Vacuum excavators are essentially used to remove soil, mud and debris from within an area, most often in the underground. They are also used for soil stabilization, clearing away any topsoil or other environmental damage from roads and sewers, and also for clearing blocked drains on the roads. They can also be used for drilling holes for utility lines or oil pipelines.
Over the years, there have been several models of vacuum excavators, including those which are powered by wood, cement, steel, hydraulics, and plastics. There are two general types of excavator: the boom truck and the arm excavator. The boom truck is most often found in open work environments like the mining industry and the construction industry, while the arm excavator is more suitable for indoor purposes.
Vacuum excavators come in different sizes, such as those that can carry up to twenty-four passengers and the ones that can carry up to three hundred passengers. All models though, have one common component, which is the vacuum excavator's blower. This is a fan system that creates a vacuum through an impeller. The blower pushes air through the impeller, which causes it to vibrate, thus producing the suction that pulls dirt out from the ground. These systems work best with negative displacement, which means that the dirt particles are pulled through the fan blades and then pushed outside of the excavator. You may learn more here.
The vacuum excavator's fan also has another function besides sucking up air and dirt. This is called a high-pressure water injection system. This high-pressure water injection system works by shooting a high-pressure water stream into the ground, which helps to break up and loosen the soil and rocks before the truck can push the soil and rocks through the vacuum excavator's auger. If this system were not in place, then the excavator would be forced to use its blacklist to dig up and transport the material rather than shooting water into the ground and breaking it up.
A vacuum excavation unit from haakerunderground.com/nozzles-2/ has three other functions other than just sucking up dirt and debris. One is to clear access to the ditches that are dug by other trucks. The other two functions are for carrying materials to the location of the site that requires excavation. Lastly, these units help to protect the machinery, the operators, and any other people that might be working around the vacuum excavator.
There are three types of vacuum excavator: wet & dry vacuum excavation, hydro excavation using water jet lance, and compressed air lance excavation. Each type has its own advantages and disadvantages. Which one you choose will depend on your specific situation. Read here: https://en.wiktionary.org/wiki/excavator.
