Get a free eBook from ABC Hansen on How to plan a silo project in pdf
ABC Hansen Africa logo. A Milling, Silos, Feedmills, Soy processing, Oil Expelling production company. Engineering Agriculture in Africa

SILO PROJECTS

ON FARM AND COMMERCIAL STORAGE OF GRAIN

This document will cover the following topics:
  1. SILO STORAGE CONSIDERATIONS
    1. Galvanized corrugated steel silos can be classed as:
    2. Other considerations when selecting a silo are:
    3. Capacities of silos
    4. Silo Accessories
    5. How many bins should be used to store a given capacity of grain?
  2. What does a silo complex normally consist of other than silos?
    1. Aeration
      • Aeration of grain
      • Temperature sensing
      • Aeration types
      • Aeration parameters
    2. Drying
      • Sould you be drying the grain?
      • Drying parameters
      • Types of drying systems
      • Energy sources and burners
    3. Pre-Cleaning
      • Sould grain be cleaned before storage
      • What Pre-cleaner should be selected
    4. Intake Systems
      • Screw conveyors
      • Bucket elevator
      • Air transport
      • Chain conveyors
      • Belt conveyors
      • Grain pump
    5. Unload Systems
      • Sweep Augers
    6. Foundation Options
      • Flat bottom silos
      • Conical below ground level
      • Conical above ground foundation
    7. Civil Works
  3. Silo selection
  4. How to compare prices
  5. Ordering Silos

Considerations when planning a silo complex

What is your main purpose in storing grain?
This would dictate your requirements and determine the type of silo you should consider to purchase.

1. SILO STORAGE CONSIDERATIONS

  • Short term storage and flow through silos - may be turned frequently but stand empty most of the year.
  • Flow through and long term storage for at least part of the crop.
  • Long term storage - more than 4 months.
  • Processing - turning the bin often as for feed mills and fine mills.
  • Processing - turning the bin two or three times annually.

1.1 Galvanized corrugated steel silos can be classed as:

  • Farm storage silos - Usually not turned more than 2-3 times annually, not very high (max +-14 rings) and built on flat foundations. Usually not stiffened but with thicker sidewall sheets.
  • Drying silos - As with farm storage silos but able to be turned more frequently and with thicker wall sheets especially at the top rings to allow for stirring equipment to be installed.
  • Heavy duty silos - As farm silos un-stiffened and generally not higher than 14 rings but able to be turned yet more frequently and can also be erected over conical foundations and as such, still heavier sidewall sheeting.
    Also to be used in areas with adverse seismic conditions.
  • Commercial silos - stiffened silos (inside or outside stiffeners) usually higher than 14 rings and up to 32 rings normally, can be turned many times (15+ times annually), used in adverse seismic conditions.
  • Agcom Silos Sometimes called Farmcon etc - Stiffened silos but with lighter stiffeners and lighter sidewall sheets, with more fastener rows, with wider sidewall panels, can be high silos and turned less frequently than commercial and more than drying silos.

1.2 Other considerations when selecting a silo are:

  • The height vs the diameter of a silo - High silos require thicker sidewalls, wide diameter silos require wider roofs and bigger foundations. Find the optimal configuration.
  • The pitch of the corrugation - the sharper the corrugation the stronger the profile. Silos should be designed to allow for these strengths vs weaknesses.
  • The mass of the silo - how much steel went into the manufacture of the silo.
  • The tensile strength of the steel sheets - the higher the tensile strength the easier the sheet would revert back to its original form when deformed.
  • The amount of galvanizing applied to the silo and the evenness of the galvanizing - its only as durable as the thinnest part. "Tropicalized" silos may have heavier galvanizing and manufactures may differ notably on this.
  • If side-drawing is required, the silo must have a special stronger design. If side loading is required, the design must likewise be stronger.
  • If heavy walkways and heavy conveying equipment are used, the silo roof bearing capacity must be sufficient.
  • Seismic conditions may require heavier silos and foundations.

1.3 Capacities of silos

Apart form the above considerations, silos are sold by capacity. The best way to determine capacity and to ensure different manufactures are matched, insist on knowing the cubic meter capacity based on a flat foundation.

