SlideShare a Scribd company logo
Bunker storage of grains
Presented By
Shilpi
Dept. Of Agricultural And Food Engineering
CONTENTS
• Introduction
• Types of bunkers
• Design consideration of bunker
• Temperature and RH relationship inside bunkers
• Conclusions
INTRODUCTION
• Modern bunker storage in Australia derives
from pit storage developed by the
Commonwealth Industrial and Scientific
Research Organisation.
• Under Australian conditions pit storage was
too labor intensive and working conditions
too severe, therefore research moved to
above-ground bunker storage.
• This is a storage system built with structural
metal studs of galvanized steel and lateral
containment elements that form a rectangular
“tray”; having a base that could be its own
ground floor.
• Effective treatment of insect infestation is
difficult in sheds and bunkers.
Situations where bunkers can provide rapid, convenient
and inexpensive solutions are:
• At terminal silos when bins are filled to capacity.
• At collection sites and regional centers where incoming harvested
grain is bottle- necked due to transportation problems.
• When grain is to be held on a temporary basis in anticipation of
higher prices.
• For national grain reserves that require long-term storage.
• As buffer stocks for food-aid under emergency situations.
TYPES OF BUNKERS
Round bales
• Using round bales is a low cost,
effective method for smaller piles.
• Put the bales in a circle around
where you will pile your grain.
• Put a plastic barrier between the
bales and grain to prevent grain
from spilling out between cracks.
• Wrap a cable around the perimeter
of the of the bales to prevent them
from shifting outward under
pressure of grain. (with a 5ft grain
wall depth, there is a force of
115lbs per foot on the bales).
Plywood Bunkers
• Full 4’x 8’plywood sheets are nailed together using 2’x 4’s.
• Sheets are bent gradually to form a circle.
• Easy to alter.
• Cover & aerate like regular outdoor pile.
• Can easily disassemble & store when not in use.
• Should consider wrapping a cable around the diameter to prevent
joints from failing.
Open bin rings
• These rings can be set on the
ground, covered and aerated like a
regular outdoor pile.
• Rings need to be anchored
according to manufacturer speci..
• These rings can be ordered with
built in auger spouts or doors.
• Can significantly increase storage
if space is confined.
Wood Bunkers
• Relatively low cost.
• Usually constructed of plywood sheets with
a stick built frame.
• Shown at right is an oak board bunker.
• Bunkers are usually self supporting.
• Can be either purchased from a lumberyard
or constructed on your own.
• Easy to alter in order to add holes for
ventilation, augers, etc.
• Should be covered and aerated like other
outdoor piles.
• Most have a self supporting
design that does not need to be
anchored.
• Makes cleanup easier.
• Have a very long life.
• Not cost effective for a small
amount of bushels.
• Need to be set on a relatively
level surface to prevent gaps
between sections.
Cement Bunkers
Steel Bunkers
• These also have a self supporting design.
• Very long life.
• Need to be set on relatively level surface
to prevent gaps between sections.
• Not cost effective for a small number of
bushels.
• Cost estimation included bunkers, and
estimated tarp & aeration cost, no site
preparation.
Earthen Bunkers
• Need to choose a soil type that will pack
well.
• Create side and back barriers using soil.
• Base of the barrier should be four times
the height of the barrier. Width at the
top of the barrier should be half of the
base.
• Dig a trench on the barrier to insert the
liner into and cover with soil.
• The cover should at least go part way
down the outside of the barrier, and can
be anchored with dirt.
• This will prevent water from running
into the inside wall of the barrier.
• The bunker floor should be leveled and earth removed in this process
should be used to form the retaining ramps along one end and along the
two sides of the bunker.
• Soil types that permit compacting will enable ramp construction to
heights of one to two meters.
• Ramp cross section should be trapezoidal.
• For a 2 meter high ramp the base should be about 8 meters wide and the
top of the ramp 3-4 meters wide.
• The closed end-ramp should be shaped to the same dimensions as the
side ramps to form a radius equal to half the distance between the
parallel side walls.
• This semi-circular end-ramp eliminates the need to fill the corners with
grain.
Ultra hermetic bunker
• Ultra Hermetic Bunker can be made very
simply by spreading out low density PE sheets on
the bottom of a U- shaped compound consisting
of an earthen ramp.
• A better solution is to cover the ground with
asphalt or concrete and to replace the earthen
ramp with a concrete or metal support wall.
• The large pile of grain is made by a grain thrower
or grain pump, to be finally covered by large PVC
sheets which come partly assembled to the site.
• The sheets will be welded together on top of the
pile with a manual heat welder. Ends of PVC
sheet and LDPE sheet are rolled together and
buried in a surrounding trench to obtain ultra
hermetic sealing.
• The ramp is covered with plastic
sheeting to prevent being flushed
away by rain draining from the
bunker “roof”.
• When disassembling, PVC sheets
will be cut neatly and stored on
pallets for reuse in next season.
• The application of this technology is
subject to certain climates and low
MC’s of grain due to risk of
condensation.
DESIGN CONSIDERATION OF BUNKERS
• Site Selection
• The site should have a low water table;
• The site should slope between 1% and 5%;
• The soil should be well-drained sandy loam, but with sufficient clay to enable soil
to cover bunkers;
• The site should be on sufficiently high ground to prevent water accumulating on it;
• The site should be clear of flash floods;
• The site should not be on filled land;
• The site should be well away from nearby building drains, etc.;
• The site should be protected from strong winds.
Considerations
• Make sure that grain is at an appropriate moisture before
using any of these storage methods (13-15%).
• Grain should be clean to allow efficient & effective
aeration, reduce spoilage, and deteriotion by rodents.
• It is important to check grain for moisture, temperature,
sanitation, etc. at least once every two weeks.
• Consider whether short term expenses are justifiable
compared to adding permanent, long term storage.
Grain Handling Equipment
• Site preparation may be influenced by the nature of the in-
loading and out-loading equipment to be used.
• If the bunker is to be loaded from the side by means of screw
augers pneumatic conveyers or endless-belt conveyers, then
side access must be sufficient for both the loading equipment,
including loading hoppers, and dump trucks.
• If the grain bulk is in-loaded from the bunker floor itself, then
the access paths on each side of the bunker will be for
maintenance purpose only, but trucking access will be required
to allow vehicle entry into the bunker.
Bunker Dimensions
• The width of the bunker is dependent upon two
variables determined by the user, namely height at the
centre and height at the sides.
• Two variables determined by the grain, namely the
angle of repose for a given grain species, and the
specific gravity of the grain itself.
• Height At The Centre. This is limited by the height to
which the in-loader can raise the grain.
• Endless-belts that project the grain in an arc may reach
8 meters or more, while augers and conveyer belts may
only reach a maximum of 6 meters.
• Height At Sides. The higher the retaining side-walls the
greater the bunker capacity per unit length.
• Corrugated steel and concrete walls are usually 0.5 to 1 meter
high, earth ramps can be raised to 2 meters.
• Ramps require a broad base which adds considerably to the
total width of the bunker site.
• Experience has shown that bunker widths of the grain-bulk
greater than 25 meters are less convenient due to the quantity
of plastic liner that must be drawn over the grain during the
covering and uncovering process.
• Once the grain height at centre and sides has been decided
upon, the following simple equations may be used for roughly
calculating the length and width of a bunker:
• Decisions on bunker capacity will also determine the
amount of plastic liner to be used.
• The larger the bunker, the smaller the surface area per unit
volume of grain, and the smaller the capital investment per
tonne of grain stored.
• Calculation should be weighed against the convenience of
building a number of smaller bunkers with the inherent
convenience of handling and managing the smaller grain
bulks.
Drainage
• Proper drainage of run-off water from the overliner is essential.
• For this reason surrounding ground should be lower than the bunker
floor and sloping away from the bunker.
• Where earth ramps are constructed, earth from outside the bunker is
used to form the ramps and by so doing the level outside the ramps
is lowered.
• The access and maintenance paths around the bunker can then be
graded to ensure run-off.
• The bunker floor should be graded from the closed end to the open
end with a slope of at least 3%.
The Bunker Underliner
• Waterproof plastic sheeting should be laid across the floor and
over the retaining walls to prevent moisture migration and gas
exchange between the grain bulk and the ground.
• It is advised use of 200 to 250 micron polyethylene sheeting
laid progressively as loading advances, with an overlap of at
least 15 cm "tile fashion”.
• Each additional sheet should be laid as described above and
sealed with tape.
• An allowance of at least 2 meters of sheeting beyond the
retaining walls should be given to enable the underliner to
be sealed with the overliner.
• Care should be taken to avoid damage to the underliner
during loading, and walking or driving over the liner
should be minimized to prevent tears.
• The underliner should be discarded and replaced after
each storage period.
Permanent floor storage system
Temporary floor storage system
Ventilation And Aeration System
• Eliminates offensive odors at the source
• Environmentally controlled structure
• Air usually not recirculated
• Filtered ventilation systems supply clean well oxygenated
• Air Reduces odor at the source
• Depends on the design of bunkers
Different system of aeration
Temperature And Moisture
Relationships In Bunker Storage
Temperature Vs Time Of Storage
RH vs time of storage
CONCLUSIONS
• Bunker storage is still only recommended where the harvest period
coincides with the dry season of the year, since loading the grain may
take many days during which time the grain is exposed to the elements.
• The bunker over-liner does not provide protection from pilfering. Also
if animals are free roaming in the vicinity, fencing should be provided
to protect the bunker.
• The plastic may be damaged by mechanical punctures and by contact
with certain chemicals.
• Technique of passing air between the grain surface and the PVC liner
reduced temperature to a steady-state value in approximately three days
while a relative humidity stratification in the grain mass was not
achieved until after seven days.
REFERENCES
• ASAE Standards. 1987. D245.4:301-305. St. Joseph, MI:ASAE.
• Freer, M. W. et al. 1988. Modeling temperature and moisture content
changes in bunker-stored rice. ASAE Paper No. 88-6050. St. Joseph,
MI: ASAE.
• Gough, M. C. 1985. Physical changes in large-scale hermeticgrain
storage. Journal of Agricultural Engineering Research 31:55-65.
• Navarro, S., Donahaye, E. Kashanchi, Y., Pisarev, V. and Bulbul,
O. (1984) Airtight storage of wheat in a PVC covered bunker.
• Yates, C. J. and R. Sticka. 1984. Development and future trends in
bunker storage. In Developments in Agricultural Engineering 5: B.
E. Ripp et al, eds. New York: Elsevier Scientific Publishing Co.

