Industrial Mixers for Water and Wastewater Treatment
Water is one of the most important resources on the planet. Clean water is necessary to support life itself and is the basis for a countless number of water-based products including food products, medical formulations, personal hygiene products and more. The purification of water, however, spans municipal processes resulting in potable water and also the treatment of wastewater from industry. The chemical reactions that are utilized in the purification of water are highly controlled including precise dosing, flow rates and agitation levels. The following are some examples of how INDCO, Inc. industrial mixers are utilized in some key steps in the municipal and industrial treatment of water:
Municipal Water Purification
The purification of ground water or that from rivers, lakes or streams is the focus of the continuous process of municipal water purification facilities. Through a series of chemical and physical processes contaminants are separated and organisms are eliminated to produce clean drinking water. A few of the common steps in the overall municipal water purification process are chemical makeup and addition, flash mixing, flocculation, chlorination and polymer addition. Each step in the process can have unique needs for agitation level and shear.
Chemical Makeup or Addition
Water purification chemicals are produced in dry powder or concentrated liquid form. Therefore, dilution either in portable tanks or intermediate bulk containers is common prior to introduction into the general process flow. Portable direct-drive clamp style mixers, such as the INDCO model D-11T for rapid mixing of low-viscosity formulations or the model GH-100T gear-driven mixer for more viscous chemicals or when there is a desire to limit shear are ideal for use in these pre-mixing steps. Models BTC-11T and BGTC-150T are corresponding direct drive and gear-driven mixers for ibc totes.
As the name implies flash mixing is the rapid integration of chemicals into the water purification process. It is characterized by high rpm mixing to maximize agitation and therefore achieve homogeneity in a short period of time. The aforementioned portable mixers can be used for smaller scale processes and more powerful top-mounted mixers are ideal for turbulent agitation in larger volume flash mixing basins. The INDCO model TM-200 is one example of a top mounted tank mixer for larger volumes.
Flocculation is the process of introducing compounds called flocculants, often aluminum sulfate (alum), into the water to attract solid particles to form clumps, or flocs. These flocs then settle to the bottom of the basin as the flow of water is gently agitated. While it is critical that complete agitation is generated to maximize the agglomeration of the solids it is equally important that shear be minimized to prevent destruction of the same flocs. Therefore, a gear-driven top mounted mixer with a hydrofoil style impeller is the best choice to achieve both goals. A model such as the TM-series mixers utilize the hydrofoil impeller design which provides the maximum agitation per unit of energy input with the lowest shear input.
Chlorination and Polymer Addition
Chlorination is a sanitization step to ensure that bacteria and other organisms are eliminated from the water. Chlorination is generally achieved through intense agitation to completely disperse chlorine into the water using either a direct-drive or gear-driven mixer design optimized to provide the agitation necessary for the chlorination tank or basin used in the process. Similarly, polymers may be added to achieve the desired water chemistry. A variety of mixers may be used for chlorination and polymer addition based on the working volume and container geometry. Contact your INDCO applications engineer for selection and sizing recommendations.
Industrial wastewater processes are often designed to settle out solids resulting from chemical or other production, dilution of chemical contents to meet EPA disposal requirements or adjustment of acidity and alkalinity. Therefore, from an agitation standpoint the range of applications can be similar to that for municipal treatment. However, it is the nature of the elements to be removed and the operating environments that can be quite different. For example, solid waste may be denser and thus require higher horsepower and torque, or highly acidic processes may need to be neutralized inside a sealed mixing tank thereby requiring more chemically resistant mixer components and perhaps a mechanical seal.
For these and a myriad of other industrial wastewater mixing applications INDCO engineers have both standard and customized designs to meet your needs. Mechanical seals prevent hazardous fumes from escaping the vessel and are available with a wide range of metallic and elastomer components. Mixing shafts and impellers are 316 stainless steel as our standard but upgrades include Hastelloy and other alloys as well as Teflon, halar and other chemically resistant coatings.