The unnoticed niche--permanent pigging.

Author:Lis, Joerg
Position::Tech Notes: Product Development

Conventional heat exchangers require downtimes for extensive cleaning, resulting in production loss. A corrugated cardboard factory was facing downtimes resulting from a plate heat exchanger, often after only a few hours use. At best it would operate properly for five days.

As a result, a new heat exchanger system with a permanent cleaning system that ran pigs was developed and patented by Jaske and Wolf GmbH an Energy & Water Solutions company in Lingen, Germany; downtime for cleaning was ended.

Permanent pigging means pigs remain in the pipeline systems and will frequently run as required, for example, every hour or every day.


The chart shows the efficiency rate during the first 23 days. The system has proved successful, already operating over 25,000 hours. Currently, other heat exchangers with permanent cleaning pigs are in operation in several industries.

The pig-run intervals can be adjusted as needed, for example, regulated by differential temperature. In this specific case, cleaning pigs circulate every 30 minutes. The pigs remain in the system and can be replaced quickly, if required.

The DUPUR[R] heat exchanger is suitable for the petrochemical industry, food industry, biodiesel plants, paint industry, thermal oil circuits in power distribution systems and geothermal heat recovery from mine water (surface brown coal mining).

Among the advantages:

* No filter is needed for pre-cleaning (high dirt contamination can be handled).

* Surface cleaning is possible within seconds and during operation.

* Cleaning intervals are adjustable in accordance to the level of debris.

* Intervals can be controlled by temperature (automated control).

* Heat transfer remains steady on a high level.

* Silt, crust formation, calcification and fouling in heat exchangers is avoided.

* No chemicals are necessary for cleaning.

* Redundant replacement systems are eliminated.

The lifetime of the pigs depends on the type and amount of debris. Some of the pigs were removed after four weeks. Others have been running more than three years. Debris will be removed automatically during uninterrupted operation.


A permanent pig system has been demonstrated as extremely efficient. This is a smart solution for several purposes and many industries.

Since recovery from wastewater has...

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