Silo safety at a pinch
Silo over-pressurization has resulted in a number of potentially serious incidents. When pumping powder, particles or granular products into a silo, increasing air pressure can damage the vessel and it is not unknown for a filter housing weighing hundreds of kilos to be ejected from the tops of a silo; at least one serious injury has occurred because of this.
As well as the more obvious dangers, there is also a potentially huge risk to the environment should an explosion occur. At the very least, the overfilling of silos can result in waste and/or contamination of product, costing thousands of pounds.
Guidelines have been issued by the Health and Safety Executive to help companies affected by this potential hazard. Essentially, all companies with storage silos need to be aware of the problem and take steps to ensure their silos are filled safely.
To help tackle this problem, AKO UK and RGS have launched a special system for the rapid and safe filling of silos using a pinch valve and special solenoid valve to control the product flow.
The AKO pinch valve is permanently mounted in the silo input line. As the tanker discharges its load using its own integral pump, a paddle switch mounted in the top of the silo senses the increasing level of contents. When the movement of its rotating paddles is restricted by the contents, it ceases rotation and trips a microswitch, sending a signal to the solenoid on the pinch valve. The solenoid activates instantly and allows air pressure to close the sleeve in the pinch valve. Simultaneously, the pinch valve triggers an audible alarm advising the tanker driver to stop his pump.
Controlled filling systems using butterfly valves are occasionally used on silo safety systems, however the flow through the valve is restricted by the butterfly disk, slowing down the filling process. Moreover, the valve seat can become contaminated with trapped product, resulting in spillage, waste and cross-contamination. The butterfly disk also wears very quickly, thereby increasing maintenance downtime.
The use of a pinch valve eliminates all these problems. A full-bore 100mm diameter allows unrestricted product flow, reducing tanker discharge time by more than 10%. Pinch valves have been used for many years in abrasive applications. Due to the sleeve technology, clear bore and their simplicity, a pinch valve’s life can, in certain applications, be up to six times longer than a butterfly valve.
Simple maintenance of the AKO pinch valve means that re-sleeves can be completed in 5–15min, depending on the size the valve. With only the sleeve to replace, maintenance costs a fraction of the cost of maintaining a butterfly valve.
AKO offer a complete range of valves for silo safety systems and silo flow aids. For further information contact the AKO sales team on tel: (01327) 312747; fax: (01327) 312565.
As well as the more obvious dangers, there is also a potentially huge risk to the environment should an explosion occur. At the very least, the overfilling of silos can result in waste and/or contamination of product, costing thousands of pounds.
Guidelines have been issued by the Health and Safety Executive to help companies affected by this potential hazard. Essentially, all companies with storage silos need to be aware of the problem and take steps to ensure their silos are filled safely.
To help tackle this problem, AKO UK and RGS have launched a special system for the rapid and safe filling of silos using a pinch valve and special solenoid valve to control the product flow.
The AKO pinch valve is permanently mounted in the silo input line. As the tanker discharges its load using its own integral pump, a paddle switch mounted in the top of the silo senses the increasing level of contents. When the movement of its rotating paddles is restricted by the contents, it ceases rotation and trips a microswitch, sending a signal to the solenoid on the pinch valve. The solenoid activates instantly and allows air pressure to close the sleeve in the pinch valve. Simultaneously, the pinch valve triggers an audible alarm advising the tanker driver to stop his pump.
Controlled filling systems using butterfly valves are occasionally used on silo safety systems, however the flow through the valve is restricted by the butterfly disk, slowing down the filling process. Moreover, the valve seat can become contaminated with trapped product, resulting in spillage, waste and cross-contamination. The butterfly disk also wears very quickly, thereby increasing maintenance downtime.
The use of a pinch valve eliminates all these problems. A full-bore 100mm diameter allows unrestricted product flow, reducing tanker discharge time by more than 10%. Pinch valves have been used for many years in abrasive applications. Due to the sleeve technology, clear bore and their simplicity, a pinch valve’s life can, in certain applications, be up to six times longer than a butterfly valve.
Simple maintenance of the AKO pinch valve means that re-sleeves can be completed in 5–15min, depending on the size the valve. With only the sleeve to replace, maintenance costs a fraction of the cost of maintaining a butterfly valve.
AKO offer a complete range of valves for silo safety systems and silo flow aids. For further information contact the AKO sales team on tel: (01327) 312747; fax: (01327) 312565.
