In 2014, we participated in a mixing equipment project for Ingevity (Zhuhai), providing bespoke solutions including special design, material selection, configuration, and parameters to replace outdated production processes and enhance stability and efficiency. Ingevity (Zhuhai), headquartered in South Carolina, USA, specializes in energy conservation (EC) and environmental protection (EP) materials, as well as high-performance activated carbon, and is a leading manufacturer in the automotive EP materials industry.

Mixer Model Selection

Considering the solid-liquid mixing reactions in the mixing process, our plough shear mixers (LDH series) were the optimal choice. These mixers were equipped with a heavy-duty drive system, including couplings and pulleys, to handle the strong resistance and chemical reactions involved in the process. We also designed the mixers with space for a future addition of a chopping machine equipped with high-speed cutter, which helps address material lumping and improves mixing efficiency.

Mixer Materials

Considering the corrosive nature of the materials handled, we used Duplex 2205 stainless steel for the mixer body and ploughs to enhance durability. Stainless steel 316L was used for other parts in contact with the corrosive materials. We also conducted a new round of Welding Procedure Qualification (WPQ) to ensure proficient welding of duplex steel and stainless steel, ensuring the feasibility and reliability of the mixing process.

Chemical Composition - Duplex 2205

Physical Properties - Duplex 2205

Non-Destructive Testing (NDT)

To meet process requirements, we had to include a jacket in the plough shear mixer for material heating and reaction. The mixer was designed to a pressure rating of 10 Bar and tested according to pressure vessel standards. We performed comprehensive Non-Destructive Testing (NDT), including 100% Radiographic Testing (RT) and Penetrant Testing (PT), to ensure the integrity and performance of the mixer.

Improvements

In early 2015, we delivered six sets of mixing equipment to Ingevity and completed installation, commissioning, and trial production by mid-year. By 2019, we observed that the mixer bodies had corroded and thinned. Following discussions with our client and analysis of specific conditions, we updated the design and made improvements by the end of 2019.

1. Hastelloy C-276 for Mixer Body and Ploughs

Due to the corrosive nature of the materials, the mixer body had thinned over time. Although it did not significantly affect the mixing performance, we still needed to address the issue. Fluor invited SGS to conduct corrosion resistance tests, based on which we decided to select Hastelloy C-276 as the replacement material for the mixer body and ploughs.

2. Mixer Body

To enhance heat transfer efficiency, we introduced a dimple jacket in our new mixers, which greatly improves heating time and uniformity, thereby increasing project efficiency.

After all those improvements, we delivered an additional six sets of mixers to Ingevity in September 2020, with installation and commissioning completed by October. The new mixers have shown significant performance enhancements, gaining more satisfaction and recognition from our client.