Case Study

Total quality from switchgear cabinet to bathroom

Duravit, a worldwide manufacturer of design bathrooms, is based in Hornberg in Germany's Black Forest region and stands for top quality and intelligent use of technology. In the bath furniture production at the Schenkenzell plant, the process cooling system for an edge banding machine needed to be replaced. For this Duravit chose a chiller from Hamburg-based cooling specialist Pfannenberg, which is now doing its job of maintaining the right temperature. “The Pfannenberg unit is top quality. You just switch it on and it works. It was delivered quickly, and the sales team put a lot of effort into it. The entire process was very smooth”, says Peter Brüstle, responsible Electrician at Duravit.

Fig. 1: The various alerts generated by the chiller enable Duravit technicians to perform preventive maintenance, contributing to higher machine availability.

With 5,700 employees worldwide and a revenue of EUR 380 million in 2013, Duravit is a leading global vendor of ceramic sanitary equipment, bath furniture, showers and bathtubs, whirlpool and wellness systems, shower WCs, saunas, kitchen sinks and accessories. Duravit makes top-grade bath furniture at the Schenkenzell site. One of the production operations is edge banding. A twelve-year-old chiller for the subsystem switchgear cabinets of an edge banding machine in the Schenkenzell plant needed to be replaced.

First comes the advice

The sanitary equipment specialist turned to the consulting engineering firm Konrad Weinmann for advice. As a sales partner and distributor for a wide variety of renowned manufacturers, this family-owned business acts as a Pfannenberg Competence Centre (PCC) when it comes to switchgear cabinet and process cooling, as well as visual and audible signaling Technology.

PCC technical sales staff member Philipp Weinmann was already familiar with the Duravit plant in Schenkenzell, and as an expert in thermal management of switchgear cabinets he knew exactly what the case was about. In cooperation with Vincent von Wieding, business development manager chiller at Pfannenberg, he performed a needs analysis and personally visited the site. At the end of this process the decision was clear: the new chiller for the switchgear cabinets of the edge banding machine would be a Pfannenberg type EB60 with a custom configuration.

Brüstle comments: “We already had some Pfannenberg chillers in use at various places in the Schenkenzell plant. When the existing chiller for our edge banding machine had to be replaced, it was clear that we needed a new solution. In the end we chose the energy-efficient solution from Pfannenberg due our good experience with them in the past.”

Reliable cooling capacity

The edge banding machine and feed unit glues edging to bath furniture. With double-sided gluing and four sides to be handled, each item passes through the machine twice – and thousands of items are processed per day. Due to high dust levels in furniture manufacturing, a closed-circuit cooling system with water refrigerant is the ideal solution for thermal management of switchgear cabinets. In the summer the ambient temperature can rise to 40°C when bright sunlight shines through the glass roof of the Schenkenzell factory building. This makes a reliable, high-performance cooling solution especially important.

The EB60 WT CE chiller (WT stands for water refrigerant, and CE means that it is certified for the European market) has a rated cooling capacity of 6 kW and delivers a continuous flow of chilled water. The water is used to cool the electronic components inside the switchgear cabinets distributed over the 50 m length of the machine, including variable speed drives and controllers. The modular switchgear cabinets are integrated into the machine as pull-out subcabinets.

Fig. 2: The edge banding machine in Duravit's Schenkenzell plant runs about 4,500 passes a day

Individually adaptable and easy service

A special feature of Pfannenberg's EB series is their modular architecture, which makes them easy to adapt to individual applications. Duravit chose the following standard options from the 30 option packages available for the EB60: flow monitor with individual alerts, level monitoring for the tank, thermostat, 6-way Harting connectors for power and signal connections, transport castors, and inlet filter monitoring with pressure sensors. In addition, Duravit opted for an especially high-performance pump with rated pressure up to 5 bar, instead of the standard 3 bar with 35 litre flow volume in 50 Hz operation.

The chiller's flow monitor keeps an eye on how much water is flowing through the cooling circuit, and the thermostat measures the water temperature. If the cooling water flow is too low or the refrigerant temperature is too high (risk of overheating) or too low (risk of condensation), the chiller sends an alert to the machine's operator console so that damage to the electronic components of the edge banding machine can be avoided and high machine availability can be achieved.

Fig. 3: The EB60 WT CE chiller, with a cooling capacity of 6 kW, cools the twelve subsystem switchgear cabinets along the edge banding machine.

The refrigerant tank (the chilled water contains 20% of the Pfannenberg Protect refrigerant) is also monitored by a sensor so that service personnel are informed promptly when the tank needs refilling. Pressure sensors also monitor the air flow through the inlet filter. This enables preventive maintenance and reduces the need for wear parts.

The alerts are made possible by chiller's ability to exchange control signals with the edge banding machine through the Harting connectors. The HMI display makes EB60 operation convenient for users, who can also view fault messages and causes on the display.

“A decisive factor for us was that the EB60 is very easy to maintain. For example, the filter mats only have to be cleaned every two to three weeks, despite the high dust level. The unit was installed six months ago, and we haven't had to replace the filter mats yet. Thanks to the various alerts, we can perform preventive maintenance to increase our machine availability”, says Brüstle.

Fig. 4: The EB60 features very high operational reliability, low maintenance and easy servicing.
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Case Study Duravit

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