The role of instrumentation from Endress+Hauser.
Conductivity measurement in the CIP system plays a key role in managing the waste of cleaning products and maintaining the quality of the cleaning agent to obtain maximum cleanability. Conductivity is used in two different applications on the CIP system, each with very different requirements.
In the storage tanks for acid and caustic the cleaning agent is adjusted to a very precise concentration. Too high of an acid or caustic concentration leads to increased costs and decreased cleaning capabilities. For each process product, a specific concentration provides maximum cleaning capability. Too much or too little cleaning agent can lead to longer cleaning times and less overall process run time.
To control the concentration percentage, the Endress+ Hauser inductive conductivity system monitors the conductivity value of the detergent, converting it to predicted concentrations internally with preset tables. The CLM 431 contains concentration tables for NaOH, HNO3, H3PO4, and H2SO4 to convert the conductivity value mS/cm to a concentration value in percent.
On the return CIP lines conductivity is used for detection of the different cleaning agents. This measurement determines when the system switches from one agent or product to the next. With a velocity of 6 ft./sec. in a 4″ pipe, 16 gallons of product, cleaning agent, or water could be wasted every second. If the interphase is not recognized immediately it may be considered waste. Depending on which stage the CIP process is at, the caustic or acid could actually be reclaimed for further use. Therefore, the fastest possible phase detection is essential. The CLS 52’s unique external temperature design allows Endress+Hauser to offer a conductivity sensor with a t90 response time of less than 15 seconds.
The contactless design of the CLS 52 makes it immune to corrosion, coatings, and polymerization at high conductivities. These conditions often cause difficulties with contacting sensors.