US2696878A - Spray machine - Google Patents

Description

Dec. 14, 1954 A. G. BRENDEL SPRAY MACHINE 5 Sheets-Sheet l Original Filed July 21 1949 INVENTOR.

ATTORNEY Dec. 14, 1954 A. G. BRENDEL SPRAY MACHINE 3 Sheets-Sheet 2 Original Filed July 2l 1949 @z um? SYM... fw'

ATTORN EY Dec. 14, 1954 A. G. BRENDEL SPRAY MACHINE Original Filed July 21 1949 3 Sheets-Sheet 5 WH fr@ /Nz fr 75 ATTORNEY United States Patent SPR'A'Y MACHINE Armin G. Brendel, Sutfern, N. Y., assignor to American CyanamidCompany, New York, N. Y., a corporation o'f Maine Original `application July 21, 1949, Serial No. 105,943,

now Patent No.12,644,516, dated July 7, 1-953. Divided 'and this application `January 27, 1953, Serial No. 333,550

This inven'tion relates to .a spray .machine fffor .use in spray driers employed for drying solid material dis- *solved "or suspended in a liquid. Although not lim -ited thereto, vthe apparatus ofthe vinvention is particularly `well adapted for l.the spraytdrjying YTof slurries #c ontaining gelatinous Jsilica, including zsiliea alumina, .silrcamagnesia and silica-aluminamagnesia compositions :for use in the catalytic cracking of petroleum=hydrocarbons `For sthis @reason v.the .invention will -be -described -in -idetail with particular reference tto :the `rspray l drying of `,this .class of materials; it being understood, however, rthat lslurrieslor solutionsof other solid or 4semi-.solid-material -may be .drieditherewith In the spray `drying .ofsilica slurries Ifor the producttion `of microspheroidal cracking catalysts a twoephase `slurry .consisting of water containing small aglobules of :hydrated silica, .silica-alumina, .silica-tmagnesia yand .the Alike "istdispersediinto `a current offh'otgasesin aspray drying chamber. `lUsuallyithe slurrysiszdispersed tby-dis charging it onto a rapidly rotating motor-driven vaned spray wheelfmounted in the top ofthedryinglcharnber. A current of .hot gases, .such .as hot .products of combustion, is admitted tangentiallyaround the spray wheel and forms a rotating vortex into lwhich the spray of 'silica slurryis projected by `centrifugal force. .Mypressent invention provides an improved :airand waterrcooled motor and an improved non-tclogging.distributor '.for'supplying the material to bezdried-to thespray lwhcel :as .will hereinafter be more fully ipointed out and tleffine'd bythe appended claim.

The invention will be further .described with reference to the specific Yembodiment thereof shown in the attached drawings in which:

fFig. l ista f'vertical section through a 'furnace-and top portion of a spray drier with parts broken away.

Fig. 2 is a vertical section through the motor and cooling jacket assembly.

Fig. 3 is a plan view of the top of the assembly of Fig. 2, showing the feed pipes and the pipes of the cooling and lubricating system, and

Fig. 4 is a plan view of the slurry and emergency water distribution plate taken on the line 4--4 of Fig. 2.

Referring to Fig. 1 it will be seen that the assembly indicated generally by reference numeral 1 consists of a drying chamber 2 having a furnace 3 superimposed thereon, both being enclosed by a cylindrical side wall 4. Supporting beams 5 carrying a central well structure 6 are mounted on the top of this wall, as by vertical beams 7. In the embodiment shown the furnace 3 is formed within the top portion 12 of the side wall 4 by an insulated ceiling 13, which is suspended from the supporting beams 5 by rods 14 and hangers 15, and an imperforate heat-radiating metal partition 16 whichk constitutes a floor for the furnace and a horizontal ceiling for the spray drying chamber. This metal partition serves the important function of radiating heat from the furnace into the particles of material in the upper portion of the spray drying chamber while preventing the uncontrolled admixture of additional quantities of hot gases therewith, which increases the drying capacity of the apparatus and aids in forming a spraydried material of controlled shape and particle size.

The partition 16 is made up of a set of metal plates laid on an equal number of radial beams 18 which are supported at their outer ends by the side wall 4. At their inner ends these beams are joined as at 20 to a Cab .drawings.

