RESEARCH LABORATORY OF THE NATIONAL LEAD COMPANY-TITANIUM DIVISION WALTER W. PLECHNER AND SANDFORD S. COLE, National Lead Company, Sayreville, N. J.
T
in red and black, which is giving excellent service in laboratories as well as in offices. Windows are of the casement type in metal frames and are provided with aluminum wire screens and Venetian blinds.
HE Research Laboratory of the National Lead Com-
pany-Titanium Division (Titanium Pigment Corporation) transferred from an old building in Brooklyn, N. Y., to a new building specially provided for it in Sayreville, N. J., in 1935. The laboratory was designed under the supervision of J. L. Turner, director of research. Additions to the laboratory facilities made necessary by expansion of the research work were completed in 1938. This laboratory is devoted to the chemistry and technology of titanium, with particular emphasis upon the titanium pigments. This specialized field of chemical engineering and applied science required certain features in design and construction which are not common to all research laboratories. The laboratories have been designed to permit the investigation of any problem using quantities of materials from purely theoretical small laboratory scale to large-scale laboratory and finally to pilot-plant-scale amounts. The basic plan of the research laboratories proper was intended to furnish an individual laboratory for each senior research scientist. The building housing the laboratories is also occupied by the administrative, engineering, and accounting offices of the titanium pigment plant of the National Lead CompanyTitanium Division. Its architecture is along conservative modern lines, providing a maximum amount of window space. The construction is of reinforced concrete. Exterior walls are brick, floors concrete, and interior walls of hollow tile having a sand-finish cement plaster. The ceilings are hung metal lath with a smooth plaster finish. The side walls above the dado are painted light green and the dado dark green, while the ceiling is white. This color combination, in a “Titanox”-C flat paint, is very satisfactory with regard to both illumination and permanence of color. The choice of green paint for the laboratory walls was based upon the desire to obtain high reflectance4 e., maximum brightness in the rooms-without the glare which might be caused by white walls and a t the same time have as little interference as possible with visual grading of the tone of white pigments, which is such an important part of the work of this laboratory. The floors are laid with asphalt-bonded asbestos tile
Layout of Laboratories The individual laboratories are approximately 19 x 19 feet, although some of the rooms are larger in order to improve their adaptation to certain types of work. Each chemical laboratory is furnished with a wall bench 17 feet long X 2 feet 6 inches wide and a center table 15 feet long X 4 feet wide with a sink a t one end. A cabinet for storage of reagents and glassware, an illuminated titration table, and a desk and chairs complete the furnishings. The oak furniture is of flush construction throughout, coated with a special acid- and solvent-resistant finish. The sink and table topp are Alberene stone and the drainage system is constructed with Duriron. The hoods are built of impregnated Transite, each equipped with a separate ventilating fan and duct to the roof. The hoods in the research laboratories are 5 feet long with a 3foot front opening provided with a glass sash which may be lowered to close the hood entirely if so desired. The over-all height is 5 feet with the top chamfered above the door opening. Exhaust is a t the top of the hood only. The fans are of the squirrel-cage type having a speed of 850 revolutions per minute and a free volume delivery of 800 cubic feet per minute. The ducts connecting the fans to the hoods and exhaust ducts are sheet iron homogenified with lead, which has given satisfactory protection against sulfuric acid corrosion. These hoods have proved entirely adequate for the handling of the sulfur trioxide and sulfuric acid fumes which accompany much of the laboratory work. The only maintenance required has been occasional cleaning of the fans, which tend to accumulate ammonium sulfate upon the blades. Service lines are provided on both the side tables and center tables. These comprise vacuum, compressed air, gas, hot and cold water, steam, and 110-volt alternating and direct current. The useful precaution of having traps 299
300
INDUSTRIAL AND ENGINEERING CHEMISTRY
