The engineering challenges are many, when it comes to pumping highly viscous fluids such as heavy oils, sludges, syrups or even molasses. The selection of pump technology becomes paramount when dealing with this condition hence in most cases positive displacement pumps majorly gear pumps and screw pumps become the best choice. There are several reasons why these types of pumps are more appropriate for handling highly viscous fluids.
Firstly, while positive displacement pump helps in broader substances which become a problem when tasked with any fluid that has high viscosity due to its nature of moving enclosed volumes. In such pumps, liquid is captured within the hollow spaces formed between the interlocking gears (in case of gear pump) or between helical rotors (in case of screw pump). This enclosed volume is then transferred from the inlet to the outlet ensuring a continuous and constant flow. Because the volume is sealed, whether it’s a heavy or light oil does not affect how efficient the pump works.
Gear and screw pumps on their second side have an intrinsic self-priming characteristic whereby they can start pumping without having to provide fluid into machinery during operation; this aspect is advantageous since thick low flowing viscous fluid cannot be pushed into machine easily. Consequently, designing of overall system by use of self-priming capability becomes simplified and facilitates its straightforward operation.
Positive displacement pumps especially gear type ones combine robustness with simplicity thus easy maintenance due to mechanical aspects associated with them. For instance in some industries where downtime may be costly thus necessitating quick servicing such as replacing worn out parts. These machines should withstand considerable forces and wear caused by moving dense media consisting solid particles too.
Moreover,the last but one feature is a wide range of flow control options that these types offer. When there is change in temperature etc.,fluid may acquire new viscosity, yet only PD machines can adjust themselves accordingly faster than other known alternatives.This makes them suitable for different commercial conditions that might change.
Anyway, there are some disadvantages. The factor is that they may need more frequent maintenance when used for highly viscous media compared to other types of pumps. They can also be less energy-efficient than alternative pump models in cases these units are not created for. Despite the above, the advantages of PD pumps suggest their applicability in the case of high viscosity fluids.
To sum up, gear pumps and screw pumps which are types of positive displacement pumps are usually utilized for pumping highly-viscous fluids. It is due to this specific reason that they have constant flow rates regardless of fluid’s viscosity, self-priming ability, strength and flexibility thus making them popular in food industry, petrochemical plants as well as waste management ones.
