US1902538A - Distilling apparatus - Google Patents

Description

March 21, 1933. w. F. BRACE El AL DISTILLING APPARATUS Filed Jan. 19, 1951 2 Shuts-Sheet 1 W ww m w a #1; W a 0 s 0 ug March 21, 1933. w. F. BRACE ET AL DISTILLING APPARATUS Filed Jan. 19, 1931 2 Sheets-Sheet 2 Patented Mar. 21, 1933 UNITED STATES PATENT OFFICE WILLIAM F. BRACE AND FERNAN D E. BELUCHE, OF BUFFALO, NEW YORK, ASBIGNOBB TO 8. I. BOWSER & COMPANY, IN 0., OF FORT WAYNE, INDIANA, A CORPORATION OI INDIANA DISTILLIN G APPARATUS Application filed January 19, 1981. Serial No. 508,590.

This invention relates to a distilling apparatus and more particularl to a vacuum distilling apparatus for han ling used solvents such as the gasoline used in dry cleaning establishments, the still first evaporating the solvent to separate the solvent impurities and thereafter separating the water from the distillate so as to provide a purified solvent which is suitable for reuse.

One of the principal objects of this invention is to provide such an apparatus which is highly efficient in its operation, compact, rugged and extremely simple to operate. 1

'A further purpose is to provide a distilling apparatus which handles large quantities of solvent and in which adequate provision is made to prevent any undistilled liquids entrained in the vapors from passing from the still and mixing with and contaminatin the purified solvent.

A urther purpose is to provide a still which can be quickly and easily cleaned by the application of live steamwithin the still and also, when necessary, tion of caustic into the same to remove any encrusted sediment or solids left in the bottom of the still.

' Another purpose is to provide preheating means for such a distilling apparatus through which the dirty solvent passes before being introduced into the still and in which special provision is made to insure that all the dirt and sediment brought into the preheater passes through the preheater and into the still without danger of clogging or impairing the efliciency of the preheater.

Another purpose is to provide such a distilling apparatus which contains a condenser for the vapors which condenser has special provision to insure a uniform flow of the vapors to be condensed through all of the tubes of the condenser thereby insuring that the condenser operates at maximum ciiiciency.

Another purpose is to provide such a disby the introductilling apparatus in which special means are provided to separate water from the distilled solvent in a simple and efficient manner thereby avoiding the necessity of special equipment to fractionally distill the product.

Other objects are to provide such an apparatus which construction and operation, can be manufactured and installed at comparatively low cost, and will not get out of order under conditions of constant service.

In the accompanying drawings:

Figure 1 is a front elevation of the distilling apparatus involving our invention.

Figure 2 is a vertical section through the still preheater and condenser thereof.

'Figure 3-3, Fig. 2.

Figure 4 is a vertical section through the separator or filter in which the water is separated from the distillate.

The dirt solvent to be distilled and reconditione for use is introduced to the system through an inlet pipe 5 from a solvent supply tank (not shown) to a feed tank 6. At its upper end this .feed tank 6- is provided with an overflow pipe which is arranged to conduct an excess of solvent back to the supply tank. The feed tank 6 also preferably has an outlet 8 at its bottom so that; any accumulated sediment at the bottom of the tank can be drawn oil.

From the feed tank 6 the dirty solvent passes through a line 9 into one header 10 of a heat exchanger indicated generally at 11. As best shown in Fig. 2, this heat exchanger 11 comprises a tubular shell 12 the ends of which are welded to circular tube sheets 13, 13, and the preferably made of welded to a ring 15 opposite header 14 is pressed metal and is which serves as an attaching flange. A gasket 16 is interposed between the ring 15 of the header and the adjacent tube sheet 13 and these parts are securely united by a plurality of bolts 17.

is simple and reliable in its The header 10 to which the pipe 9 connects is similarly made of pressed metal and has welded thereto a ring 18 which serves as an attaching flange. Between this flange 18 and the adjacent tube sheet 13 a gasket 19 is interposed and together by a plurality of bolts 20. Within the header 10 is arranged a horizontal dividing partition 21 which forms a web across the entire chamber formed by the header 10. The pipe 9 connects with the lower chamber 22 formed in this header 10 by the partition 21 and the outlet pipe 23 connects with the upper chamber 24 formed by this partition 21. It is therefore apparent that the incoming dirty solvent is forced to pass through the lower chamber 22 of the header 10, lower set of tubes 25 which are connected and are supported by the tube sheets 13, interior of the header 14, upper set of tubes 26, upper chamber 24 in the header l0, and out through the outlet pipe 23. In passing through the tubes 25 and 26 the solvent is preheated as hereinafter described. In the absence of provision to prevent it, some of the sediment would settle in the header 10. To prevent this a plurality of very small holes 27 are provided in the partition 21 which permit a small proportion of the solvent to by-pass from the chamber 22 to the chamber 24 and thereb insure a greater flow of the solvent t rough these chambers than through the tubes 25 and 26. By reason of this increased flow dirt and sediment is less likely to collect in the preheater than if all of the solvent were forced to traverse the heat interchanger including the tubes 25 and 26.

