Sizing procedure

Much of the basic theory of reaction kinetics presented in Sec. 7 of this Handbook deals with homogeneous reaclions in batch and continuous equipment, and that material will not be repeated here. Material and energy balances and sizing procedures are developed for batch operations in ideal stirred tanks—during startup, continuation, and shutdown—and for continuous operation in ideal stirred tank batteries and plug flow tubulars and towers. 

References 1 and 2 were used extensive for this section. The sizing procedure is generally that of Fisher Controls Company. 

Select appropriate design surge time and calculate full liquid volume. The remainder of the sizing procedure is done by trial and error as in the following steps. 

Each manufacturer uses different core sizing procedures. Some use graphs, others simply state how much power each core can handle for a particular application, and some use cryptic equations that are confused by the mixture of unrelated units. The following two procedures are generalized approaches for estimating the initial core size. 

I will use an MPP toroid core. The core sizing procedure is contained in Section 3.5.5. Estimate the core size required ... 

The values for pressure ratio in a practical case must include allowance for pressure drop in the interstage piping. In the sizing procedure used by manufacturers, certain adjustments must be made to the ideal for incremental cylinder sizes and allowable rod loading. Efficiency is represented by r. yi. 

Using the results of Example 2-2, size a centrifugal air compressor using the sizing procedure. A summary of the results is ... 

If the superimposed back pressure is less than the calculated critical flow pressure, the capacity of a conventional PR valve in vapor service is unaffected and back pressure is not a factor. However, builtup back pressure on a conventional pressure relief valve will affect its flow capacity and operating characteristics, and should not exceed 100% of its set pressure. If total back pressure (superimposed plus built-up) is greater than the calculated critical flow pressure, the capacity of a conventional PR valve in vapor service is affected, and total back pressure is incorporated into the sizing procedure. Any back pressure reduces the capacity of a conventional PR valve in liquid service, and... 

It is important to note that back pressure affects balanced PR valve capacities in the same way as for conventional valves, and appropriate factors are included in the sizing procedures. They are subject to the same recommended limits of maximum total back pressure (superimposed plus built-up) as conventional valves. In the case of balanced bellows valves, mechanical considerations must also be evaluated, since they may limit the maximum permissible back pressure. 

Pilot-operated valves have limitations in liquid service and reference should be made to the manufacturer for advice on sizing procedures. 

A trial and error estimate is made for determining the diameter of the flare header based upon the maximum relieving flare load and considering the back pressure limitation of 10 percent for conventional valves and 40 percent for balanced type valves. Note, however, a single main header in most cases turns out to be too large to be economically feasible. Line sizing procedures are discussed in detail in the next subsection. 

The sizing procedure for gas piping must take both high-pressure and low-pressure flow conditions into consideration if the operating pressure of the line changes over time. 

Calculations of Orifice Flow Area using Pressure Relieving Balanced Bellows Valves, with Variable or Constant Back Pressure. Must be used when backpressure variation exceeds 10% of the set pressure of the valve. Flow may be critical or non-critical for balanced valves. All orifice areas. A, in sq in. [68]. The sizing procedure is the same as for conventional valves listed above (Equations 7-10 ff), but uses equations given below incorporating the correction factors K, and K,, . With variable backpressure, use maximum value for P9 [33a, 68]. 

The following is extracted by permission from ACS Bulletin B-129 (Apr. 1992). Typical HETP is 3 in. compared to ACS product ST-100 of 7 in. Approximate comparison data are AP as low as 0.1-in. water/theoretical tray turn-dovm ratio about 20 1. Special series S construction recommended for smaller columns, and transverse Series X for larger ones. The suggested preliminary sizing procedure is ... 

Liposome size can range from around 20 nm to around 50 pm. To a certain extent, the mean diameter and distribution of the diameters can be controlled by sizing procedures after the formation of the initial liposome dispersion or by a careful selection of the preparation conditions (cf. Sec. II). Several techniques can be used to determine mean particle size and particle size distribution (Groves, 1984). 

The starting point of the approximate sizing procedure is to compose blank flow-sheets for all products (processes) specifying types of all equipment units of yet unknown capacity for each process no matter whether units are common for a majority of stages or unique for one process only. Preliminary mass and heat balances for all items and processes must be made. The size factors Sij are evaluated based on these balances. The balances can be corrected after equipment has been selected. Evaluation of size factors thus is an iterative procedure. 

In the beginning there is a general loop to decide if more lot sizing procedures should be applied to the existing quant network to meet the constraint of the minimum batch sizes of products. Then the quant network is examined, free usable stocks and free quantities of quants are made available. The material balances of any quant are calculated and decisions are taken whether quants require further explosions of their BOM. Structures for a fast cycle checking, sorting of existing quants and quant links and forecast intervals are built up. A recalculation of the due dates for all quants - also the ones of orders - can be done if specified by the user. 

