Pasteurisers used in the dairy process industry typically include a product path in which the milk is placed for treatment. A heating and/or cooling medium is passed through a separate circuit in close heat-exchange relationship with the product path via a number of heat exchange plates. Modern pasteurisers of this kind are known as HTST (High Temperature, Short Time) pasteurisers.
From time to time, leaks can develop between the heating/cooling circuit and the product path. Such leaks can be very costly, not only because the contaminated product must be discarded but also due to the cost of finding and rectifying the leak. Present preventive maintenance techniques involve shut down of the plant, dismantling of the pasteuriser, detailed examination and testing of the individual heat exchange plates using mechanical and/or chemical tests, careful cleaning of the components, re-assembly with new seals, pressure and leak testing, and recommission of the reassembled pasteuriser. Such a procedure results in considerable lost production time whilst the equipment is out of commission, is extremely labour intensive, and involves the cost of new seals. In addition, there is a substantial risk that further leaks can inadvertently be introduced during the re-building process.
An aim of the present invention may be viewed as being to overcome these problems.