Demineralized (DM) water is utilised for cooling tower make-up water when the total dissolved solids (TDS) of the raw water is very high. This is due to the fact that only a small portion of the circulating water is recycled during the process.
The ion exchange process is used to remove mineral salts from water, which is known as demineralisation. Netsol Water Solutions manufactures variety of wide range of custom-built Demineralized Water Plants [DM Plants] in India for industrial process water applications.
Manufacturing Process of DM Wastewater plants- Thermal industry
- 1. Operating Principle
A typical two-bed Demineralized Water plant, also known as a DM Plant, is made up of a succession of FRP/MS Rubber walled Pressure vessels and their internal fittings. The first unit is made up of a high-capacity strongly acidic cation exchange resin that transforms positive ions in salt and replaces them with hydrogen ions to generate acids, which are then absorbed by a strongly basic anion exchange resin in the following vessel.
This procedure produces water with a conductivity of less than 20 S/ cm at 250 ®C and total dissolved solids of less than 10 ppm. Mixed Bed Deionisers, which are meant to create high purity treated water, can provide even more high purity water. After a two-bed DM Plant, they can be used as polishing units to obtain high-purity water.
- 2. De-gasifiers
Installing degasifiers downstream of the cation unit eliminates carbon dioxide, lessening the burden on the anion unit. As a result of the lower chemical usage, there are cost savings. A mild steel rubber walled / FRP tower, as well as a blower and transfer pump made of stainless steel, are included in standard units. Optional extra pumps and blowers are available.
- 3. De-mineralizers for Mixed Beds
To obtain high purity levels in the treated water, mixed bed de-mineralisers are employed downstream of the DM unit. Packaged and custom-built mixed bed de-mineralisers are available. These mixed bed systems have a single vessel with a mixture of cation and anion resins, as well as complete service and regeneration plumbing, a self-supporting skid foundation, and regeneration chemical tanks.
- 4. Polishing of Condensate
A condensate polisher is a device that filters steam-condensed water during the steam cycle. Ion exchange resins for condensate polishing excel at trapping corrosion compounds in the condensate stream. For the removal of trace dissolved minerals and suspended debris, this polishing commonly uses ion exchange technology. It's usually found in a power plant's condensate system, and it prevents early chemical failure and deposition during the power cycle, which would have resulted in a loss of unit efficiency and probable mechanical damage to essential generating equipment.
- 5. Two-Bed DM Plants with Fully Automated Rapid Flow
Fluid Systems now offers skid-mounted, PLC-controlled two-bed fully automatic rapid DM plants with state-of-the-art counter-flow ion exchange technology that was previously only accessible in big, purpose-built plants. Volume throughput, which is pre-programmed into the PC according to the type of feed water, controls the operational cycle of these bundled rapid-regeneration systems. The ion exchange resins are never completely depleted, providing constant deionized water production.
After a two-hour minimum service cycle, regeneration takes only 30 minutes, reducing the need for standby power and large-scale water storage. Because the cation and anion beds regenerate at the same time, the effluent streams are generally self-neutralizing, lowering waste disposal costs and decreasing environmental effect.
COST OF DM WATER PLANTS: THERMAL INDUSRTRIES
No specific and accurate number can be given and may vary from company to company and on product basis.