In 2014, after receiving a bid invitation from Fluor, S&L was honored to participate in the mixing equipment project for Ingevity Zhuhai, whose headquarter is located in South Carolina of United States, specialized in manufacturing EC (Energy Conservation) & EP (Environmental Protection) materials and High-performance Activated Carbon Materials, Ingevity becomes leading manufacturer especially in EP materials industry for automobiles. After multistage technical communication, inspection visit and business negotiation, S&L finally was awarded the project. To replace the old production process and improve the stability and production efficiency, Ingevity made her first trial in this world. So, special design plans was requested included material selection, configuration and parameters of the mixing equipment.
Mixer Selection
As it is solid-liquid mixing and reacting, ploughshare mixer-LDH series is the best choice. There is centrifugal movement of the material inside mixer under high-speed operation. Besides, considering the chemical reaction and strong resistance during the solid-liquid mixing process, heavy-duty drive system including coupling and pulley provides better power and nice protection for such kind difficult material. This also prolongs the service life of equipment, reduces maintenance costs and downtime. In addition, we also keep the possibility for adding chopper in future in case the mixing is not ideal and the material gets lumps. High-speed choppers can help to disaggregate.
Construction Material
Considering the strong corrosion nature of the product material, duplex steel 2205 is used to make mixer body and ploughs, which contacted frequently with the material and easily worn out. Stainless steel 316L is used for other contacted parts. In order to be proficient in welding of duplex steel and stainless steel, new WPQ is done to ensure the feasibility.
NDT
According to the process requirements, jacket out of the plough mixer for material heating and reacting is a must. With design pressure 10Bar, the mixer is designed, fabricated and tested according to Pressure Vessel Standard. A very important step is to have necessary NDT (Non-destructive Testing) including 100% RT (Radiographic Testing) and PT (Penetration Test)
Improvement
At the beginning of 2015, six sets mixing equipment were handed over to the customer. Installation, commissioning and trial production were accomplished in the middle of the year. Four years later, the mixer body corroded and became thinner. With 3rd party serious demonstration and buyer approval, updated design with improvement was done by S&L at the end of 2019.
1) C-276 to be used for mixer body and ploughs
Obviously, thinner mixer body was caused by strong corrosiveness and abrasiveness of the materials. Though mixing effect of the equipment was not affected, this issue still caught the attention. To find most suitable material of construction, Fluor invited SGS to do corrosion resistance test for the user's material, and finally construction material C276 was selected as replacement material for mixer body and ploughs.
2) Dimple jacket outside of mixer body
In order to increase the heating transfer area and efficiency, dimple jacket is selected for new mixer. This absolutely shortens the heating time and makes the heating more uniform.
With improvements above, another 6 units of mixing equipment were delivered to Ingevity in September 2020. In October the installation and commissioning were successfully completed. It has been proved more satisfactory for the new equipment.