How to choose the material and model of the pump for conveying concentrated sulfuric acid? The specific selection parameters are as follows:
Medium: 98% concentrated sulfuric acid
Medium specific gravity: 1.84
Medium temperature: room temperature
The content of solid particles in the medium: 1% fine particles
Delivery flow design: 25 cubic meters/hour
Conveying head design: 20 meters
1. Concentrated sulfuric acid pump material:
There are many materials that can withstand concentrated sulfuric acid. The corrosion of sulfuric acid with different concentrations and temperatures is quite different. For concentrated sulfuric acid with a concentration of more than 80% and a temperature of less than 80℃, carbon steel and cast iron have good corrosion resistance. , But it is not suitable for high-speed flow of sulfuric acid and is not suitable for use as a material for pump valves.
Ordinary stainless steels such as 304 (0Cr18Ni9) and 316 (0Cr18Ni12Mo2Ti) also have limited use for sulfuric acid media. Therefore, pump valves for transporting sulfuric acid are usually made of high-silicon cast iron (difficult to cast and process) and high-alloy stainless steel (alloy 20). Fluoroplastics have better resistance to sulfuric acid. Using fluorine-lined pumps (F46) is a more economical choice. Therefore, the material recommended by the editor is fluoroplastics (PTFE/F46), because this material is not only excellent The corrosion resistance, its sealing and mechanical strength are also outstanding. To ensure the safety and longevity in the process of conveying concentrated sulfuric acid. Therefore, fluoroplastics are recommended as the material of concentrated sulfuric acid pumps.
How to choose the material and model of the pump for conveying concentrated sulfuric acid?
2. Concentrated sulfuric acid pump type:
Conveying concentrated sulfuric acid with a high specific gravity of 1.84. Obviously, a magnetic drive pump is not an ideal choice, because the magnetic torque in the magnetic drive pump cannot meet the requirements, which may cause "demagnetization" or "heating" and other undesirable phenomena (unless the magnetic coupling The device is selected as the "rare earth magnetic cylinder" with high magnetic performance, but this increases the cost of the pump), so it is recommended to build a centrifugal pump.
Three, choose the concentrated sulfuric acid pump model
According to the national standard centrifugal pump performance parameter table, the selected model is ihf fluoroplastic centrifugal pump: IHF60-50-125, flow rate Q=25m³/h, head H=20m.
Four, motor power problem:
Because the specific gravity of concentrated sulfuric acid is 1.84, we can use a simple formula to calculate the actual shaft power when the pump is working. Actual shaft power = (clean water test) shaft power × specific gravity
(Note: The shaft power tested by clean water is generally available in the manufacturer's manual or selection sample)
Therefore, it can be calculated that the motor power required for the pump is at least "2.2×1.84=4.048", so the motor power should be selected as: 4KW
5. Machine seal selection:
The original machine seal can be ignored, but the case mentioned that the medium contains 1% of fine particles. Therefore, it is best to choose a wear-resistant machine seal-cemented carbide machine seal.
