Separator horizontal separators

In modem boilers, both FT steam spaces and WT steam drums incorporate various devices to promote the effective separation of steam from water and the production of dry steam. These devices include horizontal separators and baffle plates in the steam/water space, and chevron driers, cyclone separators, and secondary steam scrubbers in the steam space. Older or simpler boiler designs with steam release velocities of below 3 ft/s (0.9 m/s) may rely solely on the natural separation of steam from water. 

Where the carryover of some fine droplets can be tolerated it is often sufficient to rely on gravity settling in a vertical or horizontal separating vessel (knockout pot). 

The design methods for horizontal separators given below are based on a procedure given by Gerunda (1981). 

The layout of a typical horizontal separator is shown in Figure 10.516. 

A horizontal separator would be selected when a long liquid hold-up time is required. 

In the design of a horizontal separator the vessel diameter cannot be determined independently of its length, unlike for a vertical separator. The diameter and length, and the liquid level, must be chosen to give sufficient vapour residence time for the liquid droplets to settle out, and for the required liquid hold-up time to be met. 

The design procedure for horizontal separators is illustrated in the following example, example 10.6. 

Horizontal separators should be designed for liquid holding times of 2-10 min. The height of Ihe vapor space should be at least 1 ft, or 20% of the diameter if that is larger.16... 

Table 1. Confusion matrix for the PLS-DA analysis of the California obsidian localities using 600 broadband LIBS spectra and 15 latent variables to produce 5 model classes. Horizontal lines separate the groupings for the Coso Volcanic Field by Draucker (2007) and the other four California obsidian localities...

Vertical blowdown drum/catch tank This type of drum, shown in Fig. 23-51, performs the same function and operates on similar princi-les as horizontal separators. These separators are usually used where orizontal space is limited. The two-phase mixture enters the vessel via a nozzle on the vertical shell and is distributed by an inlet baffle chamber. 

Vapor-Liquid Gravity Separator Design Fundamentals The critical factors in the performance of a horizontal separator are the vapor residence time and the settling rate of the liquid droplets. However, two other factors enter into the design—the vapor velocity must be limited to avoid liquid entrainment, and there must be sufficient freeboard within the vessel to allow for a feed distributor. For vertical separators, the design is based on a vapor velocity that must be less than the settling velocity of the smallest droplet that is to be collected, with due allowance for turbulence and maldistribution of the feed. The vapor residence time is a function of the vapor flow rate (mass), vapor density, and volume of vapor space in the separator, based on the following ... 

Other approaches for sizing a horizontal separator (blowdown drum) are given in Guidelines for Pressure Relief and Effluent Handling Systems (AIChE-CCPS, 1998) and API RP 521 (2007). 

Vertical Blowdown Drum/Catch Tank (See Fig. 23-51.) Some of the basic equations used for sizing horizontal separators can be applied to vertical separators however, the superficial vapor velocity for vertical separators is based on the total vessel cross-sectional area, and the vapor velocity must be less than the terminal settling velocity for the droplet size selected as the basis of design. 

The recommended design procedure is also from Guidelines for Pressure Relief and Effluent Handling Systems (AIChE-CCPS, 1998). As with a horizontal separator, the assumed value of K is expected to be suitable for most vertical separators in emergency relief services. However, if it is necessary to remove droplets smaller than 300 to 600 pm, then lower values of K should be used. 

Figure 7.15 Horizontal separation collaborating types versus classes.

The purpose of packages is to make explicit the dependencies between different areas of the development work. A variety of patterns can be apphed to help separate concerns, including vertical separation of different views, horizontal separation of different architectural and business levels, and code separations of interfaces from implementations. 

The objective is to achieve horizontal layering, separating business from technology components. 

Because the separation of the solid particles which have been thrown out to the walls is dependent on the flow of gas parallel to the axis rather than to the effect of gravity, the cyclone can be mounted in any desired direction. In many cases horizontal cyclone separators are used, and occasionally the separator is fixed at the junction of two mutually perpendicular pipes and the axis is then a quadrant of a circle. The cyclone separator is... 

