US2107369A - Apparatus for treating things with volatile solvents - Google Patents

Description

1934 `4 sheets-sheet 1 C. F. DlNLEY Filed Deo. 13,

APPARATUS FOR TREATING THINGS WITH VOLATILE SOLVENTS Feb. 8, 1938.

, INVENTOR.- Chl/mnu; E'Di E BY l W I ATTORNEYS.

Feb. 8, 1938. c. F. DINLEY 2,107,369

APPARATUS FOR TREATING THINGS WITH vVOLATILF SOLVNTS Filed Dec. 1s, 1954 4 sheets-sheet 2 TTORNEYS.

C. F. DINLEY Feb. s, 1938.

APPARATUS FOR TREATING THINGS WITH VOLATILE SOLVENTS Filed Dec. 13, 1954 4 Sheets-Sheet 3 IN VEN TOR:

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APPARATUS FOR TREATING THINGS WITH VOLATILE SOLVENTS Filed Deo. 15, 1934 4 Sheets-Sheet 4 FICS; 1M'.

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Patented Feb. 8, 1938 PATENT OFFICE APPARATUS FOR TREATING THINGS WITH VOLATILE SOLVENTS clarence F. mnley,'petroit, Mich., ssignor to James B. Bell, Philadelphia, Pa..A

Application Decemberis, 19.9.4,'sern1 No. 757,319

3 Claims.

My invention relates to treatment with solvents for such purposes as `cleaning and degreasing, and to the use of volatile solvents. It is especially adaptable and useful for cleaning 5 metal parts or objects preparatory to electroplating, enamelling, painting, and other finishing operations. Various solvents whose vapors are heavier than air may be used, such as benzine, benzol, vancl chlorinated solvents like carbon tetrachloride, trichloromethane, tetrachloromethane, dichlorethane, tetrachlorethane, trichlorethylene, and tetrachlorethylene, whose vapors are uninammable. 'Ihe work may be treated with the liquid solvent or with the solvent vapor, yor both, and in many cases, treatment in boiling liquid solvent is desirable. In suitable forms of embodiment, such as hereinafter described, my invention affords a compact and eicient machine, semi-automatic in operae, tion, wherein large quantities of work can be rapidly, thoroughly, and economically cleaned, with small labor costs and litle loss of solvent. Various other features and advantages of the invention will appear from the description hereinafter of species thereof, and from the drawings. y f

In the drawings, Fig. I is la side elevation of one preferred form of apparatus suitable for the purposes of my invention, with a diagram of certain electric circuits.

Fig. II is a corresponding diagram of a coniveyor system 'shown in Fig. I, with the casing or solvent vessel of Fig. I in vertical longitudinal section.

Fig. III is a view, with various parts in section, taken as indicated by the line and arrows III-III in Fig. I.

Fig. IV is a fragmentary view, with part of the apparatus in transverse section, taken as 3 indicated by the line and arrows IV-IV in Fig. I.

Fig. V is a fragmentary view taken as indicated by the line and arrows V-V'in Fig. I, with part of the wall of the apparatus broken away and removed.

Fig. VI is a plan view of the piping connections of the apparatus.

The apparatus shown in Figs. I, II and lII comprises a sheet metal treating vessel or enclosure I0 that contains the solvent, whether used as liquid or as vapor, and is closed toexclude air and retain any solvent vapor that may be present-,purposely or incidentally,but is preferably open upward for the introduction and removal of work. For passing the work in and out of or through the vessel Ill for treatment,

there may be a conveyor system II, shown in the drawings as of an endless chain-and-sprocket type. The enclosure or vessel II) and most of the sprockets or other guide and driving means of the conveyor system II are mounted and supported on or in a (metal) framework I2, sufliciently open to allow passage of the work (not shown) between its sides. Over the vessel III there may be a lid or cover I3 somewhat shorter than the vessel; so as to leave openings at its ends for the passage of the conveyor, and preferably removable: itis shown as having the form of a shallow pan, inverted.

To avoid confusion, only a single work carrier I4 is shown in Fig. I; but in practice, there will preferably be a number of such carriers I4, at suitable intervals along the conveyor chains, as shown in Fig. II and explained hereinafter. As shown in Figs. I and III, the work carrier I4 comprises a foraminous or openwork worksupport or shelf I5 suspended by rods I6, I6 at its ends. The rods I6, I 6 are preferably of such length that at the low points of the conveyor path, theshelf I5 will be rather close above the corresponding portion of the bottom of the vessel III, as shown in Figs. I, Il, and III.

