Is it possible to remove asbestos from pipes that make up part of a pipe bridge and reach temperatures of 350°C? Can they then be re-insulated straight away? These were two questions that BUCHEN UmweltService was asked by one of its customers not so long ago. BUCHEN decided to join forces with its sister company XERVON to take on this very unusual challenge. And this special project has proven to be a great success: having first drawn up a complex safety and remediation concept, a trial was carried out on a small section to remove the asbestos and reinsulate the pipes. This showed that renovation work can indeed be performed under such extreme conditions – a first in Germany.
Asbestos was used in pipe lagging and surface insulation systems to insulate plant parts for many, many years. A large number of companies still have such insulation in their plants and are keen to have it removed, especially as the insulation materials that are available today are far more energy efficient. What’s more, everyone is well aware of the potential problems caused by asbestos. The demand for alternative solutions is great: such renovation work not only makes good business sense, it also means existing structures can be upgraded to meet the latest technical standards making them fit for the future.
The insulation in question contained loosely bound asbestos, which meant that stringent safety measures would have been needed even under normal circumstances. The combination of asbestos and high temperatures made the task significantly more difficult.
The project was given special status right from the start as none of the authorities in Germany had reference data available for such work. What was crucial here was to develop a concept that made the work as easy as possible for the operatives and kept them safe throughout despite the extreme conditions.
The operatives’ vital functions – core body temperature and pulse – were monitored in real time throughout and the data written down in health records
Such renovation projects can only be carried out if the relevant background work has been done first. This is precisely what BUCHEN and XERVON did. To begin with, the two REMONDIS companies drew up a comprehensive HSE concept that covered health issues and other special safety measures. The customer then commissioned them to carry out the project as soon as this had been completed and all the necessary discussions had been held with the relevant authorities. This then cleared the way for the next step: to carry out a trial on a section of the pipe bridge – on both the pipes (between DN 150 and DN 350) and the corresponding pipe bends.
In autumn 2016, a number of small openings were drilled into the section of the pipe bridge that was to be renovated to gather some vital information. The engineers needed to know exactly what state the old insulation material was in as well as to measure the maximum fibre concentration and the surface and radiation temperatures.
Thanks to BUCHEN/XERVON’s concept, it is possible to renovate the pipes despite their high temperature – operations at the production plant can carry on as normal
Particular focus was put on monitoring the vital functions of the operatives carrying out the work. They all wore special protective equipment that was able to provide a particularly effective barrier against the heat, including a body suit and breathing apparatus. Their vital functions (core body temperature and pulse) were monitored in real time throughout and the data written down in health records. An occupational physician was also present at all times to watch over the process. Moreover, measurements were continuously taken of the workplace environment to make the work even safer – such as humidity levels, ambient temperature and the surface temperature of the body suits.
It was essential to gather comprehensive lists of data before the renovation work could actually be carried out
BUCHEN first carried out simulations to test different methods, materials and types of equipment – with continuous measurements being taken here as well. There were a number of reasons for doing this: to find the best cleaning process and the most suitable heat-resistant suit as well as to see whether it was possible to deploy ready-to-use glove bags to seal the workplace off from the rest of the area.
The results of these trials revealed that it was indeed possible to remove asbestos from 350°C pipes and then re-insulate them immediately if specific health and safety measures were complied with and strict working times kept to. In fact, the operatives did not find their work to be overly difficult with these measures in place. Thanks to all these steps, renovation work can now be carried out on the pipe bridge – once it has been approved by the relevant authorities, of course.
According to the schedule, up to four years will be needed to remove all the asbestos and re-insulate the pipes. BUCHEN and XERVON will be doing all the renovation, scaffolding and insulation work. This concept, therefore, offers the customer a top quality, full service solution – a solution that can be provided by just one company and that meets all health and safety factors set out in the ‘TRGS 519’ [Technical Regulations for Hazardous Substances].
It is not always possible to shut plant parts down so that they can be renovated when they are cold