Flow control system for spray applications

Abstract

A spray control system for applying a coating composition to an object. The control system includes an applicator, flow control valve, flow meter, and an electronic controller connected to the valve and flow meter. The controller regulates the flow of coating composition to maintain it at a user-specified setpoint. The controller includes a learn mode in which it learns the proper valve setting for a particular setpoint and stores a valve control signal that is later used at the start of a spray application to initially set the valve at the proper position. Then, once the flow of material begins, the controller uses either incremental or proportional control, or both, to maintain the flow at the specified setpoint. When learning a setpoint, the controller also stores the current values of a number of user-specified process parameters, such as ambient air temperature and the coating composition source pressure. These stored parameter values are then monitored during the spray application and an alarm notification is provided if they drift outside of a window about their stored values. The controller is configured to adapt to changing environmental and operational conditions by re-learning the proper valve setting for a particular setpoint each time the flow sufficiently stabilizes at the setpoint. Circuitry is also disclosed for use in connection with the flow meter to quickly determine the flow rate at the commencement of material flow and to provide fast updating of a conventional digital readout of flow rate.

Dependencies are inferred from the claim text.