SEMW, Diesel Impact Hammers are single acting free fall hammer utilizing the principle of impact atomization, as a self–energetic one-cylinder diesel engine. The hammer will be started through a Tripping Device to lift the piston and set it free falling and below process.
- Injection of the diesel oil and compression
The falling piston actuates the pump lever whereby a certain amount of diesel oil is injected onto the surface of the impact block. As soon as the falling piston passes the exhaust ports, compression of the air trapped in the cylinder commences. The increasing compression presses the impact block and pile helmet firmly onto pile head.
- Impact and Explosion
When the piston end hits the impact block, the diesel oil in the combustion chamber is atomized and the pile is driven downward into the ground. The atomized fuel ignites in the highly compressed air and the resulting explosion energy drives the pile further into the ground and simultaneously throws the piston upwards.
The ascending piston opens the exhaust ports releasing the exhaust gases, and the pressure in the cylinder returns to normal.
As the piston continues to ascend, fresh air is sucked in through the exhaust ports thoroughly scavenging the cylinder and thereby releasing the pump lever. The pump lever returns to its original sucking again diesel oil into the fuel pump.
Simple designed and high complex SEMW Diesel Hammers do not have any cams or bearings so they have little wear and almost maintenance free. They are high reliable and can be used on different pile like H-Beam, sheet piles, concrete piles, casing, etc, for both on-shore and off-shore piling job sites.