More Related Content

What's hot

Storage structures silo- shallow and deep bins
Storage structures silo- shallow and deep binsStorage structures silo- shallow and deep bins
Storage structures silo- shallow and deep bins
shyamala chinnappan
 
Glass Packaging Materials
Glass Packaging MaterialsGlass Packaging Materials
Glass Packaging Materials
Ilyana Causing
 
Storage
StorageStorage
Wheat and wheat milling
Wheat and wheat millingWheat and wheat milling
Wheat and wheat milling
BishalBarman1
 
Introduction to channa & paneer kirtiG
Introduction to channa & paneer kirtiGIntroduction to channa & paneer kirtiG
Introduction to channa & paneer kirtiG
KIRTIGAUTAM11
 
Stabilized rice-bran
Stabilized rice-branStabilized rice-bran
Stabilized rice-bran
primary information services
 
Utilization of meat Industry by-products and Wastes
Utilization of meat Industry by-products and WastesUtilization of meat Industry by-products and Wastes
Utilization of meat Industry by-products and Wastes
Thiruchenduran Somasundaram
 
Size reduction
Size reductionSize reduction
Size reduction
Dr. Ganesh Shelke
 
By-Products of Egg Industry
By-Products of Egg IndustryBy-Products of Egg Industry
By-Products of Egg Industry
Jagriti Bhasin
 
RETORT PROCESSING BY Dr.P.RAJKUMAR-HOD (F&PE)
RETORT PROCESSING BY Dr.P.RAJKUMAR-HOD (F&PE)RETORT PROCESSING BY Dr.P.RAJKUMAR-HOD (F&PE)
RETORT PROCESSING BY Dr.P.RAJKUMAR-HOD (F&PE)
kurinchisiva
 
