INDUSTRIAL AND E N G I N E E R I N G CHEMISTRY
2084
ratio of Schmidt group to turbulent PDP D ~ P Schmidt group = Schmidt group, dimensionless c
p/pD
uo do = f2kc e / E = turbulent Schmidt group, dimensionless LITERATURE CITED
(4) Bakhmeteff, B. A., “Mechanics of Turbulent Flow,” Princeton,
N. J., Princeton University Press, 1936. (2) Boelter, L. M. K., Martinelli, R. C., and Jonassen, F., Trans. A m . Soc. Mech. Engrs., 63,447 (1941). (3) Chilton, T. H., and Colburn, A. P., IND.ENG.CHEM.,26, 1183 (1Q.74). \ _ _ _ _ ,
(4) Forstall, W., Jr., and Shapiro, A. H., Mass. Inst. Tech., Meteor Rept. 39 (July 1949). ( 5 ) Gilliland, E. R., and Sherwood, T. K., IND.END.CHEM.,26, 516 (1934). (6) Goldstein, S., “Modern Developments in Fluid Mechanics,” London, Oxford University Press, 1938. (7) Linton, W. H., Jr., Massachusetts Instituto of Technology, Sc.D. thesis in chemical engineering, 1949. (8)Lurie, M., and Michailoff, M., IND.ENG.CSEM.,28,345 (1936).
Vol. 42, No. 10
(9) McAdams, W.H.,“Heat Transmission,” 2nd ed., New York McGraw-Hill Book Co., 1942. (10) Maisel, D. S., Massachusetts Institute of Technology, Sc.D. thesis in chemical engineering, 1949. ill) Martinelli, R.C., Trans. A m . SOC.Mech. Engrs., 69,947 (1947). (12) Millar, F.G.,Can. Meteor. Mem., 1, No.2 (1937). ENG.CHEM.,24,726(1932). (13) Murphree, E.V., IND. (14) Pasquill, F.,Proc. Roy. SOC.(London),182A,75 (1943). (15) Pigford, R.L., private communication, 1948. (16) Powell, R.W., Trans. Inst. Chem. Eng. (London),18,26 (1940). (17) Powell, R.W., and Griffiths, E., Trans. Inst. Chem. Engrs. (Lond o n ) , 13, 175 (1935). (18) Reichardt, H.,Angeu. Math. Mech. Forschung, 20, 6, 21 (December 1940); Natl. Advisory Comm. Aeronaut., Tech. Mem. 1047 (September 1943). (19) Sherwood, T. K.,Trans. A m . Inst. Chem. Engrs., 36,817 (1940). (20)Towle, W.L.,and Sherwood, T. K., IND.ENG.CHEM.,31,457 (1939). (21) Ton K4rm4n, Th., Trans. Am. SOC. Mech. Engrs., 61, 705 (1939). (22) Wade, S. H., Trans.Inat. Chem. Engrs. (London),20,1 (1942). (23) Williams, G. C., Massachusetts Institute of Technology, 9c.D. thesis in chemical engineering, 1942. (24) Woertz, 13. B.,and Sherwood, T. K., Trans. Am. Inst. Chew. Engrs., 35, 517 (1939).
RECEIVED March 30, 1950.
A Small Industrial Research Laboratory DESIGN AND CONSTRUCTION K. G . CHESLEY Crossett Lumber Company, Crossett, Ark.
T
HE many new labora T h e details of design and construction of a small laboplant designandconstruction ( l e , 16, 18). None of these tories which have been ratory for industrial research on lumber, pulp, paper, and built within the past few wood chemicals are given. The problem of combining publications, however, haa touched on the specific probyears have directed a conspaces for offices, laboratories, and large scale or pilot Biderable amount of attenplant equipment into a single, attractive building is dislems of designing and constructing a small industrial cussed. The use of wood to reduce costs and give a versation to the subjects of laboratory design and constructile, attractive interior is high-lighted. research laboratory. The tion. Several papers have value of research and development by smaller indusbeen published recently on the design of educational (1, %, 6, 7, 9,11, 14, 16, 28) and industrial organizations and the desirability of providing the proper facilities are recognized. The advantages of designing and contrial laboratories (9,6, 8, 18, 20-22). In addition to this, many structing separate buildings for chemistry laboratories, pilot papers have appeared on the specialized problems of design for plants, offices, and special functions are obvious. This type of radiochemistry laboratories (10, 19, 17,19, 23-26) and on pilot
Figure 1. Building Floor Plan
Figure 2.
Floor Plan for Expansion
October 1950
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
Figure 3.
