Batch Ohmic Heater
Fast, efficient heating for testing
and recipe development
Our two-litre batch ohmic heater is designed for fast, even, efficient heating of moist foodstuffs and liquids. This model has been used for recipe development, conductivity measurement, cooking testing and heating assessments. It runs from the mains electricity supply at 240 V (customised versions are available in other voltages).
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The heater has adjustable electrode separation which can be supplied with separations in the range 3cm to 30cm. Electrode separation adjustment is by insertion of different dimension interchangeable/combinable spacer sections between the electrode housings. A number of spacers are supplied allowing several permutations for separation to be configured. The heater body is made from polypropylene and the heater is rated to 10 kW.
A product volume range from around 100 ml (at 3 cm separation and 37 mm product depth) to around 2 litres (at 300 mm separation and 75mm product depth) is feasible.
The unit includes a benchtop mounted control panel with a discrete Eurotherm PID temperature controller. This provides heater power control under automatic PID control or manual heater power control. Heating under PID control can heat to a setpoint temperature and hold at this temperature. Retransmission analogue outputs (0 to 10 V DC) are provided for heater current and voltage for data logging purposes, and the control temperature can be externally monitored or logged. Data logging of all temperatures and heater current and voltage can be provided as an option using a small plc or touchscreen. Three temperature probes are provided as standard one of which is a control thermocouple.
The enclosure lid has see-through panels and is a simple lift off type with safety interlock switches which prevent heater operation and switch the heater off if they are not made. The enclosure also forms a bunded space in the event that liquids boil over or spill. The heater cell can be easily removed and placed, and easily disconnected via thumbscrews for filling, and cleaning. Multiple heater cells can be provided if required.
The heater unit is protected electrically by an insulating enclosure which has safety interlock switches and also a residual current device (RCD) monitoring circuit which monitors the current supply and return from the heater with an imbalance trip level set at 30mA.