MC Determination

Question 1

It is the amount of water present in the grain, and is expressed in percentage (%).

Answer 1

Grain Moisture Content

Question 2

Grain is ______, where moisture content may increase
or decrease depending on ambient temperature and
relative humidity.

Answer 2

Hygroscopic

Question 3

When grain is exposed to air with low temperature
and high relative humidity (RH) the grains will absorb
water from the air.

Answer 3

Re-wetting

Question 4

When grain is exposed to air with high temperature

and low RH the grains will release water to the air.

Answer 4

Drying

Question 5

Recommended MC for Drying

Answer 5

< or equal to 14%

Question 6

Recommended MC for Drying

Answer 6

< or equal to 14%

Question 7

Recommended MC for milling

Answer 7

13-14%

Question 8

Recommended MC for seed storage

Answer 8

< or equal to 12%

Question 9

Recommended MC for long term storage

Answer 9

< or equal to 9%

Question 10

Primary losses for drying

Answer 10

Spoilage, fungal damage, discoloration

Question 11

Primary losses for milling

Answer 11

breakage
grain cracking
over-milling

Question 12

Primary losses for storage

Answer 12

• Fungal, insect damage (grain storage)

* Loss of vigor (seed and long term storage)

Question 13

Moisture content is determined by removing moisture and then measuring weight loss.

Answer 13

Direct method

Question 14

measuring moisture using the
change in electrical or structural characteristic of a
material as a relationship of its moisture content

Answer 14

Indirect Method

Question 15

methods such as biting,
shaking, and crunching are commonly used by both producers
and small traders.

Answer 15

Empirical Measurement

Question 16

MC is determined with the use of

convection oven.

Answer 16

Air-oven Method

Question 17

moisture is determined by fractional

distillation.

Answer 17

BROWN DUVEL Method

Question 18

Moisture is determined by
evaporation using infrared
heaters as heat source.

Answer 18

Infrared method

Question 19

This method measures the electrical properties (resistance and
capacitance) in relation to the moisture content in the grain.
Most commonly known in this method is the use of moisture
meters.

Answer 19

Secondary or Indirect method

Question 20

measures how the material reduces the electrical

current flow. (value increases with moisture)

Answer 20

Resistance

Question 21

measures dielectric constant of grains.(value decreases with moisture)

Answer 21

Capacitance

Question 22

the ability of any substance to

store electrical energy

Answer 22

dielectric constant

Question 23

• Removal of excess moisture
for safe storage
• Delay leads to damage
• Too rapid result to stress
cracks
• Over-drying results to
economic loss

Answer 23

Drying

Question 24

is one way of increasing farmers’ income

by reducing quantity and quality losses

Answer 24

drying

Question 25

expands farmers opportunities enabling them to temporarily store and seek better markets without quality deterioration

Answer 25

drying

Question 26

Forms of losses due to delay or | improper drying

Answer 26

1. Discoloration 2. Loss of seed viability (seed growers) 3. Reduced milling recovery 4. Altered texture/ appearance and taste 5. Spillages/other physical losses 6. Price reduction

Question 27

DRYING PRINCIPLE

Answer 27

heat transfer | mass transfer

Question 28

Heat energy from the sun

Answer 28

radiation

Question 29

transfer of thermal energy through direct contact

Answer 29

conduction

Question 30

transfer of thermal energy through the movement of | liquid or gas

Answer 30

convection

Question 31

VPg > VPa

Answer 31

desorption

Question 32

VPg < Vpa

Answer 32

absorption

Question 33

VPg = Vpa

Answer 33

Equilibrium Moisture Content (EMC)

Question 34

transport heat to grain

Answer 34

air

Question 35

to hasten evaporation of moisture

Answer 35

heat

Question 36

TOO MUCH HEAT will result to ______

Answer 36

stress crack

Question 37

TOO LOW AIRFLOW – will result to _____

Answer 37

moisture gradient

Question 38

``` Occurs when: • Evaporation is faster than diffusion • When there’s uneven shrinkage between surface and inner grain •When grain is rewetted, surface expands abruptly due to absorption of moisture ```

Answer 38

stress cracks

Question 39

TRO OR POLS. IT REQUIRES LESS ENERGY TO REMOVE | MOISTURE AT THE FALLING RATE PERIOD THAN AT THE CONSTANT RATE PERIOD

Answer 39

POLS

Question 40

flue gas and other products of | combustion goes into the dryer

Answer 40

DIRECT-FIRED

Question 41

a heat exchanger is used to prevent smoke and other products of combustion to go with the drying air

Answer 41

INDIRECT-FIRED

Question 42

Grain is stationary during drying

Answer 42

batch type

Question 43

Grain moves across the drying chamber continuously and are equipped with tempering bins

Answer 43

continuous flow

Question 44

Grain is continuously | recirculated during drying

Answer 44

BATCH-TYPE RECIRCULATING

Question 45

Types of Mechanical Dryers

Answer 45

1. BATCH TYPE 2. CONTINUOUS FLOW 3. BATCH-TYPE RECIRCULATING

Question 46

Basic Parts of a Flatbed Dryer

Answer 46

burner, blower, bin/bed

Question 47

Occurs when there is moisture difference between grain at the bottom and top of the flatbed dryer

Answer 47

moisture gradient

Question 48

this where combustion gases (flue gas) is released to the atmosphere

Answer 48

chimney

Question 49

this is where the heat is transferred from combustion gases to the process air

Answer 49

heat exchanger

Question 50

this is where the ricehull fuel | is burnt

Answer 50

combustion chamber