Factors used to determine a tonnage includes:

  • The hectoliter mass of the grain - maize may have a 72kg/100liter mass while sunflower only 46kg and wheat 80 kg. Its therefore vital to know what basis the tonnages were arrived at when quoted.
  • Compaction in the case of maize may be 2% which is normally added to the mathematical tonnage capacity reached.
  • Be sure you compare the right sizes.

1.4 Silo Accessories

When evaluating silos, many accessories may be included or excluded such as:
Inside and outside ladders - regular straight ladders or spiral staircases on the outside, with or without: rest platforms, eave platform, OSHA back-guards, roof stairs with or without handrails.
Is a bin step included to enable you to easier get through the silo door.
What is the height of the door? If only one ring high, you have to squeeze in through a 700mm high door, with double ring height, it's a comfortable 1,6 meter high door.
Sealing - how is the eave sealed from the sidewall - is it airtight to allow for fumigation and does it avoid birds nesting there and wind driven water penetrating.
Is a sealing strip included between the bottom the silo and foundation floor?
Are the doors properly sealed? Can the gooseneck vents be sealed if fumigation is added later?
These factors, if not included in all offers, may involve substantial differences in cost
and may penalize one supplier unwittingly.

1.5 How many bins should be used to store a given capacity of grain?

  • How many grain types / grades would you handle? If only one type & grade - one bin may be sufficient.One large bin is always cheaper than two smaller bins for the same capacity but is it functional ? - a large bin 10% full can only be utilized for one grade / grain
  • If more than one - two or more bins should be selected.
  • If a flow-through bin is to be used only, one bin is usually sufficient.
  • If a dry-aeration system is to be considered, three bins is usually preferred (discussed later).
REMEMBER: More than one bin requires higher spending on conveyance as well as civil works. Be sure what your needs are.

2. What does a silo complex normally consist of other than silos?

  1. Aeration
  2. Drying
  3. Pre-Cleaning
  4. Intake systems
  5. Unload systems
  6. Foundation options
  7. Civil works

2.1 Aeration

Aeration of grain

The life of grain at various temperatures and moisture:
Storage of grain days at various temperatures and moisture.

What about temperature sensing?

-To show lower cost many silo companies exclude temperature sensing in their standard prices. Its very important and absolutely necessary if you you store for periods longer than 2 months. Heat must be detected early and acted upon through aeration. It is recommended that no silo be without thermo detection. Thermo sensing can be installed later but fitting harnesses for the cables from the roof is more difficult then.

-Thermo detection is the one most important aspect that, coupled with aeration and dry-aeration can preserve your grain over extended periods.

-Several options are available from low cost manual systems to advanced systems with weather stations and automatic starting of fans.

-Weather stations are important to avoid heating the grain during aeration or adding moisture during aeration when the inverse is required. Factors like ambient temperature during the entire day and night cycles, relative humidity, air pressure predicting imminent rain, cold and hot spells etc are all vital in deciding when to aerate and when not to aerate.

Temperature sensing

Simple, manual electronic

  • Inexpensive, number of thermocouples are specified.
  • Can be digital or analogue - prefer digital can be upgraded easier.
  • Hand held instrument and each silo tested manually for hot spots.
  • Can have downloadable software to PC but manually downloaded.
  • Only showing hot spots.
  • Can not remotely start aeration fans

-Advanced, electronic

  • Remote results - mobile / PC.
  • Can be wireless.
  • Shows bin capacity utilized based on thermocouples.
  • Includes a weather station optionally.
  • Remotely starts aeration fans when programmed for correct conditions.
  • Has good graphics.
  • Can alert you to problems via SMS/email.
  • Can be very expensive for small complexes.

