Petroleum Product Mixing

Side-entering mixers installed in oil storage tanks are required to perform two main tasks.

These are:

• Mobilization of sludge that settles on the base of the tank. If sludge is allowed to accumulate it can cause corrosion problems, since it contains some water, and reduce the available operating volume of the tank.  If the agitator cannot achieve this level of mixing the tank must be taken out of service on a regular basis for cleaning at a cost of several hundreds of thousands of dollars.
• Blending of the contents to ensure that the product leaving the tank has uniform gravity, viscosity and temperature. This is crucial for ensuring that accurate sampling can be achieved.  Also, the time taken to achieve homogeneity determines the productivity of the plant since the tank cannot be emptied until an accurate sample has been obtained.

The patented Advance Pitch Propeller has been developed to address both these mixing tasks. It generates a collimated flow to maximize the velocity across the floor of the vessel which mobilizes the sludge and it maximizes the velocity of the vertical flow up the opposite wall of the tank and impinging on the interface between the oil’s heavy and light components. This ensures that the light component is disturbed and drawn down into the heavy component and blended.

The increased efficiency of the Lancer Advanced Pitch Propeller allows sludge mobilization and blending to be achieved with lower power requirements than agitators fitted with traditional style propellers.

The BSER Mixing System has been developed using feedback from customers to make it easy to maintain by, for example, making openings in the housing larger to allow easier access to bearings and the seal.