26 Feb Spindle Pumps
Spindle Pumps – Their Origin, Operating Principle and Common Applications
Of the wide range of pumping equipment in use today, only two types can trace their origins back to the era of the ancient Greeks. One is the Archimedean screw, which is still used in some parts of the world today. The other employs the same mechanical principle as that primitive device which, it has since emerged, was first developed by the Egyptians, and only copied by Archimedes, is the vertical spindle or sump pump.
Though radically different in size and appearance, these two devices do have two main features in common. Firstly, they both employ some form of a screw as the means to propel the liquids they are used to transport, Secondly, in each case, the mechanism responsible for driving the screw is located clear of the fluid in transit. The design of these units contrasts sharply with that of the fully-submersible types used to propel borehole and well water to the surface. In today’s semi-submersible spindle pumps, the drive motor is mounted on the end of a long bearing column that also encloses the drive shaft. At the other end of the drive shaft are one or more screws that act as impellers to force the liquid out through a discharge tube.
Another key feature of these units is their portability. It is this ability that makes them the ideal means for dealing with accidental spillages or leakages. A burst pipe can quickly flood a basement before someone locates the main stopcock and turns off the supply. While it could take forever to clear with a bucket, spindle pumps can complete tasks like this in a fraction of the time required to drain the same area manually. These units are available in a range of lengths and horsepowers to accommodate different depths and viscosity of the spilt liquids. Wherever there is a likelihood of spillages or flooding, ensuring easy access to a portable and effective means to deal with such contingencies can be a wise precaution.
However, spills and leaks often involve liquids other than water. Where these liquids may be corrosive, any components of spindle pumps that could come into contact with them must be fabricated from a suitable anti-corrosive material. Often, stainless steel will be effective enough but, in more extreme cases, one of the new superalloys. However, non-metallic epoxy resin will not only be effective against a much more comprehensive range of chemicals; it will also be cheaper, lighter in weight, quieter and more or less vibration-free.
In America, basements are a common feature of private homes and are often located below the water table, leading to seepage, especially during heavy rainfalls. Instead of semi-submersible spindle pumps, a fully submersible sump pump should be installed permanently. The unit must be able to activate automatically when flooding reaches a pre-set depth. Activation may be triggered by the movement of a float similar to that in a toilet cistern or in response to some form of electronic detector. Once activated, a powerful motor will be necessary to raise the water to ground level before discharging it well clear of the home’s foundations.
However, spindle pumps are not only of value as a handy tool with which to clear accidental spillages and floodwater. There are many instances in which one may need to siphon off liquid from a large container into one or more smaller vessels. For this task too, a sump pump of a suitable length will almost certainly provide the most practical solution. Once again, when transferring aggressive chemicals in this manner, a non-metallic unit is strongly recommended.
Although not necessarily a source of corrosion, some fluids such as household sewage may contain solids, and which will therefore require spindle pumps with rather more horsepower than those used to transport water. Horsepower is yet another factor that a purchaser must consider when deciding which of the many available models to purchase.
With so many variables to consider, it is a given that the best way to ensure you make the correct choice will be to seek the advice of an expert in this field. As many leading South African companies that depend heavily on spindle pumps and other types of pumping equipment have learned, Prochem Chemical Pump Manufacturers are the go-to guys for expert advice, world-class products and impeccable after-sales service and support.