A lead from the 1999 IEFP (International Exposition of Food Equipment) show led to the placement of a Model FF-12 Fiber Filter at the Del Monte peach cannery in Kingsburg, California. This eighty-year-old cannery operates during a three month season each year.
Wastewater from the plant is used to irrigate a sorghum field a few miles away. An environmental problem existed because suspended solids from the wastewater formed deposits in the field.
The suspended solids come from the peach peeling operation. Caustic peelers are used, with a continuous cycle to reuse the peel water. Make-up water is adjusted so that approximately 300 gpm flows to the waste water stream.
This wastewater is filtered in rotary drum screens. In order to maximize solids capture, screens with very fine slots are used. However, even with wedgewire with 0.012" slot widths excessive suspended solids were present in the filtrate water.
The Fiber Filter was installed in series with the rotary drum screens, in the final filtering position. Dramatic improvement in solids removal was evident even with coarse 190 micron sleeves in the Fiber Filter. Since there was excess capacity in the Fiber Filter, a switch was made to finer 86 micron sleeves.
The Fiber Filter was supplied with an automatic spray ring feature. This is used to back-flush the filter sleeves. A booster pump was provided to increase the spray water to 200 psi. A timer control panel assures fully automatic, continuous operation. The timer was set to backflush every six to ten minutes.
The sludge (peel and some pits) from the Fiber Filter is landfilled.
It is notable that the wastewater contains a significant amount of dissolved solids. These measured 2o Brix. Naturally these dissolved solids cannot be captured in a filter, so they go to the spray field. Fortunately they are an acceptable environmental condition.
2013 Note: Use of the Fiber Filter was discontinued when the plant's wastewater treatment facility was expanded.
See photos below.
NOTE SLUDGE FALLING FROM DISCHARGE CHUTE
NOTE ROTARY DRUM SCREENS IN BACKGROUND