Design Overview

The designed solution uses the UR24 (High Accuracy Version) refractometer to take real-time Brix measurements which can be converted to g/L through a PI tag. The sensor is installed in a custom spool with a temperature probe and a nozzle which opposes the sensor lens. Connected to the nozzle is the steam-cleaning piping, to be sourced from a nearby steam line, which has a solenoid valve to allow for automatic cleaning when readings spike. The design also includes a blank spool to replace the spool from Maselli to allow for easy removal for any needed maintenance during a shutdown period. The UR24 is integrated into the PLC at the Cavendish Farms plant through an 8x2x22 AWG cable.

Components

Sensor

The UR24 high accuracy version is specified to have an accuracy of ±0.05 Brix with a concentration range of 0-95 Brix and a temperature range of -5-105 °C. It works by emitting light into the solution and measuring the critical refractive angle with a CCD array. Refraction is directly proportional to temperature, so a Pt100 temperature probe is paired with the UR24 for proper compensation.

Steam Piping

The stainless steel steam piping line threads directly into the tri-clamped nozzle of the custom Maselli spool. The piping instrumentation will include 2 ball valves for shut-off and flow control, a 40 psi pressure reducing valve, a steam condensate trap, and a solenoid valve to actuate the steam injection. The solenoid is connected to the interconnection box of the UR24 so that it cleans when the derivative of the readings exceeds the programmed limit.

Custom Spool

The UR24 spool unit is made of sanitary stainless steel and houses the refractometer, the temperature probe, and the steam nozzle. It is tri-clamped in-line to the water-cycling pipe of the dip tank.

Blank Spool

To allow for the design to be easily uninstalled if ever needed, while not delaying the process, a custom-length spool is also specified in the design to be installed in place of the refractometer spool.