Medium-capacity disc stack centrifuge for fats and oils refi ning PX 55 The Alfa Laval range of centrifuges for the vegetable and animal oils refining industries is continuously modernized to take advantage of developments in materials, mechanical design and fluid dynamics. The PX 55 is a medium-sized machine in this range of centrifuges. Applications Continuous degumming, neutralizing, dewaxing and washing of fatty oils, such as vegetable oils, lard, tallow and fish oil. Performance The table below shows nominal capacities. Actual throughputs vary according to the type of oil and fat to be treated. Degumming, neutralizing, washing 6,250 kg/h Dewaxing 3,000 kg/h Standard design The machine consists of a frame with a base that contains a horizontal drive shaft, worm gear, lubricating oil bath and hollow vertical bowl spindle. The bowl is fixed on top of the spindle, inside the space formed by the upper part of the frame, the solids collecting cover, and the frame hood. The hood carries the liquid discharge system. All parts in contact with the process liquid are made of stainless steel. The bowl is of the solids ejecting disc type, with an automatic hydraulic operating system for “shooting”. The standard electric motor is suitable for variable frequency drive. Design features The PX 55 is based on a unique, semi-hermetic design concept. The hermetic, bottom-fed inlet ensures a gentle, non-destructive acceleration of the feedstock up to full bowl speed. The outlets on the heavy and light phases are open, reducing the pressure drop across the separator. The feed-pressure requirement of the machine is therefore low. The outlets are equipped with stationary paring devices for removal of the different phases. The paring disc on the light phase is fixed, while the paring tubes on the heavy phase are adjustable. PX 55 complete with motor By adjusting a positioner on the heavy phase outlet, the operator can reduce or enlarge the paring diameter of the paring tubes. This patented innovation makes it possible to adjust the position of the separation interface during operation, facilitating optimal separation. With the working environment in mind, the PX 55 is designed to operate at low noise levels. This is achieved by means of rubber-damped bearing assembly, jacketed frame and an outer bowl design engineered for low wind noise. Standard equipment Each PX 55 comes complete with control unit, electric motor, inlet and outlet connections, auxiliary equipment, a spare parts kit and set a of tools.

Operating principles The oil to be separated is fed (1) into the separator bowl from the bottom through a hollow spindle (2), and enters the disc stack (3). The heavy phase and heavy sludge are forced towards the periphery of the bowl, while the light phase flows towards the centre of the bowl, from where it is pumped out (4) for further processing. The heavy phase is led over a top disc (5) into a chamber where an adjustable paring device pumps it out of the separator (6). Sludge collects in the sludge space (7) and is discharged intermittently and automatically. The discharge is achieved by...