in each laboratory vacuum line has prevented any general stoppage in the main vacuum line and pumps. The traps consist of 4-liter suction-type flasks (without a side opening) placed in the line going to the main service line. This gives an adequate trap for any overflow from the ordinary laboratory suction flasks. The tables contain drain bowls connecting to the sewer. Outlets for 220-volt alternating current are provided in the side walls for any work requiring the higher voltage. A special feature of each chemical laboratory is the permanently mounted group of stirrers. A line shaft driven by a 0.5-horsepower motor drives a group of four to six stirrer heads by means of belts and pulleys, permitting selection of desired speeds. The shaft is supported in ball-bearing pillow-blocks running in grease. The stirrer head has two thrust bearings to which the stirrer shaft is fastened by means of setscrews. Glass stirrers are usually connected to the stirrer shaft by means of rubber tubing; metal or wood stirrers by means of a collar and setscrews. Permanently mounted black-iron rods between the stirrer heads furnish the supports for the usual clamps and fasteners for holding apparatus. Agitation in apparatus from the size of a 250-ml. beaker or flask to a 5-gallon crock is conveniently accomplished with this setup. A separate room for all the balances has reduced corrosion and dust problems which had been encountered in the old laboratory where the balances were in the open rooms. A furnace room with hoods is provided for the various heat treatments and calcining schedules required in pigment research. These hoods also have individual fans to remove the gases and heat from the furnaces. Fans are of the squirrel cage type similar to the smaller hoods but have a speed of 1140 revolutions per minute and a free volume of 2050 cubic feet per minute. Both electric and gas-fired furnaces are used and provide either stationary or rotary calcination. The electric furnaces are automatically controlled. The
VOL. 11, NO. 5
control equipment for the furnaces is mounted in the hall outside the furnace room for more convenient observation of the temperatures of the furnaces. By this arrangement the controls also remain a t a more nearly constant temperature, thereby increasing their accuracy and life. A useful feature of the electrical heating system is the introduction of a variable shunt resistance in the furnace circuit for the partial lowering of primary voltage to the transformers. This has greatly reduced the surge usually found when the circuit is completely broken by the automatic control.
- -L
log" 6.
SPINDLE BRACKET STIRRER HEADS
STIRRER ASSEMBLY
The physical laboratory comprises two laboratory rooms, a projection room, and a dark room. Its equipment provides for microscopic examination, testing of brightness, hiding power, and like physical characteristics of pigments and paints. The microscopic equipment is provided with quartz optics as well as glass, so that it is possible to resolve particles to approximately 0.2 to 0.3 micron. Projection of the particles on a screen a t 8000 to 12,000 diameters allows the measurement and counting of fine particles. Centrifugal equipment has been adapted to the problem of the estimation of particles within and below the above ranges by accelerated sedimentation. The pigment- and paint-testing laboratories were designed for greater flexibility and therefore free-standing tables were used wherever possible. The table tops are covered with stainless steel. Pigment and paint which may have spilled on the surface are easily removed. The tinting strength and color laboratory was placed at a northern exposure so as to
301
minute, which maintains the room under a positive static pressure of about , 0.5 inch of water. A separate fan is provided Furnace for exhausting fumes from 5KVA the arc. Both fans are placed outside the buildTherming in order that they C couple may be serviced without entering the room, and to reduce any vibration and noise to a minimum. Cooling of the wash water for washing spectrographic plates is provided; water at 10" C. is available. The cooling unit also permits storage of the plates over long periods of time without material change in sensitivity. The cooling unit is an adaptation of a WIRINGDIAGRAM FOR ELECTRIC MUFFLECONTROL standard water-cooled refrigeration outfit of 0.5obtain a diffuse light. The installation of filtered air equiphorsepower capacity. The water passes through a &gallon ment in this and the paint-testing laboratory was found to be tank which is closely wrapped with cooling coils, and has desirable in order to lower the dust occurring a t a ground level. adequate cooling capacity to drop the temperature of water The paint-testing laboratory is equipped with a roller mill, 20" F. at a rate of 20 gallons per hour. The spectrograph is spray booth, baking oven, and testing apparatus, so that the a large Bausch & Lomb Littrow-type instrument. X-ray complete characteristics of a finished pigment or paint may equipment, in one of the chemical laboratories, finds an be ascertained in all types of formulations. important part in the research program of