Flat Bottom Silos
All of our Flat bottomed silos are designed, detailed, programmed and manufactured by Bentall Rowlands. The design of Bentall Rowlands Flat bottom silos are based upon the loads and pressures derived from the German DIN 1055 1987 standard. Structural calculation based upon BS 5950 part 5 and wind loading of 50m/sec (180m/h) for a probability period of 25 years. Standard ranges from 3.0m diameter 15 tonnes storage to 27.0m diameter 13,725 tonnes, all silos are designed for high cyclic loading, i.e. high usage of product in and out and at high tonnage rates. Silo roof panels, wall sheets and stiffening struts (up to 3mm thick) are sheared and formed from pre-galvanised steel sheet, with a minimum of G600 galvanising.
Stiffening struts (thicker than 3mm) are sheared and formed from black steel and finished hot dip galvanised after manufacture.
Bentall Rowlands silo ranges are designed, detailed, programmed and manufactured all at one site, because of this one site operation Bentalls can and often do manufacture non-standard silos, so if your needs are different from those in the standard range please do not hesitate to ask.
Key features of our storage silos:
- Strong true conical roof for maximum load bearing capacity.
- Silo cylinder with M10 bolts to maintain strength without regular re-tensioning
- Silo stiffeners with strong fish plated joints for long term stability
- Silo sidewall sheets utilize a shallow corrugation to minimise ‘hang up’ of material on walls and provide a cleaner safer silo.
A Bentall Rowlands silo can provide short and long term storage of grain, oil seeds and other granulated free flowing materials, including wood pellets, with mechanised loading/unloading options and full range of grain management systems to provide safe storage. Maximum term of storage depends on the parameters of the product: moisture content, impurities and temperature.
Choose a Bentall Rowlands silo for:
- Safe storage for your product(s) in all climates
- Our customers continue to experience low maintenance even after 25 years of use
- Prompt delivery and easy installation
- Usable capacity: up to 17,484 m³
- Diameter: from 3.0 m to 32.0 m
- Cylinder height: up to 28.44 m
- Snow load: 0.75 kN/m²
- Wind load: 50 metres per sec
All silo parts are made of high quality pre-galvanized and hot-dip galvanized steel. High specification galvanizing provides outstanding corrosion resistance.Silo Wall
Assembled from individual corrugated steel sheets with vertical stiffeners. The effective height of each ring of sheets is 1.185m. On a like-for-like basis this reduces the total number of sidewall sheets to give the required capacity thus reducing the erection time. Sheet thickness varies according to the load experienced in different parts of the silo Bentall Rowlands design the wall make up using sheets from 1mm thick, while the bottom ring can be up to 5.0 mm thick, which is achieved by doubling 2.5 mm individual sheets. All Bentall Rowlands silo sheets have metric corrugation for improved product flow inside the silo.
The Bentall Rowlands silo sidewall sheets are fastened together utilising a double row bolt pattern on vertical seams which reduces the total amount of bolts and therefore speeds up assembly.
Each silo cylinder generally has two rows of vertical external stiffeners per wall sheet. Taller silo walls have three rows of stiffeners per wall sheet. The Bentall Rowlands stiffeners are joined by using a horizontal plate to transfer the axial loading stiffener to stiffener guaranteeing even load distribution. This design does not rely on edge to edge contact or bolt shear to transfer loads. The Bentall Rowlands stiffener splice is designed to allow the stiffener to carry a greater vertical load than other designs.
Therefore in most cases no catwalk to ground supports are needed for the structure above silos which can offer significant savings compared to our competitors.Silo Roof
Roofs are generally produced with a 30° slope to compliment the angle of the products. This will optimise the packing density of the silo. Bentall Rowlands has self-supporting roofs on standard silos up to 9m in diameter (category 1). For category 2 silos we offer galvanised rafter supported roofs from 6m to 32m diameter silos and upon request can include pressure relief panels.
Silo roofs can be fitted with vents, temperature cable brackets, inspection hatches and high-level indicators. The roofs fully protect the stored product from the weather and vermin.Silo Doors
Weatherproof access doors are supplied with all outdoor silos and can be fitted in practically any silo ring to suit the plant design and are available with ladders and platforms affording safe and easy access. Bentall Rowlands can also offer a scaffold access door as an option to allow a tower scaffold to be taken into the silo for annual cleaning for assured crop applications.Fixings
Bentall Rowlands’ silos are assembled with spun galvanised grade 8.8 hardware. This type of coating provides high corrosion resistance. The sidewall sheets are fastened together utilising a double row bolt pattern on vertical seams, this reduces the total amount of bolts required which in turn speeds up assembly. Neoprene backed washers protect the zinc coating of the sheets to provide a watertight joint and protect the contents.Optional Equipment
The Low-volume ventilation systems prevent moisture condensation and formation of fungi inside the silo and allows the product to gradually cool down to its optimal temperature to stop any insect and mite activity. The ventilation system design for each silo model is based on the silo diameter, height and back pressure for various products being stored in the silo.
The ventilation system consists of:
- Centrifugal fans with inlet adaptors
- Roof vents
- Roof fans (optional)
- Aeration systems are designed to accommodate a range of air flows in a variety of crops.
- Ventilation channel layout adaptable for different discharge systems (screw conveyor / chain conveyor in silo base / chain conveyor in a tunnel)
- Perforated covers allow storage and ventilation of small grains.
Automatic digital temperature monitoring system consists of temperature cables suspended from the silo roof, junction boxes and computer software.
The main features of the temperature monitoring systems supplied by Bentall Rowlands are:
- Accurate digital sensors that do not require periodic re-calibration
- Polymer cable coating for low friction between the product and the cable reduces the load on the silo roof
- Cable breaking strength up to 10 tonnes
- Sensor interval 2m instead of usual 3m, for more accurate measurements.
- The information from the temperature cables is sent to the computer in the operator’s room. The system is supplied with user friendly software with extensive statistical functions, which can also be remote controlled via the internet.
- The information from the temperature cables can also be read on an optional handheld monitor.
Ladders and Platforms
Bolted construction with safety hoops and intermediate rest platforms according to relevant international standards. Available with non-slip treads as an option where required.
Eaves platform with drop ladder from catwalk, for access to eaves hatch. Available with non-slip ladder treads and mesh as an option where required.
Modular catwalks are available in widths from 1,200 mm to 2,000 mm wide in 200mm increments to suit a range of conveyor systems and access to the silo. The catwalks conform to most international standards. The mesh has been strategically placed to avoid normal trip hazards and improve personal safety.
Used to locally widen the catwalk to improve access for maintenance, drive sections, conveyor outlet slides and feed conveyors.