MIE.31 – Optimization of the Nozzle Calibration Process for Spraying Systems Co.

• Luis Hernandez
• Mili Isaza Gomez
• Pramesh Mirchandani
• Lopa Patel
• Ricky Torres

Spraying Systems Co. is an international manufacturer of industrial spray nozzles for a wide variety of applications. Nozzles are regularly tested to validate the accuracy of their volumetric flow rates. The purpose of this project is to improve the water nozzle flow rate calibration process for Spraying Systems’ location in Schorndorf, Germany.

The current testing process requires using a bucket and stopwatch to measure the average mass flow rate out of a nozzle, and then using density to calculate the average volumetric flow rate. This method is unreliable and time-consuming. At its location in Carol Stream, Illinois, Spraying Systems uses Coriolis mass flow meters for flow rate measurements that are highly accurate (within 0.01-0.05%) but each machine costs $5,000 to $10,000 and requires expensive yearly calibrations.

The proposed solution is an automated and digitalized system that minimizes splashing, requires no extra calibrations, has low set-up time, and is inexpensive. This solution benefits the company financially because it is much cheaper than purchasing and calibrating Coriolis flow meters. This solution also reduces the time spent performing the calibration.

Three design alternatives were proposed. The first alternative uses an ultrasonic sensor to measure the change in water level in a container. The second alternative uses a turbine flow rate sensor to measure the flow rate through a tube using the rotational speed of turbine blades. The final alternative incorporates a diverter valve to change the flow direction, and a time of flight (ToF) sensor and hydrostatic pressure transducer to measure the change in water level.

To achieve the desired result, two types of experiments were performed. First, each transducer was tested and calibrated alone with a programmable logic controller (PLC) to verify that it produced accurate measurements. Then, all transducers and components were tested together.

The final design produces two volumetric flow rate measurements based on the change in water level in a rigid container: one from the hydrostatic pressure transducer and one from the ToF sensor. A temperature sensor was used to verify that the density of water used in the hydrostatic pressure calculation is accurate. These measurements were compared and then validated by measuring the change in mass with a weight scale.

Thus, the final solution produces volumetric flow rate measurements that are reliable and do not require as much waiting time as the current method. With a final cost of approximately $1,000, this design is much cheaper than the Coriolis flow meter.