Proper storage and handling of asphalt emulsions is critical for product quality and performance. Because emulsions typically contain 30-40% water, they will freeze at 32 degrees Fahrenheit and boil at 212 degrees Fahrenheit, depending on the grade. To create the ideal product for road-ready use, the emulsion must be kept warm, but not too hot, which is why the type of storage tank used for asphalt emulsions is such an important decision.
Vertical vs. Horizontal Asphalt Storage Tanks
Vertical tanks are recommended for the asphalt emulsion industry for their practical advantage. They minimize the surface area of the finished product that is exposed to air, which can cause a skin of asphalt to form on emulsions. Vertical tanks are also generally easier to mix and insulate, and less expensive than horizontal tanks because they don’t require a support system.
While vertical tanks are better for fixed asphalt emulsion storage, horizontal tanks are often used for portable, short-term asphalt storage in the field, or very specific applications, such as seal coat materials. These tanks are easier to recirculate and drain completely.
Materials of Construction for Asphalt Emulsion Tanks
The type of construction materials used for asphalt emulsion tanks depends on several factors, including the corrosivity of the emulsion, desired storage temperature, structural demands, and the cost versus the expected operating life.
Poly-tanks are generally a less expensive option and are compatible with a wide range of chemicals. They are non-reactive, and easier to move and modify after market. However, they are limited in heating capacity and structural strength, and they typically cannot be repaired.
Carbon steel tanks are also inexpensive and easy to modify after market, but they are also easy to repair. They offer unlimited sizing options and can support high temperatures, but they provide poor corrosion resistance. Carbon steel tanks are typically used for AC, finished emulsions, hydrocarbons, and fuel.
Stainless steel tanks have high temperature capabilities and offer corrosion resistance. They also have a longer operating life, but they are difficult to modify or repair after market, and they are a more costly option. Stainless steel tanks are a good choice for emulsifier.
Fiber-Reinforced Polymer Fiberglass
FRP tanks are strong, lightweight and resist corrosion. They can also support a wider temperature range than poly-tanks and offer a longer operating life. However, they are more costly and are difficult to repair or modify. Emulsifier soap solutions are often stored in fiber-reinforced polymer tanks.
Asphalt Emulsion Terminal Construction
The type of tank used to store asphalt emulsions can and will affect the quality and performance of the product. When building, upgrading, or renovating an asphalt emulsion terminal, it’s important to work with a contractor who is familiar with emulsion manufacturing.
ECF has significant experience in designing, building and operating emulsion systems throughout the United States and Americas. We understand the nuances of manufacturing emulsions as the result of hands-on experiences and have provided designs for all types of emulsion products and systems.