large pieces of too, is susceptible to efficient recountries to be long the main abrasive and irregularly-sized clinker can be specially agitated. roval by suction. The auction is process of power development. terial is one which has necessitated
The aa can be emptied from the induced by the action of high-
Efficiency, cleanliness, improve- :
The dust is air-borne up to the atility are combined in this unique minute. The whole operation can ejector and on arrival as it is method of ash removal.' therefore “ba accomplished very quickly, and, in additibu re
merly removed by hand labour the
incombustible portion of the fuel.
To the solution of this problem the use of water under pressure has made a notable contribution. What
auch an
had been done many years before considerable ingenuity in order to hoppers and carried in the sluice-pressure water jets in an ejector, ment in health conditions, and
free from numerous,
in the removal of broken rockin render it the quarrying of gold and other, troubles invariably associated withay at a rate of one to lf tons per! the handling of this material. AL every point there, is the evidence
fore, has now been very successfully | applied to the removal of the ashes from below the boiler
This.hydrojetting" is exe Desi- ingly simple and the application equally efficient. The ashes from
!
of dificulties surmounted, so that quires the attention of a single
as the result of considerable properator only. Dealing with ong tical experience, a design of plantboiler at a time, he can even in
has been baill up, the efficiency of the largest boiler house, gecomplish Use Green Island Cement
the grate are allowed to accumulate which has appealed to those respon-in an hour or two what previously in an ash-hopper over a period sible for the design mid construc required the services of several {
In no two plants have the same
Mion of the largest boiler houses, which may be a day, and at a given time or during a given shift, and the system is to be found in the removal of the accumulation is many installations both in this effected by a single man in the country and abroad, Eccurge of an hour or so. In the first place. cooling is effected by the application of quenchers. The bottom of the ash-hopper is sloping this inclined bottom constituting the feed plate..
WASHING OUT THE ASH.
A door at the bottom is opened and a jet of pressure water is ap- plied, the ashes wing washed out into a sluiceway, along which it is) carried by the rapid flow of the water to an ash-sump, into which
i
gange of men operating, continu/ ously.
THE SLUICEWAY.
The sluiceway is formed of hait
Ench
conditions to be met, but so flexible round, nickel cast-iron liners in a is the system in its application rectangular concreta trench. that it is extremely rare to find an liner is first contracted by turn- existing plant in which it cannot buckles and then dropped into the be installed, and in the case of trench.
new
first case.
The turnbucklow
35
designs very considerable slackened and the liver springs savings in capital cost can often out and grips solidly against the In this be effected by its adoption in the side walls of the trench.
way the liners 'bre self- Although largely applied to the fixing. removal of solid ash from the The sluiceways are horizontal. normal type of boiler plant it has resulting in a considerable saving an interesting and specialised use in basement height, and the high in connection with planta in which velocity of water, comlited the ash is "purposely melted and with the special method of feed-
the
both water and ashes are colected Settling rapidly takes place, after which the water may be returned periodically removed by tapping offing, ensures the rapid and unin- in the form of slag. While this terrupted flow of this ash, which, tc the circuit for repeated use while the gttled ashes can then be system of firing, however, is not instead of dragging and slipping this along the bottom, normally rides trusferred to their destination. of extensive application in This as one lime was effected by country owing to the generally on or is held in suspension in the high fusing paint of the wth con.
water. Wear on the liners a, grabbing and then transferring to
tent of British coals, there are to- therefore, negligible, especially ne trucks.
day in various parts of the world the system is only in oporation for More recently, however, improv "some 50 or 30 boilers working on short periods ed methods allow of pumping up this principle, and all of these are tervals.
the ashes to an overhead Ashbin
.COMPLETE ELECTRICAL INSTALLATIONS
with
infrequent in
indicated, the
from which the water may be al. equipped with this system of sing. As bus bern mcat completely drained away, handling by high-pressure, water. sluiceways convey the material to and from which the ashes may,
In operation the outflowing slaga centre) sump, from which it's mecia a primary set of high-pres either grabbed or pumped, in thes sure water jeta in [17] enclosed lutter case either to overhead disintegrating chamber. A sudden ashoins or to make up now ground. chilling takes place, and the mate.This filling up of low-lying areas rial is driven against breaker is the easiest method of disposal, plates and drops down into a short and has the advantage of building length of sluiceway. Here it is up the ground with a very level
and compact foundation. picked up again by a further set of jets, which propel it against au other breaking plate, After being. operated on in this way the stag, from being molten and intensely hot, dreps down, into the main sluiceway completely cooled and disintegrated into small particles
C. M. A. CABLES.
Advice and Estimates given
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free on all types of
LIGHTING & POWER INSTALIATION.
by an experienced
ELECTRICAL ENGINEER
retained at our Hong Kong Branch
The General Electric Co. (of China), Ltd.
QUEEN'S BUILDINGS,
HONG KONG.
the average size of a pea,:
PUMPING THE MATERIAL.
It will be appreciated that the pumping of the ark mixture from the sump is problem in itself, ciling for spegel pump designi with market defences from the mors conventional type,
Thus, while the operation is iden- As may be imagined, the disintetical with that of the standard grated material is hard and glassy, centrifugal pump, special elements and the breaker plates are there-af deign are necessitated by the fore called upon to withstand "con-
nature of the material being siderable abrasive action. These handled. The abrasive liquor en- plates are therefore of special tera the suation, passes through the wear-resisting material, and are impeller, and thence to the, volute arranged for easy replacement, discharge. Between the narrow
for
Constructural Work of
Every Description.
HOW GREEN ISLAND CEMENT IS MADE
Green Island Cement is manufactured from hard limestone and clay. It is necessary that these materials should be finely ground in order that they may come into intimate contact with one another in the burning process.
The finely pulverised materials are mixed in a certain definite proportion, roughly one part of clay to three of limestone, and are fed to the Rotary Kilns,
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In these kilns they meet the hot gases and dames generated by pulverised coal blown in at the other end of the kilns, and after various chemical actions have taken place, they combine to form Portland Cement Clinker.
The Clinker is ground down with a small percentage of gypsum to regulate the setting time, and Green Island Portland Cement is thus produced.
Although sounding so simple, in reality the process is an intricate combination of mechanical, physical and chemical operations, needing great skill and care. Nothing but constant and accurate supervision will yield the results so well-known with Green Island Cement, namely, strength, uniformity and reliability.
USE GREEN ISLAND CEMENT
Issued by the
CONSTRUCTIONAL DETAILS clearances of the impeller shrouds GREEN ISLAND CEMENT CO.
and "the side plates erosion would.
At numerous points in the system ordinarily be excessive, necessitat- there are to be seen ingenious de vices for the most efficient collec-ing frequent renewals. This is tion and transport of the mixed avoided by the introduction of water and ashes. In the first place clear water at low pressure at there. tire ash hoppers are of special for-
mation, being constructed of cast. surfaces, the initial pressure of the iron plates with external steel water being boosted above that in boltings" and internally shaped to as main volite. As a result, the
2ND FLOOR,
EXOILASGE BUILDING..
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