Drainage gravity

A belt filter press consists of a gravity drainage belt, foUowed by a series of roUer presses which squeeze out water. 

Static holdup depends upon the balance between surface-tension forces tending to hold hquiciin the bed and gravity or other forces that tend to displace the liquid out of the bed. Estimates of static holdup (for gravity drainage) may be made from the following relationship of Shulman et al. [Am. Jn.st. Chem. Eng. J., 1, 259 (1955)] ... 

Method Sludge dewatered by means of gravity drainage and natural evaporation. 

Tar Sands Canadian tar sands either are strip-mined and extracted with hot water or employ steam-assisted gravity drainage (SAGD) for in situ recovery of heavy oil (bitumen). The bitumen is processed into naphtha, kerosine, and gasoline fractions (which are hydrotreated), in addition to gas (which is recovered). Current production of syncrude from Canadian tar sands is about 113,000 T/d (790,000 B/d) with expected increases to about 190,000 T/d (1.7 MB/d) by 2010. 

Drainage systems are passive mitigation systems intended to collect, control, and route spilled process liquids, rainfall, and fire water out of the process structure or area. Drainage systems provide gravity drainage of these liquids from the process structure or area in order to ... 

Valve installation attitude should promote gravity drainage. 

A represent a case in which the ice bed rides with 10 feet of its height out of the water. The particle diameters refer to equivalent diameters as defined by the Carmen-Kozeney equation which equates particle diameter to the filter properties of a bed. Because small particles give poor filterability, there will be less piston leakage for beds made up of fine particles than for those of coarse particles. Likewise, the drainage properties of the bed from the top to the screen are affected by particle diameter. If it is assumed that the minimum pressure at the screen were to be the same as the pressure above the bed—in other words, full gravity drainage—then the maximum lineal ice rate is established for each equivalent particle diameter. Calculations based on the filtration behavior of the bed and on calorimetric determinations of porosity indicate the approximate relationship ... 

Due to the above limitations SimSim can neither be used for gas or water coning modeling, nor for gravity drainage modeling. 

Gravity drainage the movement of oil in a reservoir that results from the force of gravity. 

Low gravity drainage - decreases the rate of film thinning. 

Belt Filter Presses Belt presses (Fig. 18-193) have two filter belts that move around rollers of different sizes to dewater the slurry. A typical belt press may have one or more of the following stages a preconditioning zone, a gravity drainage zone, a linear compression zone (low pressure), and a roller compression zone (high pressure). 

Testing for applications in belt presses is most commonly done by flocculation in beakers and visual observation of the size and strength of the formed floes. The conditioned sluny can be poured into a filter for a gravity drainage test. These tests can be useful for an e3q>erienced person to evaluate if a sluny can be used in belt presses and to optimize an existing belt press. However, the simulation of the final cake dryness is not... 

The fraction of oil-in-place recoverable from conventional petroleum reservoirs varies greatly with the reservoir type, oil viscosity, formation pressure, production rate, and finesse employed. The positive displacement aspect of water drive reservoirs generally gives them the highest ultimate petroleum recoveries, up to 70% of the oil-in-place [14]. Estimates of ultimate recoveries possible from gas cap drive and dissolved gas drive types of reservoirs are usually much lower, 25-50% for the former and 10-30% for the latter. Recovery from gravity drainage reservoirs will be at the lower end of the ranges of the two gas drive reservoir types. 

Adibhatla, B., Mohanty, K.K., 2008. Oil recovery from fractured carbonates by surfactant-aided gravity drainage laboratory experiments and mechanistic simulations. SPE Reservoir Engineering and Evaluation (SPEREE) (February), 119—130. 

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