Waste Liquor – Magnetic Drive Solution
A new application has been developed for the Sterling SIHI range of magnetic drive pumps for pumping media that contains solids, using pumps fitted with ceramic isolation shrouds to eliminate build-up and consequent impairment of drive operating efficiency.
An example of such an application where this has proved successful is the pumping of waste liquor in chemical processing, where media consists of an aggresive mixture of solvents and acid that tends to precipitate solids when heated. This unpleasant waste fluid has to be pumped to a suitable point where it can be burnt off safely in a controlled manner. The pumps need to be totally sealed as no leakages what so ever can be tolerated.
Magnetic drive pumps, with no shaft seals, meet this containment requirement, but are not recommended generally for pumped media containing solids since there is always the chance that these could build up and impair the drive operating efficiency.
Another factor is that the magnetic impulses tend to produce heat in the normally used metallic Hastelloy isolation shells, requiring an external water flush to cool it and to lubricate the bearings. In such an application there would be concern about the need for this water flush as it would need to be added to the waste liquor and would significantly increase the burning off costs.
Sterling SIHI's simple solution was to utilise the ceramic isolation shrouds that are fitted as standard in it's 400oC magnetic drive design. Being non-metallic, these shrouds are not subject to heating by the magnets and thus require only a minimal cooling flush. By remaining cool, they also help to avoid the precipitation of solids in the waste liquor. Furthermore, the ceramic shrouds do not contribute eddy current losses to the pumps power requirements and therefore , improve pumping efficiency.
SIHI ZLKY pumps are used for this type of processing application. Further benefits would include a significant reduction of the risk of repetitive downtime and frequent repairs; in addition the sealless pumps eliminate any possible danger to both the workforce and enviroment from leaks and cost savings are made from improved reliability.