The preheated solvent then passes from the preheater through the pipe 23 and passes through a strainer trap 28. This strainer trap can be of any usual and well known construction and removes a portion of the solids contained in the solvent before the solvent is introduced into the still. From the strainer trap the solvent passes through a pipe 29 past a valve 30 to afloat valve contained in a casing 31 and which regulates the amount of solvent admitted to the still in accordance with the level of the liquid in the still. This float valve can be of any usual and well known construction and is provided with an equalizing line 32 leading to the upper part of the still above the level of the liquid therein and with an equalizing line 33 connecting the float valve chamber with the interior of the still below the level of the liquid therein. The opening and closing of the float valve in response to the lowering and rising of the level of the solvent in the still regulates the flow of solvent through the float valve outletnline 34 which leads to the bottom of the sti these partsare firmly drawn.

When it is desired to fill the still quickly a by-pass line 35 is provided around the float valve 31, this line connecting the line 29 in front of the valve 30 with the float valve outlet line 34 and containing a valve 136 which upon being opened permits the solvent to by-pass the float valve completely and thereby permit of filling the still more rapidly. The still indicated generally at 37 is composed of a tubular sheet metal body 36 and has a ring 37 welded toits upper end, this ring serving as a connecting flange between a similar flange 38 welded to the upper dome or head 39 of the still. A suitable gasket 40 is interposed between the flanges 37 and 38 and these flanges are connected by a plurality of bolts 41. The bottom of the tubular shell 36 is enclosed by a sheet metal bottom 42 which is welded to the tubular body 36 as illustrated at 43 and is dished downwardly to a valved outlet 44 through which valved outlet 44 the sediment is withdrawn.

The level of the solvent introduced through the solvent supply line 33 is controlled by the float valve 31 so as to be maintained substantially at the level indicated in Fig. 2. This body of solvent with its contained water and dirt is distilled by means of live steam in the following manner:

The steam under pressure is supplied through a steam inlet line 45, passes through a valve 46 and line 47 to a reducing valve 48 which reduces its pressure the desired extent. From there the steam passes through a gage 49 and line 50 into the still 37. The line 50 is formed to provide a vertical part within the still and the bottom of this vertical part of the line 50 connects with the upper tube sheet 51 of a steam chest 52. This steam chest 52 also has a lower header 53, the upper and lower headers being connected by a cylindrical shell 54 which is welded to the tube sheets 51 and 53 and between the tube sheets 51 and 53 are also arranged a plurality of tubes 55, these tubes being open at their upper and lower ends so as to heat the solvent rising in them. The live steam entering the steam supply line 50 enters the steam chest formed by the tube sheets 51 and 53 and the shell 54 circulates among the tubes 55 and condenses therein, the condensate passing out through a condensate outlet line 56 and steam trap 57 The steam chest is supported on a suitable number of angles 58 welded to the interior of the shell 36 by similar angles 59 welded to the shell 54 of the steam chest and to the upper tube sheet 51 of the steam chest is also connected a pipe 60 which leads to a valve 61 on the exterior of the shell 36 and by means of which any trapped air is exhausted from the steam chest so as to inlet 44 thereof.

full efiiciency. The still also has the usual manhole 62 by means of which the still can be entered water level gage 63, pressure and temperature gages 64, 65, and the like. During the distillation process the still 37 becomes encrusted with sediment and other solids and after a long period of service the still must be cleaned. For this purpose both steam and caustic can be introduced into the still. The steam is introduced at the top of the tank through a line 66 which connects the upper part of the still 37 with the steam supply line 45 by means of a bypass line 146, the steam through this line 66 being controlled by a valve 67 and live steam is also introduced into the lower part of the tank through the by-pass line 146, by-pass line 68, valve 69 and pipe 70 containing a valve 71. The pipe 70 extends through the side of the shell 36 of the still and terminates immediately adjacent the valved out- Caustic can be introduced to the still 37 from a supply line 72 through a pipe 73 containing a valve 74. When it Is desired to clean the still 37 the supply of solvent to the still is cut oil? and any solvent in the still is withdrawn through the .valved outlet 44. The steam valve 46 also has been closed and the steam valves 69, 67 and 71 are opened. Live steam under full pressure therefore passes from the supply line 45 through line 146, line 66 and valve 67 into the upper part of the still 37. 'At the same time a part of this live steam also passes from the supply line 45 through by- pass lines 146 and 68, valve 69, line 70 and valve 71 into the bottom of the still 37 adjacent the outlet 44 thereof. Caustic is also forced from the tank 72 through the line 73 and valve 74 into the bottom of the tank. The continued application of live steam and caustic inside of the still soon cleans any sediment encrusted therein and the still is ready for reuse.

