3. Re-circulating batch dryer is a
mechanical device or machine that
removes the water from wet grains
by forcing either ambient air or
heated air through the grain bulk.
In a re-circulating dryer, the same
quantity of grain is re-cycled
through the dryer until the final
moisture content is reached.
5. 1.DRYING AND TEMPERING BIN FOR HOLDING THE
GRAINS.
2.BUCKET ELEVATORS AND CONVEYORS FOR
CIRCULATING, LOADING, AND UNLOADING GRAINS
3.BURNER FOR HEATING THE DRYING AIR
4.ELECTRONIC CONTROLLER AND ON-LINE MOISTURE
METER FOR CONTROLLING THE DRYING OPERATION
6.
7. Types of Re- circulating
batch dryers:
1.Cross flow - simpler construction ,
better with wet grain.
2.Mixed flow – better grain
quality from better mixing.
8.
9. The principle behind the re-circulating
batch dryer
As illustrated below, the grain is
constantly moving through the drying bin
from top to bottom, passing first the
tempering section and then the drying
section. Retention time for one pass is
around 60 min. Drying rate is around
1−2% per hour. Drying air temperature is
up to 55°C.
10. Safety
1. It shall have adequate provision for fire control.
2. It shall have adequate protection from or for all
moving parts.
3.It shall be provided with features for access to
parts during repair, maintenance, and operations.
11. 4.The noise emitted by the heated- air mechanical
grain dryer shall not exceed 92 dab.
5.Provision shall be made for dust control. Its dust
emissions shall be within the acceptable limits set
by the Department of Environmental and Natural
Resources (DENR).
13. Very small floor space is required.
Continuous mixing of the grains results in
very low moisture content variation.
During circulation, the grain is tempered,
which improves drying efficiency and grain
quality.
Automatic controls with automatic shutoff
make the dryer virtually fully automatic.
15. It cannot be easily automated, so
require more supervision and labor
per bushel than other types of
dryers and they have a large
temperature and moisture variation
across the grain column.
22. Quiz
IDENTIFICATION
1.It is mechanical device or machine
that removes the water from wet grains
by forcing either ambient air or heated
air through the grain bulk.
2.What do you called the simpler
construction , better with wet grain.
23. ENUMERATION:
3.Give atleast one type of re – circulating
batch dryer.
4. Give atleast one of the safety in using of
re – circulating batch dryer.
5.Give atleast one of the advantage of re –
circulating batch dryer.
24. ANSWERS:
1.Re – Circulating Batch Dryer
2.Cross Flow
3.Cross Flow
Mixed Flow
4.It shall have adequate provision for fire control.
(Other safety of re – circulating batch dryer that included in
our presentation)
5..Very small floor space required.
(Other advantage that included in our presentation)