Every bin has a cold and warm side. This results in moisture migrating through the bin with condensation and concentration of moisture in a section of the bin where the grain becomes hot and damaged and which may lead to smoldering eventually.
Heat damaged grain cracks and eventually disintegrates. In the case of wheat, the baking quality is entirely destroyed.
Aeration can also dry grain down somewhat (2-4%) provided ambient humidity is low or is burned off. Without a stirring or turning mechanism, very low heat should be applied so as to avoid heat damage to the bottom layers of grain.
Pests and insects can also easily and effectively be controlled with an aeration system.
Aeration is recommended for any grain being stored for more than 3 months.
Ensure than your system can be converted to incorporate aeration before you buy.

Aeration types

If a bin is aerated, the correct air volume and pressure should be selected for the type of grain.

The correct floor and blower will accomplish this.

Floor types include:

  • Full floor aeration - usually smaller diameter bins and drying bins.
  • Flush floor aeration - channels in various designs in the concrete floor of a silo such as double I; Y; E, square pad etc. A reputable supplier will recommend this.

Fan selection is determined by pressure and volume air and can either be:

  • Axial fans
  • High or Low speed centrifugal fans

Typical flush floor aeration designs 1

flush floor aeration design

48' diameter silo requiring 14,000 to 18,000 cubic feet per minute air (400 - 511 cubic meter per minute or up to 30,000 cubic feet per hour of air)

Other designs include double I; Y; centre pad;

Flush floor aeration designs 2

flush floor aeration design Y type

Y- type aeration for 6,000 cfm (or 170 cubic meter/minute or 10,200 cubic feet air per hour).

The air volume and required pressure must be accommodated in the design.

Complex aeration designs

complex aeration design drawing

Very complex designs such as this quad F and double I design for 2,556 cubic meter per minute air required in a 105' (32 meter) diameter silo.

Aeration design parameters

48' Diameter Aeration Systems    
  Maximum Entrance  
Airflow Ring Height Fan Trench Layout Flooring System
Range at cfm/bu Quantity Width Pattern Style Weight Part Number
UP TO 6,000 CFM UP TO 11R @ 1/10, 1 32 SQ 'Y' FLO 20 1084 05040481102
7R @ 1/7, 4R @ 1/5       AIR 18 1144 05040481107
  1 52 SQ 'Y' FLO 20 1323 05040481202
    AIR 18 1396 05040481207
UP TO 14R @ 1/10, 1 PAD FLO 20 1448 05010481202
9R @ 1/7, 6R @ 1/5       AIR 18 1538 05010481207
  2 32 2 "I" FLO 20 1199 05050481102
        AIR 18 1254 05050481107
UP TO 10,000 CFM   1 52 SQ 'Y' FLO 18 1926 05040482203
    AIR 16 2122 05040482208
  1 PAD FLO 18 1647 05010482203
        AIR 16 1792 05010482208
UP TO 24R @ 1/10, 1 72 SQ 'Y' FLO 18 2227 05040482303
16R @ 1/7, 11R @ 1/5   AIR 16 2437 05040482308
  1 PAD FLO 18 1888 05010482303
        AIR 16 2033 05010482308
  2 52 2 "I" FLO 18 1946 05050482203
        AIR 16 2102 05050482308
UP TO 14,000 CFM   1 72 SQ 'Y' FLO 16 3036 05040483303
    AIR 16 2884 05040483308
  1 PAD FLO 16 2364 05010483303
        AIR 16 2263 05010483308
UP TO 32R @ 1/10, 2 52 2 PAD FLO 16 3058 05020483203
23R @ 1/7, 16R @ 1/5   AIR 16 2925 05020483208
  2 "T" FLO 16 2797 05090483204
        AIR 16 2674 05090483208
  2 72 2 "I" FLO 16 3022 05050483304
             
UP TO 18,000 CFM   2 72 2 PAD FLO 18 3426 05020484303
    AIR 16 3688 05020484308
  2 "T" FLO 18 2835 05090484303
UP TO 32R @ 1/10,       AIR 16 3063 05090484308
30R @ 1/7, 21 @ 1/5 4 72 4 "I" FLO 18 4907 05070484303
        AIR 16 5181 05070484308
  2 52 2 'H' FLO 18 2841 05120484203
        AIR 16 3118 05120484208
UP TO 22,000 CFM   2 72 2 PAD FLO 16 3914 05020485304
    AIR 16 3716 05020485308
UP TO 32R @ 1/10, 2 'H' FLO 16 4418 05120485304
32R @ 1/7, 22R @ 1/5       AIR 16 4218 05120485308
  4 72 4 "I" FLO 16 5874 05070485304
        AIR 16 5676 05070485308
NOTES:              

1) Use "Aeration Fan Selection" program to determine NECO fan requirements for desired airflow.

