A major Indian producer of ammonium nitrate and nitric acid chemicals was using induced-draft cooling towers. In the summer and monsoon months, the outlet temperature from the cooling tower was too high.

Smartchem Technologies Ltd., a division of Deepak Fertilizers Ltd., is a major producer of ammonium nitrate and nitric acid chemicals located at Srikakulam near Vishakapatnam in AP, India. The plant was using induced-draft cooling towers with a capacity of 369,800 gal/hr. In the summer and monsoon months, when the wet-bulb temperature was around 86°F (30°C), the outlet temperature from the cooling tower was around 93 to 95°F (34 to 35°C). The higher water temperatures reduced the plant’s efficiency compared to the winter months, and the cooling tower fans were consuming a substantial amount of energy.

After evaluating its options, Smartchem decided to implement a mist cooling system from Mist Ressonance Engineering Pvt. Ltd. A system with a capacity of 184,900 gal/hr (50 percent of the total capacity) was chosen to fit the available space. The system was designed, manufactured, installed and commissioned in 2004.

The mist cooling system has been operating in conjunction with the cooling tower for almost four years. The outlet temperature from the mist cooling system is around 88°F (31°C). Due to the reduced water load on the existing cooling tower, the outlet temperature from the cooling towerhas dropped to about 91°F (33°C) compared to the previous 95°F (35°C). As a result, the temperature at the cold water suction pit (where the outlet of both the cooling towerand mist cooling system is mixed) is maintained at the required 90°F.

Due to the high efficiency of the mist cooling system, Smartchem Technologies Ltd. was able to increase its production by 5 percent. The company also has saved approximately 45 kW/hr on fan power. These benefits allowed the company to achieve a payback on the mist cooling system in less than one year.

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