Method in continuous heat treatment of a liquid the flow of which varies
AssigneeAlfa-Laval AB
InventorsMagnus Lidman, Kare Eilertsen, Alf Karlsson
Life of this patent
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Abstract
When continuously heat treating a liquid the flow of which varies, incoming liquid is preheated by already heated liquid and is then heated to a predetermined temperature-time-effect by a medium giving off heat in a second step. The flow of incoming liquid is sensed and controlled by a pump (1) with a variable capacity. The amount of heat needed to obtain the desired heating effect is influenced by a control unit (9). The heating effect is adjusted to the liquid flow by increasing/decreasing the temperature of the medium giving off heat or increasing/diminishing the flow of this medium from a heat store (6).
Claims9
A method for the continuous heat treatment of a liquid subject to biological contamination, said method comprising the steps of:
- preheating incoming liquid by passing the incoming luquid in direct heat exchange relationship through a first heat exchange section with already heated outgoing liquid, to thereby preheat the incoming liquid and cool the outgoing liquid;
- controlling the flow of incoming liquid to said first section by passing the incoming liquid into and through a variable capacity pump while sensing the flow of incoming liquid to the pump and operating the pump at a desired operating speed;
- thereafter passing the preheated liquid in indirect heat exchange relationship through a second heat exchange section with a heat exchange medium, the heating capacity of said second section being adjustable by varying the heat input thereof, said heat input being dependent upon a temperature-time effect based on the temperature of said medium and the flow thereof through said second heat exchange section;
- controlling the heating of said preheated liquid in said second heat exchange section by adjusting said temperature-time effect in response to said pump operating speed;
- and
- said adjusting step comprising the step of varying the heat input of the second indirect heating section.
Dependencies are inferred from the claim text.