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Saturday 18 February 2017

THE 3AM STARS

THE 3AM STARS
3 a.m. stars were holding
brightly tight to their dome
as desert chill challenged three
watchers alarmed from bed.
The Big Dipper’s handle
had fallen straight down,
but upness was everywhere
and never all to be taken in.
Earthbound, we flashlit our
paths around backyard cacti
while overhead, quick meteors
like flaming needles pierced
and sewed at the night.
Several arrived each minute
but seldom did any two
claim the same piece of sky.
Some blazed up so bright
they lit up the desert floor—
doubt but believe.
We embodied three generations,
we watchers who stood or sat
or reclined on a blanket.
Endless depth boggled our eyes
yet we little asked and less knew
why we were alive just then.
Boy, father, grandfather were we.
What all might have happened
or not happened in our three lives
to cause any of us to be absent?
We had beaten unmathematical odds
to meet for this familial, communal
sky harvest, as had the listening lizards
who heard our “Hey!” and “Whoa!”
and “Did you see that one?”
And how better to bond

than under a needled infinity?

JUST ASKING

Just Asking
I ask how eyes know when to wake
and lovers, when to love,
how engines feel when pulling trains,
why planets need to spin.
Does every point in cosmic space
touch every other point?
Can money buy creative thought?
Is dark the price of light?
Does every pain result in gain?
Does living have a goal?
And what’s left out when parts fall short
of summing up the whole


JUGGLER

The blue-black plate of sky
Teeters on a point of zenith
Like a juggler’s disc
Twirling on a stick.
Intrepid owls
Interrogate the
Intruding moon
Until splash jangling
Dawn splits
Night blue into
A billion oranges
Molded into a smolder.
Up comes the sane sun
Wheeling the lunatic
Moon on ahead and
Tumbles it off the brink
Of spinning sky,
To be caught by the
Juggler and thrown up
There perhaps again.


HOW I CLEAN

How I Clean
As a vaccer
I’m a slacker;
as a hacker
I’m a stacker.
I have trouble
sorting rubble
till it’s double
triple double.
I go all out
till I stall out,
then I haul out
all the fallout

HERE AND THE GROUND

Here and the Ground
The shiny car you drive is
going into the ground.
All the neighborhood trees are
going into the ground.
Buildings, all of them, are
going into the ground.
Your sofa and your dog are
going into the ground.
But soul—have you a soul
that won’t go into the ground?
What force can keep your essence
from going into the ground?
Suppose your body quits and
does go into the ground—
where will your soul then be?
My own says, “Here, right here.
“The love that makes life life is
dwelling in your here,
and all you ever gave is
coming back to your here.
“Thing and thing and thing may be
going into the ground,
but where can your here ever go
except—exactly here?”

PATH'S

Paths
Each path leads to another path
And that one to a third,
And on and on path leads to path
Until the way seems blurred.
The beauty of this path lies in
Its trodden permanence—
It beckons us to wear it thin
While traveling whence to hence.
This path winds gently left and right
As if ignoring straight—
Perhaps its founder had no sight
Or trod it very late.
Or did he follow waves of sound
That most folks fail to hear,
Which led him up and down and round
As far-off goals came near?
How paths begin we’ll never know
(The woods will never say),
But all who have a place to go
Are thankful for The Way


NIGHT

Upside-down flowers,
are we not? With stems
rooted upward into the deep?
Your soul, a kindly conduit,
umbilicates your body
into the placental night
that is fathomless and
fully empty of
where and when.
Take away the night? Absurd.
One night minus one night
equals one night.
Afraid of night?
Dread the shadows?
Learn from them.
Shadows tell stories,
emit fragrant meanings,
take you deeper than your feet.
Especially observe inner shadows,
even if they speak no words—
hear them out, and hear them in.
Look beneath shadows—
drop through into wider shadows
and feel safe in full bewilderment.
Afraid of unknowing?
Make your peace with it,
and your days may smile.
When you know definitely,
the vast night will remind you
that you know nothing.
When you wish for powers,
the night may wisely
hold them back.
But to be still with night
may bring you as much truth
as your heart can hold.
Night wants to abide
underneath your day
while you work—
wants to
enwomb you
between days.
Let night have its way,
its gentle way—
soften into its fullness.
Night is the container
of nothing less

than everything.


