A heat exchanger Furphy worth believing

Furphy Engineering, a company whose name has become part of the Australian lexicon, now has a new reason to feel unique. It is the only local manufacturer using laser welding to manufacture ATEX plate heat exchangers. Matthew McDonald writes.

During World War I, water carts made by Shepparton-based Furphy Engineering were used to deliver water to Australian troops.

Like today’s water coolers, the carts became places to meet and talk. Of course, talk has a habit of leading to gossip, so stories heard around the water carts came to be treated with scepticism. And you guessed it, they became known as ‘furphies’.

The rest is history.

Today, stainless steel tanks and vessels are Furphy Engineering’s main area of business. The company counts dairy companies, chemical companies, and breweries amongst its many and varied customers across Australia.

Manufacturers Monthly recently caught up Managing Director Adam Furphy (a fifth generation descendant of the company’s founder).

He explained that one of the standard features for many modern tanks and vessels, particularly those used in food and beverage applications, is what’s known as cavity plate, dimple plate or cooling jacket. ‘Dimple’ refers to the uniformly bumpy surface of the plate.

“It’s essentially an outer skin on the shell of the tank that is formed such that there’s a cavity between the outside of the tank and a second wrap of material and through that cavity glycol or cooling fluid can be run to cool the tank,” he said.  Alternatively a heating liquid can be used to heat the product inside the tank via the same process.

It provides a way for wine makers, dairy factories, brewers and so forth to keep their products at the right temperature to optimise their processes.

Furphy Engineering is the only company in Australia which uses a laser welding technique to manufacture Advanced Thermal EXchange (ATEX) dimple plate.

In the case of tanks and vessels, the ATEX Plates are described as single embossed whereby only the thinner outer skin of the plate is deformed when the welded plates are pressurized.

“That’s the way we’ve been doing the majority of our applications to date but recently we’ve become more interested in what we’d call double embossed ATEX applications,” said Furphy.

He explained that, unlike the single embossed material created for tanks and vessels, double embossed ATEX plates are dimpled on both sides and are therefore suitable for complete immersion in the medium to be heated or cooled, doubling the heat exchange surface area. Plates can then be banked together using manifolds and tailored to fit in an existing installation, providing a highly efficient and customisable immersion plate heat exchanger.

According to Furphy, the applications for this are far reaching. “We’ve seen inquiries for regulating key product temperatures, keeping waste water below regulatory requirements; or to simply cut costs by turning waste heat into pre-heat. ATEX allows us to tailor solutions to an even greater range of these heat exchange problems that are everywhere in industry,” he said.

The benefits

According to Stephen Lawrence, an R&D Consultant for Furphy Engineering, heat exchangers manufactured using ATEX Plates are also useful from a thermally sensitive point of view. They lend themselves to use as falling film plates in chillers and evaporators which are particularly suitable for delicate products used in food and chemical industries.

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“Making [those products] is difficult with traditional heat exchangers because you get a rather short dwell time which means you have to transfer a lot of heat from the product to the heat exchanger very quickly and thermally sensitive products like that struggle,” Lawrence told Manufacturers’ Monthly.

In contrast, using ATEX heat exchangers, the material flows down the outside of a long plate, allowing more time for it to perform the heat exchange.

“This, in turn, is more delicate on the product and gets the end result more effectively,” said Lawrence.

According to Furphy, the versatility of the technique is another advantage. “Any shape you can think of we can make in ATEX plate,” he said. “…shapes you couldn’t do before in terms of heat exchange become possible.  Examples are pipe work and gas ducting.”

In addition, the heat exchangers are made with food grade stainless steel, and are easy to clean and maintain.

Furphy pointed out that laser welded dimple plate is currently much more widely used in Europe than in Australia. He sees a gap in the market which his company is now seeking to exploit.

He offered an explanation as to why Australia is lagging behind in this area.

“A large number of the applications we’ve seen relate to energy saving of some kind,” he said. “That seems to me to be the real driving force behind the use of the products. Not all of it, but a significant feature.”

“The Europeans are more dialled into this because they’ve had a longer period of high energy prices.”

In contrast, he said, high energy prices and the need to reduce energy usage are relatively new to this country.

 “By and large in Australia industry is still getting its head around what possibilities exist and what potential there is to reduce their energy costs utilising some of the waste heat streams that perhaps exist on their existing sites,” he said.

Pointing to the example of a northern Victorian laundry operation which was able to cut its water usage by 20 per cent and its gas bill by 14 per cent by installing an ATEX heat exchanger, Furphy said the savings are there for those who want them.

Sounds like a Furphy worth believing.