How to Clean and Store ScottCart Cartridge Filters
Last Updated: 6/2021
Applies to: This guide applies to beverage producers using ScottCart Cartridge filters. It includes instructions for regeneration before storage, options for short- and long-term storage solutions, and cleaning instructions for ScottCart PES (polyethersulfone) and PP (polypropylene) filter media.
See end of article for a video demonstration of cartridge filter setup and usage.
Just like lenticular filter modules, cartridge filters should be stored wet. It is a good idea not to let your cartridges dry out when storing them so that the materials remain pliable. Otherwise, they may become brittle and cause internal turbulence and premature damage during subsequent use. Cartridges should be properly prepped for storage and stored in the correct solution to maximize cartridge lifetime.
Before being stored, cartridge filters should be regenerated properly. Some pre-filter cartridges can be backflushed whereas some membrane cartridges cannot. You can still perform a forward flow regeneration to dissolve soluble compounds in the matrix if your cartridge is non-backflushable. Please check with Scott Labs, or refer to the product technical data sheet whether your cartridge is backflushable or not.
A forward flow regeneration is completed as followed:
- Rinse with water at about twice the speed you were filtering at. Keep this high flow for 5-10 minutes
- Bring the water temperature up to no higher than 140⁰F and run for 5 minutes.
- NOTE: At temperatures warmer than 140⁰F, proteins lodged deeper in the matrix start to denature where they will stay and contribute to pressure buildup.
- Switch the pump off and close the valves so that your cartridge sits in this warm environment for 10-20 minutes.
- Bring the temperature back down incrementally by rinsing with cold water.
- Drain and store or drain and reuse. Alternatively, you can continue with a hot water or steam sanitization.
Options for cartridge storage
Inexpensive Ethanol* (Neutral vodka)
Cartridges can be stored in 40-135 proof ethanol solutions. Do not store cartridges in solutions greater than 135 proof, or the cartridge and storage container can prematurely age and crack. This storage solution is good for months to years as long as the proof doesn’t drop below 40 degrees/20% alcohol. This is the preferred method of storing ScottCart Carbon Cartridges.
Acid Sanitizers* (Nitric or Phosphoric Acid Blends)
This solution is typically recommended where there is a very short time-lapse (less than 3 days weekend) between filtrations. After this time, some acid sanitizers tend to break down (it becomes milky with a foul smell) and won't protect from microorganisms. Acid-based sanitizer solutions or oxidizing sanitizers are not recommended for long term storage.
Storage Under Pressure**
Cartridges can be stored inside the housing between uses. After a hot water or wet steam sanitization, drain the housing, close it up, and place under nitrogen or CO2 pressure. Don’t let the media dry out before placing under pressure. Maintain a pressure of between 1-1.5 bar. This is also a good way to tell whether all your gaskets are sound. Cartridges can successfully be stored this way for months as long as the pressure doesn’t drop below 1 bar. If it does, re-wet the media, sanitize, drain and store.
An insoluble food-grade gas like nitrogen is preferred. CO2 is also an option but maintaining pressure will take longer since it’s soluble and much of it will dissolve in the water left in the cartridge before the pressure starts building up. Removing the O-rings aren’t necessary for this method. Please take proper safety precautions as many cartridge housings are only pressure rated for liquid pressure, not gas pressure.
*During storage in ethanol or acids, be sure to remove the O-rings between uses, as silicone tends to stretch and break up into little pieces when stored in these solutions long term.
**Please take proper safety precautions when storing under pressure as most cartridge housings are only pressure rated for liquid pressure, not gas pressure.
Quick Guide to Storage Solution Options:
|Inexpensive Ethanol (Vodka)||> Months||*Keep strength above 20%/40 proof. *Do not use denatured spirits. *Purge out water very well before submerging to avoid lowering proof < 40 degrees. This is the preferred method of storing ScottCart Carbon Cartridges.|
|Nitric and Phosphoric Acid/Blends||Maximum 6 hours cumulative||Use at own risk. These acids damage the membrane structure at longer contact times.|
|Peracetic Acid at|
|≤ 3days||After this time the peroxide in the formulation will have broken down, offering little protection against spoilage.|
Storage at a higher concentration can lead to premature breakdown and/or damage of the media.