NIGHT THOUGHTS

Sleepless tonight inside my skin and bones,
I feel that life must be a cruel curse—
Begun with squall, cut off with pain and groans,
A little joke told by the universe.
Why am I here?
 What accident of fate Breathed life into this form I occupy?
What kind of God would bother to create A fragile human life,
Then let it die? A voice within my heart says, “Mend your ways,
And light inside your consciousness will gleam.
Your bleakness, like the earth, delays dawn’s rays,
But love and hope will end your desperate dream.
“Depression fills agnosticism’s night,
But soon your soul must rise and follow light.”

MOTHER'S SECRET

Mother’s Secret
Tell me a secret of living, dear Mother,
a new one I’ve never been told—
some hint about life to remember you by
that will stay with me when I’ve grown old.
“An overlooked secret of humans, my child,
is that each is a seed that will flower,
and that each has a future of limitless joy,
whatever the pains of the hour.
“And I tell you that no love has ever been lost
nor is anything out of place—
that your work is to strive, to give and to know
in this journey through time and space.
“Your grandmother told me the same when she died
and I willingly pass it along.
May your living go deeper than what you can see
and your heart hear the Infinite Song.”
Now rest, dear Mother, and sleep your sleep
in a region where pain is unknown.
As long as I live I will treasure your words
and will pass them along to my own.

A NOVEL BY PAUL AUSTER


Paul Auster’s digitally-titled 4 3 2 1 recounts the childhood and 1960s coming-of-age of
a literary-minded New Jersey Jewish boy—and, as befits a countdown, the novel’s most
striking and appealing trait is a feeling of onrushing momentum, which is a necessary
trait, too, given that 4 3 2 1 goes on for nearly 900 pages. The tone of the book is
normally relaxed and conversational, sometimes chatty. And yet, a discipline governs
the prose rhythms and drives the sentences forward, one sentence spilling into the next.
Sometimes, with engines racing, the simple and straightforward sentences gracefully lift
off the runway and go gliding about in midair, no longer simple and no longer held
down by the ordinary rules of grammar, but frisky and sinuous, sentences that speak in
one person’s voice, and then in someone else’s, and glide about some more, and come
down for a landing maybe a page-and-a-half later, and, still energetic, spill forward yet
again.


Here is an example, selected almost at random, describing Auster’s hero, Archie
Ferguson—whose curious name (for a Jewish kid) reflects the Ellis Island misadventures
of his Yiddish-speaking immigrant grandfather. The boy has to decide how to get from
Maplewood, New Jersey, to Manhattan: by bus, or by train and ferry?
Ferguson preferred the train-ferry solution, not only because he could walk to the station in
about ten minutes (whereas going to the depot in Irvington required someone to give him a
lift) but because he loved the train, which was one of the oldest trains still in use anywhere
in America, with cars that had been built in 1908, dark green metal hulks that evoked the
early days of the industrial revolution, and inside the car the antiquated wicker seats and the
seat backs that could be flipped in either direction, the low-speed anti-express that rattled
and lurched and sang forth a ruckus of screams as the wheels churned over the rusty tracks,
such happiness to be sitting in one of those cars alone, looking out the window at the
gruesome, deteriorating landscape of northern New Jersey, the swamps and rivers and iron
drawbridges against a background of crumbling brick buildings, remnants of the old
capitalism, some of it still functioning, some of it in ruins, so ugly that Ferguson found it
inspiring in the same way nineteenth-century poets had found inspiration from the ruins on
Greek and Roman hills, and when he wasn’t looking out the window at the collapsed world
around him he was reading his book of the moment instead now comes a list of great novelist
and then standing on the deck of the ferry if the weather was anywhere close to decent, the
wind in his face, the engine vibrating in the soles of his feet, the seagulls circling around
him, such an ordinary trip when all was said and done, a trip made by thousands of
commuters every morning from Monday to Friday, but this was Saturday, and to the fifteen year-
old Ferguson it was pure romance to be traveling toward lower Manhattan in this way,
the best of all good things he could possibly be doing not just leaving home behind but
going to this, to all this.with all this meaning the joys of Manhattan, as revealed in the fragments and
sentences to come.

