HYDRO-THERMAL DIRECT STEAM INJECTION

Many plants are scrutinising the complete energy picture in their mills and analysing each step for potential reduction of energy use. From tree to transport, the papermaking process is known as a high energy consumer. Direct steam injection (DSI) reduces energy use in many areas of the plant. It heats by injecting precise amounts of steam directly into the process fluid and can be used for any pumpable and water miscible stock. DSI provides 100% thermal efficiency using both sensible and latent energy in the steam. Energy savings can be considerable — reductions of 20-25% are common. The return on investment for these heaters is usually measured in months.

DSI heaters are plumbed directly into the process line and stock flows into the inlet and pass the heater’s diverter and diffuser. Sonic velocity steam is injected into the heater through the stem plug that has a precise geometric array of small holes in the diffuser. The turbulent nature of the discharge enables steam to instantaneously penetrate, disperse, and efficiently mix with MC pulp stock to effect uniform heating. Monitoring the stock temperature downstream simplifies steam volume control, via an actuator, to keep the stock at the desired temperature.

DSI heating is faster and more efficient than sparging or heat exchangers, resulting in optimising not only process efficiency but reducing energy costs, chemical usage and volatile emissions.

For more information please contact Hydro- Thermal Corporation: www.hydro-thermal.com or info@hydro-thermal.com; phone +1 262.548.8900/+1 800.952.0121. Contact: MG Cohodes, marketing communications manager.