NETZSCH has developed a whole range of specialised progressing cavity and rotary lobe pumps for the various fields of application in the up, mid and downstream areas. The major special feature of the self-priming, valveless rotary lobe pump TORNADO T2 is its synchronised gear with belt drive which, in contrast to standard timing gears, is extremely resilient and very easy to maintain. A belt with teeth on both sides transmits the power from the motor to both rotary lobes and synchronises these at the same time.
The strength of this rotary lobe pump in the oil and gas sector is above all characterised by it being compact and self-priming, as well as offering high capacity, reversibility and solid matter compatibility. If a solid body which could not be conveyed were actually to block the pump chamber, this would not lead, as usual, to the gearbox being damaged or the shaft broken, but simply to the belt jumping or rupturing in the worst case scenario. You only have to undo two screws to replace it. This leads to a considerable reduction in downtime and costs in comparison to a complete gear box overhaul. Likewise, the pump chamber can also be accessed for maintenance work or cleaning after the removal of a few screws. The design therefore enables a high level of operational reliability precisely in regions where service engineers are difficult to get hold of.
There are two models of the pump; firstly one with a specially shaped elastomer insert for the inside of the housing which improves conveyance, or secondly an all-metal one for more demanding media. The rotary lobes are manufactured from stainless, hastelloy or duplex steel, depending on requirements. The advantage of steel rather than elastomer bodies which are otherwise in common use, is that the steel lobes are less affected by the strong dynamic forces during rotation and have a correspondingly longer service life. They also expand less than rubber, which allows the components as a whole to be made with lower tolerances and enables higher performance. Because only soft surfaces are running on hard ones, the pump runs very quietly and hardly generates any vibrations, noise or friction heat. The rotating components are therefore preserved and last longer. Furthermore, expensive oil changes are a thing of the past throughout the service life, because the synchronisation works completely without oil.
The pump’s direction of conveyance can easily be reversed, so that the same system can, for instance, be used both for filling and emptying. The possible conveyance rates over the various sizes range from 3m³/h to over 900m³/h. The system can also be installed in any orientation and has a very space-saving design, because the motor is attached directly above the pump chamber. This was, for instance, essential for application in the ex zone 1 of a preparation unit with a very narrow design into which the pump was directly integrated. There, the conveying system ensures the inflow of the pumped oil-sand mixture, with a kinematic viscosity of 30 to 35mm²/s and a temperature of 60°C, into a separator where the remaining sand and water are separated.