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Exterior View of Laboratory Building
construction, however, is out of the question for all but large research organizations. A review of the literature not only fails to be of much wistance to a small research organization, but it actually tends to be discouraging. Small industrial rewaroh organizations may have as many different functions to perform as a large one and may be just as desirous of constructing a building whose inside and outside appearance is attractive, as well as functional. The problems encountered in balancing functional and aesthetic considerations with a limited budget are very real. Having recently completed a new industrial research laboratory which accomplishes all the desired objectives in what is believed to be an unusually satisfactory manner, a description of the building ie offered for what help it may be to others. The problem in designing a research laboratory for the Croasett Lumber Company was to provide complete facilities for industrial research on wood products, including lumber, pulp, paper, and wood chemicals. I n thia case, industrial research ia used in a broad sense to include research and development of both a longand short-term nature. The research laboratory ie set up aa a separately operating division of the company and is not concerned with the normal control and technical service activities of the manufacturing divisions. There were iifteen requirements and objectives for the new research building; i t waa to provide: 1. Functional space for precise chemical experimentation and analysis 2. A room for testing under controlled temperature and humidity conditions 3. A room for “wet” processing of fibrous materials 4. A room for hotographic and microscopic work 5. Space for $verse types of pilot plant and large scale experimental equipment 6. Space for storage of supplies and samples 7. Suitable office space 8. Space for a technical library 9. A conferenceroom 10. Rest room facilities eaaily accessible to office, laboratory, and pilot plant workers 11. Comfort cooling for office and laboratory workers during summer months 12. For changing and rearranging laboratory equipment, perviccs, and work space with a minimum of difEculty 13. For future expansion of office, laboratory, and/or pilot plant space 14. A building with a modern architectural exterior and an interior which could be shown with pride to the company’s visiting customers and business associates 15, The foregoing objectives with a reasonably limited amount of money
It is, of course, recognized that small companies cannot afford to duplicate all the expensive facilities found in large laboratories. I n some cases it is cheaper and more satisfactory to “farm out” specific projects in whole or in part to government laboratories, cooperative industry laboratories, research foundations, or university laboratories. In this caw the problem waa to design primarily for the types of projects which are best and most expeditiously handled by an industrial research group that is an integral part of the company. This laboratory was designed for such industrial research and development activities. However, it ia believed that i t would serve for other activities equally well.
FLOOR P‘UN
The first problem to
be oonsideped was, of course, the floor plan. To permit changing and rearranging laboratory e q u i p ment, services, and floor space to take care of program changes and future growth the use of a unit module has been shown desirable. The experience of Rassweler (18) and others indicated that a unit 10 feet wide is practical, and for over-all design purposes a module length of 20 or 22 feet proved best. For budgetary reasons a length of 20 feet waa chosen, giving us a standard module of 10 X 20 feet. The problem of providing one section of the building which could be finished aa an attractive office and library section, one that could be finished in a manner suitable for laboratories, and one to be left with a factory-type interior for larger scale and pilot plant equipment was solved by planning the building as a Tshaped structure. Figure 1 shows the room arrangement adopted. The offices and library comprise one wing of the T, the chemical laboratories one wing, and the pilot plant section another wing. A hall and unit space of 20 feet were provided between the office-laboratory sections and the pilot plant section for two reasons: to permit housing in a central location the rest rooms, and testing and laboratory rooms, which will be commonly used by workers in the office, laboratory, and pilot plant areas; and to permit easy expansion of laboratory and office sections as shown in Figure 2. Further expansion can, of course, be made by extending the ends of the building. The controlled-conditions testing room was placed in the center of the building across the hall from the entrance lobby in order to give an immediate view of an attractive work room and to block off from the lobby the view to the corridor leading to pilot plant and rest room. A large double glaa picture window permits visitors to see into the room without en-
INDUSTRIAL AND ENGINEERING CHEMISTRY
2086
Figure 5 . Figure I..
labby and Secretary’s Officc.
The pulp testing room was placed next to the trmpei,iture-humidity room because of work flow. The equipment room is not shown on the floor plan. This room is located directly above the lobby and the controlled-conditions testing room; this enhances the fagade of the building in keeping with its modern architectural design, which was by The Austin Company, Houston, Tes. To avoid transmission of undesirable vibrations to the building unufiually heavy steel framing was used in this section. In addition the floor in the equipment room was made of pine 2 x 4’6,nailed standing edgewise and covered with built-up asphalt for waterproofing Large compressors are further mounted on Korflund isolators. .MI these precautions have minimized the vibration However, it seems doulhful that the advantages gained in this type construction are worth the cost and effort. Tht, floor plan finally chosen accomplishes all the stated objectiveq :is far as providing space is concerned. The selection of x 20-foot unit module length gives an acceptable and workable unit for Iwth laboratory and office space. The selection of a T-shaped structura permits easy separation of the three different types of interior finishing desired for offices, laboratories, and pilot plant. In the office section, since there is no need for service connections, the widths are not held to the 10-foot interval This permits a 15 X 20 foot office which is adequate for a single private office and can be used as a joint office with desk space for four people. It also permits inclusion of a fireproof vault and secretary’s office in one ronveniently located unit adjacent to and opening into the lobby. By utilizing the hall space in the end room it permits a combination library and conference room 26 X 20 feet. Book shelves along the four walls in this room will accommodate a p proximately 1500 volumes. At one end of the room the shelves and a recessed area containing a blackboard and projection screen are enclosed in cupboards with concealed latch doors in such a manner a8 to give the appearance of a wood paneled wall. The floor area accommodates a large library or conference table for normal everyday use. In addition, using metal folding chairs, the room will accommodate romfortably 40 people for lectures and demonstrations. In the laboratory section, service connections are provided at every 10-foot interval so laboratories may be either 10 X 20 or 20 x 20 feet. In the end laboratory the hall space is utilized for a tet-iiig I t .
