DM plant, short for demineralization plant, is a water treatment system that removes all dissolved minerals and salts from water. This process is also known as deionization and is typically used in industrial applications that require ultra-pure water.

DM plants use a combination of ion exchange resins and a reverse osmosis system to remove dissolved minerals and salts from water. The ion exchange resins remove dissolved ions like calcium, magnesium, and sodium from the water, while the reverse osmosis system removes other dissolved solids like dissolved organic compounds.

The DM plant typically consists of a pre-treatment unit, a cation exchange unit, an anion exchange unit, and a mixed bed unit. The pre-treatment unit removes suspended solids and other impurities from the water before it enters the cation exchange unit. In the cation exchange unit, positively charged ions like calcium, magnesium, and sodium are exchanged with hydrogen ions. In the anion exchange unit, negatively charged ions like chloride, sulfate, and bicarbonate are exchanged with hydroxide ions. The mixed bed unit contains both cation and anion exchange resins, which ensure that the water is completely demineralized.

DM plants are typically used in industries that require ultra-pure water, such as pharmaceuticals, semiconductor manufacturing, and power plants. The quality of the water produced by the DM plant is measured in terms of conductivity, which is a measure of the amount of dissolved salts and minerals in the water. DM plants can produce water with a conductivity of less than 1 microsiemens per centimeter (µS/cm), which is considered ultra-pure.

DM plants are typically made of materials like mild steel (MS), stainless steel (SS), and fiber-reinforced plastic (FRP). The selection of the appropriate material depends on factors such as the application, operating conditions, and budget.

In summary, DM plants are water treatment systems that remove all dissolved minerals and salts from water. They use a combination of ion exchange resins and a reverse osmosis system to achieve this. DM plants are typically used in industries that require ultra-pure water, and they can be made of materials like MS, SS, or FRP.