pH Control Systems
Digital Analysis manufactures
industrial controls and pH control systems for all wastewater and pH neutralization applications found in industry.
Common applications and features include:
pH Control Applications Include:
- Continuous Flow Through pH Neutralization:
- One, Two, and Three Stage Systems
- Batch pH Adjustment
- Simplex, Duplex, and Triplex Batch
- Sequential Batch pH Adjust
- Fluoride Reduction Systems
- Heavy Metal Reduction
- Effluent Monitoring Systems
- Supervisory Control And Data Acquisition (SCADA)
- Collection / Transfer Systems
System Features.
- Completely Automated
- PLC Based, typically Allen-Bradley
- Ethernet Communications allow for access to all programmable Variables, Tuning Parameters, and Alarms.
- Remote Monitoring, Alarming, and Communications via an optional Internet Connection
- All panels are UL 508A inspected and listed
- OSHA LOTO Disconnect on all systems.
- NEMA 4X, 4 or 12 Enclosures.
- Explosion Proof.
pH Control Curve
Typical pH Control Curves used with all of our pH adjustment systems. For each pH control stage within a system the tuning parameters for the acid and metering pumps (and bulk assist pumps if used) are independently controlled with non-linear tuning algorithm that can be programmed to any curve, such as a titration curve.
pH response is not linear and cannot be controlled as such. Most pH
"controllers" on the market are not truly pH controllers because
they use simple on / off control or linear control provided by a PID
algorithm which is far too simple to account for the ever changing
control gain encountered with the logarithmic reaction of pH to
control input.
A true pH controller MUST have the ability to control to a
logarithmic and non-linear response such as the typical pH titration
curve shown here.
The curve above is the actual titration results of the pH Adjustment of an acid (HCl) with a beginning pH of 2.0 and an ending pH of 11.0.
For a more complete and in depth discussion of pH and the control of
pH see our technical article
pH Adjustment - The Basics
Control System Design
Our team of control engineers
design all of our control systems using state of the art CADD
technology that is compliant to all applicable standards including
UL 508A, NEC, NFPA, IEEE, NEMA, OSHA, and etc.
All systems come equipped with thorough documentation packages in both hardcopy and
electronic format. These documents include detail Sequence of
Operations, Bills of Materials, instruction manuals for all of the
individual components used and detailed design drawings including
P&IDs, Mechanicals, and Electrical drawings.
All systems are PLC
based, typically Allen-Bradley and the PLC programs are fully
documented and provided with the drawing package.
Control Panel Fabrication
We fabricate all of our control systems in house with our team of seasoned electricians and technicians.
All control systems are subject to our rigorous quality plan which
includes thorough testing, simulation of actual process conditions,
24 hour burn in, and more.
Electrical panels are all built to
and certified by the UL to UL 508A standards and our shop and our
systems are subject to routine inspections by UL engineers.