The Tools of the Trade: A multi-faceted approach to silo cleaning
Every silo cleaning project is unique and can vary in scope depending on a number of factors. These factors include:
- Silo size. Methods used to clean silos with large diameters with multiple discharge points will differ from methods used to clean relatively small silos with a single discharge.
- Silo shape. The flow characteristics of your silo will largely depend on your bottom configuration and any internal structures present in the silo. Cleanout of a flat bottom silo will be much different than cleaning a silo with a steep cone angle.
- Material. The methods used to clean hydrated cement will be drastically different than those used to clean grain or pet food.
- Discharge. One of the most important factors in cleanout projects is how loosened material will be evacuated from the silo. Methods and equipment will differ between air slides, conveyor belts, truck loadouts, and batching or free-flow setups.
Mole•Master has cleaned silos all over the world for more than three decades. Our success is built on understanding what tools work – and don’t work – for each type of silo cleanout project.
It’s helpful for silo owners to understand the cleaning process and tools we use so that questions or points of concern can be addressed early on in the project planning process.
Interior silo cleaning most often refers to removing non-flowing or contaminated material from a silo, but it can also refer to removing rust, construction debris, or oil residue from the manufacturing process. Silos with excessive material build-up on the interior walls can even be subject to structural deterioration or failure.
Interior silo cleaning may also be required when changing product or material type to guard against contamination of the finished product.
Failure to properly clean the inside of a silo can lead to reduced storage capacity, silo damage, spoiled products, low product quality, and ongoing production issues.
OSHA-Compliant Confined Space Entry
The most basic type of cleaning requires trained professionals to lower themselves into the silo to remove blockages, dust, or contaminants manually. The cleaning crew will bring confined space access equipment, including harnesses, mechanical retrieval systems, and suspension gear. Cleaning in confined spaces requires much effort and can be dangerous if not performed correctly, but it can be necessary at times. Mole•Master attempts to do as much cleaning as possibly without entry, having developed proprietary equipment that makes this possible.
Whip Machines – Junior 360™
A pneumatic or hydraulic whip machine is a type of silo cleaning tool that is well-suited for silos that contain build-up with an existing flow channel. The cleaning head contains two to four whips (or chains in some applications) and are powered by compressed air or hydraulics. The whips are controlled from outside the silo to maintain operator safety and mitigate the risk associated with confined space entry. The cleaning head is lowered from the roof of the silo and spins, contacting material and dislodging it from the silo walls.
Mole•Master has been manufacturing the Junior 360™ for 29 years and offers a pneumatic and hydraulic cleaning head, depending on your project needs. The Junior 360™ can clean silos of varying diameters, heights, and configurations. We also offer options to allow the Junior 360™ to be operated in explosion-prone environments. Learn more here.
CO2 Blasting – Safe-T-Shot™
CO2 blasting tubes break up material with the release of a powerful stream of carbon dioxide. CO2 tubes are able to break through hydrated lime, coal, compacted grain, and other rock-hard materials. The CO2 is liquefied and sealed inside of a heavy-walled, hardened steel tube. A fully sealed generator is activated through a minute amount of electrical current, which in turn heats up the liquid CO2 and turns it into a gas. The gas quickly expands and exits the tube out of what is known as a “firing head” at pressures that exceed 25,000 psi.
Mole•Master uses a trademarked product called the Safe-T-Shot™.
The Safe-T-Shot™ system is not an explosive and thus is safe for use in dusty, combustible environments. Additionally, it will not damage or contaminate your silo lining.
Drills/Portable Auger Systems – Arch•Master™
The most effective method for cleaning a silo that has “arched” or “bridged” material build-up is a drill or auger system. Arching takes place when material has built-up on the walls and/or cone of the silo and entirely blocked the discharge with no flow channel. In these types of silo cleanout projects, a professional will need to drill a hole through the material in order to successfully use other tools such as a whip machine.
Mole•Master recommends the Arch•Master™ for drilling through blockages. This tool is a miniaturized rock drill designed to create flow channels (up to 152 feet or 45 meters deep) in arched or bridged material of any type.
The Arch•Master™ features a high-torque, variable speed, hydraulic power head coupled with specialty, heavy-duty auger bits to drill holes of up to 10 inches in diameter.
Vacuum Trucks and Industrial Vacuum Systems
Using the existing discharge system for your cleanout project can sometimes be undesirable because the loosened material does not meet quality specifications or will not flow properly through the system. In other instances, the cleanout project is hindered from a time and financial perspective as the existing discharge rate of the silo is not fast enough to keep up with the cleaning process. A high-volume vacuum truck can greatly enhance these types of cleaning projects and is yet another tool that Mole•Master keeps in our arsenal.
We use the UltraVac HVV-4915 and the T-475 and electric HiVac 250 for most of our industrial vacuum applications. We also have a DK Vacuum Transfer Unit for projects that require grain or plastic pellets to be removed.
Finally, not all silo cleaning projects are best solved with dry methods. There are projects that are best completed by using high-pressure water to remove stubborn residue or build-up. The size of these hydroblasting tools range from handheld nozzles to large, remote-controlled machines. The type of hydroblasting tool will depend on the material being cleaned, which will affect the pressure needed to remove it from the interior wall.
Learn more about Mole•Master’s hydroblasting services.
In-House or Contract
Some projects can be performed by your team using equipment from our rental fleet or purchased from our manufacturing department, however projects of the highest technical difficulty are best handled by a team of our professional cleaning technicians.
Learn more about our cleaning services on our Silo Cleaning Services page.
Contact Mole•Master Services to discuss your next silo cleanout project and determine the tool best suited for your situation.