The reader should recall that the concentrations of the electron, pure solids, and the solvent (water), are defined as 1. The calculated value of —2.77 v matches the value of —2.8 v which was estimated from the diagram. It is interesting to note from the Nernst equation that the reduction potential for the half-reaction is dependent only upon the concentration of the sodium ion, Na" ". Neither the concentration of the hydrogen ion nor the hydroxide ion influences the potential at which the half-reaction occurs since they do not appear in the above equation. Similar calculations may be made for other concentrations of Na" ". It will be found that the horizontal line separating Na" " and Na moves from —2.71 v at 1.00 M Na+ to —2.89 v at 10 M, to —3.06 V at 10 M, to —3.24 v at 10 M, and so on. 

FIGURE 3-22 Two-dimensional electrophoresis, (a) Proteins are first separated by isoelectric focusing in a cylindrical gel. The gel is then laid horizontally on a second, slab-shaped gel, and the proteins are separated by SDS polyacrylamide gel electrophoresis. Horizontal separation reflects differences in pi vertical separation reflects differences in molecular weight, (b) More than 1,000 different proteins from . coli can be resolved using this technique. 

Recently spherical separators have gained considerable popularity. The shell consists of two hemispherical heads with appropriate internal construction. They have operating versatility comparable to the horizontal separator and are very compact and easily hooked up. 

Horizontal separators. Fluid enters the separator (Fig. 1) and hits an inlet diverter, causing a sudden change in mo-... 

Fig. 1— Horizontal separator employs four basic mechanisms to liberate gaa from liquid. Inlet diverter imposes a sudden direction and momentum change on the flowstrearn, causing heavier liquids to drop out. Gravity settling section provides opportunity for smaller droplets to leave gas stream, and mist extractor coalesces remaining liquids as gas exits vessel. In addition, entrained gas escapes In liquid collection section.

A controller opens and closes the pressure control valve at the gas outlet to maintain desired vessel pressure. Normally, horizontal separators are operated half full of liquid to maximize the gas-liquid interface area. 

Vertical separator. Fig. 2 is a schematic of a vertical separator. In this configuration inlet flow enters the vessel through the side. As in the horizontal separator, the inlet diverter does the initial gross separation. Liquid flows down to the liquid collection section of the vessel, then down to the liquid outlet. As liquid reaches equilibrium, gas bubbles flow counter to the direction of liquid flow and eventually migrate to the vapor space. The level controller and liquid dump valve operate in the same manner as in a horizontal separator. 

For applications in which there is very litdc liquid flow, a horizontal separator often will include a liquid sump on the outlet end to provide required liquid retention time. This results in a smaller overall vessel diameter. 

Horizontal separators normally are more efficient at handling large volumes of gas than vertical types since liquid droplets fall perpendicular to the gas flow in the gravity settling section, and are more easily settled out of the gas continuous phase. Also, since interface area is larger in a horizontal separator, it is easier for gas bubbles, which come out of solution as liquid approaches equilibrium, to reach the vapor space. 

In terms of the gas/liquid separation process, horizontal separators would be preferred. However, they do have drawbacks that could lead to a preference for a vertical separator in certain situations ... 

Horizontal separators. To size a horizontal separator, it is necessary to choose seam-to-seam vessel length and a diameter. This choice must satisfy conditions for gas capacity that allow liquid drops to fall from the gas to the liquid volume as gas traverses the effective length of the vessel. The design must also provide sufficient retention time to allow liquid to reach equilibrium. 

EQUIPMENT DESCRIPTION Horizontal separators. Fig. 2 is a schematic of a horizontal separator. Fluid enters the vessel and hits an inlel diverter. This sudden change in momentum docs the initial gross separation of liquid and vapor as discussed in the section on two-phase separators that appeared in WORLD OIL last month. 

Fig. 2 illustrates a typical horizontal separator with an interface controller and weir. The weir maintains the oil level... 

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