2) Select corresponding Aeration System from table above:

a. Use 32" wide trench with these NECO fans: 3/4 - 3 hp axial, 3 - 7 1/2 hp hi-speed 60 Hz cent.

b. Use 52" wide trench with these NECO fans: 5 - 15 hp axial, 5 - 10 hp low-speed 60 Hz cent., 10 - 60 hp hi-speed 60 Hz cent., 3 hp low-speed 50 Hz cent., and 3 - 60 hp hi-speed 50 Hz cent.

c. Use 72" wide trench with these NECO fans: 15 - 40 hp low-speed 60 Hz cent., and 5 - 25 hp low-speed   50 Hz cent.

3) Aeration System from higher cfm ranges may also be selected.System package includes entrance collar, floor planks, flashing, and floor screws. Package does not include fan or transition.Floor supports and entrance collar stiffeners (if necessary) must also be added to order."Flo" style flooring is slotted. "Air" style flooring is perforated.

The optional flooring layouts, design criteria for airflow in volume air as well as pressure, channel widths, number of vents, type of flooring etc. for each silo diameter.

Aeration parameters

Aeration Fan Selection
       
full floor or flush floor (trench) system flush floor FAN PARAMETERS:  
diameter (ft) 48 airflow rate (cfm/Bu)  
number of rings (32" sheets)   grain depth (ft) 4.25
  1/10 total airflow (cfm) 619
grain corn, shelled Shedd's multiplier 1.5
level or peaked fill peaked duct factor (in)  
number of fans (use 1, 2, 4, or 6 with flush floor)   a 0.000654
stirring not stirred b 0.154432
post style selected 17ga post floor area (ft2) 1810
capacity (Bu) 6185 airflow per fan (cfm)  
minimum trench width (in inches) recommended for proper airflow   static pressure (in)  
  corresponding corresponding quantity of
  transition flush floor roof vents
  part number trench size (P/N 058010)
  to use required to use with this fan:
minimum recommended fans: with this fan: with this fan: (for max cfm's)
selected fan:      
NECO 3 hp high-speed centrifugal 50Hz fan      

Typical aeration parameters for a 48' 9 ring silo with 1cfm air/10 bushels with 2 fans, peaked shelled maize, unstirred grain

2.2 Drying

Should you be drying grain?

If in a mist belt, you may loose months before being able to harvest and drying may pay for itself rather quickly.

Some areas have pests like ants, mandating early wet harvest.

You can harvest at 26% moisture and obtain higher yield and hectoliter mass.

Drying parameters

drying parameters, grain storage, silo

-Drying Simulators giving output for drying criteria based on:

  • Type of grain
  • Ambient temperature
  • Ambient humidity
  • Drying heat
  • Initial moisture

drying parameters silos and grain storage

-Typical drying requirements for low temperature, low humidity application for the same product as before. +- 3,400BTU's/kW)

-Capacity more than 10% higher with higher ambient temperature

Types of drying systems

High temperature self-contained dryers

  • Manual batch dryers
  • Automatic batch dryers
  • Continuous flow dryers

In-Bin drying - Top dryers - Roof bin batch

In-bin drying - on-floor batch

In-bin drying - continuous flow

In-bin drying - batch with Stirring machines

Low temperature in-bin drying - solar & other energy options.

