"B" Station Turbine Basement
No.6 Evaporator Bodies
Installed in 1938 when “B” Station was first brought online, the Evaporator Bodies now only exist as empty shells. All of their internal parts (tubes, pipes, valves, and fittings) have been removed over time. It appears this may have been manufactured by W. H. Bailey & Co.
Purpose
Evaporators were used to help replace water lost during the power station’s steam cycle. Water and steam could be lost through things like:
• Leaks in pipes or pumps
• Steam escaping from equipment during startup
• Water drained from the boilers to remove impurities
To make up for these losses, steam from the turbine (after it had partially expanded) was used to heat softened water supplied by the water treatment plant. This process turned the water into steam again.
However, as the water was heated and evaporated, salts and minerals became more concentrated. To prevent buildup, some of this water had to be regularly “blown down” (flushed out) and discarded as waste.
Decommissioned
The evaporators were phased out before 1955, when “C” Station was commissioned and a more advanced Demineralised Water Treatment Plant was installed. This new system was more efficient and reliable.
Even after that, the No. 6 and No. 7 evaporator units were occasionally tested and used only as backup during maintenance on the new water treatment plant.
No.1 High Pressure Feed Pump
This high-pressure feed pump was made by Mather & Platt in the UK and was installed in 1938 as one of three pumps serving the boiler plant at "B" station.
Water condensed from steam was first collected by the No.6 Turbine extraction pumps, then fed into this pump. The feed pump increased the pressure to around 800 psi before sending it to the boilers. It was powered by a 440-volt motor running at about 2,340 RPM. A similar unit was later replaced in 1955 when "C" station was brought online, using a 50Hz motor instead.
Chrysotile asbestos was later found in the fibre cement sheet inside the electric motor’s terminal box.
Also known as white asbestos, chrysotile is the most commonly used type of asbestos. It has a silky white or greyish-white appearance, with long, curly fibres and a layered, sheet-like structure.
This terminal box is where the main power cables connect to the motor. The electricity powers the motor, which turns the pump and drives the flow of water. Inside the box, three heavy-duty cables are bolted to a red metal bar known as a busbar. This setup shows that the motor used a three-phase electrical connection, which is standard for large industrial equipment. The thick insulation and bolted terminals are designed to safely handle high amounts of electrical current.
No 6 Condensate Extraction Pumps
Commissioned in 1938, these pumps was later modified in 1960 to operate the 50 Hz electrical system.
Each pump was powerful enough to handle all of the condensate produced when the turbo-alternator was running at full load. If needed, it could pump the condensate all the way to the surge tank, which sits above the turbine room at the level of the crane rails.
These condensate extraction pumps worked in sequence with the high-pressure boiler feed pumps.
This was the first unit at the power station to introduce regenerative feedwater heating. In this system, the condensate (or feedwater) was gradually heated in multiple stages as it travelled from the condenser to the boiler. This was done using heat exchangers supplied with partially expanded steam that was tapped (or "bled”) from three different stages of the turbine’s cylinder during expansion.
Several pipes around the pump have debossed markings that are difficult to read due to layers of flaking paint. While the exact abbreviations are still being confirmed, the following interpretations are currently being considered:
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Photo 6 – EOP: Extraction Outlet Pump
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Photo 6 – MIU: Main Inlet Unit
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Photo 8 – Condensate Water
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Photo 10 – HDF 222M 287 VOS:
Possible meanings:
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Heater Drain Flow – Line 222 Main – Segment 287 – Vertical Outlet Section
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Heater Drain Flow – Pipe 222 mm – Segment 287 – Valve/Outlet Section
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Photo 13 – EDP 160: Extraction Discharge Pipe, 160 mm diameter
