The inadequate level of resistance of sealing material between the individual plates of a heat exchanger has often restricted its application in chemical and pharmaceutical process technology.
A suitable solution to address this problem is the use of plate heat exchangers with laser welded modules, such as those successfully provided for a number of years by thermowave.
The greatest degree of reliability has been achieved even when using this type of heat exchanger in critical applications by substituting approximately 90 % of the gasket with a laser weld seam. The remaining elastomer ring gasket (approximately 10 % of the original gasket length) merely has the function of sealing the opening between the modules and has a chambered design such that only a small contact surface area remains between the medium and the ring gasket. In a further development, thermowave succeeded in significantly increasing the resistance of the remaining ring gasket by using PTFE-encapsulated elastomers.
However, plate heat exchangers that open and that can be cleaned on both media sides are often required in process technology. Because this is not possible for module welded devices, and the media used in the applications concerned often belong to that group of materials which is dangerous and diffused with standard elastomers, the use of plate heat exchangers for such applications has until now been limited.
thermowave was able to overcome this hurdle by consistently developing the PTFE-encapsulated ring gasket into a PTFE-encapsulated complete gasket. PTFE (poly-tetra-fluoroethylene) is a hard material which is inert to most chemicals and in addition extremely diffusion resistant. In order to be able to securely seal the plate gap despite the hardness of PTFE, close collaboration was required between the gasket tool manufacturer, the sponsor thermowave and the gasket supplier.
The result of this work, the PTFE-encapsulated complete gasket, is now available for the sizes of device that are frequently used in process technology. The use of this special gasket enables us to make a new lucrative offer to the process technology industry in the form of ThermoLine plate heat exchangers! Advantages such as an excellent cost/performance ratio, expandability and replacement of worn components are still fully present when using the PTFE-encasulated complete gasket in ThermoLine plate heat exchangers.
However the key advantage over other models of heat exchanger is the ability to open the device as required and to individually clean each plate. This of course applies to the use of all materials commonly used in process technology and which are available for ThermoLine heat exchanger plates.
The first interesting projects, including one application with Butandiol, have already been completed.