A happiness sends those phrases forward a joy in recounting the tiny details, and, then
again, a joy in formulating the phrases, and still another joy in allowing the rhythm of
the details and the rhythm of the phrases to go in and out of syncopation. Auster says it
himself “such happiness to be sitting in one of those cars” which could just as well be
the happiness of escaping the laws of syntactical gravity. It may be that, in literature,
momentum and pleasure are nearly the same thing, and Auster’s prosodic ease and
energy guarantee a certain kind of momentum.

His plot follows a different principle, though, which is the chief curiosity of the book. He
has divided Ferguson into four different Fergusons, each of them the same young boy
from the same family, but pursuing life in rotating chapters according to different turns
of fate such that, in one alternative, little Ferguson is killed by a falling tree at age 13;
and, in another alternative, his father is killed in a fire and little Ferguson grows up
alone with his mother; and, in still another alternative, his parents divorce and get
remarried to other people, which brings the boy into a new environment; and, finally,
his parents remain happily married and, in response to the Newark riot of 1967, move to
Florida, which leaves little Ferguson sane and sound and pleasingly independent. Each
set of circumstances generates its own Ferguson, as he comes of college age a Ferguson
who yearns in more-or-less happy adolescent frustration for girls, and a Ferguson who
finds himself drifting in homosexual directions; a penniless Ferguson who attends
Princeton on scholarship; a well-to-do Ferguson who attends Columbia in time for the
big student strike of 1968; and still another Ferguson, preternaturally self-assured, who
avoids college altogether and instead plunges into the bohemian life of Paris.
Auster displays a marvelous skill in spinning these variations. All of his Fergusons do
seem to be the same young person, variously adapted. And the people who surround
Ferguson likewise remain faithful to themselves in spite of the variation in their own
circumstances. His mother’s boss’ granddaughter is a girl named Amy, who becomes
Ferguson’s cousin by marriage, or his stepsister, or his pal, and goes to Barnard, or
Brandeis, or the University of Wisconsin. And, under each new circumstance, Amy is
recognizably the same girl, a little wiser and wittier and more mature than Ferguson,
and a little unattainable; and various Fergusons fall in love with her, or ought to fall in
love, or will eventually do so, in exactly the same slightly doomed and soppy way.
I wonder, though: What is the purpose of these alternative realities? The name of Jorge
Luis Borges comes up in the course of Ferguson’s Princeton experience, which, together
with the digital title, might suggest that Auster’s larger intention is to conjure the kind of
icy mathematical universe that Borges conjures the alternative universe whose
evocation has always been the grand obsession of the literary avant-garde. But, apart
from the title, nothing in 4 3 2 1 is icy or abstract or even mathematical. The alternative
histories of Ferguson in childhood and adolescence do not suggest the existence of an
alternative universe. Each of the alternative narrative strands seems to conform,
instead, to the assumptions of a single-universe realist novel. I made my way through
the book engrossed in each separate strand of the story, and repeatedly I was surprised
and disappointed to be reminded that other strands pursue alternative versions
surprised because Auster’s warm and realist storytelling does not seem to cry out for a
supernatural alternative, and disappointed because the alternative versions undermine
the convincing quality of each separate version.

But mostly my disappointment lies in the storytelling itself. The passages on family
history amount to a treacly Jewish-immigrant novel. The passages on Ferguson’s early
childhood turn out to be relentlessly cloying. One chapter after another had me, as a
faithful reader, sobbing or gasping at the final emotional or shocking note only to
discover, once I had turned the page to the next chapter, that I could no longer
remember having sobbed or gasped. Ferguson and Amy are about to sleep together for
the first time except that, gasp, John Kennedy is assassinated!

