The Pneumatic Knocker should only be operated when the silo outlet is open and equipment as outlined below is in use. Otherwise, there is risk of the product inside the silo being further compressed.
The Pneumatic Knocker is mounted according to our Installation Guideline.
The Welding Plate (AP) is welded directly onto the silo cone.
The rounding of the silo plate is balanced by flattening or by means of large welding seams.
The Welding Plate in T-Form (Type APT) is used for smaller silo diameters. Insulated or rubberised walls or aluminium silos require special mounting plates.
The Pneumatic Knocker is to be mounted so that the deaeration borings are facing downwards. Dust humidity and aggressive vapours must not enter through the deaeration borings.
Air Pressure and Operating Intervals
The compressed air is set to 4-4.5 bar, which corresponds to 0.5 bar above the release pressure of the knocker (depending on knocker type approximately 2.5 to 3.5 bar).
The length of the operating time should be so adjusted to make sure that the impact will be released (approximately 3 to 5 seconds).
The break time is selected according to material flow. It must not be too short, so that the Pneumatic Knocker has time for deaeration (deaeration time min. 4 sec) and should as far as possible be long enough to reduce the wear and tear and compressed air consumption. Shorter interval times can be reached with a larger valve or with a Quick-Action Exhaust Valve (SE).
During operation, all screws and all nuts must be checked as to their tightness and, if necessary, be tightened by means of a torque wrench.
As to the Maintenance Unit, the condensate must be discharged from the filter, lubrication oil with approx. 46 cSt is to be refilled, the adjusted pressure and the oiler function is to be checked again.
Adjusting the Electrical Control Unit
For product conveying out of a silo, cycle times of 5 to 20 seconds are recommended. Too frequent knocking should in any case be avoided, otherwise the product would be compressed. Continuous falling product should be knocked off in cycle times up to 30 minutes. If the layer of product becomes too thick, an avalanche-like break-off could block the outlet or overload the following machines. If several knockers are mounted on the periphery, it is preferable to activate them one after the other. The product flow and the air consumption is then constant. Residue in the container scales can be emptied with 2 to 4 impacts in a cycle time of 2 to 4 seconds. We are happy to supply necessary equipment for the electrical control of the knocker.
Regulations for Accident Prevention and Mounting
It is only allowed to install and use the Pneumatic Knocker as a knocking and evacuating device on silos, containers, cylinders and walls, after having paid special attention to the instructions and in accordance with the technical data given therein. Mounting, maintenance, pre-operational and operational as well as post-operational handling of the equipment and the accessories shall only be carried out by trained and qualified personal in compliance with the legal prescriptions and safety regulations. The knocker has to be installed, secured and controlled so that – in case of self loosened screws, cracked welded joints or other specific defects – there will be no danger for persons, animals, products or objects to be damaged or polluted.
The Pneumatic Knocker shall be activated only after having been tightly screwed on, otherwise its own bottom plate may be destroyed.