Metal pickling pump application: Mag-drive pumps in the steel industry

Metal pickling pump application: Mag-drive pumps in the steel industry

In recent years, many companies in the steel industry have been utilising magnetic drive pumps to handle the “high” temperatures of chemicals in combination with solids. Magnetic drive pumps not only protect the environment (leak-free operation), they offer lower power consumption and can handle high temperatures, up to 120 ºC.

Mag-drive pumps offer reduced costs over the lifetime of the pumps and are a better initial investment.

• Reduced need for spares due to the simple, modular design
• Greater time between maintenance

Where can mag-drive pumps be used in the steel industry?

One of the applications where mag-drive pumps can be used is the process of pickling.

As the steel enters the pickling process, re-circulating concentrations of acids help pickle the coiled sheets. At the beginning of the process, the steel enters in the hottest and least concentrated acid solution. It then moves through, progressively passing through cooler more concentrated acid. The maximum temperature for optimum pickling process is 96 ºC.

In these pickling processes, non-metallic (plastic or carbon) mag drive pumps are used to ensure chemical resistance against acids in the following five areas:

• Pumping the acids from storage: Mag-drive pumps are commonly used to run intermittently to fill the storage tanks in the tank farm and upgrade the regenerated acid.
• Re-circulating the pickling acids over vats: This is the most demanding processes, as the centrifugal pumps are required to continuously operate with low available NPSH. Required flows depend on the size of the pickling section, however most steel applications operate between 80 and 120 m³/h. This is achieved with the Techniflo Magnetic Drive pump from Global Pumps, with flows up to 300 m³/hr easily achievable.
• Re-generating the used pickling acid: The concentrated waste pickling is generated in a furnace under “high” pressure. Pressure is around 11 bar, and liquid temperatures are around 96 ºC.
• Circulating rinsing liquid over the cascade tanks: Rinsing is done with de-mineralised water, but as the steel sheet is contaminated with pickling acid, conventional centrifugal pumps are not appropriate.
• Pumping neutralisation liquids for water treatment: The neutralisation is done with caustics - which is why magnetic drive pumps are suitable - even as the viscosity increases at lower ambient temperatures.

Global Pumps recommend the Techniflo Magnetic Drive Pump for use in the steel industry. These mag-drive pumps are a leak-free centrifugal pump for corrosive or hazardous chemicals, including those that are dirty, aggressive and solid-laden. Their heavy duty construction makes them suitable for the harshest of conditions.

For more information on the wide range of magnetic drive pumps, and their chemical pumping abilities, get in touch with Global Pumps.