And yet, Auster does keep his momentum going, and this is not merely through feats of
rhythmic sentence construction. He paints Ferguson’s romances with Amy and other
girls in strictly sentimental colors, and likewise the gay Ferguson’s romance with a gay
expat in Paris. But he is good at conjuring sexual tensions on two occasions with the
young gay Ferguson on the brink of succumbing to a mutual desire with an older
lesbian, in testimony to the knottiness of sex and the falsity of sexual categories. A 900-
page novel had better produce an occasional scene of that sort, and it is only a pity that,
on both occasions, the looked-for doubly-gay-therefore-straight coupling never occurs.
The best aspect of the book is Auster’s portrait of the cultural enthusiasms of those years
in the version that is Ferguson’s. The phrase “How Laurel and Hardy saved my life” gets
bandied about. Young Ferguson enthuses over the avant-garde filmmakers of the 1960s,
and then again over the Marx Brothers, a grand cult object of the ’60s student avantgarde.
He enthuses over Apollinaire and the French Surrealist poets, and over John
O’Hara and the New York School of poets. He enthuses over classical music, over Bach
and the struggle to find a home for the New York Philharmonic, and over Coltrane
without a word about rock music, which I find relieving to see.

He enthuses over Manhattan, or, at least, the idea of Manhattan, and, at the same time,
he recoils from the stink and decay of Manhattan and from the misery of the Upper
West Side in the ’60s. And he responds with enthusiasm to the rumors that come his
way of the new left-wing movements of the time rumors of the Freedom Riders and
civil-rights workers in the South. The early phases of the anti-Vietnam War movement
catch his attention the street demonstrations in Manhattan in 1966 and ’67, at a
moment when most of the rest of the country was united in support of the war. And, in
conjuring all of this, Auster conjures, too, a forgotten class struggle of those years, which
was surely the antecedent of the class struggle of our own era, namely, the antagonism
of hipsters and squares the people who think of themselves as the beginning of a better
future versus the people who think of themselves as the representatives of a laudable
past. Naturally, he captures this from a hipster standpoint, teenage version.
Ferguson takes a girl named Linda to see The Loneliness of the Long Distance
Runner at a Manhattan theater and sighs at once when she says, “And you, Archie, what
makes you think New York is so much better than everywhere else when in fact it’s so
disgusting?” She condemns the hero of the movie, which, he thinks, might make sense,
and is insufferable, even so:

But she was arguing for expediency over valor, and he hated arguments of that sort, the
practical approach to life, using the system to beat the system, playing by a set of broken
rules because no other rules were in place, whereas those rules needed to be smashed and
reinvented, and because Linda believed in the rules of their world, their little suburban
world of getting ahead and moving up and settling into a good job and marrying someone
who thought the way you did and mowing the lawn and driving a new car and paying your
taxes and having 2.4 children and believing in nothing but the power of money, he
understood how useless it would have been to prolong the discussion.
And all of this erupts into public conflict during the Columbia student uprising of 1968
the uprising that pits students like Ferguson (that is, Ferguson the Columbia student
and apprentice journalist at the college newspaper; or else Ferguson the ex-Princeton
student who has transferred to Brooklyn College and whose Barnard girlfriend, Amy, is
a militant of Students for a Democratic Society) against the conservative students: “the
horde of inexperienced ephebes and virgin wankers who had grown up in small
provincial cities and suburban tract houses.”

Auster has a habit of writing about historical events with a few facts altered, which
seems to me another pointless affectation of literary experimentation. By and large,
though, his account of the uprising and the student scene is faithful unto the tiniest
details, most of them (to which I can attest in my capacity as a militant SDSer from
those days). Sometimes he faintly disguises his characters e.g., the poet Ron Padgett,
who appears under a slightly altered name as a leader of the literary aspect of the
rebellion.

