Vacuum Excavation, or Vac-Ex is generally used as a term to describe the safe exposure of live utilities beneath the ground that could be damaged by more traditional means such as mini diggers or shovels.
The process has been carried out for decades worldwide but with limited use due to the harshness of the process on machinery.
It has only been in the last 20 years that bespoke machinery has been tailor-made to carry out such a process. ‘Vacuum Excavation’ is also abbreviated and known within the industry and around the world as Vac-Ex, Suc-Ex, Vacuum-Ex, Ex-Vac, Hydro-Vac and Aqua Vac (both utilising HP water jetting), but in essence they all describe the same principles of safe excavation.
As well as being non-destructive the Vac-Ex process has a very unique property in that it can excavate very narrow and deep holes or trenches – 2 meters deep by 90mm wide is easily achievable.
The soil removal process is very rapid and can save between 4 – 5 times the time taken over hand dig. Vac-Ex units can come in different sizes, shapes and weights to suit the job at hand. Units can vary from 250kg- 32,000kg each offering a different solution to the customers’ requirements.
Breaking the ground – Compressed air either supplied on-board the unit or externally is directed through an insulated AIR-EX lance and is used to initially loosen, agitate, or aerate the ground. This loosened debris is then safely removed by vacuum.
Removing the ground – The Vac-Ex unit generates a large amount of Air Flow & Vacuum through their Vacuum Generators. These can either be Turbines, or Lobe or Venturi pumps. Air and debris enters the pipe inlet and travels through the Vacuum pipe into the Debris Chamber / Container. The Pressure drop inside the Container allows any air-borne particles to fall from the air stream. This partially clean air travels through a series of baffles which further separate debris and dust. The ‘clean’ air is then fine filtered to 5 microns before being expelled through the Vacuum Pump to the atmosphere.
Difficult ground – If the ground is found to be stubborn and AIR-EX use doesn’t seem effective high pressure water is a good alternative agitator to safely work around underground plant and equipment. The resulting materials can then be removed using the same process above. Of course the use of traditional shovels can be utilised alongside the Vacuum however we recommend all precautions are taken to prevent potential damage to underground services if present.
Transportation & Disposal – The Vac-Ex systems are sealed units therefore enabling the material to be transported without the risk of spillages or cross contamination. Depending on the machine of choice the resultant material can then be tipped to ground, bulk bag, wheelbarrow, skip and stockpile or into a controlled environment.