2,696,878 .Patented Dec. 14, 1954 r. ICC

lvertical annular bathe 21, which is spaced outwardly from `the rfcentral well t6 :and .forms i' therewith an annular.,passage.22. .Thebal'eiandlthelinner ends of the ".b'eams L18 yare :supported @byra :ring tof insulated rods 23 which textend vthrough the ceiling of "the r'furnace "and tare LThung l'from .the 'supporting :beams 5. Near `its lowterfedge, Yfand :preferably "below :the level of Ithe -beams :18, the jbathe z is finlined flinwardly: at 24 to form a V.restricted 'portion 1in twhich a iset of :inclined gas-.directing ivanes 261s mounted.

Setain fthe :outer :wall .L1-2 of :the furnace .lare La znumber of burner tunnels 27, `each enclosing agas aburner 28. These .'tunnels :and `burners are $=set at an Aangle .between the :radius .fand ith'e tangent zto the wall vof fthe furnace, so that the iam'es 'from :the fzburners atravel through a .-sp'iralpath. flt willlbenotedtthat the burnersare mounted "relatively close :to the z rnetl floor 16, yso that :this liloor soon .becomes veryhot'and radiates 'a :substantial proportion of the heat from the burners `directly `:into the :dryin'gfspace below. The products 'zof rcombustion, at the Aend cof :their :spiral fpath arounii :the furnace, :pass rupwardly over :the lvertical batli'e 21 and downwardly "through `the space T22, .being deflected `-..by the `vanes `2'6 4into-a vertically rotating path.

sThe 'drying capacity of the apparatus `of ythe ipresent invention `is such fthat fa motor can be 'used having a greater power output than any iheretofore employed 'for ithis fpurpose. 'iSuch fa motorris shown on Fig. r2of the While :this .'motor, per ese, is more =or less conventional in design zandlisfn'ot apart-of the 'present invention, its eoolingfsystemand :the structure and 1ojcation `of '.the's'lurr-y ffeed .and emergency :water distribuition pip'es, fand :particularly the distribution plate where- ,by these .are connected vwith the spray wheel 30, conf-stitute :important y:novel features tof the invention.

rReferringltoxfFig. :2, the sprayrmachin'e indicated gen .,erally :by reference numeral .'35 lcomprises a rotor 36 aand a suitable stator 37, fboth mounted 'within :a vwater jactketed A:enclosure .38. The upper 'and lower bearings :39Qand 4.0 of the lrotorzshaft 41 are `designedlfor loperation at high speeds andzaresuppli'ed withlasspray of oil through tpipes 42 and '43 crespectively. These `bearings are :mounted in iuppe'r and lower plates -45 land `46, a planafiewsof :the iupper :plate lbeing :shown in Fig. 3 the drawings. Adr duets 47 4and v21S-are providedzin the enclosure :38, ithrough `whichLair'isforcedto aid in cooling `the fmotor. 1One of fthese air pipes nis .shown at 49 on Fig. 32, `the fair being admitted through port 50 and .passing 'over the .field flpthrough thestator-37 and out through openings 52 in the upper plate 45. The machine illustrated is a two pole, 3 phase, 150 H. P., 210 cycle motor operated with a frequency generator unit which can vary the frequency up to 260 cycles or down to 158 cycles, thus giving any desired speed to the rotor shaft 41 between 9500 and 15,600 revolutions per minute.

The motor is enclosed by a water jacket 5S having a flat bottom 56 which forms with the lower plate 46 a water passage that surrounds and cools the lower bearings 40. Water inlet and outlet pipes 57 and 58 permit a continuous circulation of water through this jacket, thus protecting the motor from the heat of the furnace in which it operates. Slurry pipes 59, 60 and 61 also pass through the cooling jacket 55 in order to avoid the danger of clogging by premature heating and solidfication of the solutions or slurries to be spray dried. These pipes extend through the bottom 56 of the cooling jacket and communicate with the distributor 62, which feeds the materials to be dried to the spray wheel 30. y

The distributor 62 is made up of a lower body portion 63 and a cover plate 64 carrying a central annular shield 65, the body portion and cover plate being fastened together and to the cooling jacket by bolts 66. As is shown in Fig. 4 of the drawings the body portion 63 consists of a at circular plate 67 having a machined outer edge 68 and a set of slurry channels 69, 70 and 71 aligned at their outer ends with slurry pipes 59, 60 and 61 respectively and having a downwardly turned lip, as at 72, at their inner ends. Corresponding openings in the cover plate, as at 73, permit the solution or slurry to be dried to iiow through the channels and discharge over the lip 72 onto the spray wheel, whlch is of a conventional type, from which it is thrown o utwardly in the form of ne droplets into the drying chamber 2.

