Settler length

The settler length in Figure 3, 7.6 cm, is the normal one used everywhere except in the lG-battery, where a roughly three times longer settler is used to permit more time for phase disengagement ... 

We wish to separate titanium dioxide particles from a water suspension. The method chosen is centrifugation. The unit is a continuous solid-bowl type with a bowl diamter of 400 mm, a length to width ratio of 3.0, and the unit operates at 2,000 rpm. The feed contains 18 % (weight basis) solids and is fed to the unit at 2,500 Liters/hr at a temperature of 95° F. The average particle size is 65 /tm. (a) Determine the amount of solids recovered per hour (b) Determine the solids concentration in the centrate (c) Determine the horsepower requirments for the centrifuge (d) Size a graviy settler to remove an additional 15 % of the solids. 

A gravity settler is to be used to separate particles less than 75 qm from a flowrate of gas of 1.6 m3s 1. The density of the particles is 2100 kg-rn 3. The density of the gas is 1.18 kg-m-3 and its viscosity is 1.85x 10 5 kg-rn 1 -s 1 Estimate the dimensions of the settling chamber assuming a rectangular cross section with length to be twice that of the breadth. 

After the dispersion leaving the reactor is separated in the settler (decanter), the liquid hydrocarbon product stream is partially flashed, forming a vapor phase, mainly isobutane. The remaining liquid is hence cooled, and it is used as the coolant in the tube bundle of the reactor. As heat is transferred there, more hydrocarbons vaporize, forming a liquid-gas mixture. Obviously, temperature gradients occur on both sides of the tube bundle as a function of reactor length. Heat transfer (and temperature control) is an important design consideration in contactors. 

It follows from (13.55) and (13.56) that A), < Ay if r. is the same for horizontal and vertical settlers. The higher efficiency of emulsion separation in a horizontal separator as compared to a vertical one is explained by of the shape of drop distributions at the settler exit (Fig. 13.17). In a vertical settler, the part of the initial distribution with V > Va- gets cut off at the entrance, since drops of such volume cannot move against gravity. In a horizontal settler, drops of all sizes settle continuously along the whole length, and not only drops with V > Va-, but also a part of drops with V < Va get settled out, which does not happen in a vertical settler. 

Regarding the distribution of jump lengths, we know that the settlers did not always cover the same distance, and the distribution w x) should include the possibility of different jump lengths. This can be done by fitting the observed data to a continuous distribution. In [64], the jump distances covered by settlers were estimated from individual records obtained from the migrations.org project database, available at http //www.migrations. org. The authors collected 400 individual... 

D30. Suppose in Fxanple 13-5 that we decide to build the settler with a diameter of 1.0 m and a length of 4.0 m What safety factor are we employing ... 

Phase separation in macroscale equipment either uses density differences between the two fluids to drive the separation, as in settlers, or these differences play an important role in the technical layout of the separator, e.g. in distillation towers. In macroscopic two-phase flow, length scales vary between the size of the apparatus and the interface-dictated Laplace length scale /o/(g AQ)) of entrained bubbles or drops. The former is often on the order of meters, whereas the latter is on the order of millimeters. This significant disparity in length scales makes it virtually impossible to separate macroscopic two-phase flows in a single step. 

Apparatus Parallel plate coalescer with 7 electrodes and a height of 0.26m, a length of 0.27 m and a width of 0.17 riL This type was chosen because existing gravity settlers could be easily equipped with such electrodes and because of the homogenous field between the electives. 

The required diameter and length of a horizontal cylindrical settler can be determined from Stokes law as follows ... 

The relationship between the L ff and the seam-to-seam length of a settler is dependent on the settling vessel s internal physical design. Some approximations of the seam-to-seam length may be made based on experience as follows ... 

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