Design & development of Packhouses
Design & development of PackhousesDesign & development of Packhouses
Design & development of Packhouses
Pragati Singham
 
basic of extrusion; type of extruder; extruded producrs; cold extrusion & hot...
basic of extrusion; type of extruder; extruded producrs; cold extrusion & hot...basic of extrusion; type of extruder; extruded producrs; cold extrusion & hot...
basic of extrusion; type of extruder; extruded producrs; cold extrusion & hot...
PulkitTyagi16
 
Shrink and cling packaging of fresh and perishable foods
Shrink and cling packaging of fresh and perishable foodsShrink and cling packaging of fresh and perishable foods
Shrink and cling packaging of fresh and perishable foods
Ramabhau Patil
 
Biodegradable films for Food Packaging
Biodegradable films for Food PackagingBiodegradable films for Food Packaging
Biodegradable films for Food Packaging
Dr. Malathi A. N.
 
Bulking of sand
Bulking of sandBulking of sand
Bulking of sand
SAIPRASANNAKUMARJALL
 
Grain storage warehouses silos
Grain storage   warehouses silosGrain storage   warehouses silos
Grain storage warehouses silos
Indian Council of Agricultural Research
 
Glass Packaging
Glass PackagingGlass Packaging
Glass Packaging
palvisaha09
 
39513441 structural-design-of-steel-bins-and-silos
39513441 structural-design-of-steel-bins-and-silos39513441 structural-design-of-steel-bins-and-silos
39513441 structural-design-of-steel-bins-and-silos
141jdf
 
Final ppt.controlled atmospheric storage by M ANWAR HAQ
Final ppt.controlled atmospheric storage by M ANWAR HAQFinal ppt.controlled atmospheric storage by M ANWAR HAQ
Final ppt.controlled atmospheric storage by M ANWAR HAQ
Muhammad Anwar ul Haq
 
Ice-Cream Freezers : Types - Construction and working
Ice-Cream Freezers : Types - Construction and workingIce-Cream Freezers : Types - Construction and working
Ice-Cream Freezers : Types - Construction and working
RaihanathusSahdhiyya
 

What's hot (20)

Storage structures silo- shallow and deep bins
Storage structures silo- shallow and deep binsStorage structures silo- shallow and deep bins
Storage structures silo- shallow and deep bins
 
Glass Packaging Materials
Glass Packaging MaterialsGlass Packaging Materials
Glass Packaging Materials
 
Storage
StorageStorage
Storage
 
Wheat and wheat milling
Wheat and wheat millingWheat and wheat milling
Wheat and wheat milling
 
Introduction to channa & paneer kirtiG
Introduction to channa & paneer kirtiGIntroduction to channa & paneer kirtiG
Introduction to channa & paneer kirtiG
 
Stabilized rice-bran
Stabilized rice-branStabilized rice-bran
Stabilized rice-bran
 
Utilization of meat Industry by-products and Wastes
Utilization of meat Industry by-products and WastesUtilization of meat Industry by-products and Wastes
Utilization of meat Industry by-products and Wastes
 
Size reduction
Size reductionSize reduction
Size reduction
 
By-Products of Egg Industry
By-Products of Egg IndustryBy-Products of Egg Industry
By-Products of Egg Industry
 
RETORT PROCESSING BY Dr.P.RAJKUMAR-HOD (F&PE)
RETORT PROCESSING BY Dr.P.RAJKUMAR-HOD (F&PE)RETORT PROCESSING BY Dr.P.RAJKUMAR-HOD (F&PE)
RETORT PROCESSING BY Dr.P.RAJKUMAR-HOD (F&PE)
 
Design & development of Packhouses
Design & development of PackhousesDesign & development of Packhouses
Design & development of Packhouses
 
basic of extrusion; type of extruder; extruded producrs; cold extrusion & hot...
basic of extrusion; type of extruder; extruded producrs; cold extrusion & hot...basic of extrusion; type of extruder; extruded producrs; cold extrusion & hot...
basic of extrusion; type of extruder; extruded producrs; cold extrusion & hot...
 
Shrink and cling packaging of fresh and perishable foods
Shrink and cling packaging of fresh and perishable foodsShrink and cling packaging of fresh and perishable foods
Shrink and cling packaging of fresh and perishable foods
 
Biodegradable films for Food Packaging
Biodegradable films for Food PackagingBiodegradable films for Food Packaging
Biodegradable films for Food Packaging
 
Bulking of sand
Bulking of sandBulking of sand
Bulking of sand
 
Grain storage warehouses silos
Grain storage   warehouses silosGrain storage   warehouses silos
Grain storage warehouses silos
 
Glass Packaging
Glass PackagingGlass Packaging
Glass Packaging
 
39513441 structural-design-of-steel-bins-and-silos
39513441 structural-design-of-steel-bins-and-silos39513441 structural-design-of-steel-bins-and-silos
39513441 structural-design-of-steel-bins-and-silos
 
Final ppt.controlled atmospheric storage by M ANWAR HAQ
Final ppt.controlled atmospheric storage by M ANWAR HAQFinal ppt.controlled atmospheric storage by M ANWAR HAQ
Final ppt.controlled atmospheric storage by M ANWAR HAQ
 
Ice-Cream Freezers : Types - Construction and working
Ice-Cream Freezers : Types - Construction and workingIce-Cream Freezers : Types - Construction and working
Ice-Cream Freezers : Types - Construction and working
 

Similar to R22 bunker storage of grains

Module 1 - Jacking techniques.pptx
Module 1 - Jacking techniques.pptxModule 1 - Jacking techniques.pptx
Module 1 - Jacking techniques.pptx
ChinnuNinan
 
NRCS Pond Construction
NRCS Pond ConstructionNRCS Pond Construction
NRCS Pond Construction
Grant Schultz
 
CAISSON PPT.pptx
CAISSON PPT.pptxCAISSON PPT.pptx
CAISSON PPT.pptx
kushpatel927805
 
