Tank heating systems are often critical to most industrial applications, particularly with temperature control maintenance. For example, caustic tanks provide critical feedstock to refineries, chemical plants, and processes.
Biodiesel feedstocks such as vegetable oils, animal fats, palm oils or even jatropha will solidify at relatively normal ambient temperatures, requiring process temperature maintenance to ensure product quality. Keeping this product warm is vital to keep processes running efficiently and preventing product spoilage.
Electric tank heating systems can be designed to heat up tank contents from a lower to a higher temperature, or they can be designed to simply maintain a temperature once it is reached.
Process temperature maintenance
Many products and material arrive on-site preheated from its source of delivery. Knowing what the products can tolerate on the low end of heat is critical. Spoilage will lead to longer production times and higher costs on users end. How low can users go before the product cannot be used in the processes?
Many products and material arrive on-site preheated from its source of delivery
It’s good practice to have a plan for both how users intend to warm up materials and how they intend on maintaining a consistent temperature. These process temperature maintenance plans are generally composed of two items: insulation and heating equipment.
Temperature maintenance system
Thermal insulation is an important component of a temperature maintenance system. The type of insulation and its thickness plays a key role in keeping heat at a stable level within the processes. Heater selection is also a factor.
Tank heat can be maintained by heat trace, steam coils, heating pads or immersion heaters. Each has their own specific advantages for the application and should be a part of the process temperature maintenance plan.
Tanks will often hold product that need to be heated up. A new load of product that is below the desired temperature for tank contents could be dumped in and, as a result, lowers the average temperature. Just as with tank maintenance applications, the thermal insulation system is critical so that users don’t lose what they already have. All methods of heat-up must provide dependable heat up.
Tank maintenance applications
Since it will take 8-10x as much thermal energy to heat product in a tank up to temperature
Of primary consideration is how quickly users want to heat a tank to temperature. If they go too quickly with the wrong heating system, products can become burned or cook themselves onto the heating system.
Since it will take 8-10x as much thermal energy to heat product in a tank up to temperature, compared to maintaining temperature, they should also consider using higher 3 phase voltage.
In the U.S., most heating systems are available in 480V 3 phase. This will drastically reduce the amperage requirements which will translate into much lower costs than if using lower single phase voltages.
Most heating systems
As previously stated, the process temperature maintenance plan needs to be specific and use the right type of heater that best fits the processes.
Common heater types used to heat up a tank are heat trace, steam coils, heating pads (for smaller systems), and immersion heaters that are specifically designed for tank heating. Sensor placement in tank heaters should be carefully considered when designing a system. Level controllers should be interlocked with the heater control panel to shut the heater down in low level conditions.
Main temperature sensor
Heater over temperature sensors should be installed on the heater sheath, when using an immersion heater
Heater over temperature sensors should be installed on the heater sheath, when using an immersion heater, so that the heater is not allowed to run up to a high temperature, as this could cause damage to the tank or its contents.
Finally, the main temperature sensor that regulates the heater must be placed at or just above the heat source. Placing it up high in the tank or far away from the heater will not allow the heater to perform as intended.
Plant control monitoring systems
Control panels should be designed to allow for interface with the tank level, temperature systems, and remote plant control monitoring systems.
Modern advances have allowed for a much wider acceptance of wireless communication systems as well. Both temperature and level information can be transferred to the heater panel wirelessly. Data transfer from the control panel to the plant-wide control system will allow tank heating systems to report to the proper personnel regarding performance and reliability.
Powerblanket can help users decide on a heat plan that meets their temperature-specific needs. The team of thermal engineers are always available to talk over options and choose what is best for the processes