Tank-type classifiers

Tank through-flow classifier, 22 289, 290 Tank turnovers method, 16 688 Tank type reactor, 17 594 Tanker truck hydrogen delivery, 13 853 Tannate drug complexation, 18 710... 

Rake and Spiral Classifiers Rake-type classifiers such as the Dorrf classifier and spiral types such as the Akinsj have been the workhorses for general-classification problems for half a century, and their names describe the mechanisms installed in sloping-bottom tanks. See Fig. 19-24. Mechanically the devices are powerfully built, and functionally they are versatile and flexible. They were tfie first classifiers used successfully for closed-circuit grinding. Separations as fine as 325 mesh can be accomplished at reduced tonnage rates. 

The semibatch reactor was defined in Chap. 3 (Fig. 3-1 c) as a tank type operated on a non-steady-flow basis. Semibatch behavior occurs when a tank-"flow reactor is started up, when its operating conditions are changed from one steady state to another, or when it is shut down. Purging processes in which an inert material is added to the reactor can also be classified as semibatch operation. 

Figure 3.3 shows a simple type of classifier. In this device, a large tank is subdivided into several sections. A size range of solid particles suspended in vapor or liquid enters the tank. The larger, faster-settling particles settle to the bottom close to the entrance, and the slower-settling particles settle to the bottom close to the exit. The vertical baffles in the tank allow the collection of several fractions. 

Classification of the many different encapsulation processes is usehil. Previous schemes employing the categories chemical or physical are unsatisfactory because many so-called chemical processes involve exclusively physical phenomena, whereas so-called physical processes can utilize chemical phenomena. An alternative approach is to classify all encapsulation processes as either Type A or Type B processes. Type A processes are defined as those in which capsule formation occurs entirely in a Hquid-filled stirred tank or tubular reactor. Emulsion and dispersion stabiUty play a key role in determining the success of such processes. Type B processes are processes in which capsule formation occurs because a coating is sprayed or deposited in some manner onto the surface of a Hquid or soHd core material dispersed in a gas phase or vacuum. This category also includes processes in which Hquid droplets containing core material are sprayed into a gas phase and subsequentiy solidified to produce microcapsules. Emulsion and dispersion stabilization can play a key role in the success of Type B processes also. 

To a large exteat, the vapor pressure of the substance stored determines the shape and, consequently, the type of tank used. The roof shape of a tank may be used to classify the type of tank. This classification is self-explanatory to tank fabricators and erectors. Also important is the tank bottom. 

Tank Bottoms. The shape of cylindrical tank closures, both top and bottom, is a strong function of the internal pressure. Because of the varying conditions to which a tank bottom may be subjected, several types of tank bottoms (Fig. 7 Table 4) have evolved. These may be broadly classified as flat bottom, conical, or domed or spherical. Flat-bottom tanks only appear flat. These usually have designed slope and shape and are subclassifted according to the following flat, cone up, cone down, or single slope. 

Cleaners. Cleaner formulations can be classified with respect to the abiUty to emulsify oils, keep them in solution or to reject oils, spHt them out of solution. The latter type loosens the oil, and the separated oil does not dissolve but is rejected, and usually floats to the top of the cleaner solution. For the cleaner that rejects oil, the tank needs to be skimmed constantly. This is most easily accompHshed usiag the overflow weir, sump, and recirculating pump arrangement. OH-rejecting cleaners last longer. 

Types of Systems Generally, pneumatic conveyors are classified according to five basic types pressure, vacuum, combination pressure and vacuum, fluidizing, and the blow tank. 

Another classification refers to the shape of the vessel. In the case of the laboratory vessel installed with a stirrer, the composition and temperature of die reaction is homogeneous in all parts of die vessel. This type of vessel is classified as a stiiTcd tank or well mixed reactor. Where there is no mixing in the direction of flow as in the cylindrical vessel, it is classified as a plug flow or tubular flow reactor. 

Airborne contaminant movement in the building depends upon the type of heat and contaminant sources, which can be classified as (1) buoyant (e.g., heat) sources, (2) nonbuoyant (diffusion) sources, and (d) dynamic sources.- With the first type of sources, contaminants move in the space primarily due to the heat energy as buoyant plumes over the heated surfaces. The second type of sources is characterized by cimtaminant diffusion in the room in all directions due to the concentration gradient in all directions (e.g., in the case of emission from painted surfaces). The emission rare in this case is significantly affected by the intensity of the ambient air turbulence and air velocity, dhe third type of sources is characterized by contaminant movement in the space with an air jet (e.g., linear jet over the tank with a push-pull ventilation), or particle flow (e.g., from a grinding wheel). In some cases, the above factors influencing contaminant distribution in the room are combined. 

As mentioned earlier, flame arresters can be classified as either deflagration or detonation type. Deflagration flame arresters on tanks are designed to stop a flame from propagating into a tank from an unconfined atmo-... 

These types of agitator are used in low-viscosity systems (ji < 50 kg m 1 s-1) with high rotational speed. The typical tip speed velocity for turbine and intermig is in the region of 3 m s 1 a propeller rotates faster. These impellers are classified as remote clearance type, having diameters in the range 25-67% of the tank diameter. 

The Sundance et al. Hoadley 6-2-45-2w5m discovery well in the Hoadley (Lower Cretaceous Glauconite) Field yielded an absolute open flow of 76 MMscf/d with 60 bbl of stock-tank liquid per MMscf of gas. Classify the reservoir fluid type. What other field information would you like to have to confirm your classification ... 

Fermenters are usually classified based on their vessel type such as tank, column, or loop fermenters. The tank and column fermenters are both constructed as cylindrical vessels. They can be distinguished based on their height-to-diameter ratio (H/D) as (Schiigerl, 1982) ... 

A loop fermenter is a tank or column fermenter with a liquid circulation loop, which can be a central draft tube or external loop. Depending on how the liquid circulation is induced, it can be classified into three different types air-lift, stirred loop, and jet loop (Figure 6.22). 

To guide the reactor selection process, Walas [7] has classified reactions according to the operating mode (batch or continuous), reactor type (tank, tank battery, tubular), flow type (back mixed, multistage back mixed), and the phases in contact. This reactor classification in Table 7.2 indicates if a particular reactor arrangement is commonly used, rarely used, or not feasible. 

Pressure filters are usually operated batch-wise. The batch pressure filters can be classified as tank (pressure vessel) filters or presses. Tank filters have different types of filter elements in pressure vessels. Presses consist of a series of filter surfaces (plates). The elements are mounted on a frame and are pressed together mechanically. 

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