Fewer downtimes for Mälarenergi

The city of Västerås is one of the pioneers when it comes to district heating in Sweden. Already in the late 1940s, the municipality dared to invest in the then-new type of energy source. Today, 98% of the city’s properties are connected to district heating. Next to Lake Mälaren in Västerås is one of Mälarenergi’s large production facilities with a stationary vacuum system from DISAB. 

CHALLENGE

Long stop times during sanitation

Block 6, where waste is incinerated to produce district heating, plays an important role in production. Here, waste is incinerated to meet 50% of the city’s heating needs. The waste boilers must work hard, and the process wears on them. To keep the boilers in good condition and keep availability, ongoing maintenance and sanitation are required, which occurs twice a year. But the downtime that the maintenance entails costs. When Block 6 was put into operation, the sanitation took twelve days, where a day’s downtime is estimated to cost Mariner about 1 million in lost revenue.

SOLUTION

Extended and optimized vacuum system

After the first maintenance shutdown, a project was started where Mälarenergi invested in improving the existing stationary vacuum system. The entire operation was reviewed and with the help of DISAB, the number of suction sockets was increased and placed more strategically to reduce the number of meters of working hose. It was also ensured that there were several suction sockets on each floor of the 50-meter-high building to increase accessibility for operators and suction trucks. The vacuum system today consists of a central vacuum cleaner system with over 1000 meters of pipes connected to filter separators and vacuum units, where vacuum loaders and suction trucks are switched on to the system during downtime and audit. 

”Installationen blev lönsam redan vid första stoppet.”

Mikael Saario, Propterty manager Block 6

RESULTS

The vacuum system reduced downtime and improves the work environment

The results were already revealed at the first sanitation. From the sanitation previously taking twelve days, Mälarenergi now managed to work in three days and the investment became profitable already during the first stop. The increased number of suction sockets optimized the availability of the suction trucks and improves the working environment for operators as they never need to use more than 15 meters of the hose during sanitation. The great advantage of a stationary vacuum system is first and foremost time savings during major maintenance downtimes, but also facilitates the daily sanitation work. Mikael Saario, property manager for Block 6, explains that contractors and operators now don’t have to spend time building temporary solutions. Instead, the hoses are connected directly to the stationary vacuum system and work can begin right away.