Class 4 & 5 planning and design of greenhouses (1)
Class 4 & 5 planning and design of greenhouses (1)Class 4 & 5 planning and design of greenhouses (1)
Class 4 & 5 planning and design of greenhouses (1)
Priyanka Priyadarshini
 
pilingvtechniques used in substructure construction
pilingvtechniques used in substructure constructionpilingvtechniques used in substructure construction
pilingvtechniques used in substructure construction
ChinnuNinan
 
Interlocking pavement
Interlocking pavementInterlocking pavement
Interlocking pavement
Himanshu Gupta
 
Construction and testing of sewer line
Construction and testing of sewer lineConstruction and testing of sewer line
Construction and testing of sewer line
RAMPRASAD KUMAWAT
 
Innovations temporary storage of food grains ciphet
Innovations temporary storage of food grains ciphetInnovations temporary storage of food grains ciphet
Innovations temporary storage of food grains ciphet
Ramabhau Patil
 
Caissons
Caissons Caissons
Soil Nailing
Soil NailingSoil Nailing
Soil Nailing
Seminar Links
 
Presentation tos
Presentation tosPresentation tos
Box Pushing Technique
Box Pushing TechniqueBox Pushing Technique
Box Pushing Technique
Seminar Links
 
Well Foundation
Well FoundationWell Foundation
Well Foundation
Dave Chinmyee
 
Basement construction report
Basement construction reportBasement construction report
Basement construction report
ANKITAARORA85
 
pire and well.pptx
pire and  well.pptxpire and  well.pptx
pire and well.pptx
NisthaPathak2
 
Protected cultivation:Green house
Protected cultivation:Green houseProtected cultivation:Green house
Protected cultivation:Green house
Maya Sharma
 
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
AJAYKUMARPUND1
 
Underwater construction
Underwater constructionUnderwater construction
Underwater construction
HetviPatel58
 
Types of pile according to their composition
Types of pile according to their compositionTypes of pile according to their composition
Types of pile according to their composition
MdDiluarHossain1
 
Dishant ppt
Dishant pptDishant ppt
Dishant ppt
GLA University
 

Similar to R22 bunker storage of grains (20)

Module 1 - Jacking techniques.pptx
Module 1 - Jacking techniques.pptxModule 1 - Jacking techniques.pptx
Module 1 - Jacking techniques.pptx
 
NRCS Pond Construction
NRCS Pond ConstructionNRCS Pond Construction
NRCS Pond Construction
 
CAISSON PPT.pptx
CAISSON PPT.pptxCAISSON PPT.pptx
CAISSON PPT.pptx
 
Class 4 & 5 planning and design of greenhouses (1)
Class 4 & 5 planning and design of greenhouses (1)Class 4 & 5 planning and design of greenhouses (1)
Class 4 & 5 planning and design of greenhouses (1)
 
pilingvtechniques used in substructure construction
pilingvtechniques used in substructure constructionpilingvtechniques used in substructure construction
pilingvtechniques used in substructure construction
 
Interlocking pavement
Interlocking pavementInterlocking pavement
Interlocking pavement
 
Construction and testing of sewer line
Construction and testing of sewer lineConstruction and testing of sewer line
Construction and testing of sewer line
 
Innovations temporary storage of food grains ciphet
Innovations temporary storage of food grains ciphetInnovations temporary storage of food grains ciphet
Innovations temporary storage of food grains ciphet
 
Caissons
Caissons Caissons
Caissons
 
Soil Nailing
Soil NailingSoil Nailing
Soil Nailing
 
Presentation tos
Presentation tosPresentation tos
Presentation tos
 
Box Pushing Technique
Box Pushing TechniqueBox Pushing Technique
Box Pushing Technique
 
Well Foundation
Well FoundationWell Foundation
Well Foundation
 
Basement construction report
Basement construction reportBasement construction report
Basement construction report
 
pire and well.pptx
pire and  well.pptxpire and  well.pptx
pire and well.pptx
 
Protected cultivation:Green house
Protected cultivation:Green houseProtected cultivation:Green house
Protected cultivation:Green house
 
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
Pile Foundation by Venkatesh Taduvai (Sub Geotechnical Engineering II)-conver...
 
Underwater construction
Underwater constructionUnderwater construction
Underwater construction
 
Types of pile according to their composition
Types of pile according to their compositionTypes of pile according to their composition
Types of pile according to their composition
 
Dishant ppt
Dishant pptDishant ppt
Dishant ppt
 

More from Maya Sharma

Drying process for grain
Drying process for grainDrying process for grain
Drying process for grain
Maya Sharma
 
Waste management from fermentation industries
Waste management from fermentation industriesWaste management from fermentation industries
Waste management from fermentation industries
Maya Sharma
 
Size reduction particle charactrisation
Size reduction particle charactrisationSize reduction particle charactrisation
Size reduction particle charactrisation
Maya Sharma
 
Post harvest handling and preservation of fresh fish and seafood
Post harvest handling and preservation of fresh fish and seafoodPost harvest handling and preservation of fresh fish and seafood
Post harvest handling and preservation of fresh fish and seafood
Maya Sharma
 
Non thermal processing by combined techniques
Non thermal processing by combined techniquesNon thermal processing by combined techniques
Non thermal processing by combined techniques
Maya Sharma
 
Non thermal plasma as a new food preservation method
Non thermal plasma as a new food preservation methodNon thermal plasma as a new food preservation method
Non thermal plasma as a new food preservation method
Maya Sharma
 
Application of ultrafiltration in lactose separation
Application of ultrafiltration in lactose separationApplication of ultrafiltration in lactose separation
Application of ultrafiltration in lactose separation
Maya Sharma
 
Oscillating magnetic field for food processing
Oscillating magnetic field for food processingOscillating magnetic field for food processing
Oscillating magnetic field for food processing
Maya Sharma
 
Packaging for non thermal processed food
Packaging for non thermal processed foodPackaging for non thermal processed food
Packaging for non thermal processed food
Maya Sharma
 
Impact of non thermal processing technologies on quality of fruit juices
Impact of non thermal processing technologies on quality of fruit juicesImpact of non thermal processing technologies on quality of fruit juices
Impact of non thermal processing technologies on quality of fruit juices
Maya Sharma
 
Osmotic dehydration of fruits
Osmotic dehydration of fruitsOsmotic dehydration of fruits
Osmotic dehydration of fruits
Maya Sharma
 
