Project Background
Our customer is an innovative vegetable and fruit processing company who is developing modern methods of growing produce in a controlled environment. Rather than growing produce in the typical soil, the manufacture uses hydroponics and reusable trays for a more sustainable farming methods. The customer is currently using a conveyor system for a continuous cleaning during a full production shift. The system would need the ability to keep up with the cleaning-in-place demand. Even further into being a sustainable grower, our customer prefer a solution that optimized their water and sanitizing chemical usage by recirculating them throughout the washing cycle.
Project Hurdles
One of challenges with using reusable trays are the cleaning and sanitizing method between each growth cycle to eliminate produce cross contamination and possible fungus or mold spores from developing. The sanitizing solution must maintain a concentration of sanitizer to thoroughly clean and sanitize the trays. The sanitizer concentration will reduce as it is being circulated due to its high vapor pressure and residual solution left on the trays. The system would need to be capable of monitoring the sanitizer concentration and dose more sanitizer concentrate as needed. The system need to produce consistent sanitizer strength as well as flow and pressure to ensure good cleaning distribution.
Another challenge with recirculating the sanitizing solution would be the seeds and plant remnants that could get carried over. The seed and plant remnants were large and in great quantities which could easily clog a standard element-based filtration system in a short period of time. The filtration method would need a high capacity to handle a continuous volume of solids with the capability of simultaneous purging of the solids.
Solution
Our customer selected Placer Process as the strategic partner to design and fabricate a sanitizing solution circulation and filtration system. The system was composed of two tanks for sanitizer, a supply pump, and solids filter. The design of the solids filter allowed continuous filtration while continuously discharging filtered out solids by a perforated mesh design. By using inline analytical sensors, the sanitizer concentration could be continuously monitored. As the sanitizer concentration was reduced, a metering pump would pump sanitizer concentrate from the concentrate tank to the sanitizer solution supply tank where it would be blended with the return solution stream. All components of the system were skid mounted to a stainless steel frame to allow for complete assembly and ease of installation at our customer’s facility. A control panel was also provided to monitor and control all operations of the system automatically.
Results
The sanitizing solution circulation and filtration system met our client’s operation and cleaning criteria while providing a fully contained system. The method of skid mounting and pre-plumbing and wiring the major components and devices simplify the on-site installation requirements to straightforward pipe connections and power supply to the control panel. The chosen method of solids filtration allowed the table washer system to continuously operate without needing to shutdown due to a clogged filter and required minimal operator interaction. The automatic sanitizer dosing system provided a consistent concentration of sanitizing solution to the table washer system.
By teaming up with Placer Process team to develop a combination of filtration system as well as sanitizing circulation and distribution equipment, the tray washing system, referred to as the table washer, can be implemented in a more viable and environmentally friendly manner.