Lang factor method

Since the original factors were developed by HJ. Lang, the method is known as the Lang Factor method. However, through the years, contractors and owners have developed their own factors to reflect their particular experiences. 

The purchased cost of an item of equipment, free on board (FOB) is quoted by a supplier, and may be multiplied by a factor of 1.1 to give the approximate delivered cost. The factorial methods for estimating the total installed cost of a process plant are based on a combination of materials, labor, and overhead cost components. The fixed capital cost, C(-p, of a plant based on design can be estimated using the Lang Factor method [14] given by the equation... 

Preliminary Estimate Methods A refinement of the Lang factor method is the Hand method. The Hand factors are found in Table... 

The factor, 1.18, in Eq. (16.11) covers a contingency of 15% and a contractor fee of 3%. As with the Lang-factor method, the working capital can be estimated at 15% of the total capital investment, which is equivalent to 17.6% of the total permanent investment, or it can be estimated in detail by the method in Section 17.3. 

Land, depreciating, 280-281 Lang Factor method, 191-192 Langmuir-Hinshelwood kinetics, 704 L-aspartic acid production bacteria, filtering, 1014 continuous crystallizers, 1014 continuous filtration, 1014 filtering, 1014 intermediate storage, 1014 ion exchange column, 1014 overview, 1007... 

The cost of a unit is then obtained from Figure 9-4. To obtain the cost of the plant this figure needs to be multiplied by the number of units, a factor (1.33) to account for utilities and general facilities, and the current or projected value of the Engineering News Record Chemical Cost Index. The accuracy of this method is unknown but should be better than the Lang factor and not as good as Miller s. 

Lang method The Lang factor for a fluid processing unit starting with purchased equipment costs is 5.0. Therefore, fixed capital investment is 2,820,000 X 5.0 X 1.035 X 1.040 = 15,177,000. 

Brown developed guidelines for the preparation of order-of-magni-tude and study capital cost estimates based upon the Lang and Hand methods. Brown modified Lang and Hand methods for materials of construction, instrumentation, and location factors. He found that the modified Hand and Garrett module factor methods gave results within 3.5 percent. 

METHOD D LANG FACTORS FOR APPROXIMATION OF CAPITAL INVESTMENT. This technique, proposed originally by Langf and used quite frequently to obtain order-of-magnitude cost estimates, recognizes that the cost of a... 

Method 2. Study Estimate (Based on the Overall Factor Method of Lang, 1947a,b, and 1948)... 

For a quick estimation of the total capital investment the overall factor method developed by Lang (1948) is helpftil. The costs of each piece of equipment is estimated and summed and, finally, multiplied with the overall factor. Typically, the total costs are four times higher than the main items (Table 5.5.1). Values of this overall factor given in the literature vary in the range 3-6. According to Lang (1948),... 

The modelling of gas permeation has been applied by several authors in the qualitative characterisation of porous structures of ceramic membranes [132-138]. Concerning the difficult case of gas transport analysis in microporous membranes, we have to notice the extensive works of A.B. Shelekhin et al. on glass membranes [139,14] as well as those more recent of R.S.A. de Lange et al. on sol-gel derived molecular sieve membranes [137,138]. The influence of errors in measured variables on the reliability of membrane structural parameters have been discussed in [136]. The accuracy of experimental data and the mutual relation between the resistance to gas flow of the separation layer and of the support are the limitations for the application of the permeation method. The interpretation of flux data must be further considered in heterogeneous media due to the effects of pore size distribution and pore connectivity. This can be conveniently done in terms of structure factors [5]. Furthermore the adsorption of gas is often considered as negligible in simple kinetic theories. Application of flow methods should always be critically examined with this in mind. 

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