12x04 - Carburetors/Air Conditioners/Sugar

[bunniefuu]

Narrator: cars that don't have
fuel-injection systems

Have carburetors.

They're an integral part
of the engine

That mixes air and fuel
in specific proportions,

Vaporizes them, then sends the
mixture to the intake manifold.

The manifold
transfers the mixture

To the engine cylinders,
where combustion occurs.

Filtered air enters
the carburetor

And mixes with fuel.

When you press the gas,

The carburetor opens conduits

For the air-and-fuel mixture
to flow to the engine.

Two metering blocks control
the proportion of fuel to air.

Computer-guided precision tools
machine them out of aluminum.

Meanwhile, workers install
components called boosters

In the carburetor's main body.

These boosters spray the
fuel-and-air mixture as a mist

Into tapered conduits
called venturi.

Those lead
to the intake manifold,

Which transfers the mixture
to the engine's cylinders.

Another computerized machine

Makes each throttle shaft
from a bar of steel.

These shafts turn
when you press on the gas,

Pivoting the butterfly discs

That open those conduits
to the intake manifold.

The tooling machine
bores screw holes

For attaching the butterflies

And carves grooves to prevent
fuel from leaking out.

Workers install
the throttle shafts

In the carburetor's baseplate.

One side of this plate
will bolt to the main body

And the other
to the intake manifold.

The butterflies are made
of aluminum, steel, or brass,

Depending
on the carburetor model.

He flips the baseplate and
flares the bottom of the screws

To prevent them
from vibrating out

And falling into the engine.

After installing
an adjustment screw

For tuning the carburetor
and using thread-locking fluid

To ensure the components
don't loosen,

It's time to assemble the levers
that turn the throttle shafts.

A washer and cotter pin
hold it all together.

A few pulls on the levers

Ensure that both throttle shafts
move freely and smoothly,

Turning the butterflies

Perpendicular
to open the conduits

And flat to close them.

Next, the accelerator
pump arm --

It shoots an initial burst
of fuel when you start the car.

The carburetor's
cast-metal fuel bowls

Go into a vibrating tumbler

Where metal ba*ls
smooth their surface.

Then they receive
a protective coating.

Now a worker installs a float

To control the fuel level
inside each bowl.

This is essential
because too little fuel

Would prevent engine start-up,

And too much fuel would overflow
and cause a shutdown.

A gasket sandwiched between
the main body and the baseplate

Will prevent fuel from leaking
out and dirt from seeping in.

As a precaution, they coat
the baseplate screws

With thread-locking fluid
so they won't loosen over time.

Now the baseplate that contains

The throttle shafts
and butterflies

Is connected to the main body
that contains the boosters.

Next come the metering blocks --

A gasket over each one,
and then into a fuel bowl.

Then one block-and-bowl unit

Goes on each side
of the main body.

Just one final adjustment

To the accelerator pump lever
and arm

And the carburetor is finished.

In the quality-control
department,

Every carburetor
undergoes testing

With fluids similar to gasoline.

They check
if the accelerator pump

Squirts out enough fuel
at ignition

And during the transition from
idling mode to acceleration.

Then, once everything's running
at regular speed,

They measure the amount of fluid
the boosters spray per hour.

Once they pass quality control,

These carburetors will
really be able to rev you up.

Narrator:
in an air conditioner,

Liquid refrigerant absorbs heat
from inside the building,

Changes into a gas,
then flows outdoors.

It goes through a compressor,
then a heat-exchanger coil

That transfers the heat
to the outside air,

Turning the refrigerant gas
to liquid again.

The refrigerant then circulates
back inside the building.

This air-conditioner company

Makes its coils
entirely of aluminum,

Which is five times
more corrosion-resistant

Than coils made of copper
and aluminum.

To make the coil,

Workers position an aluminum
tube called the spine

In the middle
of this special winding machine.

Then they feed in
an aluminum strip.

The machine
slits the aluminum strip

Into thin teeth called fins.

Then it folds and wraps
thousands upon thousands of fins

Around the spine,

Making the material
they call spine fin tubing.

Each tiny fin
is a heat-transfer vehicle.