Controlled atmosphere and modified atmosphere storage
Controlled atmosphere and modified atmosphere storageControlled atmosphere and modified atmosphere storage
Controlled atmosphere and modified atmosphere storage
Maya Sharma
 
Dense phase carbon dioxide processing (DPCD) for preservation of liquid food
Dense phase carbon dioxide processing (DPCD) for preservation of liquid foodDense phase carbon dioxide processing (DPCD) for preservation of liquid food
Dense phase carbon dioxide processing (DPCD) for preservation of liquid food
Maya Sharma
 
Membrane filtration technology in food engg.
Membrane filtration technology in food engg.Membrane filtration technology in food engg.
Membrane filtration technology in food engg.
Maya Sharma
 
Ultrasound in food preservation
Ultrasound in food preservationUltrasound in food preservation
Ultrasound in food preservation
Maya Sharma
 
Effect of non thermal processing methods on microwrganisms
Effect of non thermal processing methods on microwrganismsEffect of non thermal processing methods on microwrganisms
Effect of non thermal processing methods on microwrganisms
Maya Sharma
 
Pulsed light technology in food processing
Pulsed light technology in food processingPulsed light technology in food processing
Pulsed light technology in food processing
Maya Sharma
 
Application of high hydrostatic pressure
Application of high hydrostatic pressureApplication of high hydrostatic pressure
Application of high hydrostatic pressure
Maya Sharma
 
Effect of high pressure processing on protein and starch
Effect of high pressure processing on protein and starchEffect of high pressure processing on protein and starch
Effect of high pressure processing on protein and starch
Maya Sharma
 
High pressure processing of foods
High pressure processing of foodsHigh pressure processing of foods
High pressure processing of foods
Maya Sharma
 

More from Maya Sharma (20)

Drying process for grain
Drying process for grainDrying process for grain
Drying process for grain
 
Waste management from fermentation industries
Waste management from fermentation industriesWaste management from fermentation industries
Waste management from fermentation industries
 
Size reduction particle charactrisation
Size reduction particle charactrisationSize reduction particle charactrisation
Size reduction particle charactrisation
 
Post harvest handling and preservation of fresh fish and seafood
Post harvest handling and preservation of fresh fish and seafoodPost harvest handling and preservation of fresh fish and seafood
Post harvest handling and preservation of fresh fish and seafood
 
Non thermal processing by combined techniques
Non thermal processing by combined techniquesNon thermal processing by combined techniques
Non thermal processing by combined techniques
 
Non thermal plasma as a new food preservation method
Non thermal plasma as a new food preservation methodNon thermal plasma as a new food preservation method
Non thermal plasma as a new food preservation method
 
Application of ultrafiltration in lactose separation
Application of ultrafiltration in lactose separationApplication of ultrafiltration in lactose separation
Application of ultrafiltration in lactose separation
 
Oscillating magnetic field for food processing
Oscillating magnetic field for food processingOscillating magnetic field for food processing
Oscillating magnetic field for food processing
 
Packaging for non thermal processed food
Packaging for non thermal processed foodPackaging for non thermal processed food
Packaging for non thermal processed food
 
Impact of non thermal processing technologies on quality of fruit juices
Impact of non thermal processing technologies on quality of fruit juicesImpact of non thermal processing technologies on quality of fruit juices
Impact of non thermal processing technologies on quality of fruit juices
 
Osmotic dehydration of fruits
Osmotic dehydration of fruitsOsmotic dehydration of fruits
Osmotic dehydration of fruits
 
Controlled atmosphere and modified atmosphere storage
Controlled atmosphere and modified atmosphere storageControlled atmosphere and modified atmosphere storage
Controlled atmosphere and modified atmosphere storage
 
Dense phase carbon dioxide processing (DPCD) for preservation of liquid food
Dense phase carbon dioxide processing (DPCD) for preservation of liquid foodDense phase carbon dioxide processing (DPCD) for preservation of liquid food
Dense phase carbon dioxide processing (DPCD) for preservation of liquid food
 
Membrane filtration technology in food engg.
Membrane filtration technology in food engg.Membrane filtration technology in food engg.
Membrane filtration technology in food engg.
 
Ultrasound in food preservation
Ultrasound in food preservationUltrasound in food preservation
Ultrasound in food preservation
 
Effect of non thermal processing methods on microwrganisms
Effect of non thermal processing methods on microwrganismsEffect of non thermal processing methods on microwrganisms
Effect of non thermal processing methods on microwrganisms
 
Pulsed light technology in food processing
Pulsed light technology in food processingPulsed light technology in food processing
Pulsed light technology in food processing
 
Application of high hydrostatic pressure
Application of high hydrostatic pressureApplication of high hydrostatic pressure
Application of high hydrostatic pressure
 
Effect of high pressure processing on protein and starch
Effect of high pressure processing on protein and starchEffect of high pressure processing on protein and starch
Effect of high pressure processing on protein and starch
 
High pressure processing of foods
High pressure processing of foodsHigh pressure processing of foods
High pressure processing of foods
 

Recently uploaded

Gas agency management system project report.pdf
Gas agency management system project report.pdfGas agency management system project report.pdf
Gas agency management system project report.pdf
Kamal Acharya
 
Digital Twins Computer Networking Paper Presentation.pptx
Digital Twins Computer Networking Paper Presentation.pptxDigital Twins Computer Networking Paper Presentation.pptx
Digital Twins Computer Networking Paper Presentation.pptx
aryanpankaj78
 
1FIDIC-CONSTRUCTION-CONTRACT-2ND-ED-2017-RED-BOOK.pdf
1FIDIC-CONSTRUCTION-CONTRACT-2ND-ED-2017-RED-BOOK.pdf1FIDIC-CONSTRUCTION-CONTRACT-2ND-ED-2017-RED-BOOK.pdf
1FIDIC-CONSTRUCTION-CONTRACT-2ND-ED-2017-RED-BOOK.pdf
MadhavJungKarki
 
