Banner-Day recently completed a pipe heating trial for a major food producer located in Australia. The customer was seeking an alternative pipe heating method to replace the oil jacketed pipe heating system currently used on a chocolate export line and was not familiar with impedance pipe heating technology.
Existing System Design Basis
The existing chocolate export line was designed using double-walled mild steel pipe. This piping system was also insulated and clad to minimize heat loss. Hot heating oil was circulated between the outer and inner pipe walls to ensure the chocolate was maintained at temperature and remains in its liquid phase.
This line was also configured with a pigging system. The pigging system was part of their cleaning process and it was designed to purge / evacuate all the chocolate within the line. This was necessary to prevent product cross-contamination as the existing export line handled two different products.
The pigging system was manually loaded whereby a hatch was opened at the export line manifold connection where the pig was hand loaded. Once the hatch was closed, the pig was forced by compressed air through the length of the export pipe to the pig receiver located at the filter platform just before the transport tanker fill pipe. As a result, the customer’s traditional piping system designs required large radius bends in the export line to ensure that the pig would not jam.
The customer sought to address several issues of concern with a new pipe heating solution. Those issues included:
- Moving away from continued use of their aged existing hot heating oil system.
- Implement use of a preferred piping material. Mild steel is not a preferred material for food product contact. Stainless steel is a preferred material.
- Eliminate hot heating oil system leaks.
- Minimize safety and contamination risks associated with operating the manual pigging system. Opening a product line for loading and unloading the pig risked contaminating the line.
- New transport tankers are being converted to bottom fill rather than top fill, reducing product contamination risks and increasing operator safety.
- Avoid the difficulty in detecting hot heating oil contamination in the chocolate.
Impedance pipe heating was viewed as a potentially viable technology capable of addressing all the identified issues and concerns.
To evaluate impedance pipe heating’s potential, Banner-Day worked in conjunction with the customer’s engineering team to develop a testing protocol and a test stand apparatus to demonstrate the effectiveness of impedance pipe heating as an alternative pipe heating solution. See figure 1 below.
Figure 1 - Test Stand Apparatus
Conditions of Service – Impedance Pipe Heating Test Trial
Banner-Day’s TraceFREE® impedance pipe heating test stand apparatus was configured to maintain the temperature of 12 meters of NB100 schedule 10 – 316 SS piping at process operating temperature of up to 55° C (±1° C) within a specified minimum ambient temperature condition of 5° C. The piping was insulated with 25 mm thick Armaflexinsulation fitted with a non-conductive PVC jacket.
In addition, an RTD temperature probe was used to provide temperature feedback to a digital temperature controller located in the test system’s control panel. The control panel was designed and fabricated in accordance with all applicable Australian Federal, State and Local acts, regulations, codes and practices as well as local plant standards. Twenty (20) thermocouples were strategically placed around the circumference of the pipe and spaced along its length and used to collect temperature data at various points utilizing a hand-held digital meter.
Upon completion of the test stand fabrication and with the control panel and transformer in place, Banner-Day dispatched our Director of Engineering to the plant to perform system commissioning and assist with execution of testing. While on site he also helped educate and train local plant engineering, operations, and maintenance personnel on impedance pipe heating operations, maintenance, and troubleshooting. See figure 2 below.
Figure 2 - Test Stand Apparatus and Testing Personnel
Upon completion of testing, the customer was very satisfied with the results. Testing results demonstrated impedance pipe heating’s ability to:
- Preheat a product lineprior to product being introduced into the line.
- Warma product filled line from ambient to its process operating temperature quickly.
- Maintaina uniform product temperature along the length of the test stand with the product flowing or stationary.
Based on these positive test results, the customer promptly moved forward with implementation of a TraceFREE® impedance pipe heating solution for their new chocolate export lines. The new impedance system featured use of an SCR for more precise temperature control than a typical on/off system, and utilized remote I/O for interface with the customer’s existing PLC based plant process control.
Figure 3 - Complete Test Stand Apparatus
Upon completion of installation, startup and commissioning of the new impedance pipe heating system serving the customer’s new chocolate export lines, the customer quickly enjoyed the following key benefits from the project.
- New impedance heated dedicated export lines no longer require pigging, therefore negating the need for launchers, receivers, and large radius pipe bends.
- Safety and contamination risks associated with the manual pigging system are no longer a concern for the export lines.
- Safety and contamination risks associated with using existing hot oil pipe heating system are eliminated.
- Significant maintenance cost savings were achieved due to simplicity of the impedance pipe heating solution compared to the legacy hot oil heating system.
- Impedance pipe heating system provides a very high degree of operational reliability eliminating unscheduled outages.
- Impedance pipe heating system provides very uniform heating performance critical to chocolate applications. No hot or cold spots are experienced along the length of the new export lines.
In conclusion, no matter the challenge, no matter the location, Banner-Day has the resources and the expertise to help meet your process pipe heating requirements. Contact Banner-Day today to learn how we can help overcome your process pipe heating challenges with TraceFREE® impedance pipe heating.
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