Nomenclature For Chapter 9
a length of time in actual use, years d annual depreciation, year f fixed-percentage or declining-balance factor i annual interest rate expressed as a fraction, percent 100 n service life, years R uniform annual payments made in an ordinary annuity, dollars V original value of a property at start of service-life period, completely installed and ready for use, dollars Va asset or book value, dollars V salvage value of property at end of service life, dollars PROBLEMS 1. A reactor of special...
A Slurry Containing 1 Lb Of Filterable Solids Per 10 Lb Of Liquid Is Being
The density of the plummet in the rotameter is 497 lb ft3. 9. A spherical carbon-steel storage tank has an inside diameter of 30 ft. All joints are butt-welded with backing strip. If the tank is to be used at a working pressure of 30 psig and a temperature of 80 F, estimate the necessary wall thickness. No corrosion allowance is necessary. 10. Estimate the cost of the steel for the spherical storage tank in the preceding problem if the steel sheet costs 0.25 per pound. On the basis of the data...
Figure 23
Qualitative flow diagram for the manufacture of sodium dodecylbenzene sulfonate. After removal of aluminum chloride sludge, the reaction mixture is fractionated to recover excess benzene which is recycled to the reaction vessel , a light alkylaryl hydrocarbon, dodecylbenzene, and a heavy alkylaryl hydrocarbon. Sulfonation of the dodecylbenzene may be carried out continuously or batch-wise under a variety of operating conditions using sulfuric acid 100 percent , oleum usually 20 percent SO, , or...
Nomenclature For Chapter 15
a, constant in Eq. 29 for evaluating outside film coefficient of heat transfer, dimensionless A area of heat transfer, ft2 subscripts m designates mean area subscript 0 designates outside area subscript designates film area b0 constant in Eq. 32 for evaluating shell-side friction factor, dimension-less Bj correction factor in Eq. 30 to account for friction due to sudden contraction, sudden expansion, and reversal of flow direction, dimen-sionless Ba correction factor in Eq. 31 to account for...
Relative Merits Of Plate And Packed Towers
The choice between use of a plate tower or a packed tower for a given mass-transfer operation should, theoretically, be based on a detailed cost analysis for the two types of contactors. Thus, the optimum economic design for each type would be developed in detail, and the final choice would be based on a consideration of costs and profits at the optimum conditions. In many cases, however, the decision can be made on the basis of a qualitative analysis of the relative advantages and...
Problem 1 Cost for Hydrogen Recovery by ActivatedCarbon Adsorption Process
What is the cost, as cents per 1000 ft3 at SC of 95 mol H2, for recovering hydrogen of 95 mol purity from 10 million ft3 at SC of gaseous feed per day if the following conditions apply Feed composition by volume 72.5 percent H2 and 27.5 percent CH,. A hydrogen-recovery method based on selective adsorption by activated carbon will be used. For the carbon adsorption, three separate beds will be needed so that one bed can be in continuous use while the other two are being desorbed or reactivated....
Table 11
Basic data and assumptions for reactor-design example dealing with optimization of yields for benzene chlorinator Data for chlorobenzene reactor-design example The feed rate of the dry chlorine is 1.4 lb mole of chlorine h lb mole of initial benzene charge . The following rate constants are estimated values for the catalyst used at 55 C assumed for this problem Jt, 510 lb mol ft3 -' h -' jfc, 64 lb mol ft3 -1 h _l k 2.1 lb mol ft3 1 h -' There is negligible liquid or vapor holdup in the reflux...
Problem 11 Operating Time for Catalytic Polymerization Reactor to Reach Minimum
A catalytic polymerization plant is to operate continuously with a special catalyst with properties and results as given below. Under the following specified operating conditions, how many days could each reactor remain on stream from the time of fresh catalyst age zero catalyst charge until the percent propylene conversion through the catalyst bed drops to 93.75 percent. What will the pressure drop across the catalyst bed be at that time How often should a new recharged unit come on stream if...
Problem 2 AdsorptionTower Design for Hydrogen Purification by Activated Carbon
Your plant is producing 10 million ft3 measured at SC per day of a gas containing 72.5 vol H2 and 27.5 vol CH,. It is proposed to pass this gas through activated carbon to obtain a product gas containing 95 vol H,. The activated carbon shows a preferential selective adsorption of the CH,. An adsorption-desorption-regeneration cycle using three fixed beds will be used. One bed will be regenerated and purged over an 8-h period. During this period, the other two beds will be on alternate 1-h...
