Glass lined compact heat exchangers consisting of tubes made of SiC (silicon carbide) may be used for heat exchange in corrosive applications where both material flows are corrosive. In addition, the heat exchangers are extremely compact due to the excellent thermal conductivity of SiC, and are delivered in a form that is easy to clean.

Silicon carbide is becoming increasingly popular in a variety of applications where heat has to be transferred both efficiently and effectively due to its excellent thermal conductivity of up to 160 W/m²K. Figure 1 shows the thermal conductivity of conventional materials used in heat exchangers in highly corrosive applications.

The extremely high corrosion resistance of silicon carbide materials, which is equal to that of glass lined products (with the exception of strong oxidants) makes this material eligible for use in heat exchangers.

Optimum engineering solutions are nevertheless required due to the physical properties of this material. TE offers heat exchangers for corrosive materials on one or both sides that are characterized by a proper combination of glass and silicon carbide.

THALETEC-SiC compound heat exchangers made by TE close the gap between corrosive attack on one side and on all sides. The known high corrosion resistance of glass is combined with the equally high corrosion resistance of silicon carbide and the excellent thermal conductivity of silicon carbide in these applications.

This combination results in an entirely new product with extraordinary properties. Depending on the individual application, the design consists of tube bases with a glass coat on one or both sides, where the bored holes are also lined with glass (figure 2 and figure 3). The advantage of this design is that the number of joints between tubes and tube bases is halved.

In contrast to the gasket-free concept of the glass lined U tube heat exchanger, the tubes are sealed on both ends using 2 highly resistant O-rings made of perfluoro elastomer material with FDA approval (option). The tube ends have been precision machined in the area of the tube base, and have been fitted with grooves taking up the O-rings.

Based on the tube size of 28 (diam.) x 5 and significantly thicker walls than competitive products, these heat exchangers can be excellently cleaned with product flow in the inner tube. In addition, the pressure loss is fairly low due to the relatively large internal tube diameter.

The tubes are inserted without stress into the glass lined tube base(s). This kind of connection totally eliminates mechanical stress and tension of the SiC tubes. Thermal system stress is not transferred to the tubes as a result of the gasket concept.

In view of the application limits of -1/16 bar and temperatures up to 200 °C, heat exchange surfaces of up to 25 m² can currently be achieved with a nominal width of DN 500. The body has been glass lined by the known technical processes and is also available with an external jacket on request for further performance improvements. The achievable heat transfer coefficient K amounts to 350 to 1400 W/m²K.

Possible applications include evaporators, condensers, and liquid/liquid heat exchange. Of special benefit is the option to provide corrosion resistance on the inside/outside or on both sides.

In addition to the 2-base design frequently chosen, heat exchangers with a single glass lined tube base are also available. The advantage of this design is that the number of joints between tubes and tube bases is halved compared to the design with two tube bases.

Heat exchangers installed in systems that require regular inspections and cleaning ease are additionally equipped with inspection openings on the face side.
In order to make it as easy as possible for you to define your specifications for glass lined heat exchangers with SiC tubes and to submit a query, you may download a specifications sheet here, where you can fully describe your application. Simply complete the form and send it to us, and we will be pleased to submit a proposal.

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