VARIABLE FREQUENCY DRIVE. VFDs are widely used in industrial applications for...
VARIABLE FREQUENCY DRIVE. VFDs are widely used in industrial applications for...VARIABLE FREQUENCY DRIVE. VFDs are widely used in industrial applications for...
VARIABLE FREQUENCY DRIVE. VFDs are widely used in industrial applications for...
PIMR BHOPAL
 
Software Engineering and Project Management - Software Testing + Agile Method...
Software Engineering and Project Management - Software Testing + Agile Method...Software Engineering and Project Management - Software Testing + Agile Method...
Software Engineering and Project Management - Software Testing + Agile Method...
Prakhyath Rai
 
Software Engineering and Project Management - Introduction, Modeling Concepts...
Software Engineering and Project Management - Introduction, Modeling Concepts...Software Engineering and Project Management - Introduction, Modeling Concepts...
Software Engineering and Project Management - Introduction, Modeling Concepts...
Prakhyath Rai
 
Introduction to Computer Networks & OSI MODEL.ppt
Introduction to Computer Networks & OSI MODEL.pptIntroduction to Computer Networks & OSI MODEL.ppt
Introduction to Computer Networks & OSI MODEL.ppt
Dwarkadas J Sanghvi College of Engineering
 
Data Driven Maintenance | UReason Webinar
Data Driven Maintenance | UReason WebinarData Driven Maintenance | UReason Webinar
Data Driven Maintenance | UReason Webinar
UReason
 
Operational amplifiers and oscillators notes
Operational amplifiers and oscillators notesOperational amplifiers and oscillators notes
Operational amplifiers and oscillators notes
ShachiPGowda
 
原版制作(Humboldt毕业证书)柏林大学毕业证学位证一模一样
原版制作(Humboldt毕业证书)柏林大学毕业证学位证一模一样原版制作(Humboldt毕业证书)柏林大学毕业证学位证一模一样
原版制作(Humboldt毕业证书)柏林大学毕业证学位证一模一样
ydzowc
 
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024
Sinan KOZAK
 
Object Oriented Analysis and Design - OOAD
Object Oriented Analysis and Design - OOADObject Oriented Analysis and Design - OOAD
Object Oriented Analysis and Design - OOAD
PreethaV16
 
Computational Engineering IITH Presentation
Computational Engineering IITH PresentationComputational Engineering IITH Presentation
Computational Engineering IITH Presentation
co23btech11018
 
TIME TABLE MANAGEMENT SYSTEM testing.pptx
TIME TABLE MANAGEMENT SYSTEM testing.pptxTIME TABLE MANAGEMENT SYSTEM testing.pptx
TIME TABLE MANAGEMENT SYSTEM testing.pptx
CVCSOfficial
 
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...
shadow0702a
 
Mechanical Engineering on AAI Summer Training Report-003.pdf
Mechanical Engineering on AAI Summer Training Report-003.pdfMechanical Engineering on AAI Summer Training Report-003.pdf
Mechanical Engineering on AAI Summer Training Report-003.pdf
21UME003TUSHARDEB
 
132/33KV substation case study Presentation
132/33KV substation case study Presentation132/33KV substation case study Presentation
132/33KV substation case study Presentation
kandramariana6
 
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODEL
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELDEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODEL
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODEL
ijaia
 
LLM Fine Tuning with QLoRA Cassandra Lunch 4, presented by Anant
LLM Fine Tuning with QLoRA Cassandra Lunch 4, presented by AnantLLM Fine Tuning with QLoRA Cassandra Lunch 4, presented by Anant
LLM Fine Tuning with QLoRA Cassandra Lunch 4, presented by Anant
Anant Corporation
 
Pressure Relief valve used in flow line to release the over pressure at our d...
Pressure Relief valve used in flow line to release the over pressure at our d...Pressure Relief valve used in flow line to release the over pressure at our d...
Pressure Relief valve used in flow line to release the over pressure at our d...
cannyengineerings
 

Recently uploaded (20)

Gas agency management system project report.pdf
Gas agency management system project report.pdfGas agency management system project report.pdf
Gas agency management system project report.pdf
 
Digital Twins Computer Networking Paper Presentation.pptx
Digital Twins Computer Networking Paper Presentation.pptxDigital Twins Computer Networking Paper Presentation.pptx
Digital Twins Computer Networking Paper Presentation.pptx
 
1FIDIC-CONSTRUCTION-CONTRACT-2ND-ED-2017-RED-BOOK.pdf
1FIDIC-CONSTRUCTION-CONTRACT-2ND-ED-2017-RED-BOOK.pdf1FIDIC-CONSTRUCTION-CONTRACT-2ND-ED-2017-RED-BOOK.pdf
1FIDIC-CONSTRUCTION-CONTRACT-2ND-ED-2017-RED-BOOK.pdf
 
VARIABLE FREQUENCY DRIVE. VFDs are widely used in industrial applications for...
VARIABLE FREQUENCY DRIVE. VFDs are widely used in industrial applications for...VARIABLE FREQUENCY DRIVE. VFDs are widely used in industrial applications for...
VARIABLE FREQUENCY DRIVE. VFDs are widely used in industrial applications for...
 
Software Engineering and Project Management - Software Testing + Agile Method...
Software Engineering and Project Management - Software Testing + Agile Method...Software Engineering and Project Management - Software Testing + Agile Method...
Software Engineering and Project Management - Software Testing + Agile Method...
 
Software Engineering and Project Management - Introduction, Modeling Concepts...
Software Engineering and Project Management - Introduction, Modeling Concepts...Software Engineering and Project Management - Introduction, Modeling Concepts...
Software Engineering and Project Management - Introduction, Modeling Concepts...
 
