3. Ensure accurate fermentor temperature control
Production yield is very dependent on accurate temperature control during the fermentation process. Keeping the microorganisms at a precise temperature is crucial for a high production rate and a minimum of unwanted by-products.
There are two ways of cooling the broth: either by running cooling water through an internal loop in the fermentation tank, or by running the broth through an external heat exchanger where it is cooled off.
High yield and minimum contamination
The best choice is an external, compact heat exchanger. Thanks to their small hold-up volumes they offer very accurate temperature control, thereby maximizing production yield.
A compact heat exchanger can work with a ΔT as low as 2°C (3.6°F). In many cases, this means you can cool the broth using normal water instead of chilled water and save on both energy and investment costs.
Using an external heat exchanger instead of an internal cooling loop also makes the tank easier to clean and minimizes the risk of contamination.
Alfa Laval heat exchangers are designed for compact performance and easy cleaning. Most often it is sufficient to use Cleaning-In-Place (CIP) equipment, which minimizes downtime and wear on gaskets and plates.
All our gasketed plate heat exchangers and spiral heat exchangers can be opened when necessary, giving maintenance personnel full access to all heat-transfer surfaces.
Fibrous media
When processing fibrous media it is important that the equipment does not clog up and cause costly downtime and cleaning.
Alfa Laval’s WideGap plate heat exchangers are designed for media with high contents of fibres and coarse particles. The channels are much wider than in a normal plate heat exchanger, and depending on the configuration the plates have average gap widths of 5, 8, 11 or 17 mm (0.20, 0.31, 0.43 or 0.67 in). The specially designed, corrugated plates create a highly turbulent flow that helps reduce fouling and sedimentation. WideGaps are easy to service thanks to the design of the plates and frames. For example, the herring-bone pattern of the plates increases the cleaning effect during back flushing.
Our spiral heat exchangers excel at handling long fibres. The fluids flow through two concentric, spiralling channels in opposite directions. This 
design provides optimal flow conditions for a wide variety of fluids, ensures high heat transfer and keeps the overall size of the unit to a minimum. When fouling starts to build up, the pressure behind the deposit increases (thanks to the single-channel design) and when the pressure gets high enough the fouling is flushed out.
Each Alfa Laval heat exchanger is individually configured according to its specific operating conditions to optimize heat transfer, cleaning and operating costs.
