Another reason for the superiority of American Controlled Capacity Pumps are E-Z Clean valves. Their exclusive design allows changing in minutes without disturbing piping, means less downtime for cleaning, inspection, replacement. For the widest range of jobs, they are available in a variety of corrosion-resistant materials. Spring-loaded design increases volumetric efficiency, reduces back-flow and destructive shock forces due to inertia. With spring action minimizing complete closing time, back flow is virtually non-existent, accuracy is improved. Especially effective with slurries and high viscosity liquids. Available in three series with wide pressure and capacity ranges. Series 300 Pumps adjustable in operation.. .manually or pneumatically by 3 to 15 psi instrnment air sign+ Write today for complete information. SPECIALISTS
IN
FLUID Cimli WI.
METERS
I an RU*II’
.ne* 100
e* 200
13500 Philmont Avenue Philadelphia 16. Pa.
AND
CONTROLS
Stnirt C n
VOL. 5 5
NO. 7
JULY 1 9 6 3
15
IF YOU WISH TO
BROADEN YOUR HORIZON
of iron oxide pigments. ..
Williams Can Help You I To bring yourself up to date in the matter of inorganic colors . . . iron oxides, both natural and synthetic . . . send today for our new booklet titled “Panorama of Pigmentology-at its best!” Your understanding of what’s available in the field of iron oxide colors may be greatly enlarged. Certainly your horizon will be broadened. After 85 years in the business of manufacturing inorganic pigments . . . plus the new facility of our Pigment Research and Development Laboratory . . . we have something exclusive to offer you. Try us . . either see your Williams representative . . . or write us direct to Dept. 2 , C. K. Williams & Co., 640 North 13th Street, Easton, Pa.
-
bvercome the resistance of the metals o conventional processing. This vill open the door to widespread icceptance in missiles, spacecraft, itomic energy projects, and in inlustrial applications. The new plant is a big step toward uller utilization of refractory metals. ?or example, solution to the problem d oxidation in normal atmospheres s well under way. Improved maerials are being developed, with )etter ductility at moderate temmatures; also, higher strength aloys are being developed. The new plant emphasizes inegrated, in-line mechanized procssing, from consolidation of powiered-metal starting materials to nventory control and shipping. Strict attention is given to particle
.
..
FREE. this comprehensive brochnre which brings you up to date on what facilities, and products, are available to yon in the field of iron oxides. Write for yonr copy now !
size of powders used in the sintering operation-no particle larger than 20 microns is used. Fine grained recrystallized molybdenum, for example, is ductile at room temperature, but as the grain size increases brittleness increases. Ductility is also affected by oxygen content, and so this too has to be rigidly controlled. Quality control is maintained at check points in critical locations in the processing sequence. Billets are checked for purity, and rigid control is maintained throughout the entire operation. Using advanced-design vacuum arc casting, the plant can produce ingots up to 12 inch= in diameter.
II
I
I
C O L O R S L PleMENTS
C. K. WILLIAMS 81 CO.
16
INDUSTRI
Rafmfq mfd she& me sfwed on roller hays to prof& thair swfaces
STRY
of corrosion-resistant materials. Spring-loaded design increases volumetric efficiency, reduces back-flow and destructive shock forces due to inertia. With spring action minimizing complete closing time, back flow is virtually non-existent, accuracy is improved. Especially effective with slurries and high viscosity liquids. Available in three series with wide pressure and capacity ranges. Series 300 Pumps adjustable in operation. . .manually or pneumatically by 3 to 15 psi instrument air signal. Write today for complete information. SPECIALISTS
IN
FLUID Circle No. 8
METERS on Readers’
W 13500 Philrnont Avenue Philadelphia 16, Pa.
