Inline Heating Essentials: Keeping Pipes Warm and Functional
Steve Maurer, IME
Blast freezers play a crucial role in food processing plants, particularly in preserving the quality and safety of perishable food items. These freezers operate by rapidly bringing down the temperature of food products, often within the main freezer facility, to well below freezing point. This rapid freezing process is vital for maintaining the cellular integrity of the food, which in turn preserves texture, flavor, and nutritional value.
However, one of the byproducts of this process is the generation of frost and ice, particularly as moisture in the air condenses and freezes upon contact with the cold surfaces within the freezer.
The management of defrost water, a key aspect of maintaining blast freezer efficiency, involves a series of steps to ensure proper drainage and prevent ice blockages. As the freezer undergoes periodic defrost cycles, the accumulated ice melts, creating defrost water that must be efficiently evacuated from the unit.
This is typically achieved through a system of heated drain lines that prevent the water from refreezing. To keep these drain lines clear, regular maintenance is essential. This includes periodically checking the heating elements in the drain lines to ensure they are functioning correctly, as well as inspecting the lines for any signs of damage or wear that could impede water flow.
In the facility I worked in, this required heat cables wrapped around the elevated defrost drain lines to keep the water flowing.
Because the heat cables and drain pipes were exposed to the freezer environment, it required the pipes to be insulated. That meant that replacing bad heat cables meant removing the insulation, a very time consuming process.
While many heat cables and cords are water resistant, they aren’t water tight. Therefore, they cannot be immersed in water for extended time periods.
But there is a type of heater that can be immersed.
It’s not always easy or convenient to wrap heat trace scables around water lines and drains. In fact, it may be impossible to do so. Buried water lines and drains would need to be excavated to install the exterior style heat trace cables.
A better option might be to use heat trace cables designed to fit inside the piping system. If any excavating or soil removal must be done, it is minimal. You’d need just enough to expose a portion of the piping where a special connection kit can be installed.
In this type of system, the cable is fed through the connection system, sealed with a gland pressure connection. These cables are self-regulating and can be as long as 200 feet. The temperature of the cable is, in part, controlled by the ambient temperature of the water surrounding it.
These in-pipe solutions are great for residential applications to prevent freezing, where the temperature can go as low as -40 degrees Fahrenheit.
Cables can be cut to length on the jobsite and terminated with the appropriate termination kit.
A thermostat is often used to prevent overheating, however. Not only does this prevent cable damage, but the thermostat can turn off the heat cable when not needed, saving on energy consumption and utility costs.
Many applications of in-line heating systems are residential. They can be used in both plastic and metal pipes. Their construction materials make them safe for potable water as well. And they are also safe for insulated lines as they do not come in contact with the pipe insulation directly.
For new construction or renovations, an in-the-pipe heat cable could very well be the best option to prevent water from freezing in the dead of winter.
However, one of the byproducts of this process is the generation of frost and ice, particularly as moisture in the air condenses and freezes upon contact with the cold surfaces within the freezer.
The management of defrost water, a key aspect of maintaining blast freezer efficiency, involves a series of steps to ensure proper drainage and prevent ice blockages. As the freezer undergoes periodic defrost cycles, the accumulated ice melts, creating defrost water that must be efficiently evacuated from the unit.
This is typically achieved through a system of heated drain lines that prevent the water from refreezing. To keep these drain lines clear, regular maintenance is essential. This includes periodically checking the heating elements in the drain lines to ensure they are functioning correctly, as well as inspecting the lines for any signs of damage or wear that could impede water flow.
In the facility I worked in, this required heat cables wrapped around the elevated defrost drain lines to keep the water flowing.
Because the heat cables and drain pipes were exposed to the freezer environment, it required the pipes to be insulated. That meant that replacing bad heat cables meant removing the insulation, a very time consuming process.
While many heat cables and cords are water resistant, they aren’t water tight. Therefore, they cannot be immersed in water for extended time periods.
But there is a type of heater that can be immersed.
It’s not always easy or convenient to wrap heat trace scables around water lines and drains. In fact, it may be impossible to do so. Buried water lines and drains would need to be excavated to install the exterior style heat trace cables.
A better option might be to use heat trace cables designed to fit inside the piping system. If any excavating or soil removal must be done, it is minimal. You’d need just enough to expose a portion of the piping where a special connection kit can be installed.
In this type of system, the cable is fed through the connection system, sealed with a gland pressure connection. These cables are self-regulating and can be as long as 200 feet. The temperature of the cable is, in part, controlled by the ambient temperature of the water surrounding it.
These in-pipe solutions are great for residential applications to prevent freezing, where the temperature can go as low as -40 degrees Fahrenheit.
Cables can be cut to length on the jobsite and terminated with the appropriate termination kit.
A thermostat is often used to prevent overheating, however. Not only does this prevent cable damage, but the thermostat can turn off the heat cable when not needed, saving on energy consumption and utility costs.
Many applications of in-line heating systems are residential. They can be used in both plastic and metal pipes. Their construction materials make them safe for potable water as well. And they are also safe for insulated lines as they do not come in contact with the pipe insulation directly.
For new construction or renovations, an in-the-pipe heat cable could very well be the best option to prevent water from freezing in the dead of winter.
Photo courtesy of Emerson EasyHeat™