Vol. 42, No. 10
Library
Cupboards are concealed with wnod panel doora
large wall-mounted floor to ceiling disti1lat)ion and equipment frame. CONSTRUCTION DETAILS
The building is of a modern architectural design with continuous architecturally projected steel-sash windows in the office and laboratory section. The height of the windows is a cornproink between two schools of thought as to whether windows should or should not provide an outside view to the person working a t his desk. The sill height is 45.5 inches, which gives 46.75 inches from finished floor to window glass. This is just above eye level to a person working at a desk, yet permits an outside view to the workrr when he straightens up in his chair and intentionally looks out. This has met with approval of all workers. The windows on the outside are fitted with a continuous overhead slotted-type sunshade thus eliminating the necessity for blinds or shades on the windows. In the pilot plant wing the windows are industrialtype steel sash. The structure of the building itself is steel framing with nonwall-bearing construction. The exterior walls are of concrete block, which was chosen solely for reasons of economy over either brick or structur~lconcrete. The interior walls, with the exceg t8ionof the dividing wall between the laboratory and pilot plant and the fireproof vault walls, are of wood-stud construction. This again has been found to be a satisfactory compromise between the movable and stationary partition schools which have received so much attention recently (4). Wood-stud walls are easy and economical to construct with ordinarily available labor. They can be finished in a great variety of ways. And, since the building is nonwall-bearing, they can be easily torn out and moved if there is any occasion to do so. Proponents of masonry, metal, Transite, and other building materials have caused enpineers to overlook and underevaluate the advantages of one of the oldest and most extensively used methods of wall construction. Wood-stud interior wall construction is particularly suitable for small industrial research laboratories where cost and flexibility are of equal importance. The ceiling heights are 9 feet 6 inches in the offices and laboratories, and 8 feet in the halls. The full roof height of 13 feet 9 inches is used in the pilot plant. The roof is a wood deck struc-
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
Lure aupporled on aleel iuulh& joiata rrrd covered with built-up
aaphslt and gravel. Tho width of the corridors is 5 feet 9 inches. Thia narrow corridor in passiblo beeam sll corridor doon open to the inaide. For sirfety in the laboratory Section them ia an extrs t Plant
2088
I N D U S T R I A L ANI) E N G I N E E R I N G C H E M I S T R Y AIR CONDITIONING AND OTHER SERVICES
The entire office and laboratory sections are air conditioned with a centrally controlled circulating air system. The temperature is controlled within close limits by automatic steam coils or cooling coils in the air duct. The humidity is controlled between 40 and 60% relative humidity by a water spray in the air duct to add moisture and a relative-humidity control to start the refrigerating compressor at the upper limit. When the refrigerating unit is operating to reduce humidity the cooling coils and heating coils may be operating simultaneously. The air ducts and all service piping are carried in the space between the suspended ceiling and the roof. Large hoods are provided in the laboratories, Roof ventilating fans service the hoods and ceiling vents in the toilets. To compensate for the air exhausted from the hoods and rest rooms the air-conditioning system provides for the admiasion of 33% fresh air. Heat in the building is supplied by an automatic, low pressure gas-fired boiler. Electricity is s u p plied to the building a t 2300 volts and is converted to either 110, 220, or 440 volts for laboratory use. Thus, the services provided in the laboratory and pilot plant areas where needed are gas, cold water, hot water, steam, air, and IlO-, 220-, or 440-volt electricity. I n the laboratory area all services are carried over the ceiling and in the wood stud walls. There is no exposed piping. In the end laboratmy the services are carried to the center desk and wall in a covered pipe trench under the floor. Safety showers are provided in each laboratory and the whole building is protected from fire by a complete sprinkler system. The controlled-conditions testing room is kept a t 73' F. * 8.5' and 50 * 2% relative humidity by means of a separate air-conditioning system also located in the upstairs equipment room. Laboratory furniture, benches, and tables are made of standard units all constructed of hardwoods.
