Alfa Laval Kathabar
Liquid Desiccant Products

About Liquid Desiccant Products

Basic Controls

The Basic Control scheme of a Alfa Laval Kathabar system is referred to as “pump-in, gravity equalize”. This control schematic is designed for a system with one conditioner and one regenerator which are relatively close to each other and are also at the same elevation. This is done by pumping a fixed amount of high concentration Kathene from the regenerator spray pump to the conditioner sump. The conditioner then gravity equalizes the Kathene back to the regenerator at a lower concentration. With this system configuration only one level sensing device is required. See the below figure and table for further clarification.

Basic Controls

BT Bubbler Tube – Used in conjunction with the LCP/ECP to pneumatically sense solution level
FM Flow Meter – Measures and controls the transfer of concentrated solution from the regenerator to the conditioner
LCP/ECP Level & Electrical Control Panel (PLC) – Provides:

- High level, low level alarms
- Water make-up V5
- Modulating control of V3 based on TT leaving air set-point
- Modulating control of V4 based on BT to maintain level
- Motor starters & contactors

TT Temperature Transmitter – Senses leaving air temperature and transmits the signal to the PLC in LCP/ECP for V3 modulation control to maintain set-point
V3 Conditioner Solution Cooler Valve – Receives a modulating signal from the PLC in ECP/LCP based on TT set-point
V4 Regenerator Heater Valve – Receives a modulating signal from the PLC in ECP/LCP to maintain BT set-point
V5 Water Make-Up Valve – Receives a on/off signal from the PLC in ECP/LCP based on BT low level set-point

Liquid Applications Foote