Emech Control DEMM Feature – By Glenn Baker

Maintaining the right temperature for process situations has traditionally required large amounts of energy, water and labour. Now the Emech Control system is changing that.

We all know what it’s like to be enjoying a shower and have another family member turn on a tap, which immediately affects the temperature! The resulting blood-curdling scream is enough to wake the dead!

It is this exact scenario that inspired Emech Control directors Brad Houghton and Peter Jeromson to devise a system based on an electronic mixing valve that would solve this problem once and for all. That system has now advanced to the stage where it can have huge implications on New Zealand process industry and overseas earnings.

Emech Control’s marketing manager David Parkinson takes up the story:

“It was in the 1990’s when Brad and Peter set out to develop an electronic mixer for hot and cold water. Designed for the home bathroom for use in showers and bath fillers, it comprised a high speed electronic actuator; a three-port ceramic disc mixing valve and an integrated closed-loop control; all performing to high performance thermostatic standards AS 4032-1998.

“To cut a long story short, the package was very successful, and the goal of introducing electronics into domestic water control was achieved. The technology was patented and in late 1998 the company sold the technology and intellectual property to American Standard Inc. a NYSE company, while retaining an exclusive royalty-free perpetual licence to further develop and exploit the technology for commercial and industrial use.”


The ceramic disc and its commercial benefits

The vision that Brad and Peter had for the commercial application of the system has now become a reality, with one recent example being the Richmond meat works at Takapau in Hawkes Bay. The technology is also seen to be critical in the temperature control of yeast in the wine making process – with engineers currently evaluating the system. A trial is also underway at a dairy plant to reduce the temperature variability in the pasteurisation process. Results to date have reduced temperature variability by as much as 50 percent.

Emech Control has proven the scalability of the technology for industrial water management by producing a range of three-port electronic thermostatic mixing valves and two sizes of electronic actuator units – the combination offering speed, accuracy and performance. The company has also developed two-port flow control valves – an addition to its range of precision control equipment.

At the heart of the new technology is the ceramic disc, which Parkinson says offers a lot of features over traditional valve systems.

“The most important feature is positional control – the rotary shear action of the disc unit means that it can be rotated to a position with a high degree of accuracy,” he says, adding that the design minimises water hammer (which he likens to putting the plug in on a rapidly emptying bath), and therefore assists in improving flow control.

The ceramic disc valve is said to outperform other types of valves, especially the butterfly valve which can be found in around 80 percent of all industrial applications.

“Emech views heated water as the life-blood of industry” says Parkinson. “So any saving of that resource has got to impact the bottom-line and reduce product variability. It’s all about maintaining consistency of supply, and is not unlike investing in spike protection for a PC.”

The ceramic discs demonstrate very little wear. “We have test units in the marketplace that have operated for more than 400,000 cycles and upon inspection of the discs there was very little scouring,” says Parkinson. “What we find exciting is that the ceramic discs have now become the industry standard in the domestic market. The technology is now available for industry applications (sizes 20mm to 50mm), not just in the mixing application, but also simple flow control using the two-port valve.”

Parkinson says the three-port mixing valve has had an enthusiastic response from industry – especially those that require the mixing of water to critical temperatures.

“We have visited many industries that experience big pressure fluctuations from their boiler, especially when there are a multitude of other operations around the plant. The draw off from these operations creates big slugs of hot or cold water, which inevitably affects production, and can result in product variation or even plant shutdown,” he says.

E-mech has also noticed that many operations have tried to eliminate this problem by having secondary storage tanks on site – pre-mixing their water into these tanks.

“The problem with this design is it can be wasteful in resources,” explains Parkinson. “The water in these tanks cools overnight, and at the start of the next production day boiler water is introduced to bring this tank to operating temperature. If the tank is full, then the addition of water wastes both water and energy resource until the operating temperature is achieved.”

As Parkinson points out, warm water is also an ideal breeding ground for bacteria such as legionella. “We have discovered this is a real problem in Australia, especially in processing plants located in tropical climates.”

Emech’s three-port valve reduce this risk by providing true in-line mixing. The Emech system controls to 0.5 degrees Celsius accuracy, and only uses the amount of water that is required.

“The other benefit is that you save on heating costs as the system delivers accurate control,” says Parkinson. “At some installations the payback of our units has been achieved within months. There are savings in labour, water and heating costs, not to mention increased production.”


Kiwi-built and Kiwi-backed

Emech Control has been fortunate to secure assistance from Industry New Zealand in providing research data and further development of its patented technology.

“In the past two years, Emech has focused on perfecting the design,” says Parkinson. “This meant that we had a small and dedicated team of electronics engineers, mechanical engineers and software programmers collaborating on the project. During this period, we have also had the financial backing of a major New Zealand merchant banker, which makes the product 100 percent owned and operated by New Zealand talent and business people,” he says.

Emech has also developed a smart electronic actuator that can provide placement of its ceramic discs to within 0.006 degree accuracy. The Emech engineering team worked for considerable months developing their own stepper motor driver, and configurable controller electronics. The actuated valve has been designed to operate as a stand alone unit, or be remotely operated via a traditional 4-20mA control signal. An Emech failsafe optical encoder has been built in to give the unit a position signal on power-up after any electrical supply failure.


A huge future

Emech’s patented technology is unique, and very few overseas systems can deliver the accuracy of ceramic disc technology – if they do, then they come with a very high price-tag. Since being production-ready in September 2002, Emech has identified numerous applications where its mixing unit can add value.

“Our goal is to improve productivity by minimising process variability and reduce process losses,” says Parkinson, “both in water and energy.”

Emech’s research has identified applications in the meat industry where temperature control is vital. Hand-wash, wash-down, sterilisation and processing temperatures are critical in this environment, and Emech has a solution to all these applications.

“Our present project is the application of our two-port ceramic valve in the dairy industry, which is looking for tighter pasteurisation controls in the cheese-making process,” says Parkinson.

“Our two-port ceramic disc valve, with actuator, can provide tight control of hot water into the heat exchanger, thereby reducing pasteurisation variability. This equates to improved productivity, better product, and smarter use of energy,” he says. “We know that New Zealand operators are not alone in their challenges – and if they’re happening here, then it is also happening overseas.”

Interest in the unit overseas has been very positive, and there has been a steady flow of enquiries from Australian meat processors, and companies involved in pasteurising. Millions of dollars worth of overseas earnings stands to be made in the next five to ten years.

That’s something to think about next time you take a shower.


Enquiries: David Parkinson
Marketing Manager
Emech Control Ltd
PO Box 2388
Auckland
Ph: 0-9-307 0700
Fax: 0-9-307 0800
Email: dparkinson@emechcontrol.com