Broken Lenticular Filters

[LazyMagnolia]

I need some help troubleshooting a problem with our lenticular filters. We're using a Pall housing and 0.45-micron nominal SDII modules with backflush plates installed in the system. Even with the plates we're experiencing failure of the cartridges--the plastic cage splits along the top or the bottom. This may just be a matter of poor handing at our local FedEx terminal. But just maybe we're doing something to cause the damage. Here's our basic set-up.

We use a high pressure centrifugal pump (designed for use with a Velo DE filter) to pump Bright Beer from a Bright Tank into the filter system. The filter system consists of a set of lenticulars followed immediately by a set of 0.45-micron membranes. The beer flows through another 25-ft of hose directly into the bottle filler. Inlet pressure to the filter system is set between 50 and 60 psi to achieve filler bowl pressure of around 40 - 45 psi. Flow rate is about 5.5-gpm. We do occasionally stop flow in the middle of a run to switch tanks or to do minor repairs.

We monitor DP across both elements and never exceed the allowed DP. Membranes have no problem unless the lenticular elements break and allow unfiltered beer to pass into them.

We back-flush the lenticulars every day at a low DP, per manufacturer's instructions.

Any idea what might be causing our filters to break, other than a FedEx guy playing rugby with them?

[BrewinLou]

You would generally not want to come directly out of a filter into your bottling line. The pressure changes from opening and closing valves can be pretty brutal if you have ever watched a Maheen. If I had to guess I would say the drastic pressure changes on your filler are ripping your filter pads apart. You might try to filter the brew to another tank and bottle from a tank instead of your filter, or use a grundy tank as a buffer. Just my 2 cents. Good luck.

[LazyMagnolia]

We are using a Cimec rotary filler, so pressure is pretty smooth. Any back-pressure shocks would be absorbed by the 25-ft of hose and the membrane filter before hitting the lenticular. That being said, we are installing a check valve at the inlet of the bottle filler to prevent any back-flow and back-pressure that may happen.

[BrewinLou]

How much is the pressure differential when you back flush? They are pretty sensitive.

[kererubrewing]

Is there a reason for not filtering your beer prior to bottling? The changes in flow rate seem like they would hammer the filter.

Have you considered sending some photos to Pall and asking what they would recommend?