Sven-Olaf Klüe

General Manager

Sven-Olaf Klüe has been working in the field of design, manufacture and applications of pillow plate heat exchangers worldwide for 27 years. For the past 15 years, he has focused specifically on the process-related applications of pillow plate heat exchangers in industrial applications.

Heat recovery from laundry wastewater

What Are Pillow Plate Heat Exchangers?

BUCO falling film chiller for heat recovery from laundry wastewater

Laundry waste water is highly contaminated. Our BUCO falling film chillers with its cleaning option through smooth stainless steel pillow plate surfaces, as well as possible cleaning during operation without loss of performance, is the ideal device for its purpose. Made entirely of stainless steel and with dimensions that can be adapted to the respective space conditions on site in terms of length, width and height, the BUCO falling film chiller is an unbeatable alternative in this pillow plate heat recovery application. Powerful due to the high heat transfer coefficients (up to 2000 W/m² K) of the pillow plates due to its installation for heating the laundry waste water.

The initial situation

In laundries, large quantities of hot water are needed for washing. At the same time, the same amount is produced as warm wastewater. This wastewater is heavily contaminated.

How has it been done so far?

Until now, in most cases the warm dirty laundry wastewater was discharged into the public sewer system. At the same time, expensive heating oil or gas is burnt to heat the same amount of water.

Pillow plate heat exchanger applications? Why the use of BUCO falling film chiller now?

The contaminated laundry waste water produced has a temperature of between 25 and 50 ° C. The cold fresh water from the mains is fed into a falling film chiller at 10 - 15 ° C and preheated to 20 - 45 ° C by the warm waste water flowing past outside of the pillow plates, depending on the design and size of the system. The falling film chiller is made entirely of stainless steel and, due to its smooth surface and offers no starting points for contamination due to its smooth surfaces of the pillow plates. Periodic cleaning is possible without any problems and without much effort. The wall thicknesses of the pillow plates are designed according to the water pressures.

The following aspects are decisive for the selection of these falling film chillers as evaporators for heat recovery from laundry waste water:

  • flexibility in the heat load capacity of the heat exchanger , both in terms of temperatures and the volumetric water flows of heat recovery
  • high robustness of the systems (if extreme climatic conditions or conditions far from the design conditions that are far from the design, the pillow plates‘ units will not be destroyed, as they are not they will not be destroyed because they are open systems)
  • good cleanability of the open pillow plates‘ surfaces and distribution trough, even during waste water operation
  • low control effort of this heat transfer system for laundry waste water
  • Heat transfer system with low cost per kWh and minimal refrigerant used ideal for use of heat recovery of laundry waste water
  • High efficiency heat recovery with optimal heat transfer, low pressure drop of these heat transfer waste water systems
  • Easy access to the open these heat recovery waste water systems
  • Easy to clean heat exchange systems ideal for use of heat recovery
  • Cleaning during operation possible with these heat recovery systems
  • Low tendency to fouling for this heat transfer system ideal for use of heat recovery systems
  • No seals in this heat transfer systems out of pillow plates for laundry waste water
  • No destruction of the apparatus in case of ice formation of this heat transfer system
  • Simplicity of control of these heat transfer system for laundry waste water
  • Pillow plates completely made of stainless steel, also for salt water
  • Special and customized pillow plates‘ design possible

Conclusion

Heating oil and gas consumption can be reduced by 50 % by installing the BUCO falling film chillers with pillow plates to heat the laundry wastewater. Amortisation in the shortest possible time is guaranteed.