Been a while since I've logged onto the site. Moved across the US from California to the South (Alabama) and dealing with a frustrating boss at work has made my spare time very precious. While I do love the South and Alabama (easy going) the weather patterns are not conducive to manufacturing consistent good quality food products. It doesn't help that I'm basically on my own to figure out this problem and solve it.
At any rate...since I've been with this company, April of 2018, we have had micro issues on the liquid sugar silo / tank. We store only liquid sucrose 65% and use about 10,000 gallons a day so we run through a good amount. The silo capacity is 30,000 gallons. All the incoming sugar from the tanks is clean, no APC, coliform, or yeast / mold. Occasionally, we may get a count of 100 on APC or yeast / mold, but it is pretty rare. The silo has positive HEPA air filtration and UV light on that air after the HEPA filter to the tank. There is a heater on the bottom of the tank where we can heat this
The issue we have is our yeast / mold counts will elevate over time and then spike up. After we clean the silo the counts go to zero. Sometimes we will have time to dry the silo out and sometimes we won't. Honestly, it really hasn't made a difference as the couple times we went right back in after cleaning the silo without drying we saw the same issue to the same degree. It appears to have worsened as the weather has become cooler here. During the warmer months the silo would last about 8 to 12 weeks before we had to empty and clean it due to very high yeast counts. Now, in the fall / winter months we get about 4 to 6 weeks out of the silo before we have to empty and clean it due to the very high yeast counts.
Sometimes there's a mold ring on the inside of the silo at the top and sometimes there is not. I've been the one to oversee the entire emptying and cleaning process. From a cleaning / sanitation perspective with the silo there is nothing wrong. The interior of the silo is completely spotless after CIP. We also know this because our micro load goes to zero after emptying and cleaning. Additionally, I've made progress on the cleaning of the line to the silo to eliminate all dead legs (the piping is atrocious from a sanitation perspective). However, we are challenged by a few things:
- HEPA / UV Light Box / System are located at the bottom of the silo (the silo is elevated with an enclosed walk in / out space for the outlet pumps, piping, and this HEPA / UV light box system. If we have any micro load in this area I imagine it may overwhelm this system. As such, we keep this area under the silo as clean and sanitized spotless as possible.
- The sugar receiving line is CIP'd once a week. To be honest, this seems like overkill to me and with our atrocious piping setup we dump a lot of sugar and water underneath the silo during the process likely elevating the humidity in the area where the HEPA / UV light box are located (pulling in that moisture to the top of the silo).
- Sugar receiving line and outlet lines have ball valves and butterfly valves (these are not CIP'able) and to really clean, have to be fully disassembled. I swapped one of the valves out and disassembled after CIP to show we are indeed trapping sugar in the valve.
I know the valves need to be fixed, but am really wondering about the humidity levels and the condensation. How can we better control this? Especially with the temperature swings we have here. For example today is 75oF and tomorrow will be 50oF. Humidity levels are lower this time of year.
I'm also curious about the weekly CIP of the sugar receiving line. I'm wondering if we are better off NOT washing or CIP'ing that receiving line or not as often at least. I'll need some good info for this because it will be a tough sell with my boss.
Appreciate any help or insight on this. I've been pulling my hair out over this silo / tank issue.