Dry-aeration

Energy sources and burners

  • Electricity - expensive and high infra-structural cost, clean.
  • Gas - depends on availability - high infra-structural costs , clean.
  • Diesel and light / heavy industrial oil/ bio-diesel- available, usually least expensive and little infra-structural cost, dirty, requires heat exchanger which increases outlay cost.
  • Coal - least expensive, dirty environment, requires heat exchanger.
  • Biomass- much work to be done on utilizing farm waste, briquettes, pellets etc. and probably the way to go forward. Wood commonly used in Brazil. Requires heat exchanger.
  • Other sources- mainly used in dry-aeration includes wind power, solar power where conditions are favorable. Low intensity heat usually provided and long drying times.

2.3 Pre-Cleaning

Should grain be cleaned before storage?

With high quality harvesters grain is often received well cleaned. If in doubt however, it is recommended that fines at least be removed prior to storage.

Why?

  • It concentrates in the centre of the silo, thereby risking downgrading of grain when sold.
  • It also hampers drying and aeration as it creates dense pockets.
  • It uses unnecessary storage space and drying capacity you have paid for.
  • It can contain harmful & poisonous seeds.

What Pre-cleaner should be selected?

-Cleaning is normally done at intake but may also be installed at unload.

-The cleaning capacity is determined by the intake capacity.

-Normally rotary cleaners can handle around 40 - 60 tons per hour. If intake capacity is larger two or more may be required. Rotary cleaners can sometimes separate both unders and overs but often only unders.

-Eccentric / vibratory high capacity cleaners can handle very high capacities and screens unders and overs out. Pre-cleaning capacity vs. final commercial cleaning can vary as much as 150tph pre-cleaning to only 50 tons final cleaning

-Aspiration can be used at higher capacities. This separates only the fines however and may be used in conjunction with grading separators.

-Zig Zag gravity cleaners can be installed on a downward leg, normally at loading of trucks or unload into a mill etc. This would also separate fines only.

2.4 What are the intake options?

  • Screw conveyors

  • Bucket elevator

  • Air transport

  • Chain conveyors

  • Belt conveyors

  • Grain pump

Screw conveyors

Used when bins are not too high or volume is not too big and speed is limited to 40 - 80 tons per hour:

Types

  • In a fixed installation - one intake, split, roof augers
  • As mobile auger - one auger for all bins for loading and unloading into trucks again. Often the cheapest option.
  • Augers can transfer between silos.
  • High RPM damages grain. Usually the least expensive option for smaller and few silos.

Auger capacities

auger capacities

Bucket elevator:

  • An old time favourite - can be fast, reliable, low power.
  • Requires a high structure to allow the correct gravitational angles or in combination with a chain conveyor to one or more silos, rather costly.
  • High wear and tear on down pipes.
  • High broken kernel losses due to high speed down flow if not checked.
  • Relatively expensive.
  • Requires additional foundation costs.

Air transport

  • Usually more expensive than augers and less than bucket elevators.
  • No infrastructure required.
  • Can be used to load & unload trailers & trucks in the field also - versatile.
  • One system can load and unload many silos.
  • High power consumption but can be tractor driven - then relatively cheap.
  • High wear & tear on pipe corners if not stainless steel.
belt conveyor drawing
  • High capacity 250 tons per hour.
  • Long distances.
  • Gentle action on product.
  • Reliable and relatively low maintenance.
  • Difficult flowing product.

Grain Pump

  • The preferred way to load and unload silos especially of 2 or more silos per complex.
  • The system is in the form of a tubular loop in which a chain and discs revolve to transport grain both on intake and unload legs:
  • Fast and easy, with minimal breakages, low maintenance, low wear, high capacity (from 40tph - 450 tph), flexible & over long distance, low power consumption, cost effective, minimal electric motors & switchgear, easily expandable, virtually no civil works, eliminates need for unload augers etc..
  • More expensive for use in one silo but well in line when used in systems with two or more silos.
  • Can be used a double loop for angled conveyance also.
  • Can be used for simultaneous intake and unload.

Grain loops

grain storage silo grain loop system A large silo complex using grain loops only.

2.5 Unload Systems

What are the most common unload options?

-Auger unload systems are most common. In various capacities from 100mm - 300mm or 5 tph - 150 tph.

-Beyond these capacities, chain conveyors are used. May also be used for lower capacities and preferred to down tubes where bucket elevators are used.

