Industrial pH Control Basics

pH sensor courtesy of HF Scientific

Analytical measurement and control of pH within a system is necessary for many processes common applications include food processing, wastewater treatment, pulp & paper production, HVAC, power generation, and chemical industries.

pH display
courtesy of HF Scientific 

To maintain the desired pH level in a solution a sensor is used to measure the pH value. If the pH is not at the desired set point, a reagent is applied to the solution. When a high alkaline level is detected in the solution, an acid is added to decrease the pH level. When a low alkaline level is detected in the solution a base is added to increase the pH level. In both cases the corrective ingredients are called reagents.

Accurately applying the correct amount of reagent to an acid or base solution can be challenging due to the logarithmic characteristics a pH reaction in a solution. Implementing a closed-loop control system maintains the pH level within a certain range and minimizes the degree to which the solution becomes acidic or alkaline.

An example of an automatic pH level control system is a water treatment process where lime softened water is maintained at a pH of 9 using carbon dioxide as a reagent. As the untreated water (or influent) enters the tank, the pH is continuously monitored by the pH sensor. The sensor is the feedback device to the controller where the setpoint is compared to the control value. If the values are not equal, the controller sends a signal to the control valve that applies carbon dioxide to the tank. The reagent is applied to the tank at varying rates to precisely control the pH level. With the pH level at 11 detected by the sensor, the controller commands the control valve to open and introduce more carbon dioxide. As the increased carbon dioxide mixes with the influent, the pH is lowered in a controlled manner. Reaching the setpoint, the carbon dioxide flow is minimized and the process is continually monitored for variation. The effluent is the treated water that is discharged out of the tank. The process continues to provide the lime softened water at the desired pH level.

Process Equipment Corrosion / Materials Compatibility Guide

Make sure your equipment
is compatible with your process!

Here is a handy quick reference guide for corrosion and material compatibility that can be applied for process control equipment (thanks to QCI Valves).

This chart is a guide to the engineer in the selection of materials for corrosive services. No one material can be expected to handle the wide variety of corrosive media found in industry today.  Therefore, the user must decide,  based on experience, which properties are  of prime importance in their application.

The process equipment in contact with the media should carry an A Rating. This chart is intended to be a guide, and if any questions exist on the application of a material, actual tests should be performed to determine the suitability of the material.  When in doubt, ALWAYS consult an application expert.

Material compatibility-corrosion-guide-qci-ives from Ives Equipment

Simple Ways to Maximize the Efficiency of Your Process Control Application White Paper

Siemens Integrated Drive Systems

A white paper courtesy of SIEMENS 

No matter what industry you’re in, the price of your inputs is bound to fluctuate – usually trending in a direction that doesn’t favor profits. You can’t control the rising costs of raw materials and energy, but you can control how much you get out of them. The simplest way to do this is by maximizing the efficiency of your equipment.

Performance and productivity are directly related to energy use, reliability and maintenance costs. The improved performance offered by a highly efficient drive train helps increase output and decrease energy consumption. It also reduces wear and tear, thereby limiting maintenance costs and downtime while extending the life of your equipment. To attain this level of efficiency, one need only turn to the application-specific engineering found in integrated drive systems. 

Read the entire white paper below, or you can download it from the Ives Equipment website here.

Simple Ways to Maximize the Efficiency of Your Process Control Application White Paper from Ives Equipment

HydroRanger 200 Customer Loyalty Offer from Siemens

Take advantage of this
offer for the HydroRanger200

Time sensitive post!

Siemens Process Industries & Drives Division is pleased to bring you the enhanced HydroRanger 200 HMI ultrasonic level controller for measurement in a wide range of industrial applications including water/wastewater monitoring and pumping, inventory management, truck load-outs, and open channel monitoring.

Enhancements include faster commissioning with an improved HMI (Human Machine Interface) and graphical Quick Start Wizards as well as a redesigned enclosure with removable terminal blocks and wider communications.

The HydroRanger 200 HMI provides high performance measurement of level, flow, differential level, and volume conversion, with additional alarm and pump control functions. Siemens’ patented Sonic Intelligence signal processing technology differentiates between true and false echoes from obstructions or electrical noise, giving users repeatable, fast, and reliable measurements.

Siemens is making it easy for you to see the benefits this instrument has to offer. As a loyal customer, they are offering you a 15% discount toward the purchase of the enhanced HydroRanger(s) 200 HMI version.

Call Ives Equipment at 877-768-1600 to place your order.
Use discount code: SPR6029
(Offer valid until December 31, 2016).