Product-to-product heat recovery

Wastewater, sewage, effluents and sludge are useful sources of energy with the potential to heat (or in some circumstances cool) other products or materials in industrial processes. The DTR Series of double-tube heat exchangers from HRS is designed to maximise direct (product-to-product) energy recovery from such low viscosity materials, allowing valuable heat to be recaptured before the effluent enters final treatment or is discharged to the environment.

Where biological water treatments are employed, it may be necessary to reduce the temperature of the effluent before treatment. For aerobic decomposition or other biological treatments, temperatures between 25 and 35˚C are recommended; with activity ceasing above 50˚C. However, the temperature of discharged cooling water is often around 40˚C; while work in Switzerland suggests that domestic wastewater typically has a temperature around 20˚C and rarely falls below 10˚C. Capturing the effluent closer to its source can result in higher temperatures.

Making use of any available heat is good for both your pocket and the environment, reducing the energy required for heating, with a corresponding drop in greenhouse gas emissions. Discharging water which is closer to ambient temperatures is also much better for the wider environment. The series has been designed specifically to use low viscous products (or waste streams) as the heating (or cooling) medium. The DTR series is perfect for direct sludge to sludge heat recovery and environmental industry heat recovery.

The tube-in-tube design means that the DTR series copes well with fluids that contain particles, without the worry of blockages impeding the flow of product or heating medium. Special stainless steel corrugated tubes are used to increase heat transfer and reduce fouling, making the DTR Series more efficient than similar smooth tube heat exchanger designs.

The inner tube of the DTR Series is removable for inspection, cleaning and maintenance, meaning that both the tube and shell sides can be inspected and cleaned, while the corrugated tube technology that HRS is so well known for improves heat transfer, yet reduces potential fouling compared to standard smooth tube heat exchangers. This allows the product or waste stream to run in both the inner and tubes. It also allows for easier and faster cleaning, so overall there is less operational downtime, even with high fouling products.

For large installations, multiple units can be interconnected and mounted in a frame, and a range of options, including thermal insulation and cladding in materials including stainless steel are available.

How success down under helped a British start-up achieve global recognition

When founder and CEO Steven Pither established HRS Heat Exchangers in the UK back in 1981, little did he know how significant Australia and New Zealand would be to his company’s success. Then called Heat Recovery Systems, the thermal technology specialist was a sole enterprise, acting as the UK agent for a Swedish manufacturer. Despite the long hours, single-handedly taking care of imports, sales, quotes and deliveries paid off for Steven, as the company made a healthy profit in its first 12 months.

Fast forward 38 years and HRS has received the impressive accolade of being named one of the UK’s top 200 fastest-growing firms for international sales in the Sunday Times HSBC International Track 200 league table. Specialising in the design and manufacture of its own, patented heat exchangers to the food, environmental, pharmaceutical and wastewater sectors, the company has changed immeasurably since its early days. It now boasts over 200 direct employees and has a network of offices and agents throughout the world – including Australia.

HRS’ success has been helped in no small part by a highly successful export strategy, underpinned by its dedicated office for Australia and New Zealand, which it opened in Melbourne in 2011. With this arm of the business expected to bring in sales of over €1.2m this year, Steven reveals the five cornerstones that have helped him take the company from a domestic start-up to a global corporation.

Invest in people
Look closely at any successful business and you’ll find a team of talented and committed individuals; HRS Heat Exchangers is no exception. “Our staff turnover rate is less than five per cent,” said Pither. “One employee has been with the firm since year three, and there are many more with over 20 years’ service. To build a successful business, you need core competency everywhere – engineering, sales, finance, etc – and not just in one department. Experience, reliability and knowledge are crucial to building a reputation, so we’ve worked hard to develop strong teams across the board that can deliver this.”

Like many engineering firms, HRS is at the sharp end of the skills crisis and Steven understands the importance of investing in people. “With the industry-wide skills shortage, it can be a challenge to recruit good staff, which is why we strive to hold onto the ones we have,” he explained. “To encourage staff retention, we offer competitive salaries, profit shares and bonuses; provide career development opportunities; and try to be as flexible as possible. We also offer apprenticeships, to keep the next generation of talent coming through.”

Think global
The importance of good people extends to HRS’ international operations. Although it relies on agents in some territories, the company has its own offices in Australia, as well as Spain, Malaysia, New Zealand, the US, Mexico, Russia and India.

“The vision was always to build an international heat exchanger brand,” reveals Pither. “An international presence helps you to be taken seriously by big customers; it builds confidence and trust. However, I decided early on that if HRS was to become globally successful, it was essential to find local talent in each territory who could communicate in the same language, and with the same cultural references, as our customers.”

The international gamble certainly paid off, as a combination of strong local teams and proven products is helping HRS to enjoy an impressive 41 per cent international sales growth (annual average based over two years).

Focus on innovation
Although heat exchangers remained a focus, as the business began to grow, Steven realised that his customers were looking for more than just pieces of kit; they were seeking integrated systems, which could provide entire solutions. To fulfil this growing demand, HRS acquired its own manufacturing site, and soon expanded with a bigger facility in India. These are supported by two workshops in Spain, where the company also houses its R&D and design departments. HRS’ range now includes entire wraparound solutions such as evaporators and concentrators, as well as an ever-expanding portfolio of heat exchangers.

“Thanks to our increased manufacturing capabilities, we now offer a wide range of patented and innovative designs, such as our R Series of scraped surface heat exchangers, specifically designed for viscous and challenging products with extremely high fouling properties,” Pither explained. “Our product development is customer-led, so our range comprises everything from heat exchangers with gentle handling capabilities for shear-sensitive liquids or soft fruits, to those with hygienic handling capabilities for the most stringent food or pharmaceutical demands.”

Keep the cash flowing
While a focus on people and products is essential to success, according to Steven the biggest restriction to the growth is access to finance. Developing good credit terms with your supplier is therefore crucial.

“Particularly in the early days, late payments and cash flow were a challenge,” said Pither. “We were importing equipment and had short credit terms from our suppliers, yet our customers were requesting long payment terms. This was a problem for us, so we worked hard on building a good relationship with our suppliers, proving ourselves as reliable and trustworthy. Over time, they extended our credit terms from 30 to 60 days, eventually increasing it to 90 days. The importance of this cannot be underestimated; you can have great products and a great team, but if you haven’t got cash, you’re in a dangerous position.”

Plan for the future
Finally, no business ever became successful by standing still. Despite HRS’ significant recent growth, Steven is still driving the company forward with plans for a testing facility in Spain, new process solutions, innovative prototypes, and an expanded core range of heat exchanger products.

HRS is also planning to offer a subscription to its software system, which will enable engineers to model different applications. The company hopes it will generate increased sales, as well as allowing them to spot trends by tracking what people are modelling.

And HRS’ international plans aren’t finished yet, either; Pither is focussing on developing business further in Australia and New Zealand, as well as in Russia and Latin America. But as the company has a five-year plan to increase sales more than $100 million, could he be tempted to branch out even further? “We’ve got no immediate plans to open any more international offices,” he said. “However, there are still some territories which appeal to me, such as China, Africa, and the Middle East. So, never say never.”