The most important criterion when choosing the type of gear pumps is the viscosity of the product.
The main criteria when choosing a gear pump:
- pump type: the basic principle is that external gear engagement is used for relatively low-viscosity fluids, and internal gear engagement for high-viscosity fluids.
- the size of the nozzles: the size of the nozzles and connecting pipelines are also related to the viscosity of the product. When choosing the type of pump and designing the pipeline system, the diameters of the pipelines should be accurately calculated in order to achieve the optimal flow rate for the liquid of the given viscosity.
In this case, a direct relationship is valid - for liquids with a higher viscosity should be used pipes of a larger diameter.
- pump rotation speed: the maximum speed for gear pumps is 1500 rpm. It decreases as the viscosity increases. High speeds should be chosen for low viscosity, low speeds for high viscosity.
The direct clutch with the electric motor is used at 1000 and 1500 rpm. For 500 rpm. and below - clutching with the electric motor is carried out through a gearbox or V-belt transmission.
-operational tolerances: operating clearances are set during pump manufacturing, some clearances are adjusted during pump assembly, according to viscosity ranges.
To pump a certain type of liquid, you should use a pump with appropriate working clearances, otherwise the pump may work with less pressure or stop completely.
