A range of Grundfos submersible pumps, smart digital pumps and vertical multistage centrifugal pumps were installed at this Sedibeng-based brewery’s wastewater plant and its water treatment plant.
Grundfos Associate Sales Engineer Raymond Makgoga said the installation, which is in line with the brewer’s commitment to conserve water as a precious resource, included the installation of a water recovery plant, allowing the operation to further optimise water use within its facility.
The expansion also saw the upgrading of the water treatment plant, where clean ‘raw’ water from the municipality is further purified for brewing purposes. After the beer is produced, beer residues and water used for pipe cleaning is treated to meet regulated environmental discharge limits. This can also be re-used for cleaning, reducing the need to draw on the municipal supply.
Makgoga said three Grundfos submersible wastewater pumps were provided to transfer water from the brewery to the water recovery plant. After the sedimentation process, water is pumped to the reclamation plant for final treatment. In this circuit, around 6,000 m3 of water is pumped daily, with the pumps being driven by 15 kW high-efficiency motors with IE3 rating.
“In the water treatment plant, a number of Grundfos Smart Digital S and Smart Digital XL pumps are installed, mounted on dosing skids. These must accommodate a range of chemicals from sodium hydroxide and sodium hypochlorite in the reverse osmosis circuit, to citric acid and anti-scalant in the ultra-filtration circuit.”
Makgoga said this function is a critical part of the brewery’s operation. “These systems give a high level of control, communicating vital data between the pump and the PLC so that chemical dosing is accurate and appropriate. This eliminates over-dosing and ensures that chemicals are not wasted; the Grundfos pumps are able to measure the volumes of water flow and then dose in proportion.”
The dosing pumps were supplied with the complete package including Grundfos’s CIU 500 interface. The CIU 500 is a standard interface for data transmission between an industrial ethernet network and a Grundfos pump or controller, making data exchange possible between Grundfos pumping systems and a PLC or SCADA system.
Other accessories in the package were pressure relief valves, pressure loading valves for maintaining pressure on the discharge line, and pulsation dampeners to ensure smooth dosing flow.
Energy efficiency is also an important factor, considering the significant energy consumed by wastewater treatment plants. Some 28% of the Sedibeng facility’s energy is consumed by utilities, which are therefore the first port of call for energy saving efforts.
Large pumps in the system transfer about 1,750 m3 of water per hour around the brewery, for instance, pumping 24 hours a day. To monitor and conserve energy, he says the company uses a Utilities Benchmark Model (UBM) which compares the electricity used with the kilograms of water treated and chemical oxygen demand (COD).
The use of IE3 energy efficient motors in the Grundfos pump installations has assisted in reducing energy consumption to about 1,3 kW per kilogram COD treated, from a level of over 1,9 previously. These statistics are tracked daily, and the new equipment helps to facilitate this data tracking as the operation works towards even more demanding energy saving targets.
Nancy Khumalo, Service Sales at Grundfos, said energy savings can be modelled in advance to indicate how Grundfos pump installations can improve energy consumption.
“This allows our customers to consider how the Grundfos pumps could contribute to reducing their carbon footprint and their actual electricity costs. We are also able to provide an estimation of the capital payback period based on these savings,” Khumalo said.
As part of the package Grundfos provided training and support to operator-level employees at the brewery. This allowed the plant staff to ‘take ownership’ of the equipment and understand more about its functioning.