It has been established that under vibration the shear strength of the product in a storage vessel decreases. The action of the Bin Activator is to break down the shear strength and thus induce flow.
When the Activator is switched off the material shear strength is restored and product once again ceases to flow.
By careful design, the Bin Activator eliminates ratholing, degradation and segregation of products within the silo, ensuring an even flow of material on a mass-flow basis (the first-in, first out principle).
Bin Activators are ideally suited to a cylindrical vessel, but can be successfully applied to square or rectangular bins. Their low profile allows for a substantial reduction in the silo height and its associated building costs.
A Bin Activator consists of a spun steel dish onto which a discharge cone has been fitted. Across the dish are a number of welded cross-members that support the internal baffle cone.
A vibrator motor – two on some sizes – is bolted on the outside of the dish. The degree of vibration is adjustable via out-of balance weights situated at each end of the motor.
The whole assembly is suspended beneath the outlet of the silo on a number of hanger rods, located in rubber isolation mounts. These rods ensure that vibration is not transmitted up the silo walls.
The number and style of rods depends upon the size and duty of the Bin Activator. These rods are attached to the conical section of the silo via a support ring that is welded or in some cases bolted to the cone. This ring is an integral part of the supply of the Activator.
A rubber sleeve secured by a clamping strap, seals the gap between the support ring and the Bin Activator assembly.
The diameter of the internal baffle cone is smaller than that of the Activator. The resultant annular gap between the two is pre-set to give the flow of material required.
The size of the Bin Activator is determined by many parameters including the size of the silo, the material characteristics and the discharge throughput required.
This can vary between 1/3 of the diameter of the silo for free flowing materials, to the same diameter for fibrous flaky materials. Other parameters are also considered in order to optimise the specification.
The outlet beneath the Activator must only be connected to any subsequent equipment by means of a flexible sleeve, in order to isolate any vibration from the downstream equipment.
Operation of Bin Activators:
With difficult-to-handle materials most flow problems occur after the material has flowed down the silo.
Powerful horizontal thrusts from the external vibrator motor(s) break the vertical bridge of material between the baffle cone and the dish, to feed the material into the discharge cone.
Horizontal vibrations are also converted by the baffle cone into vertical vibrations that travel up through the material to break any bridging that is likely to take place.
The Bin Activator induces a mass-flow condition within the whole silo. This balanced condition allows the material to move towards the annulus from both the periphery and the core of the silo at the same rate, thereby remixing any segregation that has occurred during the filling operation.
Ratholing within the silo cannot occur as the material in the core of the silo is supported on the baffle cone.
Light aeratable materials that would normally flush through the silo can be successfully handled, as the vibrations from the baffle cone release the entrained air, promoting normal flow.
Installation of Bin Activators:
The Bin Activator is a pre-assembled self-contained unit, which can easily be fitted to new or existing silos. The support ring supplied with each Activator is welded, or bolted, to the silo outlet.
The Activator is then suspended from the ring by the suspension rods and the flexible sleeve is fitted between the ring and the Bin Activator ensuring dust-tight operation.
The only maintenance required is periodic lubrication to the externally mounted vibrator motor.
Features of Bin Activators:
- Dog bone suspension rods
- Adjustable internal cone
- Fully welded construction
Bin Activators - Materials Of Construction:
- Carbon steel
- 304 Stainless steel
- 316 Stainless steel