Other times he introduces characters under their real names e.g., Robert Friedman,
the editor of the college newspaper (who, half a century later, is a well-known editor in
New York), or Hilton Obenzinger, poet and protester (who has written his own
novel, Busy Dying, about the Columbia uprising). And he offers a portrait of the bestknown
of the student rebels, who was Mark Rudd, the chairman of SDS Rudd, the
nimble leader of the revolution, improvising like a jazz musician. “The longer the
occupation of the buildings went on, the more impressed Ferguson was by how fluidly
Rudd adapted to each new circumstance, by how quickly he could think on his feet, by
his willingness to talk about alternative approaches to each crisis as it came up” which,
if I may add, is an accurate description. Then again, maybe Auster underestimates
Rudd. Auster’s Ferguson allows that, after a while, his old friends at Columbia, the ultraradicals,
“went insane,” which he attributes to political frustration. But Rudd the reallife
Rudd in a memoir from a few years ago, Underground: My Life with SDS and the
Weathermen, a moving book, defiant and remorseful, introduces into his own account
of those insanities a dose of sulphur, which is missing from 4 3 2 1.
What Auster’s book does have is an epic quality, sometimes with a touch of grandeur,
and this is not just because it goes on endlessly. The book is a portrait of the artist as a
young man that also manages to be a portrait of a cultural era coming into being, with
its snobberies and animosities and struggles and ideals—the era that is our own, which
is the era that began to flower amid the rebellions of 1968.

HOT BLAST OPERATION

Hot blast operation involves preheating the cupola blast air and was originally conceived as a means of reducing coke consumption. It was first adopted for foundry use in the late 1940s, early 1950s and by heating the blast air to about 500ºC, charge coke reductions of about 30% were experienced compared to cold blast operation. However, hot blast could also be employed to increase metal temperatures and carbon pick-up and this permitted the use of more steel scrap in the charge mixture.
The advantages of hot blast operation may be summarised as follows:
 reduced coke consumption
 increased metal temperature
 higher melting rate
 reduced sulphur pick-up
 lower melting losses of silicon
 increased carbon pick-up.



It is not possible to obtain all of these benefits simultaneously.
Hot blast cupolas have not been universally used in all European countries but have been very popular in Germany. In many countries initial environmental legislation was more stringent for hot blast cupolas than for cold blast. This is not the case now and the cost of the recuperator is relatively easy to justify on operating cost savings.
Most hot blast cupolas are operated on long campaigns, many with externally water cooled unlined shells in the melting zone. Several of this type of furnace have been used for the production of low sulphur ductile base iron using basic slags.
Blast heating has been carried out using both independently fired and recuperative hot blast systems. However, the high fuel costs and generally poor performance of the independent units has resulted in recuperative systems incorporating combustion of the cupola off-take gases being the most common arrangement.
In recent years there has been an interest in the use of higher blast air temperature in excess of 700ºC. Such very high blast temperatures will result in further enhancement of recarburisation of the iron, while the lower blast rates for a given melt rate and the higher bed temperatures should allow the use of smaller charge pieces such as borings to be successfully melted. It has been suggested that superheated hot blast systems will allow lower grade, smaller coke to be employed without the tapping temperature decrease, which would be experienced with conventional cupolas.
Oxygen Enrichment
Although the benefits of oxygen were known for a considerable time, it was only in the 1970s when the costs of bulk oxygen, pig iron and coke were such as to make its employment economical that it came into common use.
Compared with conventional operation, the continuous use of oxygen resulted in:
 higher metal temperatures and carbon pick-up and lower silicon losses at the same coke levels – allowing metallic charge costs to be reduced by pig iron replacement and a reduction in silicon additions
 reduced coke consumption for a given temperature
 improved tapping temperature recovery at a start of melting or following shutdown periods.

The oxygen could be introduced by three different processes – blast enrichment, tuyere injection, or well injection – in order of increasing effectiveness. However, blast enrichment was simpler and the majority of cupolas adopting oxygen technology employed this system.
More recently, the use of supersonic oxygen injection into cupolas via the tuyeres is becoming an accepted technique and a number of cupolas in Europe have installed such facilities. In this process the tuyere lance nozzles are specially designed to provide an outlet velocity in the range 2–2.5 Mach. It is claimed that this approach results in better oxygen and air blast penetration with a consequent improvement in coke bed temperature.
The injection lances are self-cooled by gaseous oxygen and are mounted centrally in each tuyere (generally tuyeres are water cooled) at a distance of between 100 and 300 mm from the exit. It is claimed that the following effects result:
 blast volume is reduced
 blast air/oxygen distribution is more uniform and furnace internal pressure is reduced
 heat losses from cupola are reduced due to more even coke bed combustion
 charge preheating is improved because there is less temperature variation over the cross-section of the cupola
 charge coke additions are reduced
 melting rate variations of -50% to +40% of nominal melting rate are possible

