Novel heat exchanger could improve sauce consistency
processing methods is being evaluated as a means of helping
manufacturers improve the consistency of their sauces.
Heat exchangers allow processors to control temperatures; an essential requirement for most food production methods. In some applications, the product needs to be held constant temperature whilst heat is liberated or absorbed. In others, the product temperature may need to be altered in order to bring about the desired change.
Campden and Chorleywood Food Research in the UK says it is doing an analysis on the innovative batch vessel developed by Ashe Morris Ltd. The heat exchanger uses a new technique, called the 'constant flux control' method, which the company licences under its Coflux branded technologies.
"This simple, innovative batch vessel has potential for several advantages over conventional processing," Campden and Chorleywood stated on its Internet site. "We are looking in particular at its potential for high-response process control, flexibility in processing varying product volumes, and reduction in burn-on of splashes."
The vessel is equipped with a sophisticated calorimetry system that enables real-time monitoring of power and enthalpy which could be used to track process reactions.
The food research firm says its staff are looking at whether the system can be used to detect the gelatinisation of starches in order to improve the consistency of 'cook-out' in sauces. They will also compare the colour and texture of white sauce prepared in a conventional steam pan with those prepared in the Coflux vessel.
Conventional heat exchangers vary the heat transfer fluid temperature to regulate heat transfer capacity during food processsing operations. Usually this is achieved by varying the flow or temperature of heat transfer fluid within the heat exchanger.
Ashe Morris says it has developed a new design can deliver stable temperature control with a substantially constant logarithmic mean temperature difference (LMTD), a method of calculating . This technique is referred to as 'constant flux control'.
The method regulates process temperature without varying the velocity or temperature of the heat transfer fluid passing through the heat exchanger.
"Apart from offering better temperature control, the constant flux method allows the user to measure heat changes in the process with great accuracy," the company claimed. "For the first time, manufacturers can use industrial reactors as reaction calorimeters. The on-line data that this provides can be used to improve the economics of manufacturing processes in a variety of ways."
Normally heat transfer fluid passes through the heat exchanger to add or remove heat from the process. The amount of heat added or removed is determined by the prevailing conditions.
In conventional heat exchangers, the amount of cooling or heating is controlled by regulating the heat transfer fluid temperature. This can be done either by adjusting the flow rate or delivery temperature of the heat transfer fluid.
Ashe Morris' constant flux technology regulates heat transfer by varying the heat transfer area. In the design the heat transfer jacket is split into multiple independently controlled elements.
Heat transfer capacity is modified by varying the area of the jacket. This is achieved by switching elements of the jacket on and off independently.
Ashe Morris has also developed a method of using calorimetry as an monitoring tool, with the data available online. Calorimetry refers to the measurement of the amounts of heat absorbed or given out during processing.