the laboratory. A constant-humidity and -temperature room allows the storage of pigments and paints and their examination under controlled conditions if desired. The constant-temperature room is 8 feet wide X 10 feet 6 inches long X 8 feet 6 inches high (inside dimensions). The wall construction is of 4-inch hollow tile covered on the outside with 1 inch of plaster and lined on the inside with 4-inch corkboard and a 0.5-inch covering of cement plaster. The ceiling was formed by sheathing with 0.75-inch matched lumber. Against the sheathing two layers of waterproof insulating paper and one layer of 4-inch corkboard were applied. The ceiling also was given an inside layer of plaster similar to the side walls. A cold-storage door insulated with 4-inch cork with a fir front and back gives access to the room. A refrigeration compressor with water, sprays, and automatic controllers maintains the desired conditions within the ranges from 40 to 70 per cent relative humidity and 65" to 80" F. dry-bulb temperature with an outside maximum of 95" F. dry-bulb temperature and a minimum relative humidity of 25 per cent. These conditions are maintained within the accuracy and sensitivity of the controller instruments with a supply of 50 cubic feet per minute of outside air into the room. A rubber laboratory for the study of pigments in rubber is equipped with a roller mill, vulcanizer, etc., and test apparatus, so that a complete set of data may be obtained on finished rubber. This laboratory directly concerns itself with the effect of pigment in rubber as a utilization problem. The spectrographic laboratory is of interest, since a dustfree room was required to test the pigments and ores. Air filtration through paper filters has proved adequate with complete change of air in 6 minutes. The filtration equipment has cooling coils which lower the temperature and humidity in the summer months. The filtration of the air is accomplished with 40 square feet of filter area, using a cellular-type paper backed up with 10-ounce flannel for final cleaning. The fan to supply air delivers 600 cubic feet per PILOT PLAXT
302
INDUSTRIAL AND ENGINEERING CHEMISTRY
VOL. 11, NO. 5
RIGHT. MUFFLES AND CONTROLS
LABORATORY ABOVE. SPECTROGRAPHIC
RESEARCH LABORATORY RI:GHT. TYPICAL
The general laboratory is a laboratory unit for preparation of pigments on a 5-pound scale, before going to semi-pilotplant scale. The semi-pilot-plant unit, which is in a building of the main plant, will handle 100-pound lots. The pilot plant was designed for production of 1 to 2 tons per day and is a complete pigment plant in a separate building of its own. The preparation of pigment from raw ore to finished pigment can be carried out at the'pilot plant, or plant product a t any point in the process may be worked up into a final pigment. A mill room contains a jaw-crusher and a roller mill for the reduction of ores; ball mills, an Aloxite edge-runner mill, and a Raymond laboratory pulverizer are provided for the grinding of pigments. The library, in a room of its own under the supervision of a trained librarian, necessarily is somewhat limited because of the highly specialized nature of the work of the laboratory. It contains some 500 volumes of books and encyclopedias, about an equal number of volumes of periodicals, 2000 trade catalogs, and 4000 pamphlets, photostats, and reprints. Subscription to 27 current periodicals is maintained. A stockroom, steam water still, compressor, vacuum pump,
necessary motor generators, and steel storage shelves for samples complete the equipment of the laboratory. A bdte noire in the design of laboratories is the choice of service equipment of the required capacity. The following data therefore may be of interest. The vacuum pump serving all laboratories has a capacity of 9 cubic feet per minute at 29 inches of mercury and is provided with an 80- allon receiver. It has proved adequate for this laboratory wtich has a heavy vacuum-filtration load. The air compressor delivers 13 cubic feet er minute at 200 pounds per square inch. This pressure is usedPfor paint spray booth service. For the laboratory service lines the pressure is brou ht down to 25 pounds per square inch by means of a governor. i n 80-gallon receiver also is used in connection with the air compressor. The distilled water is obtained from a still delivering 2 t o 3 gallons per hour using steam at 30 pounds pressure as the heat source. A 50-gallon chemical stoneware receiver allows adequate storage for the laboratory. The distilled water, chemicals, gas cylinders, ball mill, etc., are delivered to the other floors by means of a hand-operated dumbwaiter. The type of layout and the equipment described are proving to be very satisfactory for an inorganic research laboratory with a staff of twenty-six chemists and chemical engineers and twelve nontechnical employees.