· furnace shell losses are lower as higher temperatures are achieved in the centre of the cupola
 metal tapping temperature is increased
 silicon losses are reduced
 the blast temperature on hot blast cupolas is increased by the higher off-take gas temperature.
It is also claimed that the process is the first oxygen method which demonstrates a reduction in coke consumption at a constant melting rate such that coke savings fully compensate for the cost of oxygen. It is further suggested that it should be possible to use lower grade coke with consequent further cost savings.
Long Campaign Cupolas
In recent years there has been considerably increased interest in operating cupolas for extended periods, both on a daily basis and also from a refractory campaign point of view (repair after weeks rather than after melting day).
Obviously the well-established hot blast technology already discussed in an earlier section can fulfil this role successfully, However, largely as a result of work in the USA, a number of cold blast units has been adopted for the same purpose.
The cold blast furnaces include similar features to those found in hot blast plants in that the cupola shells (which may be lined or unlined) are fully water cooled and are fitted with water cooled projecting tuyeres. Tuyere blast velocities are considerably higher than conventional cold blast practice to ensure complete penetration of the coke bed, the generation of very high bed temperatures and a minimisation of heat losses, particularly through an unlined shell.

METALLURGICAL AUTOMOBILE RECYCLING PLANT

The use of cupola plant for recycling considerable quantities of steel scrap containing non-metallic material is not new. However, the use of cupola technology as the heart of an integrated reprocessing system for automobile body shells would result in a low cost bulk metal supply route for large foundry operations where there is a readily available source of suitable feedstock.
Over recent years the increasing pressures to reduce waste and improve reprocessing opportunities has resulted in many automobile manufacturers claiming a higher degree of recyclability for their products. This, together with increased use of valuable recoverable material, is likely to lead to more selective dismantling. Nevertheless, significant quantities of organic materials in the form of paints, lubricants and plastic components and the trim are likely to remain in the resulting car body shell. Zinc coated steel will almost certainly feature in the body construction, while wiring looms and electric motors may be a source of unwanted copper contamination unless removed prior to reprocessing. Car body shells can be prepared by either baling or fragmentation. Fragmentation scrap with appropriate magnetic separation and screening can be rendered clean and at adequately low levels of contamination. However, its generally small size and thin section do not make for an ideal cupola feedstock. Newer, modified cupola techniques to avoid excessive oxidation could improve this situation and lead to greater acceptability.
Baled scrap from known sources has been fairly widely used for cupola charges, although in smaller furnaces the tendency to scaffolding problems has limited its use. The use of hot blast and a tapered shell arrangement will alleviate the scaffolding difficulty and reduce oxidation problems with such feedstock.

Ancillary Equipment
Ü Environmental Control

The design of effective emission control equipment for cupolas is more difficult than for other foundry processes due to the wide range of gas temperatures (100–1200ºC), particle sizes (<1 mm to 10 mm) and flow rates involved. In addition, the presence of sulphur dioxide can cause corrosion problems and any combusted volatile matter may create condensation difficulties with filter media. The high levels of carbon monoxide can be hazardous and unacceptable from a discharge point of view unless burnt.
Most modern emission control plant for cupolas is based on the use of dry bag filter systems. Cold blast operation can result in effluent gas temperatures which vary during the campaign and are generally well in excess of that capable of being handled by economical fabric filters. Gas cooling is therefore required to prevent damage to the filter bags. However, too low a gas temperature may result in condensation of both volatile matter and water vapour leading to adverse effects on plant performance. These include blinding of the filter fabric, corrosion problems in the plant itself, and risk of fire or explosion damage due to flammable deposit ignition.
In order to heat the blast in hot blast cupolas, the off-take gases are burnt in a recuperator but the system actually used may vary depending on the condition of the gases to be handled.
Ü Dust and Waste Injection Systems
Much research and development effort has been expended over the years in attempting to perfect methods for introducing particulate materials in cupolas and these can be categorised as follows:
 exploitation of swarf and borings
 concentration of metallic elements, in particular zinc, for subsequent recovery
 recycling of waste materials such as collector waste, used sands, etc.

