HEXAN-gas detection system in largest Croatian oil factory Čepin d.d.

Modern gas detection system ensures maximum protection against explosions.

The Čepin oil factory has stood for high quality with local raw materials for 81 years and is the largest producer of crude and refined oils in Croatia.

With a processing capacity of 150,000 tonnes and a production capacity of 32 million litres per year, Čepin is an expert in this field. The popular sunflower oil is produced using hexane at a capacity of around 6,000 litres per hour.

What process is hexane used for and why is a gas detection system important?

Three basic processes play a decisive role in the production of crude oils such as sunflower and rapeseed oil: pressing and extraction as well as refining and bottling. Immediately after pressing the raw material, the oil is extracted from the solid oilseed mixture by adding a solvent (hexane). In this way, almost every drop of oil is extracted from the seeds.

As hexane has a lower boiling point than oil at 68.7 °C, it is then removed again by distillation. Thanks to the minimal heat treatment, the oil obtained remains of high quality and retains a high protein content.

Despite its efficiency, hexane is highly flammable and can explode, which is why a reliable gas detection system is essential. To ensure safety in the production of sunflower oil, the production facility relies on a reliable gas detection system from MSR-Electronic.

A large number of sophisticated gas sensors monitor the relevant area around the clock, thus ensuring continuous, safe production.

ATEX-Solution from MSR-Electronic

The modern gas detection system was equipped with gas detectors from the PolyXeta® PX2 series and the centrepiece of the system - a Digital-Gas-Controller DGC-06.

Two explosion zones (Ex-zones) were defined in the production building: In Ex-zone 1, gas detectors were installed both inside the shaft and next to the pump of the hexane tanks. With the exception of a few areas, Ex-zone 2 covers the entire building.

The majority of the gas sensors are installed in the main room with the extraction plant to ensure greater safety. All gas sensors meet the requirements for explosion zone 1. The gas sensors are installed at a height of 0.3 to 0.5 metres above the floor, as hexane in its gaseous state is heavier than air (relative vapour density: 2.97, compared to air = 1). The values measured by the gas sensors are transmitted to the DGC-06 controller. If the controller recognises that the specified limit values have been exceeded, corresponding warning processes are initiated:

1st alarm threshold at 20 % LEL – A flashing light is activated in the control room.

2nd alarm threshold at 40 % LEL – In addition, a warning tone and a monitor display in the control room are activated.

Technical data PolyXeta®PX2 with SX1 sensor head

• ATEX and IECEx certificates for electrical explosion protection
• SIL2 for the 4-20 mA, RS-485 and relay safety functions
• Enclosure: Additional FM and CSA certificate for Class I, Div. 1
• PX2-1 for zone 1 & 2, variant "Ex db" type of protection flameproof enclosure
• PX2-2 for zone 2, variant "Ex nR" type of protection
• Continuous self-monitoring
• X-change technology and simple calibration
• Alarm and fault signalling relay
• Protected against reverse polarity and overload
• Microprocessor with 12-bit converter resolution
• Optional: SSAX1 sensor head connection as an alternative to SX1 Protection class IP66 with SplashGuard accessory, LC display with status LEDs

The gas detection system was installed and commissioned by MSR-Electronic's certified partner Aurel d.o.o. from Zagreb.

Further information on MSR products can be found in the current online catalog or in the webshop www.msr-24.com.

MSR-Electronic is a manufacturer of fixed gas warning systems with decades of experience in the field of gas measurement technology. The international company with headquarters in Germany has a wide range of methods for the detection of toxic, combustible gases and oxygen. On this basis MSR-Electronic develops individual gas sensors, controllers and warning devices for many applications, such as parking garages, tunnels, petrochemical industry or shipping. The products meet more than the general standards and regulations and can therefore guarantee the safety of the plant. If you have any questions please send us an email or give us a call.