In 2018, the Environmental Manager at Bega, Northern Victoria, Mr Sean Trebley, was given the task of upgrading their Strathmerton Plant’s wastewater aeration system.
The wastewater system consisted of a DAF unit, which flowed into an aerated lagoon, and after this the effluent was stored in 2 non-aerated lagoons during winter, before irrigation in summer.
A reduction in production reduced the wastewater produced, which meant that the existing aerators onsite at Bega Cheese were de-prioritised. This led to them not being maintained as well, until they became almost unusable, but they were difficult to access for repair. This lead to the choice of expensive repairs or finding a new system that was easier to access.
Bega Cheese Management decided to investigate other more efficient methods to aerate the site’s waste water.
Sean Trebley (Recently appointed Environmental Manager for Northern Region) had a positive experience dealing with Hydro Innovations, who are the sole importer for Gorman-Rupp Pumps. Gorman Rupp have a global reputation in the manufacture of efficient pump systems.
The project began in November 2018 and took two months, completed in late January 2019.
November signalled the removal of the old redundant aerators, consisting of 2x30kw and 6x 8kw aerators.
Concurrently, the design of the new switchboard and plans for the operation to run easily and reduce maintenance and control interferences was carried out. The system design incorporates a soft starter for the 30kw motor. A 24hour clock fully automates the system and removes any start up stresses to the drive motor and pump.
The aerator was delivered around a month into the project and placed into position. Next the pipework for the suction line was installed, ready for the inaugural start up.
The Solution –EchoStorm Aerator Plus EDUR DAF Pump
In addition to the bank mounted EchoStorm Aerator, Hydro Innovations provided recommendations on how to greatly raise the efficiency and optimize their DAF plant prior to the water being transferred to the lagoon.
An EDUR DAF pump was suggested to replace their existing conventional system, which consisted of: A 7Kw recycle pump; a 3 phase air compressor; and an air saturation pressure vessel. The 1kW EDUR DAF pump replaced this entire set-up, delivering substantial energy cost savings.
It also greatly decreased the required maintenance cost and labour costs because of the reduced amount of equipment in the new system.
By optimising this system, more water can be pre-treated efficiently and effectively before being transferred to the lagoon. The pump draws water from the DAF tank, and creates a negative pressure in the suction line to enable it to draw in atmospheric air with the water. The air is sheered and pumped through a solution line with the water, where the air is forced into solution under pressure, before being released back into the DAF tank. The reduced pressure within the DAF tank draws the air out of solution, to form a tank full of micro-bubbles, which floats fat, oils and grease to the surface.