38 piston pumps monitored

Customer Success Story

More Process Reliability in Growing Silicon Crystals

At the Italian MEMC Electronic Materials plant, silicon single-crystal ingots are grown which are later processed into silicon wafers at other plants. Piston pumps play a central role in this process. Should they fail, this has an impact on the entire process. That is why the maintenance department of MEMC Electronic Materials, part of GlobalWafers, turned to Schaeffler for predictive monitoring of the vacuum pumps. They were also looking for a solution for generic units like fans and other pumps to ensure best asset availability across the whole plant. Maintenance opted for the OPTIME condition monitoring system.

Conclusion: 9 machine failures were prevented in just one and a half years. The prevention of one piston pump stop equals estimated savings in the amount of 78,000 Euro in 12 months.

“With OPTIME CM, we have finally found a solution to monitor our piston pumps very easily. We installed about half of the sensors ourselves. With the solution, we found 9 faults in just one and a half years, thereby preventing expensive unplanned shutdowns.

The simplicity, scalability and finally having more transparency about the condition of the machines excites us."

Carlos Vinicius Carnio – Maintenance Engineer & Massimo Iaderosa - Maintenance Technician

Benefits
Challenge
Solution & What's Special
Technical Information
Download
Contact

Benefits

Customer benefits

Early alarm in case of change of condition
Simple installation and easy to use
Easy scalability possible at any time
Proximity and commitment of the team from deployment to operation

Challenge

The first and most important step in the production of silicon wafers* is the growth of single crystal silicon. The Italian company MEMC has specialized in this growth of silicon crystals. In the production facility, the Czochralski process* is used for crystal growth, which essentially consists of the three steps of melting down polycrystalline silicon with dopants, dipping the seed crystal, and pulling the single crystal (ingot). The important thing in growing is to create an environment that is as pure as possible. This is ensured not only by the special nature of the crucibles but also by the piston pumps. The latter create a vacuum during the pulling process of the single crystal to avoid impurities and oxidation with oxygen. Piston pumps are important aggregates in the manufacturing process and are classified as critical by maintenance.

Why? This is summarized by the Plant Maintenance Manager:

Maurizio Ceriotti, Plant Maintenance Manager:

“When the piston pumps fail, the respective machine must be stopped, and the growing process is lost. This results in high personnel, material and scrap costs.“

MEMC used a vibration analysis system in the past. However, the system was not suitable for monitoring the piston pumps due to its complexity. MEMC therefore turned to Schaeffler Italy.

*Read more about silicon wafers and the Czochralski process in the PDF.

Solution

The experts from Schaeffler Italy recommended the award-winning condition monitoring solution OPTIME. The scalable solution consists of wireless sensors, a gateway, and digital services based on proprietary Schaeffler algorithms. Two OPTIME sensors were installed on each piston pump. One sensor directly on the pump and one sensor on the engine. Maintenance is informed about the condition of the piston pumps via a mobile terminal. In total, 9 failures were avoided in about 1.5 years. Here are two cases:

Case 1
Around 2 months after installation, a warning message was issued in the OPTIME app. The MEMC maintenance team confirmed increased vibration during a scheduled stop. As a result, the motor and anti-vibration feet were replaced.
Case 2
Over several weeks, the vibration characteristics increased steadily at the vacuum unit.
And then a tremendous increase was indicated at the piston pump motor with peak values up to 22 m/s^2, while low values were indicated at the pump. After inspection, the maintenance team confirmed that this was a lead problem at the end of the barrel, caused by imbalance. It was also found that the sleeve was perforated. The corresponding units were replaced and thus an unplanned shutdown was prevented.

Imbalance caused by a lead leakage on the vacuum pump gear
Perforated sleeve

What's Special

The maintenance department of the Italian production facility had already tested condition monitoring solutions before. But these turned out to be too complicated. MEMC is fully satisfied with the OPTIME CM condition monitoring solution. The solution is not only suitable for crystal growth, but also for the production of the silicon wafers themselves.

Technical Information

How OPTIME CM works

The sensors monitor machinery and equipment at the customer’s site. The gateway receives the data from the sensors and transfers these to the Schaeffler cloud. OPTIME CM detects problems, sends alarms accordingly and provides information on the possible cause of the problem. Expert knowledge of condition monitoring is not required as this knowledge is already integrated in OPTIME CM in the form of Schaeffler know-how.

Ideally monitored
Two OPTIME 5 sensors are installed on a fan unit (aspirator).
Centrifugal pumps
Two OPTIME sensors are installed on pump units for water circulation.
Easy installation
Installing the wireless vibration sensors and setting up the OPTIME Mobile App takes mere minutes.

Technical Information on OPTIME CM Sensor 3/5

Vibration bandwidth	OPTIME-3 2 Hz - 3 kHz OPTIME-5 2 Hz - 5 kHz
Calculated parameters	7
Sensor commissioning	NFC (Near Field Communication)
Communication	Wirepas Mesh (2.4 GHz ISM band)
Measurement cycle	Parameters: every 4 h Time signal: every 24 h

OPTIME CM is part of the Schaeffler Lifetime Solutions portfolio, which offers a comprehensive range of products, services and solutions for industrial maintenance. It is designed to support maintenance engineers over the entire lifetime of a machine.

Visit our Lifetime Solutions portfolio here:

To Schaeffler Lifetime Solutions