So, your organization decided they need a new water filtration system, and you oversee this project. Great, but how do you even begin to approach this task?
Does the quantity of water matter? What about the size of the pipes? What do you actually need to know to properly size a filtration project?
We have been dealing with these questions for nearly six decades and know that in every case, the answers will differ. In order to begin, you will need to understand the basics of how our experts begin to size a project, and it all begins with figuring out what your requirements are.
3 Questions for Project Sizing
To size a project, we will need to understand several things:
- What are your pain-points – Why do you need the filtration system?
- What are your organization’s end-goals?
- What filtration technology is best suited for your end-goals?
Pain Points
When you talk to our experts, the first thing they will want to understand would be your pain points. What that means is they will ask you to explain why you need a new filtration system:
- Regulations – For example, what degree of filtration does your local government require of you when you need to discharge wastewater into a river? Are you installing the system to avoid being fined by your municipality?
- OPEX – Are the operational costs of your current solution too high? Do you spend a lot of manpower to maintain it? Are you using expensive chemicals to clean the system? Do you currently use temporary or disposable filters?
- Production Downtime – The filtration system can often sit in the heart of your production process. Does cleaning or maintenance slow down or hinders your operations, causing disturbances and downtime?
- Product Quality – In many cases, water quality can directly affect your end product, particularly in such as food & beverage, steel mills, and the paper industry.
Diagnosis
When we dive into the diagnosis process, we must consider many factors:
- Application – Is filtration critical to your process? In such a case, we may suggest adding a redundancy system to take over when the main system goes through flushing or maintenance.
- Defining the Success Criteria – How do you define the system’s success? Are you supposed to only remove turbidity or total suspended solids (TSS), or do you have to achieve a certain filtration degree? Establishing the criteria is vital and will help us fit the best solution to your needs, preventing over-sizing/under-sizing the solution.
- Water Source and Quality – Another major factor in choosing the right solution is knowing the water source. Does the water contain chlorides or oil and grease? What is the pH of the water? Are we dealing with water heated to high temperatures? All of these will determine what construction material will be used for your filtration system, and how simple or complex it will need to be.
- Type/Load of Contaminants – This has a direct effect on the choice of filter. Do we need to remove organic materials, minerals, maybe paper fibers? Different types of contaminants require different filtration solutions.
- Particle Size Distribution (PSD) – Understanding the PSD in your water will also affect the type of solution you will need. In some cases, a coarser solution will give sufficient results with no need for much finer filtration.
- Qualifications of Operators – Will the system be maintained by experienced engineers, or will it just be visually inspected at intervals? This will have a significant impact on how simple or complex the designed system can be.
Choosing Your Technology
So, what type of technology do we choose? Screen? Discs? Microfiber? Media?
At Amiad, we do not consider one filtration technology to be superior to the others, as each has its own strengths and uses, for example:
- Disc filters use a polymeric filtration element, making them the perfect choice for work in aggressive water (seawater, high in chemicals, etc.). They can withstand high PSI, high organic loads, and filter down to 10 micron.
- Screen filters have a small footprint, can withstand high temperatures, great for high TSS and inorganic loads, can operate in low-pressure systems, and can filter down to 10 micron.
- Microfiber filters can filter down to 2 micron, are an alternative to disposable filters, but are more delicate.
These are just some examples of the differences in filtration types. For more information, see the PDF below:
Sizing
To help us assess and suggest the right filtration system to each customer, we have created a handy sizing tool.
We divide the water quality into four categories – good, average, poor, and very poor. These categories are based on various attributes, such as the existence of suspended solids, organic contaminants (fungi, bacteria), and the chemical composition of the water.
As an example, achieving a 40-micron filtration grade, with average quality water, the maximum velocity should be 200 m³/h per m² (equal to 0.57 GPM per in²). When you take the total flow needed and divide it by the relevant value in the chart, you get the total minimum filtration area necessary to accomplish that.
Pre-Sizing Checklist
Here is a quick checklist to help you prepare for our sizing conversation:
- Do you know the hydraulic parameters for the system – available/required pressure?
- What is the available footprint? – How much room do you have for the filtration system.
- What is the upstream/downstream process? – Are there any contaminants that can flow into the system and affect its efficiency, such as corrosive chemicals, flocculants/polymers, etc.? Are you protecting sensitive systems downstream (reverse osmosis, nano-filtration, heat exchangers, and so on)?
- Backwash – Does it go into a tank, a drainage system? Does the drainage need to be throttled?
- Any other site conditions – Available power supply, ambient temperatures, construction materials, compressed air availability, etc.
- Location of the site – Will the system be installed at a remote location? Will the site be monitored?
- Operator qualifications – is the team in charge of the filtration process comprised of experienced engineers or does someone just perform a quick visual inspection for leaks?
- What is the expected lifetime of the system? Is it filtration for a short-term project, that will then be moved somewhere else, or is it a long-term solution?
- Are there any design standards required for the system? (ASME, CE, DW, etc.)
There is, of course, more to the sizing process and this guide is the basics of what you need to know. Our filtration experts are always happy to listen to you and help you in sizing your project and selecting the best filtration system for your needs.
You can also contact us and we will reach out to you shortly.
