Bitumen processing: Temperature maintenance
Asphalt/ bitumen is typically stored and transported at temperatures around 150°C. At ambient temperatures, bitumen has a solid or semi-solid consistency and softens gradually when heated. For optimum viscosity it is melted directly out of drums.
Bitumen is a dark brown to black viscous liquid or solid, consisting essentially of hydrocarbon material. The bitumen used in South Africa is obtained as an end product of the petroleum crude oil refining process.
The primary use (70%) of asphalt/ bitumen is in road construction, where it is used as the glue or binder mixed with aggregate particles to create asphalt concrete.
Typical process heating solutions
Thermon solutions typically used in the storage, transport & supply side of Bitumen processing:
Case Study: Temperature Maintenance of bitumen tanks & pipelines
Application
In a particular application, a client required process temperature maintenance of between 120 and 140°C on three bitumen storage tanks and associated pipelines.
Problem
Since initial commissioning, the plant had experienced a number of tracer failures, for reasons including incorrect selection of cable and poor installation. This resulted in the need to strip off the insulation to facilitate either a repair or replacement of the affected section of cable, with plant downtime and a re-melt of the bitumen.
The heating cable on the pipework was failing on the valves and flanges where heat transfer to the body was not optimal. With incorrect cable having been installed, overheating of the cable was occuring causing the soldered joint to blow. The cables on the tanks had also failed numerous times, hampering the required conditions at which the bitumen needed to be stored.
Solution
The lines, previously traced with a constant wattage cable, had to be replaced with Thermon HPT power limiting heat trace cable.
HPT power limiting cables are designed for frost protection and also for process temperature maintenance where high temperatures up to 200°C are required.
The cable is ideal for applications where steam cleaning or purging rules out the use of lower temperature heating cables. The maximum continuous exposure temperature of up to 260°C (power-off) is not restricted by the frequency or duration of exposure.
The cable has a PFA teflon jacket, surrounded by a nickel plated copper outer braid, providing both mechanical protection and corrosion resistance. HPT-OJ cables are able to provide significantly higher outputs than conventional cables when used at higher temperatures, which results in the use of less cable and hence reduction in cost. Its low start-up current also reduces power distribution requirements.
The client continued the replacement of the constant wattage cables on the pipelines with Thermon HPT cable. Between 500 and 1000m of cable was installed and fully operational without subsequent failure.
The heat tracing on two of the three storage tanks was replaced during the client's shutdown periods with Thermon Mineral Insulated (MIQ) cable. The installation consisted of over 1100m of MI cable per tank and the design utilised the existing control system and junction boxes so as to reduce of the overall cost of the project. Stripping and replacement of the thermal insulation was managed by Thermon, allowing us to provide the client with a complete turnkey solution.
Selected components used in bitumen processing:
Electronic
Heat Tracing Control
Immersion Heater
for Oil Heating Systems
Click on components for more information & to request a quote.
Other components also suitable for similar applications
Thermon SA strives to enhance customers' operations by providing innovative and reliable heating solutions at the lowest cost of ownership. We design, manufacture, install and maintain electrical heating systems and controls catering for your specific requirements. Contact our engineers for a discussion & find more information on other components used by clients with similar applications + get a quote:
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