In general, work is treated with liquid or vaporous solvent (or both) in the lower partof the vessel I0, while its upper portion serves mainly to prevent or minimize loss of solvent u vapor from the vessel. For when the solventemployed is highly volatile like gasoline or benzine, or when the work is immersed in the solvent while itself hot or warm, or when the solvent is used hot or even boiled during use, or when the solvent is purposely used in the vapor state,-in all such cases, solvent vapor will be present, and will tend to accumulate to the point of overflowing over the upper edge of the vessel I0. As shown in Figs. I and II, the vessel I0 has a plurality of distinct treating compartments or wells 20, 2|, 22 separated by dams consisting of partition-like upward folds 23, 24 of the sheet metal forming the bottom of the vessel. In these several wells 20, 2l, 2 2, articles or work may be more or less differently treated with the solvent. As here shown, also, the well is provided with heating means, such as a steam coil 25near its bottom, for heating, vaporizing, or even boiling a body or bath of the liquid solvent retained in said well. The escape of solvent vapor thus or otherwise present in the vessel I0 may be prevented by suitable upward extension of its walls as at 26, and by condensation of the vapor from this upper part of the vessel. The cover I3,

when used, also serves to minimize the unavoidable minor losses of solvent vapor, by preventing drafts of air above the vessel I0 from causing eddies in the latter and thus drawing or forcing solvent vapor up over the edges of the vessel.

Condensation of vapor from the upper portion 26 of the vessel I0 may be eifected by the external atmospheric cooling of the walls at 26, if they are of sumcient height; though generally it is preferable to supplement or (largely) replace atmospheric cooling with more eifective cooling means,s o that the vessel I0 need not be so deep as mere atmospheric cooling would require. The particular type and arrangement of cooling means-whether internal or external, and whether on one side, two or more sides, or all around the vessel Ill-is'broadly immaterial, ex-

cept that the greater the extent of the cooling means perimetrically of the vessel, the less its extent vertically need be to give adequate exposed cooling area. The solvent vapor, being heavier than air, will always flow by gravity toward the region or area where it is most rapidly cooled and condensed,just as if there were an actual outlet for the vapor at such region.

As shown in Figs-I, II, and III, the upper ves- K sel walls 26 are (externally) water-jacketed at 21 on three sides, above the wells 2| and 22,-

thus causing acontinual flow of the solvent vapor rising from well 20 over well 2| into and across through well 22, where a body or bath of solvent vapor accumulates and is retained. 'I'he jacket 21' has an inlet 21a for water or other cooling medium at its lower corner on one side of the vessel I0 and anl outlet 21h at its upper corner on the other side of the vessel ID'. Part of the pure liquid solvent condensed by the cooling Jacket 21 on the vessel walls 26 runs down directly into the well 2|, where a body or bath of this liquid solventv is accumulated and retained. The rest of the condensate runs down into a trough 28 extending around three sides of well 22 and over dam 24 to a point above well 2|. At the opposite sides of the vessel I0, the trough 28 slopes downward toward well 2|, and from the trough ends drain pipes 29 deliver the pure condensate near the bottom o1' well 2| 'I'hus the condensate is diverted to well 2| to the exclusion of well 22. Such'vapor as condenses on walls 26 directly above well 28 (by atmospheric cooling) runs down into well 20. As shown, wells 2| and 22 are both unheated.

Thus, it will be seen, well 26 normally contains (boiling) hot solvent about up to the level shown in Fig. II;l well 2| normally contains the relatively cool and pure condensed solvent to the level determined by the lower of dams 23 and 24 (preferably the latter), as shown; and well 22 normally contains solvent vapor with which it is kept charged, as already explained. The

condensate from trough 28 introduced throughv ing the liquid solvent in the well 2|, and this.

water would tend to waterspot the work treated in the well 2 Preferably, the distances or intervals along the conveyor chains from one work carrier I4 :to the next correspond` to the distances or intervals ofl travel of the work carriers along the conveyor path between their adjacent treating' positions or low points in the seriesof wells 28, 2|,

22. These distances or intervals are preferably the same for the treating positions in wells 2| and 22 as for those in wells 28 and 2|.