A N D
CONTROLS
Service Card
VOL. 5 5
NO. 7
JULY
1963
15
M A R T I N F. PUlNN
FLUIDIZED BED DRYERS technology has been applied to a wide Fluidued vanety . ofbedsolids handling systems of which fluidized bed drying is but one. Typically, such an operation involves separating a liquid from a solid using gas as the fluidizing medium. Fluidized bed drying is indicated wherever gentle handling conditions are required, wherever close control is needed (this particularly refers to operations which must be maintained very close to operational limits), or wherever small driving forces must be utilized. Difficult material handling characteristics of the wet feed may be solved by fluidized bed drying. The equipment is relatively simple and compact-an advantage in many situations. Consideration of the .mechanisms of fluidization and drying, in combination, leads to very interesting observations. In the fluidized bed, the solids particles are in a state of virtually uninhibited motion. Any particle has free acces to all parts of the fluidized bed at any given time, and. is not defined in space except as a function of time. The top level of the bed is a region rather than a line. The general condition of the fluidized regime is one of rapid heat and m a transport. On the other hand, when drying of a single particle is considered, evaporation from its surface as well as diffusion of moisture to the surface, is usually an operation' which requires time for completion. It has been demonstrated many times that the fluidized bed of solids is a remarkably effective solids mixer. Indeed fluidized bed units have been utilized for this purpose. For example, consider a bed of red particles. While this bed is in the active state of fluidization required for drying, a small quantity of green particles is charged to the bed. It is observed that the green particles are completely dispersed throughout the bed almost instantaneously. For the sake of further example, consider that a given material is red when dry, and green when wet. It is readily apparent that there is immediate distribution of wet feed throughout the bed. With this condition in mind, one would expect that it would be virtually impossible to achieve very low product moisture levels when the moisture of the incoming feed material is extremely high. Indeed, it appears that the product moisture should be a direct function of the feed moisture and that the physical separation between feed point and discharge point is highly important in the fluidized bed dryer. It would seem that baffling between the feed and discharge points would be quite effective, and that mu!tistage drying operations would be required when operating through a large moisture range. 18
INDUSTRIAL AND ENGINEERING C H E M I S T R Y
1
.I
7. A gpical fluidized Bcd dryur m'fh infagd malm. Air gar passes from thc fan' or b l o w (I)fhrough a Jiltm (2) and hafcr (3) info flu plenum c h b n (4). From h plnvun chmnbn tha air p m a through II d@sm pi& (5), through thu solids bcd (6),and into fhc dusf sepmator (7). H m fha air czhawfs of fhc top (8) and dusf is yn'fhdrawn at thr botfom. We: matmil is fed info the bed through (I rolory oolvi (9). Lky product is discharged fhrough (1 dowmomcr (70) into fhc lolun unit, a coolcr. Discharge of dry, cool solidr is fhrough (I mtmy oalvc (77) rzpc
or
0 t h
,
I&EC REPORTS
-
All tungsten and molybdenum sheets are processed in hydrogen furnaces that can be maintained at temperatures beyond 3000' F. Annealing is done in a continuous-run horizontal furnace that can handle strips up to 40 feet long. GE is the first to introduce a precision-graded system of molybdenum alloys, which in this case is molybdenum sheet in classes 100, 200, and 300, all designed for use in specific metalworking techniques. Class 100 is processed for optimum strength and ductility at room temperature, and is recommended for critical operations such as deep drawing and severe die-forming. Classes 200 and 300 are for less critical forming operations. Refractory metals are ideal for rocket nozzles and propulsion components and show promise for use as flame shields, blast tubes, manifolds, power rectifiers, and power tubes. In specialized applications, molybdenum is promising as honeycomb panel material for leading edges of high speed re-entry vehicles. Molybdenum and tantalum because of their high corrosion resistance, are attracting more attention in the chemical industry, particularly for corrosion-resistant vessels, tubing and piping, valves, and other components. Tungsten, because of its high density, may be useful in nuclear applications as a shielding material. Also sintered blanks of tungsten can be extruded into tubing for holding molten metals such as sodium. The space electronics industry has created the need for ductile, thin gage, high purity metallic materials that are capable of retaining structural stability at the tremendously high temperatures generated by high-output power tubes. Refractory metals provide the solution to this problem in a large number of cases.
Here are spray nozzles that operate automatically under remote control . , for spraying synchronized t o any "on-off" cycle. Available as pneumatic or hydraulic atomizing nozzles i n a variety of body designs and in a wide choice of spray patterns and capacities. These modern nozzles offer dependable performance, eliminate waste of liquid sprayed. For complete information, just send for Bulletins 114 and 115.
.
WRITE FOR BULLETIN 114 Automatrc PNEUMATIC Atomizing Spray Nozzles BULLETIN 115 Automatic HYDRAULIC Atomizing Spray Nozzles
SPRAYING SYSTEMS CO., 3255
Circle NO. 59
y&
Randolph St., Bellwood, 111.
on Readers' Service Card
&dm m
AND
m
SAFE W
0
in a HAWS Emergency Drench Shower. Burning, corrosive, caustic contamination can inflict injuries more dangerous than blazing clothing! Contamination by acids, chemicals, volatile fuels, radioactive elements, etc., must be instantly countered by fil:sr nid. Immediate drenching with clear water is the first precaution against permanent injury. HAWS leads in design and production of Emergency Drench Showers! Ask for our complete catalog.
Model 8590 M u l t i p l e nozzle shower drenches victim f r o m a l l angles.
DRENCH SHOWERS Sitice 1909
D. R. GOTTLIEB
VOL. 5 5
NO. 7
JULY
1963
17
