Batch Controller - Model 515-CR02

The 515 CR02 application is a single loop process controller measuring the volume flow in a main and process line using analogue flow inputs. It can operate in local (manual), loop, ratio or blend mode and has a tuning menu to easily determine the Proportional Band and Integral Time Values used in the PI control algorithm.

The main and process flows are used to determine the net volume flow. The operator can view the actual ratio and deviation, with the ability to change the controlling setpoint directly from the main menu (if access has been authorised).

The PI control of the process flow is via a 4-20mA proportional valve or pump controller. It has integral wind-up protection and a deadband and output ramp time can be programmed to reduce wear on valves and actuators and provide for smooth operation.

Calculations

There are three types of control modes in which the process flow is dependent on the main flow. These are RATIO, BLEND-1 and BLEND-2 modes where the relationship between the flows are as follows:

Ratio Control Mode:

The process flow is a ratio of the main flow (o-400% range)

Pflow
Ratio% = —————- × 100
Mflow

Blend Control Modes:

These modes cater for blending points before and after the main flowmeter. The process flow is a ratio of the net (combined) flow (o-80% range).

Pflow
Ratio% = —————- × 100
Netflow