As shown in Figs. I and III, the framework I2 l comprises separable lower and upper sections 30,

3|, associated, respectively, with the vessel I0 and the cover I3. These sections 30, 3| are separable at a plane corresponding approximately to the upper edges of the vessel III, where they have longitudinals 32, 33 of angle section, respectively.

The lower frame section 30 comprises a rectangular base 34 constructed of longitudinal and transverse channel members, and side frames attached thereto 'and including uprights 35 connected at their upper` ends by the longitudinals 32, and intermediately by longitudinals 36 of angle section. The side walls of the vessel III may be secured to the longitudinals 32, 36, and its bottom may be secured to the base 34, which is shown provided with a'saddle vstructure 31 secured thereon and engaging against the side wall of well, 28, under the bottom of well 2|, and under the bottom and against the side of well 22. This structure 31 comprises longitudinal angle bar frames under the sides of vessel I8', and transverse webs 38 under the corners of well 2|. At their top and intermediate longitudinals'32 and 36, the side frames of section 30 are interconnected by transverse 'angle bar members '38.

The upper frame section 3| comprises a rectangular top structure 4| constructed'of longitudin'al and transverse channel members, and side frames attached thereto and including uprights 42 and43 (the former-corresponding to the lower uprights 35) connected at their lower cover |3 are shown secured to the longitudinals 33. At the longitudinals 33, the side frames of section 38 are interconnected by transverse an? pipe 28 into the bottom of well 2| agitates this whole well 2|, so that lint and other dirt loosened by the pure solvent in this well is flushed or washed off the work more thoroughly. As

here shown, the tops of dams 23 and 2.4 slope l rather gently upward away from well 2l toward their crests, to facilitate overflow of drops of gle bar members 44. To the longitudinals 33 are secured vertical bars 45, 46, 41 which extend down into the vessel I0 and carry (sprocket) guide means for the conveyor system II.

The conveyor system `comprises a pair of endless sprocket chains 48, 48 suitably spaced from one another and travelling over a closed course that is determined by guide means mounted on the frame structure I2, and mainly on its upper section 3|. The conveyor chain guide means includes a numberpf relatively small (sprocket) Wheels 50 mounted on spindles carried by brackets or bosses 5l ailixed to the inner sides of the members of the upper side frames, y

lpairs of the (sprocket) wheels 50 whose bracket bosses 5I are mounted directly on the longitudinals of the top structure' 4|, there are two pairs 'of such guide wheels 56 whose brackets 5| are mounted on the inner sides of bracket plates 52, 52 upstanding from the (left-hand) ends of the top longitudinals and of bracket plates 53, 53 depending from said longitudinals near their right-hand ends. An additional pair of the guide wheels 56 have their bracket bosses 5| mounted on brackets 54 upstanding from the top longitudinals and adjustable in ways 55 extending lengthwise of said longitudinals, by means of endless adjusting screws 56 suitably mounted` on or adjacent said Ways. These adjustable brackets 54, 54 serve as take ups for independently adjusting the two chains 48, 48 to the desired degree of tautness or slackness. For sustaining the long uppermost chain runs between the guide wheels of the brackets 52 and 54, suitable chain ways or guides 51 may be provided, mounted on the top structure 4I by means of angle brackets 58, as shown in Figs. I and III.

There are also pairs of large sprockets 59, 66 on transverse shafts 6|, 62 which are mounted in bearing brackets 63 projecting outward from the lower uprights 35 at each end of the lower frame section 36. These sprockets 59, 66 are so located relative to the path of travel of the work and the work carriers I4 that the shafts 6|, 62 do not interfere with them. The upper portions 64 of the shaft bearing brackets 63 are removable, so that the shafts 6|, 62 and their sprockets 59, 66 can easily be released and removed. 'I'his allows the whole conveyor system Il to be lifted out of or away from the vessel I6 and the lower frame section 36, along with the cover I3 and the upper frameA section 3| ,-which may normally be secured to the lower section 36 by bolts (not shown) through their engaging members, or in any other suitable way. The conveyor system I I may conveniently be driven by an (electric) motor 65 mounted on transverse angle bar members 66, 66 interconnecting the horizontals 36, through a speed reduction gearing 61 and a chain and sprocket drive 68 to a sprocket wheel 69 on the outer end of the sprocket shaft 62, outside the corresponding bearing bracket 63.