-Belt conveyors especially where sensitive products are handled, high capacity and long distance.

The Grain Pump combines all the advantages and none of the disadvantages.

hutchinson grain pump for silos and grain storage

Sweep Augers

A sweep auger is used to gather the last remaining grain in a flat bottom silo after it has stopped flowing, to the center of the bin for unloading. Several options are available:

  • Standard sweep - carried into the silo via the door (insist on 2 ring doors as access is just so much easier) when the grain level permits. A lighter duty sweep for bins not in excess of 36' diameter.
  • Commercial sweep - as the standard but heavier duty often used in larger bin of 42' - 54'
  • Power sweep - drive is outside and engaged from outside the bin. Sweep stays inside the bin even when full of grain. The price normally includes the unload auger and used in bins of all diameters.
  • Tractor sweep - as for the power sweep but for very heavy duty for 75' - 105' diameter bins.
  • Sometimes the door opening is large enough to accommodate a Bobcat to bring remaining grain to the center for unload - used in very large 90' and 105' diameter bins.

2.6 Silo foundation options

Flat bottom silos

Why the first choice?
  • Over the silo life of 30+ years, any below ground level conical floor will leak because of soil movement, water table rising, floods etc.
  • An above ground level foundation will stay dry and in good shape for many years.
  • Cheaper & easier to construct.
  • Full floor aeration can be properly installed. Poor aeration in conical silos.
  • Movement inside the silo is easy.
  • Sweep augers eliminate the need for collection in a conical bottom.
  • No sump pump and water trap is required.

Conical below ground

Why would you consider a conical below ground level floor?

  • Additional storage is gained but at high cost.
  • One transport auger less can be used for small installations.
  • No sweep auger is required.
  • For short term storage not requiring aeration

Conical above ground foundations

This is preferred by many silo operators due to:

  • Easier unload through gravity. No reliance on equipment that may be under grain.
  • Used especially in large concrete silo complexes.
  • Allows for reclamation tunnels still above ground level.
  • Aeration can be done properly.
  • Usually airtight silos.
  • Expensive option.

Civil Works

Soil stability dictates the silo foundation requirements and civil works. First step is a proper soil analysis. Soil stability at 96 Kpa and 190 Kpa would have a large impact on civils. The engineer should decide to what level and with what measures the soil conditions should be improved. This may be excavation and backfilling, concrete filling, bigger foundation footprint, more re-bar or a combination of the above.

Site selection

Make sure your site is:

  • As level as possible - earthworks are expensive
  • Not too near your home - dust and noise can be excessive.
  • Secure - many tons can be stolen from silos before you notice. Damage to grain and equipment may also result.
  • Surface water - ensure your silo can not be flooded and is elevated high enough with good drainage and above flood levels.
  • Soil stability
  • Is there enough space for expansion? Truck movement? Trailer movement?
  • Is the site accessible from main roads? Are roads reliable?
  • Electrical power can be expensive to move far.
foundation note ABC hansen Africa silos grain storage

Arrangement and layout. Consider the following:

  • Grain handling & cleaning equipment
  • Wet holding, drying, cooling, storage bins
  • Dryer - if not in-bin
  • Weighbridge & office.
  • Management building
  • Feed processing and storage
  • Electrical service, roads.
  • Turning circles of various trucks

Typical foundation design drawings

foundation design of a silofoundation design of a silo detailed

Obtain drawings for the specific silo foundation and be sure to understand this or get help.

Soil should be properly stabilized and compacted and dug to correct depth.

Sufficient re-bar should be used as specified.

Correct cement mix at 25MPA should be used. If lower grade cement is used, the mix should be adjusted. 19mm stone should be used.

The ring beam carries most pressure.

All cement casting should be done continuously.

Correct levels should be found.

The bin may be fixed to the foundation with chemical bolts or with the foundation rebar.

