FINALS - 1st module

Question 1

the process of removing the excess moisture from the product

Answer 1

drying

Question 2

This is by direct exposure of
material to be dried into the heat of the sun.
The speed of drying is highly dependent on the
intensity of the sun during drying.

Answer 2

Sundrying –

Question 3

This is with the use of a
device to heat the air either with the use of the
sun, fossil fuel or biomass and force it into the
bin or cabinet to dry the product.

Answer 3

Mechanical Drying –

Question 4

A batch-type dryer with
horizontal holding bin for granular
product and is used for drying at a
maximum drying layer thickness of 45
cm.

Answer 4

Flat-Bed Dryer –

Question 5

A device for removing excess moisture generally
by forced ventilation with or without addition of heat, to
prevent the development of favorable environment for
the growth of molds insects that normally cause
spoilage.

Answer 5

Dryer –

Question 6

A mechanical dryer used
to remove moisture from a product by blowing artificially
heated air until the required moisture content is
attained.

Answer 6

Heated-Air Mechanical Dryer

Question 7

A mechanical dryer
used to remove moisture from a product by blowing
ambient air until the required moisture content is
attained.

Answer 7

Unheated-Air Mechanical Dryer –

Question 8

A batch-type dryer
with vertical
holding bin and is
used for drying at
the same layer
with the flat-bed
dryer.

Answer 8

Vertical-Bin Dryer –

Question 9

A batch-type dryer
normally used for
drying granular
products at a depth
more than 45 cm.
Drying time for this
type of dryer are
normally longer

Answer 9

Deep-Bed Dryer –

Question 10

A batch
dryer equipped
with conveyors to
circulate or mix
granular product
during drying
operation.

Answer 10

Re-circulating-Type
Dryer –

Question 11

A type of mechanical
dryer wherein the
granular product is
passed continuously
through a drying
chamber utilizing
agitator until the
product reaches the
specified moisture
content reduction per
pass and subsequent
cooling is effected
through the tempering
bins before subjecting
to another pass.

Answer 11

Continuous Flow Dryer
–

Question 12

In this type,
the materials to be dried is placed
in a bin or container, and air is
forced through the mass until it is
dried. This system are simple,
moderately inexpensive, and serve
as storage units after drying is
accomplished.

Answer 12

Batch or Bin Dryer –

Question 13

In this
type of dryer, the material is allowed to
flow from a vertical column where heated
air is forced across the column bed. This
type of dryer is moderately expensive due
to the need of material handling devices
to cause the movement of the product.

Answer 13

Continuous-Gravity Flow Dryer –

Question 14

In this type of dryer, the
materials are not free flowing. The are
applicable for chopped forage, fruits and
vegetables, livestock feed, and fertilizer
components. It has high initial cost and
required more floors space per unit of
capacity the the batch of column dryer.

Answer 14

Rotary Dryer –

Question 15

In this type of dryer,
materials that cannot be dried in the
previous types are applicable for this type
of dryer. Fruits and vegetables are the
best example of product that is suitable
for this type of dryer. In this type, the
materials are placed in a shallow trays
which are stacked inside the dryer drying
chamber.

Answer 15

Tray Dryer –

Question 16

In this type f dryer, water
is removed from solutions or suspension
and dry the resulting powder to moisture
content that approaches the equilibrium
with the exhaust drying air. This type of
dryer is usually expensive and are
commonly used for food, chemicals, and
pharmaceutical.

Answer 16

Spray Dryers -

Question 17

This is a type
of dryer suitable for drying
powdered or granular products
where product undergoes drying
process as it moves along with the
heated air inside a duct or drying
chamber at a known terminal
velocity.

Answer 17

Fluidized-Bed Dryer –

Question 18

Fuels for Crop Dryers (4)

Answer 18

Electricity
 LPG
 Kerosene
 Biomass (rice husks, corn cobs,
sugar baggasse, wood, etc.)

Question 19

Parts of Mechanical Dryer
It is a device that supplies the
needed heat for drying.

Answer 19

Burner

Question 20

the flame heats directly the
drying air and is forced through the drying
chamber by means of a fan or blower.

Answer 20

 Direct method –

Question 21

the drying air is being
heated through a heat exchanger in order that
the product of combustion will not mix with
the drying air and the product.

Answer 21

 Indirect method –

Question 22

It is
used to converts heat
from the flue gas into
clean air. It is used by
the dryer that is heated
by indirect method
especially those that
employs biomass
burner.

Answer 22

Heat Exchanger –

Question 23

It is used
to supply the required
amount of air and
pressure needed by the
system. A fan may either
be an axial, vane-axial, or
tube axial. On the other
hand a blower could be
either radial, backward,
forward-curved, or a
mixed flow type.

Answer 23

Fan or Blower -

Question 24

It is where
the product undergoes drying
process during operation. It
may be inside a bin, a
cylinder, a tray, or a cyclone.
The product inside the
chamber are allowed to be
stationary, mixed, float, or
fluidized during the drying
process to enhance drying.

Answer 24

Drying Chamber –

Question 25

It is
a component of the
dryer where the velocity
pressure of the air is
converted into static
pressure to obtain a
much uniform air
distribution within the
chamber.

Answer 25

Plenum Chamber –

Question 26

This includes accessories
such as thermometer,
thermostat, manometer,
gas valve, switches and
others to monitor and
control the conditions
during drying.

Answer 26

Safety Control Network –

Question 27

Moisture Content formula

Answer 27

Wi ( 1 – MCi ) = Wf ( 1- MCf )

Question 28

Moisture Removed formula

Answer 28

MR = Wi - Wf

Question 29

Bin Capacity Formula

Answer 29

Cb = ( L x W x H ) x g/1000

Question 30

Drying Capacity Formula

Answer 30

Cd = Wi / Td

Question 31

Moisture Reduction Per Hour Formula

Answer 31

MR = (Wi - Wf ) / Td

Question 32

Heating System Efficiency Formula

Answer 32

hs = Qsd 100 / Qaf