J&E Hall keeps cool in the desert

Extreme heat and the harsh conditions of a desert-like environment were just two of the problems facing J&E Hall’s design engineers when they were asked to develop a chiller system to cool methanol at the chemical plant of Cristal, a pigment manufacturer based at the Yanbu industrial complex in Saudi Arabia. Cristal manufactures titanium dioxide pigment and cools its heat exchangers with methanol, which presented a more serious problem: flammability. This meant the methanol had to be kept supplied at -23°C, and if the methanol cooling system stopped working the entire factory plant would have to shut down.

J&E Hall’s contracting division designed a duplex chiller pack containing two of the company’s HallScrew HS2035 single screw compressors - each with an output of 600kW - to ensure that the methanol was kept to the correct design temperature at all times.

Particular attention was required in three areas: paint on the chiller pack had to withstand the extreme heat, sand and aggressive chemicals; all instruments and motors had to be able to cope with the hostile climate; all components had to meet the standards laid down by the ATEX regulations.

At the chemical plant, water - at a temperature of 34°C - is available for condenser cooling. This is preferred to air, which can reach temperatures as high as 50°C. The chiller system runs on R134a refrigerant, which operates at lower pressure and is thus suited to the high ambient conditions found at the chemical plant. A common oil separator kept the design of the system straightforward and made it easier to operate.

Acoustic lagging on the separator and the compressors maintains noise levels at 85 dbA at one metre. Instrumentation and control for the chiller package is provided by a J&E Hall Fridgewatch microprocessor-based system.