detailed note on vacuum centrifuge with application working principle design.

1. Vacuum
Centrifuge/Concentrators
Presented by-
SALMAN KHAN
SAHIL DOGRA
SREERAM PRAKASH

2. Why use a vacuum centrifuge?
❏ In the conventional centrifuges , the rotor spins in air or some other gas at
atmospheric pressure.
❏ The gaseous friction on a spinning rotor increases at a relatively high rate so that
the power required to drive the rotor also increases rapidly. As a result, the
temperature of the rotor rises drastically, sometimes exceeding the boiling point
of water.
❏ As the rotor surface near the periphery moves faster than near the axis, a
thermal gradient or variation in temperature through the rotor wall is
established along the radius with the periphery at a higher temperature than the
axis.
❏ These small radial temperature gradients produce convection within the
centrifuge, and these convection currents can cause remixing and disturb
sedimentation.

3. PRINCIPLE
A vacuum centrifuge concentrator uses a
vacuum, centrifugal force, and sometimes heat or
gas blow down to evaporate liquid and
concentrate DNA, RNA, nucleotides, and other
proteins for further use or study.
❏ The heat buildup and convection problems
caused within a centrifuge by air resistance
can be avoided by spinning the rotor within
an evacuated chamber.

4. Acid-Resistant CentriVap® 16 Vacuum
Concentrators
CentriVap® DNA Vacuum Concentrators

5. What other advantages ?
❏ The elimination of air resistance also makes possible the attainment of high
rotational speeds with relatively little expenditure of energy.
❏ Many vacuum-type centrifuges are ultracentrifuges; i.e., they operate at
speeds of more than about 20,000 revolutions per minute.
❏ A vacuum centrifuge concentrator concentrates solutes from a liquid sample
into a dry state or a wet pellet state.
❏ The most advanced modern centrifugal evaporators not only concentrate
many samples at the same time, they eliminate solvent bumping and can
handle solvents with boiling points of up to 220 °C.
❏ Centrifugal vacuum concentrators can automate the evaporation process. In
comparison to rotary evaporators, they save time for the laboratory staff
when running series of samples.

6. DESIGN
● A centrifugal evaporator often comprises a vacuum pump connected to a
centrifuge chamber in which the samples are placed.
● Many systems also have a cold trap or solvent condenser placed in line
between the vacuum pump and the centrifuge chamber to collect the
evaporated solvents.
● The most efficient systems also have a cold trap on the pump exhaust.
● There are many further developments available from manufacturers to
speed up the process, and to provide protection for delicate samples.

7. Genevac™ miVac Centrifugal Concentrators

8. WORKING
❏ The system works by lowering the pressure in the centrifuge system - as the
pressure drops so does the boiling point of the solvent(s) in the system.
❏ When the pressure is sufficiently low that the boiling points of the solvents are
below the temperature of the sample holder, then they will boil.
❏ This enables solvent to be rapidly removed while the samples themselves are not
heated to damaging temperatures.
❏ The centrifugal force generated by spinning the centrifuge rotor creates a pressure
gradient within the solvent contained in the tubes or vials, this means that the
samples boil from the top down, helping to prevent "bumping".
❏ The most advanced systems apply the vacuum slowly and run the rotor at speeds of
500 x gravity - this system is proven to prevent bumping and was patented by
Genevac in the late 1990s.

9. APPLICATIONS
● Centrifugal vacuum concentrators can be applied in residue analysis
successfully.
● Even methanol/water- or acetonitrile/water-mixtures as extracts from food or
other samples can be concentrated without separation of water prior to the
evaporation process.
● Sulfonamides and other drugs can be concentrated with 100% recovery.
● For more volatile substances (such as organochlorine pesticides or
polychlorinated biphenyls) centrifugal vacuum concentrators can be used for
preconcentration .
● Used in proteomics, genomics, cell biology, microbiology, and drug
development.Evaporate liquid and concentrate DNA, RNA, nucleotides, and other
proteins for further use or study.

11. REFERENCES
● https://www.biocompare.com/Lab-Equipment/23816-Vacuum-Centrifuge-
Concentrators/
● https://www.britannica.com/technology/centrifuge/Vacuum-type-
centrifuges
● https://en.wikipedia.org/wiki/Centrifugal_evaporator