For more than 50 years, Jahnel-Kestermann constructs agitator drives and drives for the chemical, pharmaceutical and food industry. Based on this long-time experience there is a standard programme for agitator drives having agitator shaft diameters from 80 to 220 mms that is composed of fix components and is used preferably for new machines. Furtheron, there are many innovative driving solutions for shaft diameters up to 380 mms and shaft torques up to 318 kNm. Especially the agitator drives for the Polypropylene production according to the BASF procedure are to be accentuated.

Irrespective of the shaft diameter, all drives have the same construction principles:

• flexible element between motor and gearbox (motor coupling, belt drive)
• gearbox with integrated fix bearing for the agitator shaft
• agitator support with fix coupling between gearbox and agitator shaft, loose bearing and shaft sealing (stuffing box, mechanical seal etc.)

If a mechanical seal is used as shaft sealing, it can be mounted and removed without dismantling the drive on all Jahnel-Kestermann drives. All necessary work steps are possible into an exactly defined removing direction. The advantage for the plant designer is that the space around and above the vessel bottom can be used in an optimal manner.

Due to the different weights of mechanical seals for shafts from 80 to 380 mms shaft diameter, there are mechanical and hydraulical change devices. In order to keep the stand-still time for a sealing change as low as possible for the end-user, Jahnel-Kestermann has developped a symbiosis between agitator support and agitator gearbox. Thus, even changing of mechanical seals having a single weight of 1200 kgs is possible within one day.

Individual requirements by our customers as top- and bottom-drives, small mounting height of drive with seal change guarantee, high vessel pressures and extreme loads on the gearboxes can be realised by Jahnel-Kestermann without any problems. In co-operation with the plant designer or end-user, we always try to find the most elegant solution.

Another achievement of Jahnel-Kestermann is the design of drives and agitator supports with regard to the axial and radial forces influencing the stirrer. For this, we use several calculation programmes and the FEM analysis. On this basis, construction with optimised material use is possible. For the user of drive, this results in a high functionality at a small weight.
As the noise of a chemical plant is very relevant, the Jahnel-Kestermann drives are very silent. For fulfilling this statement, the gearing is optimised by calculations and manufactured on a high manufacturing level. The reached result is checked during a test run of gearbox under load on our test bench and documented by a test report.

We offer our knowledge of gearbox technology in connection with our mobile measuring technics as service for evaluation of existing plants or for the preventive maintenance of our own drives as well as those of other manufacturers. If damages at gearing or bearings of gearbox are found, we have the possibility to deliver a replacement. This is, of course, also true for agitator drives of the first generation.