Key points
Dosing pumps are the traffic officer of chemical processing systems. Also known as metering pumps or chemical dosing pumps, they help manage how much gets through, when and from what direction. One of the harshest environments pumps endure is working with nylon 66 — also known as polyamide 66 or PA66 — a versatile engineered thermoplastic known for its high strength, toughness, and excellent mechanical properties.
Polymers are used in almost every aspect of modern-day living and have experienced growth in demand and production year-over-year, which is forecasted to continue. Its heat resistance makes it especially suitable for the automotive industry, which has seen an increase in reliance on the polymer for both automotive parts and, recently, in the production of batteries for electrical vehicles (EVs).
While nylon 66 is a specific use case, dosing pumps are used across chemical processing industry and beyond, including water treatment, pharmaceuticals, oil and gas, personal care, food and beverage, and beyond. The chemical process for creating nylon 66 results in:
- High Strength and Stiffness: Nylon 66 exhibits exceptional tensile strength and stiffness, making it suitable for mechanical integrity and structural stability applications.
- Good Wear Resistance: Its abrasion resistance is superior to many other engineering plastics, making it suitable for parts exposed to friction and wear.
- Chemical Resistance: Nylon 66 resists the attack of many chemicals, oils, and solvents, making it suitable for various industrial applications.
- Temperature Resistance: It has a relatively high melting point and can withstand moderate temperatures, making it suitable for applications where exposure to heat is involved.
- Dimensional Stability: Nylon 66 maintains its shape and size even under various environmental conditions, contributing to its reliability in applications that require precise dimensions.
There are many takeaways from nylon production when it comes to the needs, benefits and recommendations for dosing pumps — many of which can be applied to the processing systems as a whole, no matter the industry.
What’s a Dosing Pump? What Role Does it Play?
Dosing pumps are engineered to deliver liquids with high precision and accuracy. This is crucial in applications where even slight variations in chemical concentration can have significant impacts on the overall process.
When it comes to the nylon 66 application process, dosing pumps play many important roles to ensure product quality, including accurate ingredient dosing,, ratio control, and the ability to withstand extremes in temperature and pressure.
For example, dosing pumps move concentrated polymer salt (6-15% H2O) into an evaporator where 99% of the water is removed. The water within the salt mixture evaporates by increasing temperatures from roughly 250° to 280°C and using a high-pressure stream at 254°C and 41Barg.
This creates very harsh conditions. The dosing pump must be chemically resistant to the nylon salt. It needs to be able to operate at high temperatures and pressures while ensuring the constant flow of product into the evaporator under these conditions. Quality control is essential to ensure consistency and performance of the final product.
Few pieces of equipment can withstand such an environment, but the qualities of the dosing pump let it stand up to the task.
Increasing Flexibility, Compatibility and Accuracy
From water to chemicals, dosing pumps are available in various materials and designs to handle a wide range of chemicals and fluids. This ensures compatibility with different dosing applications.
In nylon 66, dosing pumps are used in multiple applications, similar to other industries across the board. It can add flavourings or colouring to products in the food and beverage industry, chemicals to water treatment systems, fertilisers in agricultural applications and even medications in healthcare settings.
Whenever accuracy and consistency are required in a processing system — and when is it not — a dosing pump can play a role. They are engineered to deliver liquids with high precision and accuracy. Additionally, a reliable, quality pump can maintain a consistent flow rate. This is crucial in applications where even slight variations in chemical concentration can have significant impacts on the overall process.
Decreasing Risk and Cost
An efficient system is often a more cost-effective system in comparison to alternatives.
In nylon 66, costly raw materials, like certain acids and compounds, including adipic acid and hexamethylenediamine, play a vital role. These pumps help prevent wastage and unnecessary consumption by accurately dosing chemicals or additives. This can lead to cost savings, especially when dealing with expensive or sensitive substances.
In processes where hazardous chemicals are used, dosing pumps can improve safety by minimising direct human contact with the substances, reducing the risk of spills and exposure.
As automation continues to play an exponentially growing role in chemical processing, reducing the need for humans to handle and become exposed to hazardous materials, dosing pumps can be easily integrated into automated systems and controlled remotely. They can be programmed to dose at specific intervals or based on sensor readings, making the dosing process more efficient and adaptable.
Reliability, Maintenance and Longevity
There are reports of some of our pump customers still using the same pumps for upward of four decades — an example of how well these can withstand and maintain reliability with the right upkeep.
Dosing pumps are generally designed for low maintenance and can operate continuously for extended periods with minimal intervention.
It’s crucial for manufacturers to choose a pump that’s built with quality to last, as well as a partner who can help calibrate to their select materials and products. Optimal stroke speeds and settings paired with the proper preventative maintenance schedule can significantly improve these pumps' longevity.
SPX FLOW has customers who went from experiencing frequent delays in maintaining their fleet of pumps that transfer highly abrasive liquid slurry in the production of Hexamethylenediamine to finding a solution with the right dosing pump.
After consulting with the customer, the NOVADOS diaphragm pump from Bran+Luebbe offered the right features to avoid abrasion from the fast sedimentation of the slurry in the pump chamber. The customer has been able to avoid failure or loss of production due to unplanned maintenance for years.
The Right Pump for the Job
Hard-working, dependable and effective dosing pumps are crucial in accurately and reliably dosing chemicals and liquids in various industrial processes. Nylon 66 is just one example where this workhorse pump does the job of many. Efficiency, safety and cost-effectiveness are also benefits.
When choosing the right pump for the job, manufacturers should invest in an equipment partner that offers quality, service and knowledge to ensure their pumps last decades.
