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barcode reading in asp.net CONTROL OF A STEAMJACKETED KETTLE in Software
CONTROL OF A STEAMJACKETED KETTLE Code128 Reader In None Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications. Code 128 Code Set C Maker In None Using Barcode creation for Software Control to generate, create ANSI/AIM Code 128 image in Software applications. The dynamic response and control of the steamjacketed kettle shown in Fig. 21.1 are to be considered. The system consists of a kettle through which water flows at a variable rate w lb/time. The entering water is at temperature Ti, which may vary with time. The kettle water, which is well agitated, is heated by steam condensing in the jacket at temperature TV and pressure pv. The temperature of the water in the kettle is measured and transmitted to the controller. The output signal from the controller is used to change the stem position of the valve, which adjusts the flow of steam to the jacket. The major problem in this example is to determine Code 128 Code Set C Scanner In None Using Barcode decoder for Software Control to read, scan read, scan image in Software applications. Create Code 128C In Visual C# Using Barcode printer for VS .NET Control to generate, create Code 128 Code Set A image in VS .NET applications. Temperahurtur~txisuring \ Painting ANSI/AIM Code 128 In VS .NET Using Barcode printer for ASP.NET Control to generate, create ANSI/AIM Code 128 image in ASP.NET applications. Code 128 Code Set C Maker In .NET Using Barcode generation for .NET framework Control to generate, create Code 128 image in .NET framework applications. rc Condensate I ; Code 128 Code Set B Generator In Visual Basic .NET Using Barcode generator for VS .NET Control to generate, create Code128 image in .NET framework applications. Create EAN13 In None Using Barcode creator for Software Control to generate, create GS1  13 image in Software applications. WC I
Encode EAN / UCC  13 In None Using Barcode generation for Software Control to generate, create UCC.EAN  128 image in Software applications. Bar Code Maker In None Using Barcode printer for Software Control to generate, create bar code image in Software applications. FIGURE 211 C4mtml of a steamjacketed ke.ttle.
Data Matrix 2d Barcode Drawer In None Using Barcode drawer for Software Control to generate, create ECC200 image in Software applications. Creating Code 128 Code Set C In None Using Barcode encoder for Software Control to generate, create USS Code 128 image in Software applications. the dynamic characteristics of the kettle. The kettle is actually a nonlinear system, and in order to obtain a linear model a number of simplifying assumptions are needed. Analysis of Kettle The following assumptions are made for the kettle: 1. The heat loss to the atmosphere is negligible. 2. The holdup volume of water in the kettle is constant. 3. The thermal capacity of the kettle wall, which separates steam from water, is negligible compared with that of the water in the kettle. 4. The thermal capacity of the outer jacket wall, adjacent to the surroundings, is finite, and the temperature of this jacket wall is uniform and equal to the steam temperature at any instant. 5. The kettle water is sufficiently agitated to result in a uniform temperature. 6. The flow of heat from the steam to the water in the kettle is described by the expression 4 = U(Z ,  To) where q = flow rate of heat, Btu/(hr)(ft2) U = overall heattransfer coefficient, Btu/(hr)(ft2)( F) TlJ = steam temperature, T To = water temperature, I The overall heattransfer coefficient U is constant, Royal Mail Barcode Encoder In None Using Barcode creation for Software Control to generate, create Royal Mail Barcode image in Software applications. Creating Code 39 Full ASCII In None Using Barcode creation for Microsoft Word Control to generate, create Code 3/9 image in Office Word applications. 320 PROCZESS
Code 39 Full ASCII Printer In Visual C#.NET Using Barcode maker for Visual Studio .NET Control to generate, create ANSI/AIM Code 39 image in VS .NET applications. EAN13 Recognizer In Visual Basic .NET Using Barcode scanner for .NET Control to read, scan read, scan image in VS .NET applications. APPLICATIONS
1D Barcode Generator In Visual Studio .NET Using Barcode creator for ASP.NET Control to generate, create Linear Barcode image in ASP.NET applications. UCC128 Printer In None Using Barcode creator for Word Control to generate, create GS1128 image in Office Word applications. 7. The heat capacities of water and the metal wall am constant. 8. The density of water is constant. 9. The steam in the jacket is saturated. The assumptions listed hem am mote or less arbitrary. For a specific kettle operating under a particular set of conditions, some of these assumptions may require modification. The approach to this problem is to make an energy balance on the water side and another energy balance on the steam side. In order to aid the development of the transfer functions, a schematic diagram of the kettle is shown in Fig. 21.2. The symbols used throughout this analysis am defined as follows: Ti = To = TV = T, = W= w, = w, = m = ml = v = c = Cl = A = t = H, = H, = u, = temperature of inlet water, T temperature of outlet water, F temperature of jacket steam, F temperature of condensate, T flow rate of inlet water, lb/time flow rate of steam, lb/time flow rate of condensate from kettle, lb/time mass of water in kettle, lb mass of jacket wall, lb volume of jacket steam space, ft3 heat capacity of water, Btu/(lb)( F) heat capacity of metal in jacket wall, Btu/(lb)(T) crosssectional area for heat exchange, ft2 time specific enthalpy of steam entering, BtuAb specific enthalpy of condensate leaving, BtuAb specific internal energy of steam in jacket, BtuAb Pv = density of steam in jacket, lb/ft3 GS1128 Creator In None Using Barcode creator for Online Control to generate, create USS128 image in Online applications. Encoding Code 3 Of 9 In None Using Barcode creation for Online Control to generate, create Code 3 of 9 image in Online applications. FlGURE 213
Schematic diagram of kettle.
THEORETICAL
ANALYSIS
OF COMPLEX PROCESSES
An energy balance on the water side gives wC(Ti  To) + UA(T,  To) = rnC% (21.1) InEq.(21.1),thetermsC,U,A,andmareconstants.ThefirstterminEq.(21.1) is nonlinear, since it contains the product of flow rate and temperature, that is, wTi and w To. In order to obtain a transfer function from Eq. (21. l), these nonlinear terms must be linearized. Before continuing the analysis, we shall digress briefly to discuss the general problem of linearization of a function of several variables. Consider a function of two variables, z(x,y). By means of a Taylor series expansion, the function can be expanded* around an operating point x S,yS as follows: z = Z(XstYs) + g IX& (x  x,) + 2 lx,.y, (Y  Ys) + higherorder terms in (X  x,) and (y  yS) The subscript s stands for steady state. In control problems, the operating point (x s,ys), around which the expansion is to be made, is selected at steadystate values of the variables before any disturbance occurs. Linearization of the function z consists of retaining only the linear terms, on the basis that the deviations (x  x J, etc., will be small. Thus, (21.3) z = zs + z&$(x  x,) + Z,,(Y  Ys) where znS and zY, are the partial derivatives in Eq. (21.2). If z is a function of three or more variables, the linearized form is the same as that of Eq. (21.3) with an additional term for each variable. The linearization expressed by Eq. (21.3) may be applied to the terms WTi and wT,, in Eq. (21.1) to obtain (21.2)

