Production flow analysis

To form a production family, one has to consider the manufacturing method. The first well-known production family formation method was called production flow analysis (Burbidge 1975). First, production flows, or process sequences, for aU parts are collected. An incidence matrix with columns... 

Flow analysis production flow analysis (i.e., throughput). 

Production Flow Analysis The study of the routing of a part, component, or system through the various machines and workplaces and the operations it undergoes in a manufacturing or integration facility. 

King, J. R. Machine Component Grouping in Production Flow Analysis An Approach Using a Rank Order Clustering Algorithm. Int J of Prod Res. 18 (2) (1980 ) 213-232. 

PCs all have one thing in common. They monitor the process variables, compare them to values known to be acceptable, and make appropriate corrections without operator intervention. The acceptable range of values can be determined by using melt flow analysis software and/or trial and error when the machine is first starting its production. Using the software approach, the acceptable process values are known before the mold or die is ever built. It should be noted that none of the PC solutions address the problem of the lack of skilled setup people. Most of the PC systems available today are rather complex and require skilled people to use them efficiently or at least start up the line. 

An essential method used in this work is quick ampoule sampling of volatiles.8-9 Small samples of the gaseous reactor effluent (e.g., 1 ml) are recovered in glass ampoules for later analysis. The capillary end of the evacuated ampoule is inserted into the product flow. The capillary tip is broken and the ampoule filled... 

Figure 3.1 shows a typical laboratory flow reactor for the study of catalytic kinetics. A gas chromatograph (GC, lower shelf) and a flow meter allow the complete analysis of samples of product gas (analysis time is typically several minutes), and the determination of the molar flow rate of various species out of the reactor (R) contained in a furnace. A mass spectrometer (MS, upper shelf) allows real-time analysis of the product gas sampled just below the catalyst charge and can follow rapid changes in rate. Automated versions of such reactor assemblies are commercially available. 

A hot tap shall not be considered a routine procedure, but shall be used only when there is no practical alternative. A hot-tap thermal analysis program shall be used to review, analyze, and provide the product flow and weld parameters during the hot tap. Examples of conditions where hot tapping is not permitted are as follows ... 

Fixed capital investment Working capital requirements Total capital investment Total manufacturing expense Packaging and in-plant expense Total product expense General overhead expense Total operating expense Marketing data Cash flow analysis Project profitability Sensitivity analysis Uncertainty analysis... 

Another study used a life-cycle perspective to model the quantities of engineered nanoparticles released into the environment [8]. The ENMs nano-Ag, - 2, and carbon nanotubes (CNTs) were studied. The quantification was based on a substance flow analysis from products to air, soil, and water in Switzerland. The life-cycle of the nanoproducts formed the basis for assessing the mass flows of the ENMs from the products to the environment during the use phase and disposal. The following... 

A discounted cash flow analysis is performed on those capital cost and production cost figures reported in Ref. PT1 (plant capacity of 280 tonne of 60% nitric acid). Although the plant cost data relates to a US plant, the figures still indicate the trend. 

Inspecting Equation (5.29), we notice that three of the state variables (namely, Mr, My, and Ml) are material holdups, which act as integrators and render the system open-loop unstable. Our initial focus will therefore be a pseudo-open loop analysis consisting of simulating the model in Equation (5.29) after the holdup of the reactor, and the vapor and liquid holdup in the condenser, have been stabilized. This task is accomplished by defining the reactor effluent, recycle, and liquid-product flow rates as functions of Mr, My, and Ml via appropriate control laws (specifically, via the proportional controllers (5.42) and (5.48), as discussed later in this section). With this primary control structure in place, we carried out a simulation using initial conditions that were slightly perturbed from the steady-state values in Table 5.1. 

To determine the required selling price of hydrogen, a cash flow analysis was performed using an after-tax internal rate of return (IRR) of 15%. Other major assumptions used in the analysis were equity financing for a 20 year plant life including two years of construction time, a 90% on-stream factor with 50% plant capacity in first year of production, 30% of capital investment is spent in the first year and 70% in the second year, a tax rate of 37%, and ten year straight-line depreciation. 

Several reactor types have been described [5, 7, 11, 12, 24-26]. They depend mainly on the type of reaction system that is investigated gas-solid (GS), liquid-solid (LS), gas-liquid-solid (GLS), liquid (L) and gas-liquid (GL) systems. The first three arc intended for solid or immobilized catalysts, whereas the last two refer to homogeneously catalyzed reactions. Unless unavoidable, the presence of two reaction phases (gas and liquid) should be avoided as far as possible for the case of data interpretation and experimentation. Premixing and saturation of the liquid phase with gas can be an alternative in this case. In homogenously catalyzed reactions continuous flow systems arc rarely encountered, since the catalyst also leaves the reactor with the product flow. So, fresh catalyst has to be fed in continuously, unless it has been immobilized somehow. One must be sure that in the analysis samples taken from the reactor contents or product stream that the catalyst docs not further affect the composition. Solid catalysts arc also to be fed continuously in rapidly deactivating systems, as in fluid catalytic cracking (FCC). 

---