I hope it was good and easy to understand for all those who are looking for useful information on filters.
In this part, I am putting some facts related to payback or economics understanding for replacement decision and I will also cover various other factors apart form major cost items which works out in favor of CIP.
After deciding to go for CIP type filters as per criteria in first part of this post, please look for following parameters which can justify your decision based on cost payback. They are.
1. Capital cost of proposed new filtration system.
2. Filter element life & cost of spare elements.
3. Manpower reduction or increase and cost impact of it.
4. Product loss - Saving or Increase.
5. Space requirement - Saving or increase
6. Capacity of the system.
7. Downtime and production loss.
8. Energy cost including all aspects as described in Part-1 of this post.
9. Cost of cleaning system.
10. Cost of disposal.
11. Change in Cost of Consumables
12. Other cost factors if any.
It is always recommended to make a tabular comparison with comprehensive study as it is not very easy to decide about the replacement of any filtration system because it is the toughest unit operation and further you need of lot of re-search work on trying new system's suitability for your fluid, for your process. So be careful and give appropriate weight to each important factor without any preoccupied decision.
Generation of waste and associated management cost factors are very high now in any chemical plant so be careful that all such cost factors are included in your evaluation.
Now to achieve the reduction in such cost factors like waste management etc. CIP is the first switch from disposable media such as cartridge or bag filters. the initial cost of such disposable filters is less and therefore, they are the first choice in general but in the long run if we analyse the life cycle cost including all cost factors as indicated in the first post, the CIP filters are more advantageous.
Following are the major factors which can lead to significant improvement.
1. No Waste Disposal
2. Cleaning frequency Vs change out frequency
Generally disposable media is discarded at fix frequency which is usually higher than required to safeguard the production and to maintain uninterrupted operation. On the other hand cleaning generates less effluent due to precise requirement whenever it is indicated based on differential pressure. This avoids unnecessary load on ETP by doing the cleaning activity at right time. So overall cost is less.
3. Reuse of Waste
In general, the cleaning fluid is compatible with the process so in most of the cases it can be recycled back to the process system without any effluent load. Even if it is very diluted washing it can be recycled in the next cleaning operation and thus reduction in overall effluent load can be achieved.
4. Loss of Product
Generally if you are using disposable media, mostly the process liquid or solid are lost with it and that is a direct loss of yield. This is mainly due to drainage of dead volumes, opening of seals etc.
As explained in the first post, many possibilities of spillage, exposure of workers, landfill liabilities etc etc are associated with disposable system where frequent opening of the entire system is required specially in pharma & food industry.
Apart from above direct benefits many indirect cost items are always there in proportion to the manual activities. So naturally those costs are very high for disposable media compared to CIP filters.
In next article I will try to describe few CIP filter in a short post.