What’s the most common problem in a water treatment system?
The most common problem would be change in influence, changes in the quality of water that comes in where by the system does not change or respond favorably.
From a basic level if you have 20mg per litre of polymer being dosed to remove solids from the water and your solid levels don’t increase you end up having solids coming out the other end.
It’s difficult to be able to change the process when what it is that you’re processing changes, water in this case. To be able to keep the same outcome, the product needs to maintain the same conditions.
The challenge with water treatment is that the systems are exposed to environmental factors, to problems associated to the processed product so the only thing that’s consistent is the fact that the water conditions are going to change all the time.
It is important to have a treatment program from a chemical perspective that buffers the changes to a degree. To have a process that can detect changes and respond appropriately is also extremely important, that is Automation. Fit for purpose application, automation and broad-spectrum chemistry are key factors in maintaining a water treatment system. Under normal operating conditions this should buffer out most of the changes which gives you a good result.
But there’s always a chance of a catastrophe scenario where the changes are so big and so broad, that the measures that are in place can’t deal with it effectively. The trick is to get 90-95% compliance and on the odd occasion when things go wrong, work with the issue. We believe that is better to have a system that’s 90% perfect and 10% a challenge rather than 10% perfect and 90% trying to get this stuff not to happen.
You complicate the system too much that it becomes so complex to run and operate just for that 10%, as long as it’s simplified.
In order to control big changes you’re going to have a lot of equipment or staff or people, it’s hands on. You need to weigh up the costs financially from a business perspective.
Environmentally, if that 10% has a huge environmental impact to the point where it’s unacceptable, then yes you need to put measures in place to make sure that 10% becomes 1%, where as if it’s once in a blue moon that it goes a little pear shaped its ok as long as you’re not polluting the environment and doing something outlandish.
Sustainability - What’s the percentage of recycling that you do with the chemical containers?
I guess 80 20 rule, 80% are recycled and 20% are replaced cause they do get old. You’ve got corrosion and you have to have a certain level of reliability and risk minimization. Packaging is, from an environmental perspective, crazy. You see it all the time people deliver chemical in a 1000L IBC, and they pay for that IBC, then that IBC gets re-used one more time and it usually ends up with a waste product in it, then it gets pumped away or taken away and maybe gets recycled to another company and probably ends up taken to landfill or destroyed or damaged. So we try and keep that in house and recycle our packaging as much as possible so that we become more competitive cause the customer has to give the packaging back and also cause we have less waste into land fill and the environment. And also as it makes good business sense, if the packaging is tested with low risk, there is no reason not to recycle.
In saying that though, nothing lasts forever and so you need to keep on top of it.
It comes down to age and handling with the 80/20%, and also the care people take, some people get a little heavy handed with the equipment.
The recycling does not affect the product at all. We recycle product to product, so we wont put different chemicals in each IBC, even though they get inspected and cleaned. You can do that with a little bit of management and a little bit of care, its not difficult to do, unless you were maybe a multi national company, which is then an issue as you don’t have the viability of putting a support structure behind it, its cheap, it becomes a commodity and becomes easier to throw away. Sustainability needs to become profitable or at least cost neutral otherwise it goes against its own meaning.
We believe to recycle of packaging, minimising the costs to buy more packaging, we minimize landfill. When the packaging is not safe anymore we replace it.
Why is Automation important?
In a treatment plant setting it “frees-up” the operator to analyse the system more holistically rather than having to be consumed with repetitive tasks and processes. Automation also increases the availability of a treatment system beyond operator working hours.
Cooling requirements for control panels (heat issues) and the different ways of cooling
However, three types of cooling are normally utilized:
- Convection – transfer of heat from the surface of the control panel
- forced ventilation – fan pumping cooler ambient air into the control panel and then convection is conveyed to the panel internal components
- Air condition – instead of pumping ambient air into the cabinet air is cooled within the air conditioner unit and circulated within the cabinet.
Tips to keep control panels working properly?
- Ensure no ingress of dust, liquids, or vermin. So all penetrations must be utilized by cables or blocked and all door seals must be functional. Mounting points of the cabinet should not be susceptible to any ingress.
- If the cabinet is exposed to vibration a periodic tightening of all terminals will ensure cabling will remain connected and circuits working.
- If the control panel is cooled by fan or air conditioner make sure filters and vents are clean and free of dust and debris. The air conditioner will have its own maintenance requirements from the manufacturer.
- If the control panel has a HMI touchscreen ensure that “clean” fingers are used to operated and wipe with a damp towel to keep it clean and functional.
Best process of choosing a PLC and control system?
The PLC must be fit for purpose in both function and the environment it will be installed.
- Does the PLC have sufficient inputs and outputs
- Does the PLC have the correct type of inputs and outputs – digital and/or analogue
- Does the PLC need to communicate with another system? Is that form of communication protocol available with the PLC being considered?
- There aren’t too many features that are not going to be used. PLC’s have a plethora of features but there is no need to pay for high level and expensive features that will not be used
- Are spares readily available – for replacement or expansion
- How much is the PLC and associated programming software – does that sound reasonable when compared to the process being controlled?
- Is a touchscreen HMI to be used with the PLC or SCADA software?
- Can enough information be available at an operators finger tips quickly to ensure intuitive navigation of the control system and facilitate a quick response to a process
- Is there an existing brand or model used by a client that they wish to use to minimize the number of spare components kept in stock or because of the clients in-house knowledge base.
What is the reliability of new technology compared to old technology?
New technology is just as reliable.
What new technology brings to the table is typically increased functionality and ease of use. It is also supported when it comes to fault finding or expansion.
Modern PLC’s and HMI’s in general are:
- Faster meaning the workload of the control system can be increased in relation to an old system
- Have more standard features that used to require additional models or equipment
- Able to store and transfer information more effectively
- Can display the information more effectively for less cost (HMI screens in particular )
- Supported by local distributors who can supply replacement parts, components for expansion and assistance with troubleshooting.
- Types of equipment are now able to communicate and transfer large amounts of status and control information compared to old technology based system. Example: a variable speed drive connected to a PLC via Ethernet can transfer virtually all status information to the PLC well beyond the available status outputs at the terminal strip.