Now to form the coil.

They hook the end
of the spine fin tubing

To an automated winder.

It spirals the spine fin tubing
into a large cylindrical shape.

When they finish winding
the coil,

They cut the end free
from the feeder,

Then apply hot glue
to hold everything together.

The next machine presses
the coil on all sides

To form it into the shape
of the air conditioner.

A worker now cuts into the coil
and bears a row of tubing.

These cuts determine
the circuits,

The term for the path
the refrigerant takes

As it flows through the coil.

The pipes that feed these
circuits are made of copper,

But copper doesn't fuse
directly to aluminum.

So workers must first solder on
transition tubes

Coated with
a zinc/aluminum alloy.

Then they attach
the copper manifolds

That distribute the refrigerant
to the circuits.

Once all the refrigeration
components are in place,

Workers subject the coil unit
to an underwater pressure test

To make sure there are no leaks.

In another department,
workers have assembled

The air conditioner's
compressor.

They mount the compressor to a
weather-resistant plastic base,

Then cover it
with a sound reducer,

A vinyl jacket filled
with fiberglass insulation.

Now they add the coil.

It sits between posts
in the base.

For an air conditioner
to work well,

It can't have air or moisture
in its refrigeration system.

So workers hook up the unit
to automated machinery

That completely evacuates
the lines.

Next, workers connect wiring
and install corner supports,

Then begin assembling
the unit's exterior housing.

The top perimeter piece
is shaped

To direct the airflow
out of the unit.

A motorized fan
pulls air into the unit.

A plastic grille lets air exit

And keeps debris
from falling inside.

Finally, they seal
the refrigerant lines

By brazing shut a pair of tubes.

The housing parts are made
of zinc-coated steel.

The factory spray-paints them

Then bakes the paint
for maximum durability.

Air conditioners sit outdoors

So they have to withstand
all kinds of weather.

The factory sends sample units

To a performance-testing
laboratory.

It runs them in extreme heat,
extreme cold, rain, and snow

To see if,
under such harsh conditions,

They keep their cool.

Narrator: next time you reach
for the sugar bowl,

Try to imagine that it was once
so rare and expensive

It was called white gold.

Producing sugar
from the sugarcane

First took place in india.

About 300 b.c.,

Alexander the great's army
reported seeing a reed

That gives honey without bees
growing there.

This table sugar
has many names --

Mill white, plantation white,
and crystal sugar.

But it all comes
from the sugarcane.

It looks a lot like bamboo
with fully grown st*lks

That can measure
up to 20 feet high.

Here in the field,

A worker pares away the husk
from a stalk of sugarcane,

Then chews the cane's raw pulp

To extract
the stalk's sweet juice.

This machine harvests the cane
by cutting it at the base.

Rotating scrolls feed the cane
to the chopper drums inside.

As they chop the cane,

A fan blows the lighter leaves
and tops back onto the field.

The heavier lengths of cane drop
into the base of a conveyor,

Which feeds them
into the transport bin

That follows alongside.

Trucks rapidly transport
the cut cane

To the sugar mill
for processing.

Once cut, sugarcane begins
to lose its sugar content,

And damage to the cane
during harvesting

Accelerates this decay.

At the mill, trucks empty their
load onto a receiving table.

It feeds a belt conveyor

That takes the cane
through two separate washes.

The cane must be
as clean as possible

Before extracting the juice.

But first, the cane's
hard structure is broken down

Inside this crusher,

Where rotating hammers break
the cane into small pieces.

A conveyor loads it
into a milling tandem

Designed to extract the sweet
juice from the crushed cane.

In this milling tandem,
the cane passes through a series

Of five or more
consecutive mills.

Large cylinders compress
the cane fiber.

The juice pours out
of the milling tandem

And diverts into a channel
away from the bagasse,

The dry pulp that remains
after extracting the juice.

A worker supervises the
operation at each of the mills.

A vat collects the juice

That flows from the top
and bottom of the mills.

Now that the juice is extracted
from the sugarcane,

It's time to process it.

However, before turning
the juice into sugar crystals,

A sample goes through
a series of tests

At the sugar mill's laboratory.

