Danfoss ensures a smoother operation for a purification plant in Italy

Friday, September 8, 2023

Tailor-made spiral configuration to ensure a smooth operation for an Italian purification plant

eco center AG has replaced its current shell-and-tube technology with spiral heat exchangers from Danfoss. Clogging and weekly cleaning of the heat exchangers is now history - with a return of investment in just one year.

Since eco center AG replaced its current shell-and-tube technology with spiral heat exchangers from Danfoss, clogging and weekly cleaning of the heat exchangers is now history - with a return of investment in just one year.

In 2020, Danfoss supplied two spiral heat exchangers to the purification plant eco center AG, a society of the municipalities of South Tyrol and the Autonomous Province of Bolzano, Italy.

The company operates the most important waste disposal facilities including wastewater service sewerage and wastewater treatment) and supports environmental research projects to investigate the impact of its activities in the surrounding area.

The recuperator (tubular heat exchanger) needed to be replaced with another type of heat exchanger due to frequent clogging.

The clogging occurred 1-2 times per week, and the plant had to stop the entire process to clean the shell-andtube heat exchangers.

  • The quality of the industrial wastewater quality is variable throughout the year and even weekly
  • Suspended solids in the wastewater (up to 1,500 mg/liter)
  • The plant needs to heat a large amount of wastewater (flow rate is 145 m3/h) at a consistent temperature of 23.2°C

eco center AG requested the following:

  • Maintain 1.400 kW and 150 m3/h
  • Avoid clogging issues
  • Advanced control and modularity
  • Ensure installation in an accessible location

Danfoss offered a tailor-made spiral configuration manufactured with

  • Easy opening hinged covers
  • CIP joints on connections for cleaning without opening
  • Separate drain connections

The replacement with the Danfoss spiral heat exchangers includes a highchannel design and extra length to ensure less cleaning (compared to the former shell-and-tube technology that needed cleaning 1-2 times per week)

Advantages

The best compromise between efficiency and functionality

Adequate free flow of suspended solids

Modularity (during maintenance, the second heat exchanger operates half power)

Easy to check and clean automatically.

Danfoss spiral heat exchangers offers a wide range of benefits

  • Single-channel design that generates high shear rates which contribute to a self-cleaning effect, preventing clogging of the unit. Spiral heat exchangers are the perfect solution for challenging, high-viscosity media.
  • Very compact solutions, our spiral heat exchangers have minimal space requirements. Despite their small stature, the long, curved flow paths allow for very high heat transfer coefficients up to twice as high as their shell and tube counterparts.
  • Limited need for maintenance and cleaning ensures extended operational uptime. If the need for cleaning arises due to particularly difficult media, the hinged covers provide easy access to the entire heat transfer surface.

This enables eco center to operate at full capacity without losing valuable production downtime due to frequent cleaning and maintenance.

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