FEATURE FILTRATION & SEPARATION IS THIS THE END OF SINGLE USE FILTERS?
For years disposable cartridge filters have formed a key part of the water filtration market. However, Amiad Water Systems says it now makes sense to consider price-competitive self-cleaning alternatives
D
isposable cartridge and bag filters are a simple and typically lightweight
filter element, manufactured from a variety of materials and can cater to a range of filtration requirements. These consumable filters are placed inside a pressure vessel housing and the water flows through the filter material. Solid
Consumable Filters Low Self-Cleaning Filter Med/High Low
particles suspended in the water are trapped on the filter and will build up over time. The Differential Pressure (DP) across the filter will increase over time and once it reaches a maximum value the disposable filter will need to be replaced. Consumable filters generally work best in situations where there is not much solid material in the water as otherwise they would block very quickly and need regular replacement. Replacement will mean stopping the
water flow, and replacing the blocked cartridge or bag with a new one. Once the vessel is bolted shut the water flow can resume. Once used these single use filters are thrown away, and because they are classified as a waste they typically end up in landfill. As the cost of disposal increases along
with growing concern over single use plastics, what was once viewed as an essential part of the filtration market is now being questioned. In the first instance we are not talking
about needing to invent anything new here as the technologies are already available. Self-cleaning filter systems have been around for decades. The principle of a self-cleaning filter is that unlike the disposable filter, when the filter element is blocked there is a system that removes the solid particles from the filter element and returns it to a clean condition. Once the self-cleaning process is complete the filter can then carry on filtering the water until it needs its next cleaning cycle. The question must be asked, if the
technology is available then why are disposable filters still used? The answer is broadly speaking broken into 3 parts. 1. Capital costs – a throw away item is
likely to be cheaper in the short term 2. Good for small systems
34 MAY 2020 | PROCESS & CONTROL 3. An accepted technology for a given
filtration degree As we are talking about a consumable
item the purchase cost may be lower but you will need to consider the total cost of ownership and factor in labour cost for changes, production downtime and waste disposal costs.
Capex Cost Replacements Labour for changing/service Total Cost of Ownership (25yrs) High
Medium/High Low
High Medium The long-standing Achilles heel of the
self-cleaning filter has been its relative capital cost and complexity when compared to equivalent sized consumable filter system. It was this market challenge that the research and development team at Amiad tackled. The company sought to develop a self-cleaning filter which could compete at the same price point as the equivalent consumable filter system. In 2016 the company launched the
Sigma series filter and then followed this up in 2018 with the Mini-Sigma filter. The Sigma is a series of automatic self- cleaning filters which are lightweight and constructed from a durable, corrosion resistant polymeric housing. Being compact and modular the system can be used in various installation configurations. The new range also includes the Sigma Pro automatic polymeric multi-screen filters, offering a large screen area whilst maintaining a small footprint, and the ADI-P electronic controller, which can be linked to a mobile app for advanced monitoring capabilities and control functionality. By lowering the capex cost the argument
has now been turned in favour of the automatic self-cleaning filter. With the purchase price no-longer ‘too high’ to consider as a viable alternative to the single use filter, users will see a return on
Globally the consumable filtration market accounts for $1.6 Billion per year, and will continue to have its place in the market. Yet, a greater awareness of the problems caused by single use plastics will mean a more sustainable approach will be favoured in the future
their investment through reduced downtime and an increase in productivity.
CASE STUDY EXAMPLE A steel mill in Yorkshire, UK had an existing bag filter housing installed on one of their critical water supply lines. The filter bags had to be changed every 12 hours, resulting in high operational costs and time issues for personnel. The mill was looking for a solution that would reduce these costs, remove the need for site engineers to change the filter bags each shift, and improve their water quality to the spray nozzles. A series of water samples were analysed
As the cost of disposal increases along with growing concern over single use plastics, what was once viewed as an essential part of the filtration market is now being questioned
for TSS, oils and Particle Size Distribution (PSD). These results were reviewed by Amiad Water Systems to understand which particles were causing the mill issues. Following this analysis it was recommended that the mill utilise a high solid handling filter with a 200 micron wedge-wire screen [the automatic ABF 3000 brush cleaning filter]. Following the filter’s installation, the bag filter housing downstream was able to go one week between bag changes instead of only 12 hours. After 9 months operation the steel mill
then decided to upgrade their entire mill water feed system and installed a higher grade filter, again with a 200 micron screen. This filter now treats all incoming water supply to the mill and is capable of filtering up to 650m3
the whole steel mill has been improved. We are starting to see changes emerge
with improved alternatives disrupting the status quo and offering cost effective alternatives. When considering ‘cost’, we also need to remember the hidden costs of single-use filters, such as disposal and the fact that each of these filters are going to remain in our landfills beyond our great grandchildren’s lifetimes.
Amiad Water Systems
www.amiad.com
/hr. Water quality to
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44
