Mineral buildup in heat exchanger tubing walls

In summary, the conversation discusses different techniques for minimizing mineral build-up on the walls of a geothermal heat exchanger. These techniques include using magnets, plastic materials, and avoiding water treatment. The conversation also mentions the use of copper in residential oil burners and the possibility of using constant vibration or electric current to eliminate fouling. Additional resources are provided for better understanding and practical examples.
  • #1
design-assoc
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In a geothermal heat exchanger where well water is cerculated up from one well and down another [some distance away] where water treatment is certanly not premissable; what techniques are available to minimize mineral? build-up on the exchanger [tube] walls.

[1] I have heard of putting magnets on both sides of the entry pipe that may help some and has been used sorrounding water heater entry pipes [What might be the mechanism of desolution here?]

[2] Is the extent of the buildup related to delta tempeture difference on the localized surface or more the material of the exchanger tube, and of the deposeted material as in the use of copper in a "tankless coil" for a residential oil burner. [Which clogs in 3 seasons]

[3] Has anyone heard of using plastic materials for heat exchanging "tubes" to limit buildup; although certanly at some loss of heat transmission; or do the deposets even stick to plastic. [ok in this situation of low opreating tempetures]

[4] Any other odd experience eg. constant [audio] vibration or circulating electric current locally in the tubes? to eliminate fowling and retain constant transfer performance
 
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  • #3


I would suggest the following techniques to minimize mineral buildup in heat exchanger tubing walls:

1. Chemical Treatment: One of the most common methods for preventing mineral buildup is through chemical treatment. This involves adding chemicals to the water supply to prevent the minerals from depositing on the walls of the heat exchanger. This method can be effective, but it may not be suitable for all situations, especially in cases where water treatment is not permissible.

2. Magnetic Treatment: The use of magnets to prevent mineral buildup is based on the principle of magnetic water treatment. It is believed that the magnetic field created by the magnets alters the structure of the minerals in the water, making them less likely to adhere to surfaces. However, the effectiveness of this method is still debated and may vary depending on the type of minerals present in the water.

3. Material Selection: The type of material used for the heat exchanger tubing can also play a role in minimizing mineral buildup. For example, using materials such as plastic or stainless steel can be beneficial as they are less prone to corrosion and mineral deposits compared to copper.

4. Regular Cleaning and Maintenance: Regular cleaning and maintenance of the heat exchanger can also help prevent mineral buildup. This can include flushing the system periodically and removing any deposits that have formed on the walls of the tubing.

5. Design Modifications: In some cases, modifying the design of the heat exchanger can also help reduce mineral buildup. This can include increasing the flow rate or changing the direction of the water flow to prevent stagnant areas where minerals can deposit.

In terms of the specific questions posed:

1. The mechanism of dissolution in the case of using magnets is not fully understood. Some theories suggest that the magnetic field may alter the structure of the minerals, making them more soluble in water and less likely to form deposits.

2. The extent of mineral buildup can be affected by both the temperature difference and the material of the exchanger tube. Higher temperature differences can lead to faster deposition, and certain materials, such as copper, may be more prone to mineral buildup compared to others.

3. The use of plastic materials for heat exchanger tubing may be effective in limiting mineral buildup, but it can also result in a loss of heat transmission. The effectiveness of this method may also vary depending on the type of minerals present in the water.

4. I am not aware of any specific experiences involving constant audio vibration or circulating electric current to prevent mineral buildup in heat exchangers. However
 

1. What causes mineral buildup in heat exchanger tubing walls?

Mineral buildup in heat exchanger tubing walls is caused by the precipitation of minerals, such as calcium, magnesium, and iron, from the water that passes through the heat exchanger. These minerals can form deposits on the walls of the tubing and reduce the efficiency of heat transfer.

2. How does mineral buildup affect the performance of a heat exchanger?

Mineral buildup in heat exchanger tubing walls can significantly reduce the efficiency of heat transfer. This can lead to decreased performance, increased energy consumption, and even equipment failure. The buildup can also restrict the flow of water, causing pressure drops and potentially damaging the heat exchanger.

3. Can mineral buildup be prevented?

Yes, mineral buildup can be prevented through proper water treatment. This includes using water softeners or chemical treatments to remove minerals from the water before it enters the heat exchanger. Regular maintenance and cleaning of the heat exchanger can also help prevent mineral buildup.

4. How often should heat exchangers be cleaned to prevent mineral buildup?

The frequency of cleaning depends on the type of heat exchanger and the level of mineral content in the water. In general, heat exchangers should be cleaned at least once a year, but in some cases, more frequent cleaning may be necessary. It is important to monitor the buildup and clean the heat exchanger as needed to maintain optimal performance.

5. How can mineral buildup be removed from heat exchanger tubing walls?

Mineral buildup can be removed through chemical cleaning, mechanical cleaning, or a combination of both methods. Chemical cleaning involves using acidic or alkaline solutions to dissolve and remove the minerals. Mechanical cleaning involves physically removing the buildup using brushes, scrapers, or high-pressure water. The best method for removing mineral buildup will depend on the type and severity of the buildup, as well as the type of heat exchanger.

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