Most injection systems have been based on lancing systems incorporation in the tuyeres but it has been found that the cooling effect involved has restricted the opportunities for significant continuous injection because of the need to melt the material collected in the coke bed. It is, therefore, of considerable interest to increase the continuous injection rates and to establish practical feed rates for various waste materials.
Some work undertaken in Germany has been carried out using oxy-fuel burners in the tuyeres of a hot blast cupola. The technology should be transferable to most types of cupolas.
A mixture of natural gas and oxygen is supplied to the burner with dust being injected through the burner pipe from a specially designed transporter unit and ejected through the burner outlet.
Oxy-fuel burners result in very high flame temperatures compared to fuel-air systems, since no nitrogen has to be heated.
Each type of particle influences the overall melting process in a different way, for instance the carbon containing flue ash/cupola dust acts as a supplementary fuel. In these trials the injection rates were restricted by iron quality considerations rather than blockage of the coke bed in front of the tuyeres.
Other advantages of tuyere oxygen injection, such as charge coke reduction, reduced blast air requirements, better carbon pick-up and metal temperatures can be achieved by use of the burners when injection is not being employed. This makes for increased furnace flexibility. Recycling of dry bag filter dusts by cupola injection can result in the concentration of zinc such that it can be sold to a zinc reclaimer.
Ü Waste Heat Recovery

The exhaust gases leaving a cupola are at a high temperature and contain combustible elements which could be exploited as an energy source. Clearly this energy is utilised in hot blast cupolas to good effect but even in these cases less than 50% of the energy available is employed The available waste heat could be used for a variety of other applications by employing suitable heat exchanger systems. Indeed a few examples do exist of hot water and steam production for space heating and process heat. Space heating and hot water production for ablutions and other uses may not be required consistently but one interesting example of a process heat application is for steam generation to power an electricity generating set and compressor. Foundries usually require both electricity and compressed air during their operating hours and therefore there is a continuous outlet for the waste heat from the cupola plant. It is claimed that the use of this system on a 50 tonnes/hr hot blast facility results in an energy utilisation approaching 100%.
Other possible applications of cupola exit gas energy could be for charge material and coke drying and preheating duties to prevent condensation in bag filter outlet chimneys, dust extraction systems and shake-out drums.
The need for high efficiency gas cleaning equipment on modern cupola installations provides the possibility of waste heat recovery, which requires evaluation.

INTRODUCTION ON METAL CASTING

Introduction on Metal Casting
In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow
cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also
known as a casting, which is ejected or broken out of the mold to complete the process. Casting
is most often used for making complex shapes that would be difficult or uneconomical to make
by other methods.
Molding or moulding (see spelling differences) is the process of manufacturing by shaping liquid
or pliable raw material using a rigid frame called a mold or matrix. This itself may have been
made using a pattern or model of the final object.
A mold or mould is a hollowed-out block that is filled with a liquid or pliable material like
plastic, glass, metal, or ceramic raw materials. The liquid hardens or sets inside the mold,
adopting its shape. A mold is the counterpart to a cast. The very common bi-valve molding
process uses two molds, one for each half of the object. Piece-molding uses a number of different
molds , each creating a section of a complicated object. This is generally only used for larger and
more valuable objects.
The manufacturer who makes the molds is called the moldmaker. A release agent is typically
used to make removal of the hardened/set substance from the mold easier. Typical uses for
molded plastics include molded furniture, molded household goods, molded cases, and structural
materials.
Casting processes have been known for thousands of years, and widely used for sculpture,
especially in bronze, jewellery in precious metals, and weapons and tools. Traditional techniques
include lost-wax casting, plaster mold casting and sand casting.
Metal casting is one of the most common casting processes. Metal patterns are more expensive
but are more dimensionally stable and durable. Metallic patterns are used where repetitive
production of castings is required in large quantities.
Casting is a 6000 year old process.The oldest surviving casting is a copper frog from 3200 BC.
The modern casting process is subdivided into two main categories: expendable and nonexpendable
casting. It is further broken down by the mold material, such as sand or metal, and
pouring method, such as gravity, vacuum, or low pressure.
Casting is a manufacturing process by which a liquid material is usually poured into a mold,
which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified
part is also known as a casting, which is ejected or broken out of the mold to complete the
process. Casting materials are usually metals or various cold setting materials that cure after
mixing two or more components together; examples are epoxy, concrete, plaster and clay.
Casting is most often used for making complex shapes that would be otherwise difficult or
uneconomical to make by other methods.



