US1883908A - Evaporator top - Google Patents

Description

Oct. 25, 1932. c. e. HAWLEY EVAPORATOR TOP Filed Dec. 6, 1927 Patented Oct. 25, 1932 UNITED STATES- PATENT OFFICE CHARLES GILBERT HAWLEY, CHICAGO, ILLINOIS, ASSIGNOR T0 CENTRIFIX CORPORATION, OF CLEVELAND, OHIO, A CORPORATION OF OHIO EVAPORATOR T0]? Application filed December S, 1927. Serial No. 238,155.

This invention relates to improvements in evaporators, such as are employed in reducing and refining processes; and in particular relates to improvements in the oil-leading portions or tops of evaporators; the object of the invention being to detrain and preventthe loss of the moisture or liquid entrained bythe vapor about to pass to the condenser or other vapor terminal.

The invention comprises a centrifugal separating unitor units of an immovable or fixed type combined with a diaphragm-like floor for supporting the same within the evaporator top and which, being interposed in the path of the off-going vapor, serves to throw down and return the entrained fluid or permit its return, to the evaporating vessel.

The invention, though of much practical importance, is extremely simple in construction, is easily applied or built into evaporator tops; and, without any attention whatever from an operator, automatically and continuously performs the detraining function very perfectly.

The invention will readily be understood on reference to the accompanying drawing; in which, Fig. 1 is a vertical section (on the line 1-1 of Fig. 2) of a typical evaporator containing a plurality of the centrifugal devices or units embodying this invention; Fig. 2 is a horizontal section on the line 2-2 of Fig. 1; Fig. 3 is a vertical section showing the combination or incorporation of this invention with an evaporator top proper; Fig. is an end elevation of the parts appearing in is clearly shown in the drawing, the invention involves the modification of the tops or upper parts of evaporators. As shown in Fig. 1 the upper part of the evaporator body is so modified; while as shown in Fig. 3 it is an upper part proper or cylindrical enlargement of the body which is modified. In the first instance the top of the evaporator is modified by the provision and installaion of a horizontal floor 3 which but for the fact that it contains a plurality of round openings i would shut ofi' the lower. from the upper portion of the evaporator body 5. In the second case the cylindrical extension or chamber 6 is modified first by the installation of a partial partition 7 and nextby a floor 8, which like the other contains a plurality of holes for the passage of the vapor. In Fig. 1 the vvapor outlet is marked 9. In Fig. 3 the vapor outlet is marked 10. The centrifugal units marked A in both cases have openings in their tops which either register with or form respective openings in the plates or floors. These units are attached to the floors fixedly, as by means of bolts, either engaging the under side of the plate, as shown in Fig. 1, or the top of the plate, as shown in Fig. 3. The'liquid, W, to be concentrated occupies the lower partof the evaporator vessel, and through the medium of the heat transfer device 11 (of any suitable construction) and usually under the aid of an assisting vacuum attheoutlet of the evaporator the moisture contentof the liquid is evaporated, leaving the heavier products in the vessel or pan.

The vapor rising beneath the described floor encounters the centrifugal units AV These furnish vortexial avenues of escape into the chamber or space above the fioor. In other words, the units A. as about to be detailed, are so constructed that the vapor which enters them and seeks escape therethrough is set into very rapid vortexial rotation. As a result of that rotation the heavier substances, meaning the minute particles of moisture entrained by the vapor, are centrifugally separated. The units A are so constructed as to momentarily retain the separated moisture and finally to allow the moisture to drain back by gravity into the lower parts of the vessel. Little if any moisture passes upward through the units and into the outgoing space above them. However in any event should any pass it would emerge into that space in a whirling condition, and due to a sudden reduction in velocity occasioned by expansion in the larger chamber would be precipitated upon the top of the floor. To disnose of any such stray quantities of fluid the floor is provided with one or more drains, preferably in the form of pipe 12 leading downward and water sealed at the lower end. that is sealed by a quantity of the liquid under treatment.

While these centrifugal units A may be variously modified and designed, each thereof preferably comprises a top ring containing the center outlet of the unit; next a circ'umferential series of long and tangentially positioned tuyere blades which depend from said ring; and finally a tuyere bottom which is secured to the lower ends of said blades. Obviously a substantially,cylindrical chamber is formed'by the tangential blades, and that cylinder is of larger diameter than the outlet at the top, so that an overhanging part of the top ring )artially closes the top of the chamber. The blades form an equal number of tuyeres or slot-like openings which enter this chamber tangentially. The vapor pass ing inward therethrough at high velocity of necessity takes on a whirling or vortexialmotion within the chamber. A first centrifugal separation takes place. upon the blades themselves. The moisture gathered thereon cannot escape at the top by reason of the overhanging ring, and before it can be carried through the outlet it has spiral'ed toward the bottom of the chamber, remote from the outlet. It will be noted that the described slotv like tuyeres are of considerable width and relatively great length so that the aggregate entrance area provided thereby is made to greatly exceed the area of the outlet at the top of the unit. Thereby it is insured that the state of pressure within the separating chamber shall belittle less than the pressure in the underlying evaporating chamber. The described bottom of the unit is provided with a number of openings adequate to the dischar within the cylindrical chamber of the unit, but of so little area in the aggregate as to permit the inward passage of so small a quantity of vapor as to leave the vortex virtually undisturbed.- Under these pressure conditions the separated liquid drains from the bottom openings by gravity, the upward rushof vat. por through the bottom openings being insufficient to overcome or lift the weight of the liquid. The operation here described goes on continuously in each of the centrifugal units A. Theoretically the entire operation might be performed by a single unit having a top outlet adequate to pass the vapor without an opposition suilicient to cause a material drop 'of pressure; which if permitted would result in demanding the expenditure of more heat or power in the evaporating process. However as these units operate cen-, trifugally it is far better to secure an adequate area by increasing the number of outlet openings through making them smaller. By

- making them smaller the diameters of respective cylindrical separating chambers may be reduced. and by such reduction the centrifugal efiiciency of the unit is increased.

Hence this invention provides for and comprehends the combination of a plurality of centrifugal units of limited diameters. Again, in adopting the multiple principle it becomes possible to further avold objectionable pressure drops by making the aggregate area of the unit outlets greater than the outlet (9 or 10) of the evaporator." This is a preferred feature of the present invention.

Having thus described my invention I claim as new and desire to secure by Letters Patent 1. An evaporator top containing a substantially horizontal floor and the latter containin a pluralityof vapor passages, in combination with centrifugal'entrainment separators positioned below and co-acting with respective. passages and means for draining said floor.

2. An evaporator top having a vapor outlet, in combination with a substantially horizontal floor forming a partition in said top and. in advance of said outlet, means for draining said floor, and a plurality of entrainment separators supported by said floor, containing substantially cylindrical separating chambers and having respectively smaller CHARLES GILBERT HAWLEY.

of all the liquid separated and settled

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