Lackeby Roto-Sieve Drum screen, Procarne slaughterhouse, Mexico
The company used to have settling traps that were cleaned by hand every day because they were closely checked by the sanitation authority since there were a lot of problems in the sewer due to their discharge.
The problem was so big that the company was planning to close the facility and either stop processing meat (selling the bulls alive to other processors) or to move the facility out of the urban area. Neither of the scenarios were preferable by the management.
The wastewater treatment plant in Säter is designed for 8,000 PE.
In addition to wastewater, external sludge from wells and septic tanks are received, but also screenings from some smaller nearby treatment plants.
The customer’s equipment for external sludge treatment was built up around a receiving tank containing two step screens. However, the equipment was sensitive to gravel and grit and they frequently experienced severe problems with screenings clogging the screens discharge zones.
In particular, problems were identified at the times when they received external screenings from the nearby smaller treatment plants.
These problems were to the extent that a plant operator had to work full time to manually clean the discharge zones during operation.
This was costly and resulted in a very poor working environment.
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.
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.
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.
Lackeby Floating decanter, Grödaland WWTP, Norway
IVAR wastewater treatment plant Grødaland in Hå municipality is a chemical /
biological sewage treatment plant with four SBR tanks and flotation facilities. The facility was rebuilt in 2008 and as a solution for the biological treatment
they chose an SBR process. The requirements were a maintenance-free and reliable design, with efficient decanting and minimal need for electric components.
The choice was the Lackeby Floating decanter because of the robust, innovative and maintenance-free design.