First, a technician
adds a thickener

That binds to impurities
in the juice

And then filters it to obtain
a clear, clean juice.

Then he pours it
into a polarimeter,

A machine that measures
the concentration of sugar.

The juice from the mills

Now falls through
this 33-foot-high tower

As sulfur-dioxide vapors
rise through it.

This process,
known as sulfitation,

Bleaches the juice.

Then the juice flows

Through a device
that measures its p.h. Level.

While at a separate vat,

Workers add powdered lime
to water,

Preparing a solution to which
they will then add the juice.

An agitator mixes the
cane-juice-and-lime solution

For about six hours to complete
a process called alkalization.

It regulates the juice's
p.h. Level and helps clarify it.

In reaction to the lime,

The juice's color changes
from brown to yellow.

Next, the juice goes into
these clarifier tanks.

It takes over two hours
for the juice to settle

And for the impurities to fall
to the bottom of the tank.

A sample taken from the tank

Shows how the sludge
collects at the bottom,

While the clarified juice
collects at the top.

Next, we'll see
how this clarified juice

Transforms into flowing crystals
of white sugar.

Narrator: christopher columbus
never made it to asia

But discovered the caribbean

And later brought
sugarcane plantings there.

Sugarcane provides sugar

But also syrup, molasses, rum,
and ethanol.

The many types of sugar
available in stores

Differ in crystal size or color,

Depending on
how they are processed.

Workers filter
the residue known as mud

From the clarifier tanks
to extract any remaining sugar.

There's no waste here.

The mud will fertilize
the cane fields,

And the bagasse
will be burned as fuel.

The clarified juice collected
from the clarifier tanks

Now boils
in a series of evaporators.

This brings the concentration
of the sugar and the juice

Up from 15% to 60%.

Then the juice collects
in 15-ton tanks

To clarify even more.

Any sediment left in the juice
floats to the top.

A rotating paddle
skims this residue off

To the sides of the tank.

These tanks
produce a type of syrup

That goes on
for still more processing.

Workers now pour

Microscopic sucrose crystals
suspended in alcohol

Into the syrup.

This milky solution binds to
the sugar present in the syrup

And helps draw it out.

Next, it all boils
in large vacuum pans,

Forming sugar crystals.

As the water in the syrup
boils away,

Workers regularly check to see
how the sugar is crystallizing.

The goal -- to produce a thick,

Crystallized paste
known as mesquite.

It then goes into
a high-speed centrifugal machine

To remove the sugar crystals
from the uncrystallized syrup.

Inside, the sugar spins
at 1,200 revolutions per minute.

This action draws the molasses

To the outer shell
of the machine,

While the crystals remain
in the inner basket.

Sprays of water
wash the crystals,

Then the water is drawn out so
that only the crystals remain.

This centrifuge
works much the same way

As a washing machine
set on the spin cycle.

It draws out moisture
from the sugar

Much like you draw out the wash
water from a load of laundry.

Next, a conveyor belt
carries the sugar crystals

Out of the centrifuge.

This mill produces raw sugar,

Which has a higher molasses
color and is unbleached,

And plantation white sugar,

Which has less molasses and
is bleached a brilliant white.

The sugar on the conveyor
now goes into a large dryer.

Hot air blows into this dryer

To bring the sugar's
humidity level down to .02%.

That's standard for table sugar.

The dried sugar pours out from
the dryer into a bag on a scale.

It's full when it weighs in
at 2,200 pounds.

A hoist then carries the bags
to a platform

At the far end
of the packing facility.

At 3.3 tons,
that's a heavy load.

It lowers each bag over a chute

That leads to
the factory's main floor.

Workers carefully open
each bag in turn

And pour out the sugar
directly into the chute.

It feeds
an automated packaging machine,

Which fills a series
of 4½-pound plastic bags,

Seals them, and separates them.

This packing facility
produces 200,000 bags a day.

That means processing 400 tons
of white sugar daily.

This fine plantation-white sugar

Is available in a variety
of convenient packaging options,

And that should sweeten
anyone's day.

If you have any comments
about the show,

Or if you'd like to suggest
topics for future shows,

Drop us a line at...