Following a profitable two-year trial of interval timers on packaged wastewater therapy plant blowers has resulted in a median 50% power discount at a website in Cornwall.
The partnership between WCS Environmental Engineering (WCSEE) and Juliots Effectively Lodge Retreat has set a precedent for ongoing design and energy-saving requirements on the wastewater therapy specialist’s HiPAF – high-performance aeration filter – system.
Power prices
The HiPAF packaged wastewater therapy system was put in at Juliots Effectively Lodge Retreat in Camelford, North Cornwall, in 2019 to customized design specs and environmental consents. This included a stringent Surroundings Company effluent discharge allow for organic oxygen demand, suspended solids, and ammonia.
The plant is sized for a inhabitants equal of 1,230 and constantly processes hundreds as much as 181m3/day wastewater. Whereas the HiPAF operation was extremely efficient all year long, retreat park managers discovered that rising power costs meant payments had been increased than anticipated, particularly in the course of the peak demand intervals of summer season and weekends.
Air blowers are an integral a part of the HiPAF system, offering oxygen to the micro organism in the course of the cardio course of. Nonetheless, with out timers put in, blowers sometimes function 24/7, which may account for greater than 90% of the power utilized in a HiPAF.
Whereas power effectivity has all the time been a key design focus of the HiPAF system, the engineering staff at WCSEE took the chance to work intently with Juliots Effectively to determine methods to additional cut back power consumption. This included gathering and analysing knowledge to evaluate how seasonal variability impacts wastewater stream charges into the HiPAF and the way dissolved oxygen (DO) ranges within the cardio digestion tank have an effect on the necessity for blower operation.
Evaluation of the information helped in understanding how cost-effective timers positioned on the blowers could possibly be used to cut back power consumption and payments.
Trial interval
Over the two-year trial interval, two timers had been retrofitted on the HiPAF at Juliots Effectively, one on every blower alternating every week to make sure even put on. It’s doable to start out and cease the blowers as much as ten occasions per hour, so the WCSEE staff began with quarter-hour on-off intervals as a baseline.
When the blowers had been off, DO ranges within the cardio digestion tank had been measured to make sure that 5-6mg of DO per litre of effluent had been maintained at the least stage, as is required for environment friendly therapy and operation of the HiPAF.
By incrementally tweaking and lengthening the timers, it was doable to determine the optimum time interval for the blowers to be off, whereas remaining throughout the DO limits.
By the top of the trial, it was confirmed that Juliots Effectively can now safely function the HiPAF blowers at intervals of 10-minutes-on and 20-minutes-off to take care of minimal DO limits. This optimised answer has led to appreciable power financial savings whereas totally assembly the necessities of the Surroundings Company discharge consent.
Rick Ackroyd, normal supervisor at Juliots Effectively Lodge Retreat mentioned, “With power prices rising steeply, we had been on the lookout for methods to cut back our carbon footprint and power use throughout the location. WCSEE has been a devoted accomplice in serving to with that aim.
“We worth their persistence and dedication in serving to us discover an efficient answer, making certain we now have a strong and environment friendly wastewater therapy system with the bottom doable power consumption, particularly throughout peak intervals.”
Setting a precedent
Excessive power costs and web zero carbon commitments imply energy-efficient wastewater therapy is an growing concern for house owners and operators of packaged methods. To fulfill rising expectations, blower timers pre-set to 15-minute intervals are actually fitted to all WCSEE HiPAF wastewater therapy methods as normal, making certain essentially the most cost-effective, energy-efficient system doable, and forming a part of WCSEE’s normal management philosophy.
The corporate’s skilled technicians can work intently with shoppers post-installation to additional improve the HiPAFs performance, with timers already delivering efficiencies on a number of websites.
WCSEE technical director, Andrew Baird, mentioned, “By working in shut collaboration with Juliots Effectively Lodge Retreat, we now have been in a position to ship the very best worth whole-life value for the consumer in addition to enhancing the design and operation of the HiPAF wastewater therapy plant.
“Given the rising value of power, and governments’ web zero ambitions, we look ahead to working with our present and future shoppers to rollout this energy-saving enhancement to our extremely efficient organic therapy expertise.”