Preferably, the travel of the conveyor system II is intermittent, with stationary periods while the carriers I4 are in the wells 26, 2|, 22. Such intermittent operation of the conveyor system may be produced automatically, or semi-automatically, as preferred, by suitable control of the electric supply circuit 16 of the conveyor motor 65 by the conveyor itself. As shown, the conveyor is provided with a cam device 1| for each carrier I4, attached to one of the sprocket chains 48 at the carrier I4 (or in suitable position relative thereto), and* the motormsupply circuit 16 includes a self-closing cutout or' limit 'switch 12 (shown as mounted on the chain guide 51) adapted to be wiped and opened by each cam 1I,-thus stopping the motor 65 and the conveyor each time a cam acts on the switch 12. This cutout switch 12 comprises a blade 13 pivoted at 14 and normally held against the contacts 15, 15 (so as to close the circuit 16), by a leaf spring 16. There is also a (manual or push-button) switch 11 connected in parallel with the cutout switch 12, and thus adapted to close the circuit 16 independently of the switch 12,-but preferably self-opening as under the action of a spring 18;

The switch 12 always stops the motor 65 and the conveyor with three successive carriers I4 in treating position in the wells 26, 2|, 22. When the resulting dwell of these carriers I4 in the longitudinal members of the base.

wells 26, 2|, 22 has suced for the proper treatment of the work carried by them, the operator closes the switch 11 and holds it closed awhile,

thus keeping the motor 65 and conveyor in operation until the cam 1| which last opened the switch 12 has cleared its blade 13 and allowed it to close across the contacts 15, 15 and so complete the motor circuit 16 independently of the switch 11; whereupon the operator may release the switch 11 and allow it to open. The conveyor II will then continue in operation until another cam 1| has reopened the switch 12, thus again automatically stopping the conveyor with carriers I4 in the wells 26, 2|, 22.

For handling liquid solvent and transferring it from one part of the apparatus to another, as may be required, there is shown a system including a (rotary, centrifugal) pump 86 with a suction line 8| having connections to the bottoms of the Wells 26, 2| and 22 controlled by suitable valves 82, 83, 84, and a delli ery line having connections to or above the upoer parts of said wells (above their normal liquid le "els in ordinary operation) controlled by valves 86, 81, 88, and also an external discharge connection controlled by a valve 89. The pump 86 may be driven by an (electric) motor 96 directly connected thereto, and mounted, along with the pump, on transverse angle bar members 9| (Figs. I and IV) interconnecting the By means of the pump 86 and its connections above described, liquid solvent can be transferred from any one of the wells 26, 2|, 22 to any other, or discharged from any or al1 of said wells, as may be desired. Preferably the capacities of the wells 26, 2|, 22 are such that any two of them can hold all the solvent used in the apparatus.

In ordinary operation, any liquid solvent overflowing from well 2| over dam 24 into well 22 may be periodically drawn out, so as to keep down the liquid in well 22 to the level shown in Fig, 1I, and preferably returned to well 26. As a means for doing this automatically by appropriate operation of pump 86, there is shown (Figs. I and V) an (electric) float switch 93 connected to well 22 and responsive to the liquid level therein, for controlling the supply of (electric) power to motor 96: i. e., the switch 93 closes when its float is in the full-line position of Fig. V, and opens when the iioat is in the dotted position. For this purpose, valves 84 and 86 may be opened and an (electric) switch 94 in the motor supply circuit 95 may be thrown into the full line position of Fig. I, so as to interpose oat switch 93 betweenl the motor 96 and the system 95. When it is desired to use pump 86 in any other way, switch 94 may be thrown into the dotted position of Fig.

other position of switch 93,'motor 96 and pump 86 will be cut out of operation.