Introduction to Computer Networks & OSI MODEL.ppt
Introduction to Computer Networks & OSI MODEL.pptIntroduction to Computer Networks & OSI MODEL.ppt
Introduction to Computer Networks & OSI MODEL.ppt
 
Data Driven Maintenance | UReason Webinar
Data Driven Maintenance | UReason WebinarData Driven Maintenance | UReason Webinar
Data Driven Maintenance | UReason Webinar
 
Operational amplifiers and oscillators notes
Operational amplifiers and oscillators notesOperational amplifiers and oscillators notes
Operational amplifiers and oscillators notes
 
原版制作(Humboldt毕业证书)柏林大学毕业证学位证一模一样
原版制作(Humboldt毕业证书)柏林大学毕业证学位证一模一样原版制作(Humboldt毕业证书)柏林大学毕业证学位证一模一样
原版制作(Humboldt毕业证书)柏林大学毕业证学位证一模一样
 
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024
 
Object Oriented Analysis and Design - OOAD
Object Oriented Analysis and Design - OOADObject Oriented Analysis and Design - OOAD
Object Oriented Analysis and Design - OOAD
 
Computational Engineering IITH Presentation
Computational Engineering IITH PresentationComputational Engineering IITH Presentation
Computational Engineering IITH Presentation
 
TIME TABLE MANAGEMENT SYSTEM testing.pptx
TIME TABLE MANAGEMENT SYSTEM testing.pptxTIME TABLE MANAGEMENT SYSTEM testing.pptx
TIME TABLE MANAGEMENT SYSTEM testing.pptx
 
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...
 
Mechanical Engineering on AAI Summer Training Report-003.pdf
Mechanical Engineering on AAI Summer Training Report-003.pdfMechanical Engineering on AAI Summer Training Report-003.pdf
Mechanical Engineering on AAI Summer Training Report-003.pdf
 
132/33KV substation case study Presentation
132/33KV substation case study Presentation132/33KV substation case study Presentation
132/33KV substation case study Presentation
 
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODEL
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELDEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODEL
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODEL
 
LLM Fine Tuning with QLoRA Cassandra Lunch 4, presented by Anant
LLM Fine Tuning with QLoRA Cassandra Lunch 4, presented by AnantLLM Fine Tuning with QLoRA Cassandra Lunch 4, presented by Anant
LLM Fine Tuning with QLoRA Cassandra Lunch 4, presented by Anant
 
Pressure Relief valve used in flow line to release the over pressure at our d...
Pressure Relief valve used in flow line to release the over pressure at our d...Pressure Relief valve used in flow line to release the over pressure at our d...
Pressure Relief valve used in flow line to release the over pressure at our d...
 

