Downtime does not have to be thanks to Predictive Maintenance
Cement plants all over the world run around the clock to meet the huge demand. If a machine fails due to damage or malfunction, an entire plant stands still for hours or even days. Clinker production is interrupted and with every hour in which no cement is delivered, the financial damage increases – time is also money here.
It must be possible to prevent such downtimes with modern technologies, said the small start-up company PREMAS Preventive Maintenance Service AG. Managing Director Michael Bruckhaus comments: “Our goal is to predict when heavily stressed parts of a plant have reached their lifetime or show signs of fatigue. In this way, unwanted downtimes can be prevented, and maintenance can be optimally planned – not too late, not unnecessarily early, but just when it is necessary.”
With the vision of a standardized and easy-to-install system that can be put into operation without much specialist knowledge, the young company developed PREMAS® 4.0 for its first customer, the AUMUND Group. AUMUND manufactures various conveyor machines and systems and sells them to cement plants all over the world. The compact PREMAS® 4.0 enables “predictive maintenance” especially for machines that are in operation 24/7 or where inspections are difficult or impossible to carry out. These include, among other things, so-called belt bucket elevators, which AUMUND develops and sells. These are vertical material conveyors that transport, for example, the ground limestone for clinker production in the cement plant. These machines, which are up to 170 m high, are equipped with a belt made of steel cables and rubber to which the cups – containers in the shape of a shovel – are screwed on. Some plants transport 10,000 tons of material at about 80 degrees Celsius every day, and the load on the plant components is enormous. A critical point for damage is the connecting piece of the belt, a screwed clamping connection. Bruckhaus describes what happens when a belt tears: “Within seconds, a gigantic bucket salad of up to 680 buckets and 340 m of belt is created in the bucket elevator chimney – it is probably useless to mention that this cannot be dealt with within a few hours.”
Optimal maintenance thanks to the Internet of Things
The system developed by PREMAS uses sensors inside the machines to collect all the necessary data to determine the operating status and maintenance requirements of the system. For this purpose, PREMAS® 4.0 uses the information from the machine’s own sensors. For example, it measures the motor current, detects whether a belt is going wrong, and determines the stress factor of a belt based on the number of starts of the machine. PREMAS has also equipped its system with additional sensors and developed an algorithm that can predict its service life with temperature and length measurements of the belt. Because the rubber becomes brittle over time and the belt must be replaced every five to ten years, depending on the load. “We are constantly developing the solution,” says Carlos Pinzon, Product Manager Digital Solutions at PREMAS, “by critically testing existing and new sensor technologies and optimizing the system.”
„We are convinced that predictive maintenance has a future. With PREMAS® 4.0, we can better plan maintenance, which saves costs and human resources. The PREMAS® Portal is easy to use and clear.“
Ramona Keller, Head of Maintenance, Jura-Cement-Fabriken AG
This is a summary of the Siemens Insight 2/2021, published in German and French.
A translation of the full article in EN can be downloaded below (translated by PREMAS AG).