MEAT, POULTRY & SEAFOOD
Improving efficiency in
meat processing Chris Little, Director, HRS Heat Exchangers
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ach year Australia wastes around 7.3 million tonnes of food (equal to ~300 kg per person), which accounts for more than 5% of Australia’s greenhouse gas emissions1. Not only does this waste have significant environmental impacts, but there are economic costs as well (the government estimates food waste costs the economy $20 billion each year). Australia has set itself a target to halve food waste by 2030, and all aspects of the food chain, from farmers through to consumers, have an important role to play in reducing the nation’s food waste. The processing sector is one area where some minor changes and specifying the right equipment can lead to significant economic and environmental improvements. Food waste costs processors money in various ways. If a product is produced (or even partially processed) and then not sold, it has incurred costs including the cost of the raw material ingredients and the energy and labour that has gone into its production. It has also prevented the production of useful product which can be sold (an opportunity cost), and there may well be disposal and treatment costs associated with getting rid of the waste product. These costs can soon add up even at low levels, and each of these factors will have both a financial and an environmental (carbon) cost, so minimising or preventing waste has huge benefits for companies and the wider community. One easy area to target is to minimise the losses of product which occur in equipment, and in an ideal world two different techniques will be used in combination. The first is to design food processing equipment, such as tubular heat exchangers, which prevents product adhering to surfaces in the first place — keeping it flowing through the system. The second aspect 36
November/December 2021
is the use of dedicated systems to clean and recover product from equipment after processing and before full cleaning occurs. Many modern heat exchangers are designed to handle viscous materials without fouling. Some of these units use corrugated tube designs, but in the most demanding situations, scraped surface heat exchangers are used as the scrapers continually remove residues, preventing the build-up of potential waste material. These heat exchangers can be used for numerous processes, including heating and cooling, cooking, concentrating, pasteurising and sterilising. This scraping action provides two advantages. Firstly, as the material being treated is kept moving and does not adhere to the tube surface, losses during processing are minimised. Secondly, because a ‘fouling layer’ is not built up, the optimal thermal performance of the heat exchanger is maintained, increasing process efficiency and reducing energy use or treatment times. However, no matter how much you avoid product buildup during operation, equipment eventually needs to be cleaned. Depending on the range of products handled and product complexity, this may be required several times a day between production
www.foodprocessing.com.au
