HERMETIC supplies sophisticated canned motor pump for diesel desulphurisation

Leakage-free pump solution for the oil and gas industry

The core of the 10-ton pump system is a CNKfH+D 300-500 canned motor pump. The water-cooled motor of the pump according to API 685 has a shaft power of 185 kW. All pressure containing parts were made of forged solid materials. The housing is made of highly resistant SS 316 Ti stainless steel and has been tested at 310 bar. With a system pressure of 112 bar and an operating temperature of 405 degrees Celsius, the integrated, compact unit is designed for a nominal pressure of 130 bar. In addition to the rotor lining, the motor housing serves as a secondary containment, which provides a leak-free, safe pump solution.

Low-wear and low-maintenance design principle

The design-related omission of wear-prone components such as shaft seals, couplings and bearings reduces the maintenance and repair costs and ensures a longer service life. The “ZART” (Zero Axial and Radial Thrust) technological part from HERMETIC ensures a contact- and wear-free running of the rotor unit. It is based on comprehensive axial thrust balancing in conjunction with hydrodynamic sleeve bearings. While relief mechanisms in the control unit continuously monitor the axial position of the pump shaft, a fine fluid film between the rotating and static sleeve bearing component allows a full “floating” of the rotor. For the monitoring of the the axial thrust balancing, the pump is equipped with the HERMETIC “MAP” technology. The rotor position monitoring detects the slightest plays in the rotor movement and serves as a kind of early warning system to prevent undesired operating conditions and expensive damage. Due to this hydraulic power balance, the HERMETIC pump operates without radial and axial wear, thus offering plant operators significantly longer service life.

Entire system with integrated measuring and control equipment

To ensure high availability and durability, the canned motor pump was provided with additional measuring and control equipment. To prevent potential motor and bearing damage, this particular process avoids gas accumulations on the motor side, which can escape from the pumped medium. A dosing pump precisely tailored to the application generates a fine, uniform counterflow in the rotor space, which prevents this. A level indicator integrated in the system monitoring indicates whether there is no gas in the circuit. While a heat barrier prevents the heat transfer from the pump to the motor part, an external heat exchanger ensures the dissipation of motor heat loss. To prevent overheating, a temperature monitoring of the motor winding is integrated. Another sensor monitors the temperature of the motor cooling circuit, which ensures the cooling performance and the functional safety. Other components such as safety valves and an extensive, rigorous testing and inspection procedures including X-ray tests, vibration tests and ultrasonic tests as well as comprehensive documentation complete the scope of supply to a highly reliable system. HERMETIC pumps demonstrate their safety and performance in currently 15 large refineries worldwide.