Case studies

Lackeby Heat exchanger sludge/water, Drammen, Norway

The arriving raw waste is unsanitary, why the first step is pasteurization (sterilization). This is done in a thermic hydrolyzing process (pressure boiling with steam), in which the media is heated to a minimum of 133°C and hold for 20 minutes. The maximum temperature is set to 160°C and for that the pressure demand is 5-6 bar. When the boiling time is over, the temperature is quickly reduced to about 40°C, in which the cellular walls and fibers breaks up into smaller particles. This is where the use of a heat exchanger is the most efficient and cost-effective way.



Lackeby Heat exchanger air/water, Ryaverket, Sweden

Already in 1995, during the refurbishment of Ryaverket WWTP, the plant had a big focus in energy management. They wanted to maximise any energy recovery as well as lowering the operational costs in terms of maintenance cost and manhour used for maintenance.
The blowers that distribute aeration into the biological tanks was generating a lot of heated air that was wasted when heating the wastewater. To recover this energy as well as lowering the lifetime of the EPDM membranes was a priority identified by Ryaverket WWTP.

heat exchanger air/water ryaverket


Lackeby Roto-Sieve drum screen, Bioenergi i Luleå, Sweden

Bioenergi in Luleå previously used a decanter-centrifuge to separate and dewater wooden fibers from the cooling water in their scrubber. The solution to centrifuge the cooling water is common in the business, but the disadvantage is high energy consumption and at the same time the need of maintenance is high. Since the cost of maintenance had increased, the MD Conny Holmberg saw the need to find a
new, effective and priceworthy solution.
The answer was found during a visit to, at that time, Lantmännen Agroenergi in Ulricehamn, nowadays named Scandbio Ulricehamn. They had recently replaced their Rotopass sieve with a Lackeby Roto-Sieve® drum screen model RS 24. The application was uncomplicated and dependable, which suited Managing Director Conny Holmberg. After bringing in references, they decided to purchase a Lackeby Roto-Sieve® drum screen with a Lackeby Screw conveyor press.

RS Bioenergi


Lackeby Roto-Sieve septic unit, Broby WWTP, Sweden

Broby WWTP, a small waste water treatment plant, had a great need of reducing the momentarily high biological load which occurred when receiving septic sludge (also known as external sludge). The high load caused instability in the biological treatment process which resulted in a waste water treatment plant with substantial problems to meet the effluent terms of condition.
Therefore, they very much needed to find a septic unit that combined a short truck off-loading time with a high screening capacity and which immediately could send the sieved effluent further on to the sludge storage.

RS septic unit Broby