Client: Furness General Hospital
Job: Hotwell Tank Replacement
Location: Barrow in Furness
Modular feedwater tank design and installations provide a scaleable solution for boilerhouses where space and access are restricted. A recent project for Furness General Hospital demonstrates our approach to designing a solution that enabled the boilerplant to remain in operation during works and reduced on-site time.
Scope of Work
Furness General Hospital released a tender document in early December 2018 outlining the scope of works. The existing 12m3 mild-steel hotwell tank, which comprised three separate but linked tanks, had become heavily corroded on the inside plate surfaces. Following a site visit we submitted a design and installation proposal to replace the existing tanks.
Located on a mezzanine level within the boilerhouse, the limited space and restricted access required careful consideration and our design engineers produced a bespoke modular hotwell design that would allow for ease of installation.
The design phase included the submission of CAD drawings, plant and electrical schematics and a 3D rendered view. A bespoke tank control system was also designed including the scope for integration with the Hospital building management system (BMS). A modular tank design of this nature can be scaled to suit any tank capacity and is ideally suited to specific sites where access is an issue. The installation of three tanks rather than a single hotwell also means that in the event of a fault in a single tank the boiler system would still be fully operational.
In order to keep the boilerplant operational, a mild-steel temporary tank and stand was constructed, delivered to site, and installed within the boilerhouse. All the services, including steam, condensate return and Mains Cold Water (MCWS) were connected to the temporary tank.
Once this was complete and the system was operational, the old tanks were cut into sections and lowered from the mezzanine level to ground level prior to disposal. Following removal, the area was de-cluttered and tidied to ensure the clean and efficient installation of the new tanks.
The new set of three stainless steel tanks were constructed in modular form at our works. This included adding connections, access lids, bracings and partial cladding and insulation to cut down the on-site time required. The modular tanks were then delivered to site.
Once on-site our install team hoisted the tanks one-by-one to the mezzanine level before the top and bottom sections of each tank were welded together. The tanks were then lifted into final position.
Our specification and design process enabled the bulk of the pipework construction to be completed prior to installation, again cutting down the on-site time. These pre-fabricated pipe sections for the vents, drains, overflows, condensate returns, steam injection and feed outlet pipework were then bolted in situ.
Prior to the final on-site tie-ins, the MCWS was then re-piped through a new water softener and chemical dosing unit supplied and installed by McEwens that was better suited to the overall system configuration. This too was skid-mounted and pre-piped at our works, ensuring only final tie ins were required on-site.
As part of the design process we worked closely with the PLC and HMI suppliers to develop a bespoke control system for the three-tank configuration. The touch-screen HMI enables operators to regulate the water fill level and temperature within each tank and set alarms in the event of a rise or fall in both levels. The tank information is also fed back to the Hospital’s BMS and can be operated remotely.
The project was successfully handed over to trust on 7th June 2019, with the boilerplant fully operational on the new hotwell tank installation.
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