Vol. 42, No. 10
The building as finally constructed accomplishes all the desired objectives. Choice of proper unit module, floor plan, architectural treatment, and materials of construction has made it p o s sible to build a small industrial research laboratory that compares favorably with the larger and more elaborate laboratories. LITERATURE CITED
Adams, C. S., IND.ENQ.CHEM., 39,457-61 (1947). Bailar, J. C., Jr., J . C h m . Education, 24, 327-8 (1947). Beach, D. M., TND. ENQ.CHEM., 39,448-53 (1947). Bown, Ralph, and Rose, R. S., Jr., C h a . Inds., 65, 352-3 (September 1949). (5) Cairns. R. W., IND.ENQ.CHEM., 39,440-3 (1947). (6) Case, L. O., J . Chem. Education, 24, 338-40 (1947). (7) Cavelti, J. E., Ibid., 24,324-7 (1947). ( 8 ) Darby, G. M., Roberts, E. J., and Grothe, J. D., IND.ENQ. CHEM.,39,453-6 (1947). (9) Dowswell, H. R., J . Chem. Education, 24,350-3 (1947). (10) Garden, N. B., IND.ENQ.CHEM., 41, 237-8 (1949). (11) Hard, C. D., J.Chem. Education, 24,333-7 (1947). (12) Japs, A. B., IND.ENQ.C H ~ M40, . , 2021-7 (1948). (13) Levy, H. A., Ibid., 41,248-50 (1949). (14) Lewis, H. F., J . Chem. Education, 24,320-3 (1947). (15) Lynch, A. A., IND.ENG.CHEM.,40, 2011-13 (1948). (16) Marvin, G. G., J . Chem. Education, 24,329-32 (1947). (17) Norris, W. P., IND.ENG.CHEM.,41, 231-2 (1949). (18) Rassweiler, C. F., J.Chem. Education, 24, 346-50 (1947). (19) Rice, C. N., IND.ENG.CHEM., 41, 244-8 (1949). (20) Rochow, E. G . , Chemistry &Industry, 61,986-7 (1947). (21) Sjorgren, C. N., and Deal, J. M., IND.ENG.CHEM., 41, 1657-64 (1) (2) (3) (4)
(1949).
(22) (23) (24) (25) (26) (27) (28)
Smith, P. C., Ibid., 39, 440-7 (1947). Swarthout, J. A., Ibid., 41, 227-8 (1949). Ibid., pp. 233-6.
Thompkins, P. C., and Levi, H. A., Ibid., 41, 228-31 (1949). Ibid., pp. 239-44. Van Arsdel, W. B., and Eskew, R. K., Ibid., 40,2014-20 (1948). Weber, H. C., J . Chem. Education, 24,341-6 (1947).
RBCEIVED March 8. 1950.
Deasphalting Crude Residuum for Catalytic Cracker Commercial Production Using Horizontal Settlers and Propane Solvent E. CLARENCE ODEN AND EDWARD L. FORET Cities Service Refining Corporation, Lake Charles, La. D a t a obtained on a commercial propane deasphalting unit for approximately 4 years of operation are presented. An average of 20,000 barrels per day of crude residuum was charged to the propane deasphalting unit to produce approximately 75 volume % catalytic cracker feed stock and 25% asphalt. Mixed base Gulf Coastal crudes varying from sweet to sour were processed on topping units at coil outlets varying from 650" to 740' F. to produce feed stock for the deasphalting unit. The data include curves correlating the effect of operating variables on the quantity and quality of products produced. Methods of predicting yields and quality of products based on the typical analyses of feed stock are presented in the form of graphs. The degree of purity of the propane solvent, propane to oil ratios and their effect on yields and quality of product, methods of propane recovery, and losses normally incurred are discussed. Included in the discussion are a description of the unit, the operating limitations, flexibility of operations, capacity limitations, maintenance requirements,
service factor, and operating labor requirements. A process flow sheet is included with typical operating conditions that will be helpful to process engineers,
T
HERE are two systems, vacuum distillation and propane
deasphalting, in commercial use for removing valuable heavy gas oils from petroleum residues. These systems are very competitive, based on the number of commercial installations of each. This report is being presented principally to present data and correlations useful for predicting yields of asphalt and deasphalted gas oil (the valuable heavy gm oil extracted from asphaltic petroleum residues) and quantities and qualities when produced from petroleum residues by means of propane extraction. The propane deasphalting system is believed to have some advantages over the more common vacuum distillation system of removing heavy gas oil from petroleum residues. Pilot plant data obtained prior to and during World War I1 indicated that a propane deasphalting unit could compete with
