Titanium pump solves sewage spill challenge

Sewage spill containment at waste transfer stations means handling corrosive sewage. Specifying a suitable pump is a challenge for wastewater consultants.

Sydney Water’s new sewage collection station at Douglas Park, southwest of Sydney, is emptied by tanker on a daily basis. The large spill containment pad ensures any corrosive sewage leaked during the transfer is collected in the sump pit.

The organisation required a pump that was capable of handling this liquid. MWH Global, the wastewater consultant that designed the sewage collection station, selected a Tsurumi TM series titanium submersible pump for the drainage sump.

“Ferric chloride is added to sewage in the holding tank for odour control,” said Mark Rush from MWH Global. “As a result, the collection pit needed a pump that would handle corrosive liquids.”

The series is particularly suitable for applications where corrosion is an issue. The stator housing is titanium, while the pump casing, stand and motor cap components are all manufactured from FRP resin-moulded material. Although the range was originally designed for sea water, it is also suitable for highly corrosive chemical applications in food and chemical plants.

The pumps are compact in design and are available with single- or three-phase motor drives. They are capable of a flow of 240 L/min right up to 350 L/min. Heads vary from 9 to 15 m.

The pump used in the Douglas Park station sump pit is a Tsurumi 50TM2.4S single-phase submersible with flows to 290 L/min and a max head of 12 m. The series features a vortex impeller made from glass-fibre reinforced resin. An antiwicking cable gland prevents water incursion due to capillary wicking should the power cable be damaged or the end submerged.

A dual silicon carbide mechanical seal is protected in an oil chamber so neither seal face contacts the pumped liquid. This eliminates abrasion and facilitates cooling and lubrication of the seal faces. The oil chamber incorporates an oil lifter that ensures lubrication even if the oil level in the chamber drops. This increases the time between routine pump maintenance.

The series is also available with floats for automatic operation, with the float height able to be preset. Installation is simple as there is no external control panel or additional wiring required.

Image caption: Barry Cook, Sydney Water, installs a TM series titanium pump at the sewage collection station at Douglas Park to handle the sewage spills during transfer to collection tankers.