The static mixer heat exchanger prevents large temperature differences in the product
Cooling and heating viscous products is usually difficult in comparison to watery products. This is primarily because forced convection is missing, the flow patterns are in the laminar area and therefore adequate replenishment of product to the heat exchanging surface fails. This can lead to large temperature differences in the product and can have a negative effect on the quality of the end product.
Heat exchanger according to the basic principles of the static mixer
Because static mixers purposefully disturb the flow patterns in a tube, it is possible to improve the heat transfer with static mixers when cooling and/or heating. This principle was the basis of the development of the type of heat exchanger that PRIMIX manufactures.
Heat exchanger construction
The PRIMIX inline heat exchanger consists of single or multiple parallel mounted pipes. The heat-exchanging medium flows around these pipes; that can be either cold or hot water, as well as hot oil or steam. The viscous product flows through the heat exchanger tubes and exchanges its heat on the colder or warmer surface of the tube. The spiral-shaped mixing elements which are placed in these heat exchanger tubes disrupt the laminar flow pattern, allowing a better renewal rate of product on the heat-exchanging surface and thus a more efficient cooling or warming-up process.
With ACT 20% - 100% more heat transfer
The Advanced Connection Technology (ACT) used in the PRIMIX heat exchangers, results in additional contact surface and a 20% to 100% better heat transfer. With this technique, the mixing elements are seamlessly soldered into the tube. The slit, which is located between the spiral shaped element and the inner wall of the tube, gets completely filled with soldering material. By ensuring optimal conditions during this soldering process this connection between tube and element works as a heat conductor. As a result, the surface of a mixing element also gets involved in the process of heat exchange, resulting in a more compact and efficient design of the heat exchanger.
Minimisation of the residence time spread in the heat exchanger
In the design of the heat exchanger minimisation of the residence time spread is achieved by the optional use of dedicated adapters with razor-sharp edges. The flat inflow surface of the pipe sheet has thus been completely concealed resulting in a significant improvement in the flow pattern. The design is used as standard for viscous and responsive liquids where minimization of the residence time spread is important. Further minimization of the residence time spread is achieved by providing the heat exchanger elements with very smooth surfaces in places where the product to be cooled comes in contact with the heat exchanger surface. The reliability of the PRIMIX constructed static mixer heat exchanger has proven itself in crucial applications in the chemical, petrochemical, pharmaceutical and food industries. Explosive and toxic process media are reliably mixed and thermally treated in this way.
Laminar flow heat exchanger – motionless mixer system
The viscosity of the flowing product has great influence on the flow pattern through the empty tube. This flow pattern is mostly laminar and really not turbulent. A laminar or layering flow pattern means that, in theory, liquid in the centre of the tube flows the fastest and the liquid closest to the tube wall is stationary. The in between layers of liquid behave like circles of equal flow; they are the flow layers or laminar flow pattern. With a motionless mixer system or static mixer this flow pattern is broken. Liquid on the inside tube wall is folded in and the liquid in the middle flows towards the tube wall again, allowing more liquid to come into contact with the inner wall. In a pipe heat exchanger, this inside tube wall is used to exchange heat; the static mixer improves this process significantly.