High quality tube couplings for safer operation
A glass tubular PBR in which the tubes are aligned horizontally, is typically built the following way: Up to ten tube segments of 5.5 meters in length each, are connected together as one tube, which lie on one level. Manifolds or u-bends then connect these tubes with each other on the different levels.
The individual tubing segments and the u-bends or manifolds in a PBR have to be securely connected to one another. Until now, this was usually done, by using one of the following two methods:
- Adjacent tubing ends are pushed into a piece of silicone hose. The hose is then tightened with hose clamps.
- The tubing ends are pushed into a plastic hose, which is then heated using hot air. The plastic collapses onto the glass tubing tightly forming a shrink sleeve.
These connection methods are associated with a wide range of problems, most importantly none of the possible solutions offer much resistance to pressure. In recent years, more professional couplings made of special polymers for the use in PBR systems have become available. These couplings withstand higher pressures of up to three bar (43.5 psi).
Positively, the innovation continues: recently, slim couplings have become available that are just as pressure resistant as their larger counterparts are. These slim versions are more easily mounted, reducing the dead space even more around the tube connection and, additionally, are more affordable. If food grade couplings are required, these are now available as well.
You can learn more about the topic of high quality tube coupling and other important milestones within the innovation of tubular glass PBRs in our free e-book “Why is a photobioreactor made of high end glass even better today than it was five years ago“