Problem 3 Design of Sulfur Dioxide Absorber
You are a member of a group of design engineers designing equipment for the recovery of SO, from stack gases. The group leader has asked you to determine the optimum size of the SO, absorption tower. Specifically, he has asked you to determine the height and cross-sectional area of the optimum absorption tower and to present your recommendations in the form of a formal report. Your group has held several meetings to discuss the proposed overall design. Following is a list of conditions,...
Problem 15 Cost For Producing Butadiene Sulfonef
A design has been completed for the production of butadiene sulfone from 1,3 butadiene and sulfur dioxide. Based on the following results from the completed design and the basic company requirements as listed, determine what the selling price of the butadiene sulfone product should be as dollars per pound based on A The case where the company demands a 20 percent continuous nominal interest rate of return after taxes on any investment i.e., profitability index r is 20 percent . B The case where...
Info Tzr
7. Capacity of Plant for Producing Acetone from Isopropanol 841 8. Equipment Design for the Production of Acetone from Isopropanol 842 9. Quick-Estimate Design of Debutanizer 844 10. Economic Analysis of Formaldehyde-Pentaerythritol Plant 846 11. Operating Time for Catalytic Polymerization Reactor to Reach Minimum Allowable Conversion 848 12. Sizing and Costing of Multicomponent Distillation Column for Biphenyl Recovery Unit 849 13. Design of Reactor for Coal Conversion to Nonpolluting Fuel Oil...
Allowable Vapor Velocity
The limiting vapor velocity for practical operation of a packed tower is set by the flooding point. As in the case of towers utilizing finite-stage contactors, the design engineer can determine the necessary diameter of a packed tower on the basis of the limiting vapor velocity. The maximum allowable vapor velocity is commonly designated as the superficial velocity at the flooding conditions. Because the tower operation may become unstable as the flooding point is approached, the design value...
Table21
Typical labor requirements for process equipment 3 4 5 6 8 1 0 20 30 50 100 Plont capacity, tons of product day
C4H8 C4H10 CgHlg
The unit is to produce product alkylate at a rate of 1700 m3 day 10,693 bbl day . The yield is 1.72 m3 alkylate per m3 butylene consumed 1.10 m3 of isobutane are consumed per m3 butylene consumed. The reactor effluent is to contain 75 vol isobutane. It may be assumed that the recycle is pure isobutane and that propane, alkylate, and n-butane are completely recovered as pure products in the columns. Propane and n-butane do not react. Under these conditions, a How much of each of the feed streams...
The General Process
The process is to be carried out at a sufficiently low temperature for the biological substances to remain essentially unchanged, except for the removal of oil and water. The top temperature limit for the insoluble materials and the oils The raw fish as received are ground and delivered to a slurry tank where the pulped material is agitated. The slurry is then sent to cookers where the oil is extracted by a suitable solvent and the water is evaporated along with the solvent. The evolved vapors...
Info Kwb
_ inflow rate of i J -outflow rate of i J where Xie final conversion based on fraction of entering material i converted total volume of the back-mix reactor In case the feed reactant material ' in Ft on which the conversion is based enters the reactor with part of the material already converted, the initial or entering conversion becomes Xio instead of zero as was the case for 'Eq. 64 . Under these conditions, Eq. 64 assumes the more general form of It is normally necessary to use a simplified...
Problem 18 Recycle Compressor Power Cost for Methanation Unit of SNG Plantf
In the design of a substitute natural gas SNG plant for producing SNG from coal, you have been asked to determine the power cost, in dollars per year, for compressing the recycle gas for the bulk methanation portion of the plant with a single bulk methanator using electric-motor-driven compressors of conventional centrifugal type with adiabatic efficiency of 75 percent and maximum compression ratio per stage of 3.5. Following are the special conditions for your design in this preliminary...
Problem 5 Economic Analysis of Chlorine Recovery Systemf
The data shown in Table 6 have been obtained for a chlorine recovery system in which all values have been determined at the optimum operating conditions of retention time and recycle rates. Determine the following 1. The percent Cl2 in exit gas at break-even point. 2. The maximum net annual savings and percent Cl2 in exit gas where it oocurs. Total annual operating costs fixed costs, production costs, overhead, etc. , dollars Gross annual savings by using process, dollars
Plot The 1985 Purchased Cost Of The Shell-and-tube Heat Exchanger
1. The purchased cost of a shell-and-tube heat exchanger floating head and carbon-steel tubes with 100 ft2 of heating surface was 3000 in 1980. What will be the purchased cost of a similar heat exchanger with 200 ft2 of heating surface in 1980 if the purchased-cost-capacity exponent is 0.60 for surface area ranging from 100 to 400 ft2 If the purchased-cost-capacity exponent for this type of exchanger is 0.81 for surface areas ranging from 400 to 2000 ft2, what will be the purchased cost of a...
