The heart of the STRATCO grease manufacturing process is the proprietary STRATCO Grease Contactor reactor. The STRATCO Contactor™ reactor consists of a pressure vessel, a circulation tube and a hydraulic head assembly with a mixing impeller and driver. The outstanding feature of the Contactor reactor is its high turbulent circulation in a closed cycle path. All energy input through the mixing impeller is expended within the materials being mixed and there is virtually no pressure differential between the Contactor reactor's inlet and outlet.

The Contactor reactor is first charged with the specified base oil which is at its storage temperature. A hinged opening at the top of the Contactor reactor is used for charging the active chemical ingredients used in the grease formula. Once the specified amount of the raw chemicals is loaded, the charge opening is closed and the Contactor reactor is heated.

STRATCO provides reliable, state-of-the-art production technology, equipment and services to maintain our customers' competitive advantage in the global market of lubricating oil and grease.
The development, design, fabrication, and operation of STRATCO process equipment is backed by more than 80 years of experience with over 400 units installed throughout the world. The first STRATCO Grease Contactor™ reactor (installed in 1929) is still in service today. This is indicative of the quality, reliability, and dependability of our equipment.

STRATCO offers to manufacturers around the world a semi-continuous process to manufacture various types of greases, ranging from calcium, lithium, and sodium to more specialized greases such as aluminum complex, polyurea, etc. The process is similar to that of the conventional kettle process, but more efficient and flexible allowing the manufacturer to minimize unit manufacturing costs while maintaining high standards of quality.

Our proprietary design for the unique mixer/reactor - known as the STRATCO  Contactor™ reactor - revolutionized production of lubricating greases. The unique features of the Contactor reactor are its highly turbulent circulation in a closed cycle path and its relatively large heat transfer surface, which contributes to the vessel's enhanced performance as compared with a typical kettle process.

The STRATCO Contactor reactor consists of a pressure vessel, a circulation tube and a hydraulic head assembly complete with the mixing impeller and driver. The Contactor reactor by design has a highly turbulent circulation path.  All energy input through the mixing impeller is expended within the materials being mixed.  The high dispersion mixing in the Contactor reactor is achieved by the proprietary hydraulic head assembly. Frequent and forced changes in velocity and direction of flow occur around the impeller area. This results in a zone of high shear and intense mixing, which reduces the time required to complete the saponification reaction.
Material is pulled down through the center of the circulation tube by the impeller, reversed and then forced up through the annular space. Because the impeller is located on the bottom, dry materials are kept in suspension until they dissolve or are reacted.

The heating medium is circulated through the double-walled circulation tube inside the Contactor. The outside of the Contactor reactor is also jacketed.  An alternate design can be furnished to use high pressure steam.

Because of the double-walled circulation tube and the outside jacket, the Contactor reactor has approximately three times the heat transfer area of an open kettle or other pressure (autoclave) type reactors of the same volume. The flow path, forces the circulating material to remain in contact with the total heating surface area at all times. Also, the heat transfer in the Contactor reactor is enhanced by the high velocity of material flowing past the heat transfer surfaces.

The Contactor reactor’s impeller is connected to a two-speed motor normally turning at 1,200 RPM. The motor is mounted below the vessel and out of the operating area. The shaft is sealed from the process fluid by a mechanical seal which can be replaced from outside the Contactor reactor without removing the head.