One of the greatest skills of chemical engineers is their ability to innovate. But I am constantly amazed at all the new ideas and processes that are being developed.
This project succeeded in restoring the required design capacity to an important works which was suffering from process problems and reduced output.
They managed to do this while reducing the construction period from 30 to 10 months and achieved major cost savings.
The design and construction of the works included the latest thinking on rapid gravity filter process design and using pre-fabricated modular stainless steel units.
In August 2012 United Utilities (UU) and KMI Plus came together to begin a major construction project at the Lostock Water Treatment Works in Bolton, UK.
The project was started to support United Utilities’ Haweswater Aqueduct Outage project, planned for October 2013 by finding a way for the works to achieve a stable, consistent flow of 180 million litres per day. But they only had 12 months to do it in.
To do this UU and KMI Plus followed a revolutionary Future Concept of Design and Assembly (FCDA) principle, a break from the more traditional methods of design and construction.
The innovation that resulted from this was the concept of extending the works filtration capability by the addition of six new state-of-the-art pre-fabricated modular stainless steel rapid gravity filters, and associated backwash facilities.
An end-to-end process review had been completed and it identified the solution as the refurbishment with process enhancements of the existing rapid gravity filter units and construction of additional filter units to reduce the solids loading.
This would allow them to stop using coagulant aid which had caused mud-balling and bed cracking. Extensions to the clean and dirty backwash facilities and filter-to-recycle equipment were also required.
Through apply FCDA and incorporating past experiences the team were able to:
- reduce the loading rate
- change the mode of level and flow control to minimise floc breakup
- investigate and rectify problems with concrete erosion under low pH conditions
- modify filter floors to give more robust performance
- resolve problems with the combined air limited water backwash system by incorporating media retaining baffles
By working in this way UU and KMI Plus were able to successfully complete this project in a constrained time scale, in fact finishing a month early!
It is hoped that the FCDA principle can be used as a future template so that all projects at UU and KMI Plus can be delivered as quickly.
This change in methodology is a brave undertaking on a project of such scope and I think its success speaks of the importance of always being willing to innovate.
To find the solutions to the many problems facing us today we always have to be willing to try something new.