Patent Considerations
A patent is essentially a contract between an inventor and the public. In consideration of full disclosure of the invention to the public, the patentee is given exclusive rights to control the use and practice of the invention. A patent gives the holder the power to prevent others from using or practicing the invention for a period of 17 years from the date of granting. In contrast, trade secrets and certain types of confidential disclosures can receive protection under common-law rights only...
Info Jdh
If a respirator contains 100 g of this charcoal and breakthrough occurs when 82 percent of the adsorbent is saturated, how long can the respirator be used in a dichloropropane concentration of 750 ppm when the temperature is 80 F Assume that the flow rate of contaminated air through the adsorbent is 45 I min. The molar volume of the dichloropropane may be assumed to be 100 cm3 g mole. Determine which of the following liquids used in the laboratory could form flammable air-vapor mixtures if...
Problems Skh
1. It is desired to have 9000 available 12 years from now. If 5000 is available for investment at the present time, what discrete annual rate of compound interest on the investment would be necessary to give the desired amount 2. What will be the total amount available 10 years from now if 2000 is deposited at the present time with nominal interest at the rate of 6 percent compounded semiannually 3. An original loan of 2000 was made at 6 percent simple interest per year for 4 years. At the end...
Perpetuities And Capitalized Costs
A perpetuity is an annuity in which the periodic payments continue indefinitely. This type of annuity is of particular interest to engineers, for in some cases they may desire to determine a total cost for a piece of equipment or other asset under conditions which permit the asset to be replaced perpetually without considering inflation or deflation. Consider the example in which the original cost of a certain piece of equipment is 12,000. The useful-life period is 10 years, and the scrap value...
Figure 57
In transferring the cost of chemical A to the inventory and cost-of-sales accounts, there is a question as to what price applies for chemical A. There are three basic methods for handling problems of this type. 1. The current-average method. The average price of all the inventory on hand at the time of delivery or use is employed in this method. In the preceding example, the current-average price for chemical A would be 0.0380 per pound. 2. The first-in-first-out or fifo method. This method...
Cost Indexes
Most cost data which are available for immediate use in a preliminary or predesign estimate are based on conditions at some time in the past. Because prices may change considerably with time due to changes in economic conditions, some method must be used for updating cost data applicable at a past date to costs that are representative of conditions at a later time. This can be done by the use of cost indexes. A cost index is merely an index value for a given point in time showing the cost at...
Plant Overhead Costs
The costs considered in the preceding sections are directly related with the production operation. In addition, however, many other expenses are always involved if the complete plant is to function as an efficient unit. The expenditures required for routine plant services are included in plant-overhead costs. Nonmanufacturing machinery, equipment, and buildings are necessary for many of the general plant services, and the fixed charges and direct costs for these items are part of the...
Problems
1. Using Chemical Abstracts as a basis, list the original source, title, author, and brief abstract of three published articles dealing with three different processes for producing formaldehyde. 2. Prepare, in the form of a flow sheet, an outline showing the sequence of steps in the complete development of a plant for producing formaldehyde. A detailed analysis of the points to be considered at each step should be included. The outline should take the project from the initial idea to the stage...
Exposure Evaluation
If health hazards are to be controlled, they must be recognized and evaluated. A logical place to initiate the process of health-hazard recognition is with a total inventory of all materials present in the various stages of the process. Even when materials are present in only trace amounts, there is more than enough present to produce a potentially hazardous situation in a localized work area. Generally, feedstocks and products of a process are well known. Intermediates, by-products, and waste...
Loss Prevention
The phrase loss prevention in the chemical industry is an insurance term where the loss represents the financial loss associated with an accident. This loss not only represents the cost of repairing or replacing the damaged facility and taking care of all damage claims, but also includes the loss of earnings from lost production during the repair period and any associated lost sales opportunities. As noted in the previous section, there are numerous hazards associated with chemical processing....
Factors Affecting Profitability Of Investments
A major function of the directors of a manufacturing firm is to maximize the long-term profit to the owners or the stockholders. A decision to invest in fixed facilities carries with it the burden of continuing interest, insurance, taxes, depreciation, manufacturing costs, etc., and also reduces the fluidity of the company's future actions. Capital-investment decisions, therefore, must be made with great care. Chapters 7 and 10 present guidelines for making these capital-investment decisions....