image description image description image description

Direct and Indirect Heat Transfer

During the pulping process, the digester is heated up to cooking temperatures of 155-180oC. The heating is done with direct or indirect steaming.

The direct heat transfer is done by introducing medium pressure steam into the circulation line with direct steam nozzles. No heat exchanger is needed due to the small amout of steam required, and at the same time, heat exchanger cleaning or repairing is eliminated. 

The indirect heat transfer is done by shell/tube heat exchanger. This allows condensate return to the power plant and reduced evaporation load.

  • Direct steam nozzle designed to achieve efficient steam mixing resulting in smooth operation
  • Equipment in contact with liquor: Stainless steel or higher grade wetted parts when low metal content in pulp is targeted
  • Direct steam nozzle: no maintenance and simple construction
  • Heat exchanger: condensate return to the power plant and reduced evaporation load
general requests

Direct and Indirect Heat Transfer

During the pulping process, the digester is heated up to cooking temperatures of 155-180oC. The heating is done with direct or indirect steaming.

  • Further Details

    The direct heat transfer is done by introducing medium pressure steam into the circulation line with direct steam nozzles. No heat exchanger is needed due to the small amout of steam required, and at the same time, heat exchanger cleaning or repairing is eliminated. 

    The indirect heat transfer is done by shell/tube heat exchanger. This allows condensate return to the power plant and reduced evaporation load.

  • Technical Information

    • Direct steam nozzle designed to achieve efficient steam mixing resulting in smooth operation
    • Equipment in contact with liquor: Stainless steel or higher grade wetted parts when low metal content in pulp is targeted

  • Benefits

    • Direct steam nozzle: no maintenance and simple construction
    • Heat exchanger: condensate return to the power plant and reduced evaporation load

Feedback

Thank you, Your Comments / Suggestions submitted successfully.