Silicon Carbide Shell and Tube Heat Exchanger

Corrosion resistant silicon carbide shell and tube heat exchangers are designed for cooling, condensation, heating and evaporating highly corrosive chemicals. Constructed using directly sintered silicon carbide tubes sealed in PFA/FFKM lined F4 headers or steel headers, these heat exchangers feature superior corrosion resistance.

TEMA classifies heat exchangers by their front end stationary head and shell configurations. They can operate with either parallel or counter flow.

Advantages

A Shell and Tube Heat Exchanger consists of silicon carbide tubes enclosed within a stainless steel or PFA lined shell, where one fluid circulates through its tubes while the other flows over them and through the shell itself, with heat transferred via conduction from one fluid to the next. Suitable applications for such an exchanger include cooling, condensation and heating processes as well as absorption or evaporation applications.

Silicon carbide possesses outstanding corrosion resistance, standing up well against sulfuric acid, nitric acid, phosphoric acid, mixed acids, hydrofluoric acid and strong alkalis. As such it makes for an excellent replacement for graphite in highly corrosive environments. Furthermore, directly sintered silicon carbide (SSiC) can be easily welded compared with SiSiC which contains free silica that may be attacked by chemical solutions and washed out of a heat exchanger through chemical attacks on free silica present within an infiltrated silicon sic (SiSiC).

Shell and tube heat exchangers are more compact than plate-type heat exchangers, and offer the advantage of being easily opened for inspection without dismantling. GAB Neumann’s SR type heat exchangers feature a trunnion-supported baffle system, enabling access for cleaning on both ends – providing easy maintenance access on either end.

Anwendungen

Silicon carbide offers many applications in industrial environments and is an economical alternative to more conventional heat transfer materials. With superior corrosion resistance and thermal conductivity, silicon carbide provides longer lifespan with reduced maintenance costs and increased energy efficiency.

Heat exchangers with this design consist of an enclosed bundle of tubes filled with one fluid running through them while another passes over, keeping their paths apart without direct contact between fluids. Turbulence generated by flow baffles in the shell and internal turbulators within tubes helps enhance performance by eliminating any dead spots within its processes.

Ceramic tubes feature tight structures that naturally resist fouling, increasing time between cleaning cycles and decreasing downtime. Furthermore, SiC’s excellent thermal conductivity and low CTE make it an excellent material choice for applications involving rapid temperature fluctuations.

Umax heat exchangers feature a sanitary design that makes cleaning and repair simple without disturbing other tubes in their assembly or having to take parts out. This reduces downtime and costs significantly while leaving an inherently fouling resistant surface pressure washed or chemically cleaned without damage; further increasing reliability with double O-ring seals being simultaneously applied on both tube sheets and secondary counter plate.

Design

Silicon carbide shell and tube heat exchangers transfer heat between hot fluids and cold fluids using tubes encased within a cylindrical steel shell. One key requirement of such heat exchangers is their ability to handle large temperature variations and high levels of pressure; baffles help manage flow while internal turbulators ensure uniform tube side turbulence to enhance heat transfer efficiency while decreasing fouling issues.

Corrosion resistance is an integral component of silicon carbide shell and tube heat exchanger design, and these units can often be seen being integrated into chemical or pharmaceutical processes that use highly corrosive substances. To keep their ability to handle diverse chemicals intact, F4 or PFA lining is often employed on both its tubes and shell.

SiC ceramic tubes’ tight structures make them inherently resistant to fouling compared to other materials commonly used in heat transfer applications, which significantly increases operational time between maintenance downtimes and leads to greater productivity. Furthermore, this type of ceramic boasts high thermal conductivity, low CTE values, and exceptional strength that make it virtually immune to thermal shock.

Installation

Design of a silicon carbide shell and tube heat exchanger is heavily determined by process conditions, so selecting an appropriate device type and size depends heavily on factors like flow rate, temperature range, design pressure/temperature ranges, material compatibility/fouling issues as well as numerous other considerations. TEMA also regulates its structure design through specific identifications/classifications of various shell-and-tube heat exchanger types.

Thermal apparatus typically comprises of a shell with a channel cover fitted with baffles. Inside this channel is lined with a tube sheet – upon which are tubes located. Each tube sheet features its own holding seat equipped with circular coaxial seats designed to accomodate end portions of silicon carbide tubes.

Silicon carbide tubes are sealed using perfluoro elastomer (PFKM) O-rings pressed simultaneously onto both tube plates, creating a double seal to protect the heat exchanger from aggressive chemicals as well as high temperatures and pressures. Corresic’s range of SR shell-and-tube and SE block heat exchangers offers ample solutions for highly corrosive or abrasive industrial processes, including diluting concentrated sulphuric acid concentrations.