It is very important to maintain a constant flow of liquid through the apparatus at all times when the furnace 3 is in operation as otherwise the spray wheel 30 and probably other parts of spray drier would be damaged by the hot furnace gases. Provision is therefore made to discharge a stream of water on the spray wheel if the slurry pipes should become clogged or if the regular feed of slurry should be interrupted for any other reason. For this purpose an emergency Water pipe 75 (Fig. 3) is located above and in communication with a water channel 76 in the body portion 63 of the distributor. This water channel has a dam 77 across its inner end to prevent the channel from becoming clogged by hardened slurry during normal operation. Preferably the flow of water in the pipe 75 is controlled by a valve that is cross-connected to the slurry feed so that the water valve will open automatically when the ow of slurry is interrupted.

The spray machine 35 is adapted to iit closely within a vertical cylinder 80 in the central well structure 6, and i'.

is provided with an outer ilange 81 which rests on an inner shoulder 82 .in the cylinder 80 when the motor spray wheel are in operative position. The feed slurry, cooling water, compressed air, oil and emergency water are supplied to the inlet pipes shown on Fig. 3 of f the drawings by suitable ilexible connections, which are not shown, so that the spray machine 35 can be raised through the cylinder 80 and removed for cleaning or repairs at any time. Electric current is also supplied to the motor by a flexible cable, which is not shown, and a suitable thermocouple well may also be provided if desired. The central cylinder 80 is braced against vibration by a set of brackets 83 which span the annular space 84 between the inner cylinder 80 and the outer, insulated cylinder 85 of the central well structure 6. It will thus be seen that the spray machine is protected from the heat of the furnace, rst by a layer of insulation 86 on the inner wall of the furnace, then by the air space 84, then by the water in the cooling jacket 55, and then by the cooling air.

The operation of the apparatus is best shown by`a speciic example of results which have been obtained herein. A slurry of a hydrated silica-alumina catalyst, containing 87% of silica and 13% of alumina on the dry basis and prepared by suspending in water a precipitated, filtered and washed silica-alumina produced as described in the patent of K. D. Ashley and A. O. Jaeger, No. 2,478,519, dated August 9, 1949, was sup plied at a solids content of about 6.88.0%. Natural gas was used as fuel in the furnace 3, which furnace contained 6 gas burnerscach having a capacity of 6,000,000 B. t. u. per hour. The gas ow was estimated at 2380 lbs. per minute, based on the heat balance. The outlet gas temperature in the pipe 11 was 250 F. The following operating results were obtained When a 9-inch diameter, 45 V-type spray wheel was use Atomizing Speed, R. P. M.- 10,700 10, 700 12, 700 10, 700 12,700

Side Inlet Dampers 33 open closed open open closed Gas Temp. F.) in Passage 710 750 640 640 600 Screen Analysis:

-40 mesh, percent 10D 100 100 100 100 -100 mesh, percent.. 95 97 99 99 100 -200 mesh, percent. 62 71 84 73 85 -40 microns, percent", 28 31 40 30 43 -20 microns, perceut 6 6 8 7 9 -10 microns, percent 0 0 0 0 2 Water Content of Product,

percent, 13 14 13 12 12 This is a division of my copending application Serial No. 105,943 led July 21, 1949, now Patent 2,644,516.

What I claim is:

In a spray drier, a spray machine comprising a motor having a -vertical rotor shaft, a spray wheel attached to the lower end of said shaft, a distributor between said motor and said spray wheel containing a plurality of feed channels adapted to supply liquid material to be spray-dried to said wheel and also containing an emergency water channel having a dam to prevent clogging by material from said feed channels, a water jacket surrounding said motor and slurry pipes and an emergency water pipe extending through said water jacket and communicating with said feed channels.

References Cited in the file of this patent UNITED STATES PATENTS

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