Automatic antifoam control system

  • World’s smallest antifoam control system with miniature foam detector, ANTIFO and subminiature syringe pump, DOZITO
  • No expensive level sensors / antifoam probes needed
  • Prevents overdosing of antifoam agent

Working principle of automatic antifoam control

The presence of foam in the reactor vessel is detected by measurement of the electrical conductivity.

Foaming causes an increase of electrical conductivity. The electrical conductivity can be measured without any expensive anti-foam probe.

Instead of an antifoam probe, two needles of the quadruple port (large side neck) of the LAMBDA MINIFOR laboratory fermentor vessel are used as electrodes. As a consequence, no additional port has to be used for anti-foam detection and control.

ANTIFO: Antifoam detector and controller

The antifoam detector / controller ANTIFO detects the presence of the foam based on the measured electrical conductivity and sends the impulsion to the subminiature syringe pump, DOZITO. The miniature syringe pump, DOZITO, then adds a small amount of antifoam liquid into the reactor vessel. If the foam signal persists, a new portion of antifoam agent is added after twenty seconds. Particular care is taken to prevent an overdosing of the antifoam agent.

ANTIFO works either with the DOZITO miniature syringe pump or the LAMBDA laboratory peristaltic pumps.

DOZITO: Miniature syringe pump

The DOZITO syringe pump is the smallest of all other laboratory pumps on the market; it is hardly larger than the syringe itself. A completely new motion principle is used in the DOZITO syringe pump (no motors, no electromagnets, no compressed gas and the like). The setup and use of the DOZITO syringe pump is very easy.

LAMBDA supplies the DOZITO mini-pump for the controlled addition of antifoam liquid into the fermentation vessel of MINIFOR laboratory fermentor and bioreactor system.

The dispensing of the antifoam liquid can be set up from one drop to 15 drops in one step. The pump is vertically fixed using a magnetic support, so that it takes only about 10 cm2 foot print. It is very important to spare space around the fermentor vessel.

The DOZITO can also be used for the dosing of small repetitive amounts of other liquids (e.g. oils, adhesives, cements, glues, etc.) in the laboratory or industrial applications. Since no compressed air is used, the volumetric control is much easier.

No overdosing of antifoam agent

The addition of too much antifoam agent is detrimental for the oxygen transfer rate in the culture medium.

The excessive addition of antifoam liquid (anti-foam over-dosage) is avoided by the introduction of a waiting time interval of about 20 seconds, after the first antifoam agent addition. The second addition of antifoam substance occurs, only when the foam did not disappear during the elapsed waiting interval time. Additionally, the antifoam dose can also be controlled by the volume step setting on the LAMBDA DOZITO miniature syringe pump.

Applications of automatic antifoam control

Fermentation is often accompanied by foam formation because of the high foaming tendency of solutions containing biomaterials such as nucleic acids or proteins.

Bioreactor medium with high protein concentrations leads to foaming than simple media. Foam has to be reduced to a minimum in order to prevent medium loss, clogged aeration filters and contamination risk.

The automatic antifoam system is recommended for:

• Medium with BSA
• Formation of high protein concentration
• Fed-Batch with C-feed and high cell density of E. Coli or yeast