MEGTEC RTOs with DAQSTATION

Introduction

MEGTEC Systems, a major manufacturer of Regenerative Thermal Oxidizers in DePere, Wisconsin is now specifying DAQSTATION for use with their equipment. These oxidizers, commonly known as RTOs, are found in Paint Finishing Operations, Chemical, Petro-chemical and Ethanol Production, Ink Coating and Odor Abatement, and many other applications on a global basis.

Many RTOs are similar to large furnaces that eliminate manufacturing and production byproducts such as vaporized solvents or airborne pollutants.

Application

The EPA requires data acquisition devices to be incorporated into an RTO for the purpose of long-term data retention. These devices provide a record of temperatures maintained inside the RTO as proof that all pollutants were eliminated before venting factory air back into the atmosphere. DAQSTATIONS retain this data in a secure format for review upon request. End users also periodically file formal reports with state inspectors to satisfy local reporting requirements. PLCs and HMIs are often found in the RTO for control and logic functions with respect to firing rates and damper positions. An important part of basic instrumentation of an RTO is interconnectivity between the different instruments.

Solution

A recent application included Allen Bradley SLC500 PLC and PanelMate HMI for process control of the RTO. A Modbus ProSoft card was added to the PLC and used to feed information into the DAQSTATION via Modbus RTU. This customer wanted to eliminate the costly Modbus ProSoft card and communicate directly to the DAQSTATION.

The PanelMate HMI was designed to interface to multiple PLCs. One of the drivers available was Modbus RTU as supported via RS-485 in the DAQSTATION. Chris Smith, Midwest PSE, mapped the Modbus Register values from the PanelMate directly into the recorder using a 'Library Message" command thereby eliminating the ProSoft interface card and costs associated with it.

DAQSTATION provides local displays for Trending, Digital, Annunciator and History modes but their main function is data retention for regulatory requirements. DAQSTATION is a standalone instrument with intelligence to support dual comm protocols and easily interface to remote instrumentation, plus provide detailed reporting as required by numerous regulatory agencies.