While various modes of operation and use of the apparatus will be apparent from the foregoing description, one preferred mode of operation is as follows:

The wells 26 and 2| having been initially filled with pure liquid solvent such as trichlorethylene about to the levels shown in Fig. II, and steam being supplied to the coil 25, the solvent in well 26 may be heated up to any temperature desired for treating the work, and even kept boiling. Vapor rising from the solvent in well 26 will rise above dams 23, 24 and spread or ow toward the right (by gravity) into well 22, displacing the (lighter) air. Water (or other cooling medium) I, so as Ito cut out float switch 93, and connect 5 "motor directly into tri-e systemes. For-any will be circulated through the jacket 21. As the accumulating vapor in the upper portion 28 of the vessel reaches the cool area produced by the jacket 21, it will begin to condense, and will thus 4be prevented from rising more than about midheight of this condenser 21, and, a fortiori, from overflowing or escaping from the open vessel III, -since the vapor is heavier than air. In other words, the condenser at 21 will draw and keep down the vapor level well'below the top of the `vessel I0 andthe cover I3.

The endless conveyor system I2, driven. by the motor 65, will travel in a closed course including upright loops of approach and recession down y around the large (sprocket) wheels 59, and up again, to the left and to the right of the vessel I0; an intermediate work-treating path of travel with runs down into, through, and up out of vessel I0, and up and down into and out of each of the wells 20, 2 I, 22; and a return path/of travel connecting said loops of approach and recession above the vessel and the top structure 4I.

In the well I0, the work will be initially cleaned of grease and dirt by the (hot) solvent. In the well 2i, any dirty solvent clinging to the work will be rinsed off by the much purer and cooler condensed solvent supplied thereto from the condenser 21 and trough 28. Having been heated up in well 20 by the hot solvent and cooled ofi again considerably in well 2|, the work will enter well 22 cooler than the vapor in the latter, which will therefore condense on the work and thus rinse it exceedingly clean of any last traces of grease. Ascending from the well 22, the work will dry ofi by the time it leaves the vessel I0.

The'work to be treated and cleaned can be' placed on the carriers I4 while the latter are at the loop of approach around wheel 59; and the cleaned work can be removed at the loop of recession around wheel 60. Preferably, the conveyor II will be (automatically) stopped (as above explained) with each carrier I4 in treating position near the bottom of each of wells 2II, 2i, 22, successively,'-long enough each time for the solvent toA act on the grease and dirt. Thus the travel of the conveyor I I to carry each carrier I4 from one treating position to the next may be quite rapidmuch faster than would give adequate treating time in each well if the conveyor travelled uninterruptedly.

Having thus described my invention, claim:

1. Apparatus of the character described, for treating things or work with volatile solvent whose vapor is heavier than air, comprising in combination an air-excluding treating vessel open at its upper portion for the introduction and removal of work, and provided with means affording in said vessel separate solvent wells, one for hot solvent, one, unheated, for liquid solvent con- 2. Apparatus of the character described, for` treating things or work therein with volatile solj vent whose vapor is heavier than air, comprising in combination an air-excluding treating vessel open at its upper portion for the introduction and removal of work, and provided with means affording in said vessel separate wells for hot solvent, i

for condensed solvent, and for solvent vapor; a travelling conveyor for carrying Work into treatlng position in each of said wells, one after another; means for automatically stopping the conveyor with a given piece of work` carried thereby in each of said treating positions, one after another; means for heating and vaporizing liquid solvent in said hot solvent well, and thus supplying solvent vapor to said' solvent vapor well; means above said wells for retaining and condensing the solvent vapor; and means for collecting the condensate and supplying it to said condensed solvent well to the exclusion of the solvent vapor well.

3. An apparatus of the character described for treating things or work with volatile solvent whose vapor is heavier than air, comprising in combination a framework including open side frames; an air-excluding treating vessel mounted in said framework substantially below its top and between said side frames, and open upward for the introduction and removal of work; an endless conveyor for carrying the work suspended therefrom, and means for operating said conveyor over a closed circuit with a return run and guide means therefor mounted on the side frames at the top of the frame, and with'a primary course including upright approach and recession loops guided by means on the opposite ends of the frame beyond the ends of the vessel, extending down from upper guide means and up again substantially to the top of the frame, guide means mounted on the side frames at the top of the framework furthe conveyor travel from and to said loops, and a work-treating path of travel between said latter guide means at opposite ends of the frame including runs downward and upward into and out of the open top of the vessel; and means for retaining solvent vapor in the vessel and preventing overflow thereof, including condensing means exposed to the vapor substantially below the top of the vessel for correspondingly drawing down the vapor level in the vessel.

CLARENCE F. DINLEY.

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