Pumps are the main components of a number of production facilities. That is why it is extremely important for them to function properly and to be maintained permanently and preventively. Along with the traditional conventional monitoring of the condition of the pump and dynamic equipment in general, they are increasingly used for online monitoring. Among the most frequently monitored indicators of pump health and normal operation are seals, cavitation and vibration.
Any malfunction in the pump auxiliary seals can cause an unwanted change in the working fluid level. This is usually caused by leaks, high pressure or mechanical damage to the seal. The monitoring of the seals, performed independently or as part of a complex pump monitoring platform, aims at forecasting, locating and eliminating these problems in order to ensure optimal efficiency and continuous operation of the equipment. Auxiliary systems for lubricating seals can operate in atmospheric conditions or under pressure. Unsealed systems are designed to drain leaks to the lubricating fluid, which is used as a buffer. Subsequently, the leak can escape from the system through the external seal. The double mechanical seals with an airtight construction prevent precisely this leakage of fluid into the environment.
Cavitation monitoring solutions are designed for high-pressure multistage pumps that cannot operate in cavitation conditions even for a short period. The sensors installed in the system monitor the flow and pressure in the discharge pipe, the level in the suction vessel, as well as the differential pressure through the suction filter to prevent cavitation.
Centrifugal pumps accelerate liquids to higher speeds, creating a drop in static pressure when the pump is sucked. If the pressure of the liquid falls below the pressure of the gaseous fraction of the fluid, bubbles form. When the pressure rises, bubbles accumulate, causing mechanical damage to the impellers and the inner surfaces of the pump chambers. Cavitation can damage pump components and interrupt flow, accelerate bearing wear and damage seals. This phenomenon usually occurs when the pumps are operated outside their design ranges, but can also be caused by abrupt, intermittent or abrupt limitation of the suction or discharge operation of the system.
The occurrence of cavitation and damage to the seals is difficult to detect in a timely manner during regular inspection and maintenance, but with the help of solutions for continuous online monitoring of the pump can be registered and localized even preventively. State-of-the-art technology in the field is designed to track fluctuations in exhaust pressure to signal a possible episode of cavitation. By combining measurement techniques that track the progress of industrial processes and the operation of equipment, and a combination of cavitation and vibration monitoring, a more comprehensive view of the condition of operating facilities can be achieved.
Vibration monitoring is applied to many types of dynamic and especially rotary equipment. It is designed to detect some of the most common causes of malfunction of pumping equipment, including bearing wear, shaft joints, misalignment, impeller damage, cavitation, and more. The pumps generate vibrations in a wide range, which are an indicator of the operating condition, the presence of malfunctions and damage.
The vibration transmitters used in the vibration monitoring systems monitor the machines and equipment for vibrations with amplitude of oscillation frequency outside the permissible values, and based on the analysis of the shape of the vibration signal the nature of the cause can be determined. them. Increased vibration can lead to seal damage, costly repairs, production interruptions or shutdowns, reduced productivity, the risk of fines for leaking hazardous material, or the risk of fire if the leaking material is flammable.
Unlike physical inspection of vibrations on site, where there are certain restrictions, online vibration monitoring is proven in practice as a reliable solution for preventive and timely detection of various causes of deterioration of the performance of pumping equipment.