Sludge builds up in tanks and vessels over time. The sludge needs to be removed at regular intervals in order to maintain a smooth running operation. Sludge removal can be a hazardous task if performed manually. For this reason tank and vessel sludge removal is carried out remotely wherever possible, or with minimum man-entry in confined spaces.
A range of technologies have been developed for the oil and gas industry, as well as the chemical industry and others for sludge removal. Vacuum transfer systems can pump sludge safely from its source to a transport or storage source. Apart from someone controlling the system remotely, no one needs to be near or even very close to the tank or vessel having its sludge removed.
Of course, often it isn't possible to remove sludge, mud or scale from a tank or vessel by a remotely controlled system and no man-entry requirement. Often man-entry becomes essential, and often too it is in a confined and awkward space, which makes the operation potentially hazardous.
For this reason there are highly trained operatives in the field who follow proven procedures that are known to be safe and efficient. The job gets done with the least possible risk to those involved, and the sludge removal and cleaning is maintained at an acceptably high and efficient level.
An Attendant stays close to the point of man-entry. He constantly monitors the situation in the confined space. He keeps in constant communications with the Entrants working inside to ensure that all the accepted best working practices are maintained and followed to ensure the safest possible level of working conditions.
The Entrant or Entrants working in confined spaces in tanks or vessels need to breathe safely.
It is also necessary to maintain a constant monitor on gas build up within the confined space where the Entrants are working. For this reason gas monitoring equipment is used and constantly checked. The typical gases checked for are carbon dioxide and hydrogen sulphide, but other gases can be monitored as well if there is a reason to suspect their potential presence.
The systems typically in use will use visual and audible alarms if any toxic gases are detected while operators are working on sludge removal within the confined spaces of tanks or vessels. These can be high density bright flashing lights combined with loud audible alarms. There can be other alarm systems in use, such as vibrating alarm devices for example, depending on the particular situation involved.
Tank and vessel sludge removal is not usually an easy job. It requires a high emphasis on safety for those involved. For this reason remote sludge removal systems are preferred, but unfortunately are not always practical or possible to use. The industries that require sludge removal are constantly working to improve working conditions and to maintain or even increase safety for all workers.