3. Silo selection

What quality silo am I offered? How is this evaluated? Easy, inspect and research:

  • Workmanship by appraising other similar installations,
  • Galvanizing is it consistent - (its only as good as the thinnest or poorest part),
  • Precision - if excessive drilling is needed to line up holes, galvanizing & silo strength is damaged,
  • Steel strength (mild steel vs. high tensile strength (65,000psi is the norm)
  • Quality of fasteners and seals,
  • Corrugation length (the longer the corrugation the less the profile, thus the strength and amount of steel used (compare a 4" vs. a 2.66" corrugation)

-Who do I deal with and who is the erector?

-Known suppliers erecting their own silos should be preferred in general. Subcontractors and indent agents often leave you with no security after an installation has been incorrectly completed. Avoid companies working out of a post office box and email only.

-What brand am I buying? While small brand silos may be suitable, the really world class large scale companies would give you more peace of mind. Avoid developing world manufacturers. The alarm bells should ring if the silo is too cheap. It's a project that should serve you for 30 years, buy on quality and peace of mind, not on cost.

-Select companies with its own workshop who can react to emergencies by manufacturing a part if required.

4. How do I compare prices?

Make sure you compare apples with apples.

  • Capacity: Make sure you work on cubic meters rather than "tons". Tons are not exact and can apply to various arbitrary densities. Some sellers include compaction of grain in their "tons" capacity. Others include the space in conical bottoms as "tons capacity" when quoting silos.
  • Quality: See previous sections.
  • Do not necessarily buy the least expensive bin. It's a 30 year investment. Buy the best quality for the purpose to be used.
  • What is included? Inside & outside ladders? Eave platform? Spiral staircase? Rest platforms? Special OSHA certified ladders & platforms? Roof ladders?All these items cost money but may improve convenience, safety etc.
  • Capability to side draw on a silo for instance offers lower unload costs for up to +-60% of the silo but the silo must be designed for that with stronger sidewalls. This means grain can be directly discharged from the sidewall into a truck until the grain will no longer flow.

5. Ordering silos

-Obtain at least 2-3 quotations from reputable suppliers

-Ask for and follow up on at least 1 genuine referral provided by the supplier.

-Plan well in advance. If you intend putting up your own storage, allocate at least 4-6 months for the project. Do not buy from a supplier simply because he has stock at the moment.

-Ensure you order the right model and quality silo as agreed to. Recheck the capacity in cubic meter and convert to tons at 0.75 for maize and 0.80 for wheat. "High Compaction rates" may be used by some dealers to inflate silo capacity.So are conical floors.

-Compare different silo weight from suppliers.

-Compare roof carrying capacity.

-Compare steel tensile and galvanizing.

-Be prepared to pay a +-30% deposit and to issue a bank guarantee for the remainder, payable on delivery. Obtain a proper contract and/or tax invoice. Most banks will finance silos in their Asset Finance Divisions.

-Ensure you have read and understand the fine print and exclusions. Often foundations are quoted but it excludes sand, cement, bricks and stone. What exactly are included then?

Do you pay for manual labourers? How many would be needed? Do you pay for accommodation and subsistence? For how many and how long? Is crane costs included? If not what crane and how long would rental be? Should you provide power and services such as toilets and showers on site and do you have that available? Who will offload the trucks? Do you get operations and installations manuals? Is there assistance with start-up? Is it needed / charged? Is your price delivered on site or ex factory USA / CIF Port / are any charges such as clearing excluded?

More information

-It has been attempted to touch briefly on the major aspects you should consider when starting your own grain storage complex.

-Obtain more information by ordering:

"THE GRAIN DRYING, HANDLING AND STORAGE HANDBOOK" at a price of R250 + VAT for South African buyers by contacting us at the detail below or by visiting www.abchansenafrica.co.za

The ABC Africa Group

-The ABC Africa group consists of associated companies manufacturing and/or supplying as authorized agents within the African market mainly, the following main types of agro equipment:

  • Grain Storage, Handling, Cleaning & Drying Equipment
  • Grain milling equipment and mill consumables, including roller fluting and stone dressing services.
  • Oil seed Expelling & Soya bean Processing
  • Feed mills
  • Weighbridges, livestock scales & tipscales


Copyright © 2019 ABC Hansen Africa. All Rights Reserved.