Epoxy is the cured end product of epoxy resins, as well as a colloquial name for the epoxide
functional group. Epoxy resins, also known as polyepoxides are a class of reactive prepolymers
and polymers which contain epoxide groups. Epoxy resins may be reacted (cross-linked) either
with themselves through catalytic homopolymerisation, or with a wide range of co-reactants
including polyfunctional amines, acids (and acid anhydrides), phenols, alcohols, and thiols.
These co-reactants are often referred to as hardeners or curatives, and the cross-linking reaction
is commonly referred to as curing. Reaction of polyepoxides with themselves or with
polyfunctional hardeners forms a thermosetting polymer, often with strong mechanical properties
as well as high temperature and chemical resistance. Epoxy has a wide range of applications,
including metal coatings, use in electronics / electrical components, high tension electrical
insulators, fiber-reinforced plastic materials, and structural adhesives. Epoxy resin is employed
to bind gutta percha in some root canal procedures.
Epoxy resins are low molecular weight pre-polymers or higher molecular weight polymers which
normally contain at least two epoxide groups. The epoxide group is also sometimes referred to as
a glycidyl or oxirane group.
A wide range of epoxy resins are produced industrially. The raw materials for epoxy resin
production are today largely petroleum derived, although some plant derived sources are now
becoming commercially available (e.g. plant derived glycerol used to make epichlorohydrin).
Epoxy resins are polymeric or semi-polymeric materials, and as such rarely exist as pure
substances, since variable chain length results from the polymerisation reaction used to produce
them. High purity grades can be produced for certain applications, e.g. using a distillation
purification process. One downside of high purity liquid grades is their tendency to form
crystalline solids due to their highly regular structure, which require melting to enable
processing.
An important criterion for epoxy resins is the epoxide content. This is commonly expressed as
the epoxide number, which is the number of epoxide equivalents in 1 kg of resin (Eq./kg), or as
the equivalent weight, which is the weight in grams of resin containing 1 mole equivalent of
epoxide (g/mol). One measure may be simply converted to another:
Equivalent weight (g/mol) = 1000 / epoxide number (Eq./kg)

Plaster, Concrete, Or Plastic Resin
Plaster and other chemical setting materials such as concrete and plastic resin may be cast using
single-use waste molds as noted above, multiple-use 'piece' molds, or molds made of small rigid
pieces or of flexible material such as latex rubber (which is in turn supported by an exterior
mold). When casting plaster or concrete, the finished product is, unlike marble, unattractive,
lacking in transparency, and so it is usually painted, often in ways that give the appearance of
metal or stone. Alternatively, the first layers cast may contain colored sand so as to give an
appearance of stone. By casting concrete, rather than plaster, it is possible to create sculptures,
fountains, or seating for outdoor use. A simulation of high-quality marble may be made using
certain chemically-set plastic resins (for example epoxy or polyester) with powdered stone added
for coloration, often with multiple colors worked in. The latter is a common means of making
attractive washstands, washstand tops and shower stalls, with the skilled working of multiple
colors resulting in simulated staining patterns as is often found in natural marble or travertine.

Resin Casting
Resin casting is a method of plastic casting where a mold is filled with a liquid synthetic resin,
which then hardens. It is primarily used for small-scale production like industrial prototypes and
dentistry. It can be done by amateur hobbyists with little initial investment, and is used in the
production of collectible toys, models and figures, as well as small-scale jewelry production.
The synthetic resin for such processes is a monomer for making a plastic thermosetting polymer.
During the setting process, the liquid monomer polymerizes into the polymer, thereby hardening
into a solid.

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