A manual batch sizing procedure was used to determine constant batch sizes for all operations. Batch sizes for tasks running on the resources i i, R3..., R, R, i 9 are fixed to 10. The batch size of T2, which was experimentally identified as a bottleneck, was chosen as 20. With respect to R(, and R7, the batch sizes for the... 

Sizing procedure The cyclone is sized by choosing a superficial F factor for the skirt in the range of 8.0 to 5.0 in USCS units (10 to 6 in... 

The sizing procedure is presented in Guidelines for Pressure Relief and Effluent Handling Systems (AIChE-CCPS, 1998). Figure 23-53 shows the dimensions of a cyclone separator designed in accordance with this procedure. If liquid is continuously drained from the cyclone to a separate accumulator, a vortex breaker and false bottom should be used (Fig. 23-53, view BB). 

The control valve/pump sizing procedure proposed above is not without its limitations. The two design equations for the maximum and minimum conditions in general terms are ... 

In the preparation of white paper the FB A is added either at the pulping stage, prior to producing the paper sheet (one-third of the manufacture), or during a subsequent sizing procedure on the preformed sheet (two-thirds of the manufacture). The... 

The chemical process gives the enthalpy of reaction, the flow rate, the reaction time, and the required reaction temperature. The first step in the sizing procedure is to calculate the required number of channels for the heat exchanger. Then the pass arrangement is selected in order to achieve the highest possible Reynolds number within an acceptable pressure drop. For example, if the total number of channels is fixed by the residence time channels in series will induce high velocities and high pressure drop channels in parallel will induce low velocities and low pressure drop. The second step is to estimate the heat transfer coefficient and to check that the heat flux can effectively be controlled by the secondary fluid (the lower heat transfer coefficient should be on the reaction side). 

The procedure used for fire sizing depends sometimes on the codes and engineering practices applied in each installation and determined by the end users. The following sizing procedure, according to API RP 520 Part 1 (see codes in Chapter 4), is the most commonly used. 

API Recommended Practice 520 Part I, Sizing and Selection This API design manual includes basic definitions and information about the operational characteristics and applications of various pressure relief devices. It also includes sizing procedures and methods based on steady state flow of Newtonian fluids. This RP covers equipment that has a maximum allowable pressure of 15 psig (1.03 barg) or greater. 

Sizing procedures to design a mixer for one closely sized particle settling velocity are modified considerably when there are other solids present. Figure 17 shows the effect of settling velocity on power when there are other solids present in the system. The slope is much less pronounced than it is when a single particle size alone is being suspended. 

Tower and heat exchanger sizing procedures — Peters and Timmerhaus Venture Analysis 11) ... 

The first step in developing a sizing procedure is to determine which phase is dispersed. Selker and Sleicher [19] foimd that the value of the parameter 0, defined by Equation 6.15.1 in Table 6.15, could be used as a guide to determine the dispersed phase. After calculating 0, then use Table 6.13 to identify the dispersed phase. 

The equations for sizing rotary-drum filters are summarized in Table 6.18. Equation 6.18.1 is the liquid mass balance. In this procedure, y is a mass fraction. Because the cake is wet, the liquid entering the filter will be less then the liquid leaving. Equation 6.18.2 is the solids mass balance, assuming that all the solids in the slurry are removed. Solve Equation 6.18.2 for the cake formation rate, me. Then, solve Equation 6.18.1 for the filtrate volumetric flow rate, V2. Next, calculate the filtration area from Equation 6.18.5 and the dmm area from Equation 7.18.6. Finally, select a standard rotary filter from Table 6.20. The calculation procedure for sizing a rotary filter is outlined in Table 6.19. Example 6.5 illustrates the sizing procedure. 

The first step in the sizing procedure is to determine the minimiun liquid flow rate for an absorber or the minimum gas flow rate for a stripper. For gas absorption, die entering liquid and gas concentrations are known, which is shown in Figure 6.16. The subscript 1 refers to the top of the separator, and the subscript 2 to the bottom of the separator, as shown in Figure 6.16. The fractional absorption and therefore the exit gas concentration is also known, fixing point 1 - at the top of the column. The exit liquid concentration is not known. Therefore, point 2 - at the bottom of the column - is not fixed. The minimmn liquid flow rate occurs... 

Using the orifice meter as an example. Example 8.2 illustrates the sizing procedure. Calculating the orifice diameter requires assigning the pressine drop across the orifice. 

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