What should be considered when using a micro air pump for particle counting applications?
Q: What should be considered when using a micro air pump for particle counting applications?
A: Particle detection differs from gas analysis as it involves measuring the mass and number of particles. The common method used is the laser scattering method. The gas to be tested is passed through a laser beam, and the scattering of the beam is observed for detection and counting. This application requires a pump that can control the flow rate and demands stable airflow with minimal pulsation.
Both micro diaphragm pumps and rotary vane pumps are commonly used as sampling pumps. Diaphragm pumps generally have slightly higher pulsation compared to rotary vane pumps. However, diaphragm pumps with multi-chamber structures or those equipped with flow stabilization devices can achieve flow stability comparable to rotary vane pumps.
Importantly, diaphragm pumps can utilize various corrosion-resistant rubber materials, offering far superior media compatibility and a significantly longer operational lifespan than rotary vane pumps, effectively reducing the total life cycle cost. Hilead Technology can integrate various flow stabilization components based on customer requirements to effectively eliminate gas pulsation while meeting the flow rate requirement of 2.83 L/min.
Additionally, it is recommended to place the sampling pump at the very end of the gas path, operating in suction mode. Installing a filter between the detection chamber outlet and the pump inlet prevents impurities from entering the pump and affecting the media entering the chamber, thereby extending the pump’s service life.
Q: How to choose a more suitable micro vacuum pump for “vacuum filtration” applications?
A: Vacuum filtration, also known as “suction filtration,” is an application that uses vacuum-generating equipment, such as vacuum pumps, to accelerate the separation of solid-liquid mixtures.
The equipment used typically includes a Buchner funnel, a filtration flask, and a vacuum pump. When selecting an appropriate micro vacuum pump, two main factors should be considered:
(1) Consider the pressure resistance of the funnel and filter paper to determine the required vacuum level for the pump.
(2) Consider the power supply for the application scenario. For example, when used in the field without mains power, a low-power micro vacuum pump powered by batteries can be chosen.
Furthermore, when using a micro vacuum pump in this scenario, customers need to prevent liquids and other solid impurities from entering the pump chamber, as this can affect the pump’s service life.
Q: How to select an air pump suitable for aeration or gas washing applications?
A: In the field of chemical analysis, gas washing typically involves bubbling gas through a washing bottle filled with liquid to remove impurities soluble in the liquid or to remove or convert specific components through reaction with the liquid. In aquaculture, aeration increases the dissolved oxygen levels in the water. In wastewater treatment, the purpose of aeration is to prevent solids from settling in the tank, enhancing contact between organic matter, microorganisms, and dissolved oxygen, thus ensuring the oxidation and decomposition of organic pollutants by microorganisms under sufficient oxygen conditions.
Both aeration and gas washing usually require the exhaust tube to be submerged below the liquid surface to achieve optimal results. Therefore, this application requires an air pump capable of delivering positive pressure. Depending on the required flow rate, our series of combined pressure/vacuum pumps, such as the D15, D23, D35, D50, D60 models, are most suitable.
When selecting a pump, it’s crucial to consider the water pressure at the exhaust port (Pump Output Pressure = Actual Required Pressure + Water Pressure). The water pressure is determined by the depth of the gas outlet below the liquid surface; the deeper the outlet, the higher the output pressure required from the pump. When the pump’s output pressure equals the water pressure, the pump will deliver zero flow, as the flow rate decreases with increasing pressure.