Industrial Zero Liquid Discharge (ZLD) Manufacturer & Supplier in India

Zero Liquid Discharge (ZLD) is an advanced wastewater treatment approach designed to eliminate any liquid discharge into the environment. The process focuses on treating, recovering, and reusing wastewater by converting it into reusable clean water and solid waste residues, making it a highly sustainable solution for industries aiming to reduce environmental impact and improve water efficiency.

Multiple Effect Evaporator

A Multiple Effect Evaporator (MEE) is an industrial evaporation system used for concentrating liquid solutions efficiently by utilizing multiple stages (effects) of evaporation. Depending on process requirements, MEE systems can be configured as falling film, forced circulation, or a hybrid combination of both technologies to handle different types of feed characteristics.

In a Multiple Effect Evaporator, the vapor generated in one effect is reused as a heating medium in the subsequent effect, significantly reducing steam consumption and improving overall energy efficiency. This cascading utilization of vapor makes the system highly economical for large-scale industrial applications.

Key advantages of Multiple Effect Evaporators include high energy efficiency, improved concentration capability, operational versatility, effective heat integration, and environmentally friendly operation. These systems are widely adopted across industries due to their ability to minimize energy costs while maximizing productivity.

Due to their strong energy-saving potential and high operational efficiency, Multiple Effect Evaporators are considered one of the most reliable solutions for industrial evaporation and concentration processes.

Advantages of Using a Thermo Vapour Recompressor (TVR) in MEE

A Thermo Vapour Recompressor (TVR) significantly enhances the steam efficiency of a Multiple Effect Evaporator (MEE) system by improving energy utilization and reducing overall steam consumption. In this process, a portion of the generated vapor is entrained and recompressed using motive steam, allowing it to be reused as an effective heating medium in the system.

By recycling and upgrading low-pressure vapor, the TVR system reduces the dependency on fresh steam input and improves the overall thermal performance of the evaporator setup, making the process more energy-efficient and cost-effective.

For example, in a two-effect evaporator system integrated with a Thermo Vapour Recompressor (TVR), steam consumption can be reduced by approximately 30–35% compared to a conventional two-effect evaporator. This improved efficiency makes the performance of a two-effect system with TVR comparable to that of a standard three-effect evaporator, offering similar output with significantly lower operating costs.

Typical schemes offered in MEE

• Falling Film Evaporators
• Forced Circulation Evaporators
• Multi-Effect Evaporator(MEE) i.e. Combination of Falling & Forced .
• MEE with Pusher Centrifuge
• MEE with Agitated Thin Film Dryer(ATFD)
• MEE with Pusher and ATFD.
• Mechanical Vapour Recompressor (MVR) based MEE

ZERO LIQUID DISCHARGE (ZLD)

Implementing a Zero Liquid Discharge (ZLD) system using Multiple Effect Evaporators (MEE) can significantly reduce the environmental impact of industrial wastewater and support sustainable water management practices. However, ZLD systems are complex in nature and require proper engineering design, process integration, and controlled operation to achieve maximum efficiency and compliance with environmental regulations.

In typical industrial applications, an MEE system can concentrate a liquid solution only up to a certain limit, typically from an initial concentration (x%) to an intermediate concentration (y%). Beyond this point, additional separation and drying technologies are required to achieve complete Zero Liquid Discharge.

To achieve full ZLD, additional equipment such as a Pusher Centrifuge and an Agitated Thin Film Dryer (ATFD) are commonly integrated with the MEE system.

An MEE combined with a Pusher Centrifuge is generally used when the process stream contains a high proportion of crystalline salts, allowing efficient solid-liquid separation of crystals.

An MEE integrated with an ATFD is suitable for effluents containing non-crystalline solids or higher organic content, where further evaporation and drying are required to achieve solid residue formation.

In advanced ZLD systems, a combination of MEE, Pusher Centrifuge, and ATFD is often employed. In this configuration, crystalline salts are first separated using the centrifuge, while the remaining non-crystalline solids and organic components are further concentrated and dried in the ATFD, ensuring complete elimination of liquid discharge.