Jensen Series 400 Vari-Angle Side Entry Mixer
Mixers equipped with the optional Jensen Vari Angle Side Entry Mixers feature will completely remove sediment build ups from old tanks which means freedom from manual tank cleaning. Vari Angle allows the flow stream to be directed to any area of the tank assuring complete tank cleaning. The Vari Angle feature is a precision, ball-type stuffing box allowing 60º angular movement. Sealing is accomplished by Teflon® impregnated non-asbestos packing which is fully adjustable to eliminate leaks. Mixer weight is supported entirely by two heavy duty, pin type hinges. As with all Jensen Mixers, no turn-buckles, tie rods, bases, or other extra supports are required. Angle changes can be made easily by one man, or automatically controlled by the optional Mechanical Actuator.
- Increase storage capacity by elimination B.S.& W.
- Remove risk of water/sludge breaking free and entering desalter causing desalter loads considerably above normal.
- Avoid extended loss of tank use by traditional mucking out routines.
- Avoid cost of traditional tank cleaning operations.
- Have tank readily available for emergency repairs.
- Avoid stratification, uniformly blended crude cargo to refinery.
- Solids represent at best a few % (1-2% according to Shell Oil Co.) of tank bottom sludge. Most sludge is refinable oil. Tank bottom sludge represents an inventory not being used. A 286′ ø tank contains 11,437 bbls/ft. So 2-3 ft. of sludge represents 22,874 – 34,312 bbls of “lost” cargo/tank. At $57.00/barrel that is $1,303,818.00 – $1,955,784.00 recovered per tank.
- Jensen is the only mixer with propellers individually pitched to draw 90% available motor HP for the given application. All others are a compromise – sometimes severe.
Initial Solids Suspension Control:
Run mixers while filling tank & shut-off 1-2 hours after tank is full.
re-start mixers 4-6 hours prior to pumping out & initially check for solids content every hour until solids reach maximum allowable.
Repeat this operating procedure until pattern can be established allowing a determination of number of hours of mixer operation that yields maximum allowable solids concentration.
Once the tank bottom is clean the incoming solids should be sufficiently low in concentration to pump them back out ensuring that the tank bottom remains clean.
References:
A). “Source Control Pays Off for Chevron” – Oil & Gas Journal, 8/7/78
B). “Tank Mixing of Crude Oil” – Pipeline Technology, 11/8/54
C). “Jet Mixing of Two Liquids” – A comparison showing the distinct advantage of mixers over Jet Nozzles.
D). “A Discussion of Refinery Tank Cleaning” – H.E. Knowlton, 5/10/83
E). Excerpts from Royal Dutch / Shell Group Tech Spec for Side Entry Mixers – Source: DEP-31.51.10.31 Gen.PG12 & 13 (special note: This data was adopted directly from Jensen’s Recommended Practice).
Experience:
Jensen has more than 15,000 Vari-Angle Tank Mixers in service worldwide on crude oil, No. 6 F.O. & Bunker Tanks. Major users are Shell Oil Co., Sunoco, Coastal, Valero, Aramco, Mitsubishi, Caltex, Pemex, Petrobras, Statia, TransCanada Pipeline, Lagoven, Chevron Texaco, Exxon Mobil, Conoco Phillips, Rayong, Yukone & Irving Oil.