Specific Process Requirements Of The Sewage Treatment Plant

Understanding your sewage treatment plant's specific process requirements is essential before choosing an electric submersible mixer. Mixing may be required in different ways at different stages of wastewater treatment. For instance, the primary settling tank's mixing requirements are distinct from those of the aeration basin or anaerobic digester.

To avoid disturbing the settled sludge in the primary settling tank, gentle mixing is required to facilitate the separation of solids from liquids. A low-speed mixer with a large diameter impeller may be appropriate for this purpose. However, to maintain the microorganism suspension and ensure proper oxygen distribution, the aeration basin, where biological treatment takes place, requires more vigorous mixing. Here, a high-velocity blender with a more modest impeller measurement may be more proper.

The mixing requirements for processes like nitrification, denitrification, and dephosphorization can change depending on the treatment method. For instance, the mixer in a sequencing batch reactor (SBR) system needs to be adaptable enough to handle a variety of mixing intensities at different points in the treatment cycle.

You can choose a mixer that can deliver the right level of mixing intensity and flow patterns for each stage of your treatment process if you know these process-specific requirements.

Evaluate The Characteristics Of The Medium

The best electric submersible mixer is heavily influenced by the characteristics of the wastewater that is being treated. The viscosity, density, temperature, pH value, and solid content are important variables to take into account.

The mixer's flow patterns and the power required for mixing are influenced by viscosity. Higher consistency liquids for the most part require more power and bigger impellers to accomplish viable blending. The overall mixing dynamics and the buoyancy of suspended solids are both affected by the medium's density. During the treatment process, temperature can have an impact on biological activity as well as viscosity, which could influence mixer selection.

The pH worth of the wastewater is essential, particularly in organic treatment processes. Because mixer components can corrode at extremely high pH levels, it is essential to select a mixer made of materials that can withstand the particular pH range of your wastewater.

In the treatment of sewage, the amount of solids is especially important. High solid content may necessitate more robust designs due to the potential for increased wear on mixer components. Additionally, it may have an impact on the amount of power required to keep solids suspended. To prevent solids from settling, an anaerobic digester with a high solids content might require a mixer with a larger impeller and more power.

Determine The Tank Type And Size

The electric submersible mixer you select will have a significant impact on how your treatment tanks are set up. The mixing patterns and the number of mixers required for optimal performance are influenced by the tank's shape and size.

When compared to square or rectangular tanks with the same volume, round tanks typically require fewer mixers. A single mixer of the right size can frequently produce a uniform circular flow pattern in a round tank. However, to avoid dead zones in the corners of square or rectangular tanks, multiple mixers may be required.

Another important aspect is the tank's water depth. To ensure thorough mixing throughout the tank's volume, mixers with longer shafts or multiple mixers at various depths may be required for deeper tanks. The total amount of mixing energy required is determined by the tank volume, which in turn influences the size and number of mixers required.

In a large aeration basin, for instance, a grid of multiple submersible mixers may be installed to ensure uniform mixing and oxygen distribution. On the other hand, a single mixer of the right size might be all that is needed in a smaller equalization tank.

Choose The Tight Power And Impeller Diameter

It is essential to choose the right power and impeller diameter for your electric submersible mixer if you want to achieve the best mixing performance while using the least amount of energy possible.

The mixer's power needs are mostly determined by the tank's volume and the characteristics of the medium being mixed. When in doubt, the power necessity increases with tank volume and liquid thickness. However, the application's specific power requirements may differ significantly. For instance, a low-intensity mixing application in an anaerobic digester might require 5-10 watts per cubic meter or more, whereas a gentle mixing application in a primary clarifier might only require 1-2 watts per cubic meter of tank volume.

Another important aspect is the diameter of the impeller. Higher flow rates at lower speeds are typically produced by impellers with a larger diameter, which can be more energy-efficient for some applications. Due to space constraints, they may not be suitable for all tank configurations. For applications with high shear or limited space, smaller diameter impellers operating at higher speeds may be more effective.

A ratio is a common way to describe the relationship between impeller diameter and tank size. For instance, in a round tank, an impeller measurement that is 0.3 to 0.5 times the tank breadth is frequently successful. However, depending on the application and mixer design, this may differ.

It is essential to keep in mind that while larger impellers and higher power can result in more intense mixing, they also consume more energy. As a result, when selecting these parameters, it is essential to strike a balance between mixing efficiency and energy efficiency.

Electric Submersible Mixer Manufacturers

When choosing an electric submersible mixer manufacturer, you should consider product quality, reliability, after-sales service, and compliance with industry standards. Tianjin Kairun is one such manufacturer, and our products are certified to ISO 9001 quality management system. Our company has implemented a strict quality management system to ensure consistent product quality. If you need help choosing an electric submersible mixer manufacturer, please feel free to contact us at catherine@kairunpump.com.

References:

1. Metcalf & Eddy, Inc. (2003). Wastewater Engineering: Treatment and Reuse. McGraw-Hill.

2. American Water Works Association. (2012). Water Treatment Plant Design. McGraw-Hill.

3. Water Environment Federation. (2018). Design of Water Resource Recovery Facilities, Manual of Practice No. 8, Sixth Edition. McGraw-Hill Education.

4. Tchobanoglous, G., Burton, F. L., & Stensel, H. D. (2003). Wastewater Engineering: Treatment and Reuse. Metcalf & Eddy, Inc.

5. Henze, M., van Loosdrecht, M. C., Ekama, G. A., & Brdjanovic, D. (Eds.). (2008). Biological Wastewater Treatment: Principles, Modelling and Design. IWA publishing.