Armstrong International has supplied a 650 kW Digital-Flo heat exchanger package to a North London Hospital.
Replacing a storage calorifier, it uses a constant 1 bar g steam pressure to provide domestic hot water at a safe, stable temperature, controlling to 60°C (+/–1°C) at varying demands, from 0 to 625 L/min. The company said: “Such close control offers enhanced safety, and ensures lower energy usage than ‘traditional’ systems. Control is achieved using the Brain digital recirculating valve, specifically designed for domestic hot water applications. The Brain can manage a thermal disinfection regime, and can be controlled locally, or remotely via a building energy management system.” In the event of a high temperature alarm, steam instantly shuts off, and the Brain fails to the cold position. Legionella proliferation is reduced in the heat exchanger, as water is heated to above 70°C. The Brain replaces a steam control valve; PID controller; high temperature limit thermostat; high temperature limit controller; cold water injection valve; internal circulating pump, and compressed air requirement.
