Supplier sign in
Home
STAY INFORMED
Subscribe to our monthly newsletter.
Your email address will never be disclosed to any third party.
Read our privacy notice.

       

Specialist article
04.02.2022  |  1895x
Share this item

Promoting the flow in silos and cleaning the silo walls

Flow in a silo can be promoted with a hammer. But the use of pneumatic knockers is a much better way. This gives maximum impact, without damage.

APPLICATION


The Pneumatic Knocker is used for bulk goods with flow problems, such as bridging, funnel flow and stagnant zones, when high speed shakers and vibrators with soft sine-shaped oscillations are no longer effective.

Better than a hammer

The effect of the knocker is comparable to the infamous "silo hammer", but without the damage a hammer can do. Dents by hammers wil complicate the material flow even more. And cracks and ruptures can also occur.
The effectiveness of the knocker is evaluated according to the following rule: If the product can be knocked off or made to flow with a hand hammer, the Pneumatic Knocker is also effective.

Mounting of the knocker

The knocker is normally controlled by an electrical control system with a solenoid valve. Within the area where the knocking takes place there should be enough space for the impact to expand in all directions.
Reinforcements of the silo walls and additional ribs should be avoided, as this increases the weight and the strength of the silo walls and thus reduces the effect of the knocker.

Impact energy and impulse

The Pneumatic Knocker produces an ideal elastic shock that is specified as the impact energy: E = m/2 * v^2 [kgm/s2 = Nm] and as impulse: J = m * v [kgm/s = Ns]. There is no impact force or out-of-balance such as vibrators generate.
Operation of pneumatic knocker at bridging and cleaning out of the silo
Operation of pneumatic knocker at bridging and cleaning out of the silo

CONSTRUCTION & FUNCTIONING

singold pneumatic knocker – Type K
singold pneumatic knocker – Type K
The air hammer achieves a very high impact energy through the stored and immediately released compressed air energy.

The left picture shows the construction of the knocker: The piston (1) designed as a permanent magnet, adheres in the end-position to the anchor plate (2) until the compressed air fed through the lid (3) overcomes the magnetic force.

The impact piston (1) loosens from the anchor plate (2), is very highly accelerated by the accumulated compressed air and hits onto the striker (4) with a speed of 6 to 7 m/sec., which transmits the impact to the silo wall.
After deaeration of the knocker, the impact piston (1) is pressed back into the starting position by means of the spring (5).

SIZES & SELECTION CHART

Selection Chart for Pneumatic Knockers for a 60° cone
Selection Chart for Pneumatic Knockers for a 60° cone
The singold Selection Chart provides a rough reference for selecting the adequate size and number of Pneumatic Knockers for round silos of 60° cone. In case of rectangular containers, a minimum of two knockers are mounted on the less steep sides.
Important parameters for the selection of the right knocker:

Mechanical aspects

  • Thickness of the container
  • Container material
  • Container diameter
  • Operating temperature
  • If present, insulation thickness for the selection of the mounting
  • Choice of version in aluminium, steel or stainless steel
  • Protection type for operating environment

For the electrical components:

  • Desired operating voltage
  • Number of knockers
  • Protection type for operating environment

MOUNTING & OPERATION


For the assembly and operation of the pneumatic knocker the components shown in the figure below are required:
Components needed for assembly and operation of the pneumatic knocker
Components needed for assembly and operation of the pneumatic knocker

  • Attaching the Pneumatic Knocker Welding plate AP. With small pipes, small containers or containers with insulation welded plate in T-shaped APT
  • Pneumatic 3/2 way solenoid valve in the desired control voltage.
  • Electrical control for solenoid valve to desired control voltage. An existing PLC control can also be used.
  • Pneumatic connectors and cables
  • Maintenance unit for pressure reduction to 3.5 bar operating pressure, drainage and lubrication of the knocker is recommended.

Company information

More items

The wide range of singold knocker variants singold has the ideal pneumatic knocker for every system: high temperatures, special hygiene requirements, very large silos, etc. Even Distance-Knockers when direct mounting is not possible.
The wide range of singold knocker variants
singold has the ideal pneumatic knocker for every system: high temperatures, special hygiene requirements, very large silos, etc. Even Distance-Knockers when direct mounting is not possible. Just as the application scenarios for pneumatic knockers are diverse, so too are the requirements. Whether high temperatures, special hygiene requirements or very large silos, singold gerätetechnik gmbh offers a wide range of pneumatic knockers so you’ll have no problem finding one perfectly suited to your specific needs. Application temperature is crucial The most important factor in selecting the optimum knocker is the application temperature. For temperatures up to 60 °C, a standard version with a plastic piston can be used. For applications above 60 °C, the piston is made of aluminium. Cover and anchor plate, tube and striker are made of aluminium, steel or stainless steel, depending on the individual application situation. The pneumatic knocker can even be used with wall temperatures of over 140 °C. A T-shaped welding plate to increase the distance to the hot wall, a heat-dissipating plate and a heat insulation plate are available as accessories in this
18.10.2021  |  1223x  |  Product description  | 
K160: The Most Powerful Pneumatic Knocker in the World singold gerätetechnik gmbh produces and sells the world’s most powerful pneumatic knocker.
K160: The Most Powerful Pneumatic Knocker in the World
singold gerätetechnik gmbh produces and sells the world’s most powerful pneumatic knocker. While competitor models can at best cover a wall thickness of up to 12 mm, the K160 can knock walls with a thickness of up to 25 mm. This makes it suitable for massive, heavy-duty containers. For example, it is used in the mining industry for discharge chutes, in the building materials industry for gravel bunker outlets, in the chemical industry for mixing plants, in the lime industry for silos with a capacity of over 200 tonnes and in the fertiliser industry. Supernatural Strength The powerful model has an impact energy of 423 newton metres. This corresponds to the energy generated when a weight of 42.3 kg is dropped from a height of 1 metre. This high impact energy cannot be achieved with human forces, even if a 20 kg sledgehammer were used. The reason? The acceleration and, consequently, the final velocity of the impact weight in the knocker is far higher than the final velocity that a human being can generate. When the piston, which is designed as a magnet, is
13.09.2021  |  1369x  |  Product description  | 

Related categories

PORTALS
BulkSolids-Portal Schuettgut-Portal Recycling-Portal
Related
Bulkgids.nl
SIGN UP FOR OUR NEWSLETTER
Newsletter archive
Service and contact
ContactDisclaimerPrivacyAdvertising
FOLLOW US
Linked