|Citric Acid 1-2% Solution||≤ 3days||After this time bacteria will target this solution. Commonly used in wineries with 50-200 ppm of added SO for long term storage. Periodically add more SO by dropping in an Inodose effervescent tablet. Care should be taken if bacteria is already present in the cartridge, then bacterial spoilage will begin within hours without added SO .|
|Citric Acid 1-2% in combination with 50-200 ppm SO2||≥ 3 months||After this time bacteria will target this solution. Commonly used in wineries with 50-200 ppm of added SO for long term storage. Periodically add more SO by dropping in an Inodose effervescent tablet. Care should be taken if bacteria is already present in the cartridge, then bacterial spoilage will begin within hours without added SO2.|
|SO Solution without Acidifying 50-200 ppm or ≤1000 ppm||≥ 3 months||Not as efficient as acidifying the solution first, but still a solid choice to store your media. You can use up to 1000 ppm of SO which helps to bleach the media if your intention is to remove color. The lower the pH of the solution, the more effective the SO will be. Add more SO periodically (Inodose effervescent tablets) to make sure the solution stays effective.|
|Sulfuric Acid 2% Solution||6 weeks +||Recommended by the manufacturer for long term storage.|
|Caustic Soda (NaOH or KOH 1-2%)||≤ 12 hours||Can be detrimental to some media types. Check with your supplier.|
|Ozone Water/Gas||Not recommended by the manufacturer||Instant destruction of media.|
|Iodophor or other Iodine-based Sanitizers||Not recommended by the manufacturer||Permanent staining and impossible to remove.|
WHERE TO STORE CARTRIDGES
You can make your own storage containers to store the submerged cartridges in. Simply use plumbing water piping and cap one end to make it leak-proof. The storage solution filled tube can be capped or covered with plastic wrap. Stand the cartridges upright in these tubes and use a bungee cord to secure them to a barrel rack, wall or table. Make sure your cartridges are fully submerged in the storage solution. Alternatively, you can leave your cartridges in the housing with your chosen storage solution. Small, 10” cartridges can be stored in a zipped plastic bag in the storage solution of your choice.
This procedure applies ONLY to ScottCart PES (polyethersulfone) and PP (polypropylene) filter media. This procedure does NOT apply to Dual Layer CA cartridges or ScottCart Carbon - consult product specific instructions.
For general cleaning of ScottCart PES and PP Cartridges, we recommend using Destainex-LF. It was specifically formulated for the wine industry to clean wine-related soil and neutralize microbial contaminants. This formulation removes protein and color stains via an oxidation process, and this non-hazardous fully ‘built’ cleaner rinses freely from equipment with a single pass rinse. It’s non-corrosive, non-tainting to wine and cider and is fully biodegradable.
NOTE: The procedure below only applies to ScottCart PES and PP cartridges.
Step 1: Prepare cleaning solution
- Add Destainex-LF to warm, moving water of approximately 104°F to 140°F (40°C–60°C). Recommended dosages are 0.75 – 1.5% v/v.
- Mix with a perforated paddle or with a motor impeller in a tank or container to provide the solution volume and allow the mixture to clarify (this takes only a few minutes). Excessive foaming may occur if the solution is not in full mixture.
Step 2: Circulate through filters
- Circulate at moderate pressure through the entire system to clean, making sure that the housing is properly vented. To force cleaning solution into all of the pores, the outlet valve can be slightly closed to bring the outlet pressure up to between 3psi-5psi for a few seconds.
- After the cycle, drain the solution and thoroughly conduct a single pass rinse with clean water and bring the backpressure up to between 3psi-5psi to ensure proper rinsing.
- pH test the wastewater stream with a digital meter or paper pH test strips from time to time to ensure that the waste stream is approximately pH 7.0/neutral. If the rinse water pH is at 8 or higher, you need to do an additional rinse or use an acid rinse like StarSan or Peracetic acid, both of which are sanitizers. Inspect and repeat if necessary.
A note on temperature:
Cleaning at lower or higher temperatures won’t improve the cleaning capability of the chemical. Protein char film is not expected to be present if the process is conducted with Destainex-LF on a regular basis.Shop Cleaning
For more information, check out our Cartridge Filter Setup & Usage video for step-by-step instructions: