EQUIPMENT
Optimizing mechanical filtration within an aquaculture system Wil Conn, Carles Pellicer-Nàcher and Johan Jibert, Veolia Water Technologies AB - Hydrotech Mechanical filtration, where suspended solids are removed from the water column through water passing through a filter media, is an important process within many aquaculture production systems (Bregnballe, 2022). These systems can include recirculating aquaculture systems (RAS), flow-through systems, as well as those systems that are hybrid in design – where system water is both recirculated and a proportion discharged (and new water brought in) on a regular basis. Hydrotech has played a leading role in innovating and inventing mechanical filtration options for use within the aquaculture industry. Our innovations include the drum filter (introduced in 1990), the disc filter (introduced in 1995) and the belt filter (introduced in 1999). Our commitment to innovation is supported by the depth of knowledge held within our human capital and our dedication to providing the best aftermarket service and support we can. At Hydrotech, we understand that a fit-for-purpose mechanical filtration solution is key to supporting the overall success of the facility it is located within. No matter the mechanical filtration option selected, whether it be drum, disc or belt in nature (Fig. 1), or how you measure the “success” of a filter install, there are two recommendations that, if addressed,
Drum filter
will support a successful installation and operation of your selected solution. These two recommendations have been filtered through more than 12,000 Hydrotech units delivered worldwide for a range of aquaculture applications. Acknowledging that the majority of mechanical filters currently deployed within aquaculture today are drum filters in nature, the following points are targeted toward drum filters.
Recommendation #1: Know your hydraulic profile Understanding the hydraulic profile that your filter will operate within is a fundamental pillar for success. At the simplest level, it is the relationship between the water level and flow of influent to the filter, the water level within the filter drum and the water level external to the filter drum, and how these levels are impacted during the operation of both the filter and the plant as a whole. It is important that the hydraulic profile is determined at both normal operating levels and during periods of peak flow/loads (e.g. dropping water volume from production tanks to support harvesting) so that the filter can be sized correctly, installed correctly and operate as expected within the range of flows and total suspended solids loads the filter will experience within day-to-day operations.
Disc filter
Belt filter
Figure 1. Graphical representation of three types of mechanical filters that are commonly deployed within aquaculture.
Hatchery Feed & Management Vol 11 Issue 2 2023
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