Conventional Evaporator

A New Concept Conventional Evaporator:

The MVR plastic evaporator is a never-before concept introduced by Windsor Sathyam, featuring a unique heat exchanger made of polymer. Today, plastics are utilised in areas previously considered impossible. Industrial-scale evaporation is one of them. Windsor Sathyam MVR's evaporation technique works in exactly the same way as conventional mechanical vapour recompression or multi¬effect evaporator, but with a lower temperature difference. The Windsor Sathyam MVR is designed to work efficiently at low temperatures without steam or coolants, saving operating costs drastically. The evaporator is based on the Mechanical Vapour Recompression principle. The energy source of the system is the latent heat released when the vapour evaporated from wastewater is condensed. This vapour is used as the heating medium after its pressure and temperature are increased using a high speed centrifugal fan as the vapour re-compressor.

Preheated effluent is pumped to the horizontal cylindrical vessel and uniformly distributed on the patented heat transfer element made of polymer. The polymeric heat exchanger modules are placed one after the other along the length of the vessel. As the water flows down, evaporation takes place. The vapours are sucked by a high-speed centrifugal fan, (kept outside the vessel) which increases the pressure and saturation temperature. The saturated vapours condense on the inner surface of the patented heat exchanger and releases latent heat to the effluent. The clean condensate is then collected in a pipe connecting all the heat exchanger modules at the bottom. The concentrated effluent is pumped out for disposal or further treatment in a crystalliser. The entire system works under vacuum and the volatile gases, if any, are removed by the vacuum pump.

Advantages over Conventional Evaporator:

Windsor Sathyam MVR evaporator addresses three main drawbacks in conventional evaporator using steam in treatment of high TDS (Total Dissolved Solids) wastewater:
1. High Operating Cost
2. Scaling
3. Corrosion
Though evaporation is logically the most efficient treatment method for wastewater, it is not preferred due to high operating cost. But Windsor's patented polymeric heat exchanger has the 3-in-1 treatment advantage, i.e., saves cost, reduces scaling and eliminates corrosion problems. An evaporator that offers the most desirable results: predictable operating costs and reduced costs of environmental impact.

Besides the NIVR process, this evaporator has several other merits when compared to conventional evaporator:
• The heat energy required in evaporation is proportional to the temperature difference and the area of heat exchanger surface. Conventional MVR evaporator operate at a higher temperature difference and lower area of heat surface. Windsor Sathyam MVR evaporator works with higher area of heat transfer surface and lower temperature difference and this means lesser energy per unit of condensate produced
• Being made of polymer, larger surface areas are inexpensive. This means lower replacement cost of heat exchanger at a fraction of the equipment cost
• The MVR evaporator requires no steam except for the initial heating
• Scaling and fouling on a flexible plastic film is much lower than conventional metallic rigid surfaces
• Due to polymeric heat exchangers, corrosion is not an issue at all and therefore no need for costly metallic materials like titanium alloy, etc.
All the above translate into low running cost. The equipment consumes 8-12 kWh per m3 of condensate only and there is no steam consumption except to the extent of initial heating-up. It is only a fraction of the running cost with steam evaporator.

More Merits...

Using MVR evaporator as a sole treatment method, for example, in textile waste water treatment gives some unique benefits:
• The primary, secondary and tertiary treatment needed in processes based on reverse osmosis can be skipped. The effluent from the collection sump is pumped directly to the Evaporator after simple pretreatment like flotation or online neutralisation.
• No colour removal and hence no sludge.
• No biological aeration and clarification.
• No reverse osmosis, which requires extensive pre-treatment like sand filter, carbon filter, ultra filtration etc.
• No process interruptions due to cleaning of RO membranes.
• The process depends only on the evaporator and not on different steps like colour removal, aeration, clarification and reverse osmosis and therefore the process sequence becomes very simple. More steps mean more chances of imbalance in the treatment. The process, variables are minimal and therefore the wastewater treatment is more feasible.
• No civil structures for primary clarifier, biological aeration and secondary clarifiers etc.
• The capital investment is only marginally higher than conventional treatment followed by reverse osmosis and conventional evaporator. This simplified process of 100% evaporation route for the entire treatment of wastewater is eminently suited for new treatment plants.
The evaporation method is the only treatment that removes impurities from coarse particle size down to ionic size. Windsor Sathyam MVR saves energy by working efficiently and the energy costs can be up to 80% less than other equally efficient technologies. Large heat transfer surface area and low-pressure operation enable the use of compressor fans and correspondingly low energy consumption. Windsor takes care of the solids in wastewater that are to be removed or recovered before release, which in turn ensures that the cleaned wastewater is as harmless as possible. The chemical-free process inside the heat exchanger, with the reduced number of stages in the process, makes the treatment system more conducive to the environment as well.

Besides, Windsor Sathyam MVR system design allows new innovations to be retrofitted to existing plants.

Unique Services

At Windsor, one has an array of options to choose, which suits any given industrial need. The company helps from the basic analysis to systems design, installation and start up after-sales support to ensure a plant's reliable long-term operation. It also helps a smoother transition from conventional evaporator to the MVR plastic evaporator.

Preliminary Analysis:

The analysis of the water sample helps in determining the viability of evaporation and the process parameters and whether any pre- or post-treatment is needed.

Design & Implementation

Based on analysis, the plant is designed and built to optimum quality standards. The key component, polymeric heat exchanger is manufactured at our own plant.

Service & Support

To assure optimum performance throughout, the company undertakes annual operation and maintenance contract.

(Windsor Sathyam Separation Systems, 61/2 U R Nagar, Park Road, Anna Nagar West Extension, Chennai 600 101. Tel: 044-26151554, 26153058. Fax: 91-44-261530 87.