R22 bunker storage of grains

  • 1. Bunker storage of grains Presented By Shilpi Dept. Of Agricultural And Food Engineering
  • 2. CONTENTS • Introduction • Types of bunkers • Design consideration of bunker • Temperature and RH relationship inside bunkers • Conclusions
  • 3. INTRODUCTION • Modern bunker storage in Australia derives from pit storage developed by the Commonwealth Industrial and Scientific Research Organisation. • Under Australian conditions pit storage was too labor intensive and working conditions too severe, therefore research moved to above-ground bunker storage. • This is a storage system built with structural metal studs of galvanized steel and lateral containment elements that form a rectangular “tray”; having a base that could be its own ground floor. • Effective treatment of insect infestation is difficult in sheds and bunkers.
  • 4. Situations where bunkers can provide rapid, convenient and inexpensive solutions are: • At terminal silos when bins are filled to capacity. • At collection sites and regional centers where incoming harvested grain is bottle- necked due to transportation problems. • When grain is to be held on a temporary basis in anticipation of higher prices. • For national grain reserves that require long-term storage. • As buffer stocks for food-aid under emergency situations.
  • 5. TYPES OF BUNKERS Round bales • Using round bales is a low cost, effective method for smaller piles. • Put the bales in a circle around where you will pile your grain. • Put a plastic barrier between the bales and grain to prevent grain from spilling out between cracks. • Wrap a cable around the perimeter of the of the bales to prevent them from shifting outward under pressure of grain. (with a 5ft grain wall depth, there is a force of 115lbs per foot on the bales).
  • 6. Plywood Bunkers • Full 4’x 8’plywood sheets are nailed together using 2’x 4’s. • Sheets are bent gradually to form a circle. • Easy to alter. • Cover & aerate like regular outdoor pile. • Can easily disassemble & store when not in use. • Should consider wrapping a cable around the diameter to prevent joints from failing.
  • 7. Open bin rings • These rings can be set on the ground, covered and aerated like a regular outdoor pile. • Rings need to be anchored according to manufacturer speci.. • These rings can be ordered with built in auger spouts or doors. • Can significantly increase storage if space is confined.
  • 8. Wood Bunkers • Relatively low cost. • Usually constructed of plywood sheets with a stick built frame. • Shown at right is an oak board bunker. • Bunkers are usually self supporting. • Can be either purchased from a lumberyard or constructed on your own. • Easy to alter in order to add holes for ventilation, augers, etc. • Should be covered and aerated like other outdoor piles.
  • 9. • Most have a self supporting design that does not need to be anchored. • Makes cleanup easier. • Have a very long life. • Not cost effective for a small amount of bushels. • Need to be set on a relatively level surface to prevent gaps between sections. Cement Bunkers
  • 10. Steel Bunkers • These also have a self supporting design. • Very long life. • Need to be set on relatively level surface to prevent gaps between sections. • Not cost effective for a small number of bushels. • Cost estimation included bunkers, and estimated tarp & aeration cost, no site preparation.
  • 11. Earthen Bunkers • Need to choose a soil type that will pack well. • Create side and back barriers using soil. • Base of the barrier should be four times the height of the barrier. Width at the top of the barrier should be half of the base. • Dig a trench on the barrier to insert the liner into and cover with soil. • The cover should at least go part way down the outside of the barrier, and can be anchored with dirt. • This will prevent water from running into the inside wall of the barrier.
  • 12. • The bunker floor should be leveled and earth removed in this process should be used to form the retaining ramps along one end and along the two sides of the bunker. • Soil types that permit compacting will enable ramp construction to heights of one to two meters. • Ramp cross section should be trapezoidal. • For a 2 meter high ramp the base should be about 8 meters wide and the top of the ramp 3-4 meters wide. • The closed end-ramp should be shaped to the same dimensions as the side ramps to form a radius equal to half the distance between the parallel side walls. • This semi-circular end-ramp eliminates the need to fill the corners with grain.
  • 13. Ultra hermetic bunker • Ultra Hermetic Bunker can be made very simply by spreading out low density PE sheets on the bottom of a U- shaped compound consisting of an earthen ramp. • A better solution is to cover the ground with asphalt or concrete and to replace the earthen ramp with a concrete or metal support wall. • The large pile of grain is made by a grain thrower or grain pump, to be finally covered by large PVC sheets which come partly assembled to the site. • The sheets will be welded together on top of the pile with a manual heat welder. Ends of PVC sheet and LDPE sheet are rolled together and buried in a surrounding trench to obtain ultra hermetic sealing.
  • 14. • The ramp is covered with plastic sheeting to prevent being flushed away by rain draining from the bunker “roof”. • When disassembling, PVC sheets will be cut neatly and stored on pallets for reuse in next season. • The application of this technology is subject to certain climates and low MC’s of grain due to risk of condensation.
  • 15. DESIGN CONSIDERATION OF BUNKERS • Site Selection • The site should have a low water table; • The site should slope between 1% and 5%; • The soil should be well-drained sandy loam, but with sufficient clay to enable soil to cover bunkers; • The site should be on sufficiently high ground to prevent water accumulating on it; • The site should be clear of flash floods; • The site should not be on filled land; • The site should be well away from nearby building drains, etc.; • The site should be protected from strong winds.
  • 16. Considerations • Make sure that grain is at an appropriate moisture before using any of these storage methods (13-15%). • Grain should be clean to allow efficient & effective aeration, reduce spoilage, and deteriotion by rodents. • It is important to check grain for moisture, temperature, sanitation, etc. at least once every two weeks. • Consider whether short term expenses are justifiable compared to adding permanent, long term storage.
  • 17. Grain Handling Equipment • Site preparation may be influenced by the nature of the in- loading and out-loading equipment to be used. • If the bunker is to be loaded from the side by means of screw augers pneumatic conveyers or endless-belt conveyers, then side access must be sufficient for both the loading equipment, including loading hoppers, and dump trucks. • If the grain bulk is in-loaded from the bunker floor itself, then the access paths on each side of the bunker will be for maintenance purpose only, but trucking access will be required to allow vehicle entry into the bunker.
  • 18. Bunker Dimensions • The width of the bunker is dependent upon two variables determined by the user, namely height at the centre and height at the sides. • Two variables determined by the grain, namely the angle of repose for a given grain species, and the specific gravity of the grain itself. • Height At The Centre. This is limited by the height to which the in-loader can raise the grain. • Endless-belts that project the grain in an arc may reach 8 meters or more, while augers and conveyer belts may only reach a maximum of 6 meters.
  • 19. • Height At Sides. The higher the retaining side-walls the greater the bunker capacity per unit length. • Corrugated steel and concrete walls are usually 0.5 to 1 meter high, earth ramps can be raised to 2 meters. • Ramps require a broad base which adds considerably to the total width of the bunker site. • Experience has shown that bunker widths of the grain-bulk greater than 25 meters are less convenient due to the quantity of plastic liner that must be drawn over the grain during the covering and uncovering process.
  • 20. • Once the grain height at centre and sides has been decided upon, the following simple equations may be used for roughly calculating the length and width of a bunker:
  • 21. • Decisions on bunker capacity will also determine the amount of plastic liner to be used. • The larger the bunker, the smaller the surface area per unit volume of grain, and the smaller the capital investment per tonne of grain stored. • Calculation should be weighed against the convenience of building a number of smaller bunkers with the inherent convenience of handling and managing the smaller grain bulks.
  • 22. Drainage • Proper drainage of run-off water from the overliner is essential. • For this reason surrounding ground should be lower than the bunker floor and sloping away from the bunker. • Where earth ramps are constructed, earth from outside the bunker is used to form the ramps and by so doing the level outside the ramps is lowered. • The access and maintenance paths around the bunker can then be graded to ensure run-off. • The bunker floor should be graded from the closed end to the open end with a slope of at least 3%.
  • 23. The Bunker Underliner • Waterproof plastic sheeting should be laid across the floor and over the retaining walls to prevent moisture migration and gas exchange between the grain bulk and the ground. • It is advised use of 200 to 250 micron polyethylene sheeting laid progressively as loading advances, with an overlap of at least 15 cm "tile fashion”. • Each additional sheet should be laid as described above and sealed with tape.
  • 24. • An allowance of at least 2 meters of sheeting beyond the retaining walls should be given to enable the underliner to be sealed with the overliner. • Care should be taken to avoid damage to the underliner during loading, and walking or driving over the liner should be minimized to prevent tears. • The underliner should be discarded and replaced after each storage period.
  • 27. Ventilation And Aeration System • Eliminates offensive odors at the source • Environmentally controlled structure • Air usually not recirculated • Filtered ventilation systems supply clean well oxygenated • Air Reduces odor at the source • Depends on the design of bunkers
  • 30. Temperature Vs Time Of Storage
  • 31. RH vs time of storage
  • 32.
  • 33. CONCLUSIONS • Bunker storage is still only recommended where the harvest period coincides with the dry season of the year, since loading the grain may take many days during which time the grain is exposed to the elements. • The bunker over-liner does not provide protection from pilfering. Also if animals are free roaming in the vicinity, fencing should be provided to protect the bunker. • The plastic may be damaged by mechanical punctures and by contact with certain chemicals. • Technique of passing air between the grain surface and the PVC liner reduced temperature to a steady-state value in approximately three days while a relative humidity stratification in the grain mass was not achieved until after seven days.
  • 34. REFERENCES • ASAE Standards. 1987. D245.4:301-305. St. Joseph, MI:ASAE. • Freer, M. W. et al. 1988. Modeling temperature and moisture content changes in bunker-stored rice. ASAE Paper No. 88-6050. St. Joseph, MI: ASAE. • Gough, M. C. 1985. Physical changes in large-scale hermeticgrain storage. Journal of Agricultural Engineering Research 31:55-65. • Navarro, S., Donahaye, E. Kashanchi, Y., Pisarev, V. and Bulbul, O. (1984) Airtight storage of wheat in a PVC covered bunker. • Yates, C. J. and R. Sticka. 1984. Development and future trends in bunker storage. In Developments in Agricultural Engineering 5: B. E. Ripp et al, eds. New York: Elsevier Scientific Publishing Co.