The solvent passing up through the tubes 55 of the steam chest 52 is rapidly raised to its boiling point and is thrown violently upward out of the upper ends of these tubes. To prevent the solid entrained solvent from passing over the vapors a baflle 75 is provided. This bafile 75 consists of an upper inverted dish shaped part 76 which surrounds and is welded to the vertical part of the steam supply line 50 and has a down turned rim so as to deflect the vapor and its entrained liquid downwardly toward the body of undistilled solvent in the still. This inverted dish shaped portion 76 of the, baflle is supported by an inverted conical support (7 which also surrounds and is welded to the vertical part of the steam pipe 50 and at its outer rim is welded to the under side of the inverted dish shaped baflle 7 6 within the down turned rim thereof. It will therefore be apparent that the greater part of the entrained solvent carried up by the boiling and vaporization of the solvent in the tubes 55 will be returned and prevented from passing over with the vapor. In the dome 39 of the still 37 is arranged a vapor outlet pipe 78 which depends into the still. This vapor pipe can be of any suitable form but is preferabl welded to a ring 79 which is in turn wel ed to the dome 39. To prevent any entrained solvent from passing out through this pipe 78 with the vapors a trap 80 is arranged under and surrounding the lower end of this vapor outlet pipe 78. This trap can be of any suitable form but is preferably in the form of a box made of sheet metal or the like and dome 39 by means ofsuitable hangers 81 through a return line 82 which delivers it to the body of the solvent in the bottom of the still. To the upper side of the ring 79 forming part of the vapor outlet pipe 78 is secured the inlet 83 to the preheater 11. This inlet 83 comprises a pipe which is trap 80 passes outv welded to the side of the shell 12 of this preheater and communicates with the interior thereof and to the lower end of the pipe 83 is welded a ring 84, this ring 84 being connected to the ring 79 of the vapor outlet pipe 78 by means of screws 85 or in any other suitable manner. The vapor passing into the preheater shell 12 circulates around the tubes 25 and 26 therein and thereby heats the incoming undistilled solvent flowing through the tubes 25 and 26 as previously described. At the opposite end of the preheater 11 an outlet pipe 86 is welded, this pipe also being welded to the dome or top head 87 of a condenser indicated generally at 88. This condenser comprises a tubular shell 89 which at lower end is welded to a similar tube sheet 91. Between these two tube sheets 90 and 91 and within the shell 89 are arranged aplurality of tubes 92 which communicate with the headers at the upper and lower outlet 86 of the preheater as described and has welded to its lower end a ring 93 which forms an attaching flange for this header. A gasket 94 is interposed between this attaching flange 93 and. the tube sheet 90 and these parts are securely united by means of bolts 95 or in any other suitable manner. The lower header 96 is similarly made of sheet metal and has welded .thereto a ring 97 which serves as'an attaching flange. Between this attaching flange 97 and the-tube sheet 91 a gasket 98 is interposed and these parts are drawn together by means of bolts 99 or the like. In order to distribute the vapor and condensate from the preheater 11 uniformly to the various tubes 92 of the condenser 88 a distributing bafiie 100 is arranged within the upper header 87. This distributing baffle 100 is of frustal form with an opening at its top and its bottom and is supported by suitable angles 101 so that the incoming vapors from the preheater 11 are spread out and uniformly distributed over the open upper ends of the tubes 92. The cooling water for cooling the condenser is admitted through a cooling water inlet pipe 102 which communicates w'th the shell 89 and this water circulates around the tubes 92 and up through the shell 89 in counter flow to the vapors descending in the tubes 92 and out through its'cooling water outlet 103 at the upper end of the shell 89. The vapors flowing down through the water 1 cooled tubes 92 therefore condense, the condensate collects in the lower header 96 and is pumped out through a condensate outlet pipe 104.

This condensate outlet 104 connects with the inlet of a pump 105 which can be driven in any suitable manner as by means of pulleys 106 and the condensate is pumped through a pipe 107 into the bottom of a water separator 108. Connected to the pipe 107 is a stand pipe 109 at the upper end of which an expansion chamber 110 is arranged. The upper end of this expansion chamber can be provided with a vent pipe. Before the addition of this stand pipe 109 and the expansion chamber 110, it was found that air would sometimes be drawn from the condenser by the pump 105 and the pump would race and force the air through the separator at high velocity and disturb the proper operation of the separator 108. By the provision of the stand pipe 109 and expansion chamber 110, such air, instead of being forced through the separator 108, is forced up through the stand pipe, expansion tank 110 and out through the vent pipe. At the same time the stand pipe 109 normally provides a head of condensate between the outlet of the pump 105 and the separator 108 so that a substantially uniform flow of liquid through the separator 108 can be maintained. The water separator 108 as best shown in Fig. 4 consists of a tubular shell 111 which is closed at its lower end and its bottom downwardly dished so that the water separated out can be removed through a valved outlet 112. The water, in the case of gasoline, is heavier than the solvent and hence on flowing into the bottom of the separator, the greater part of the water settles to the bottom and is withdrawn at intervals through the petcock 112.

Substantially all of the water settles in the lower part of the shell 111 but a small amount does not settle and this moisture must be removed by additional filtration. To remove this moisture a fibrous filter is arranged in the separator 108 which is preferably constructed as follows:

To the sides of the interior of the shell 111 is welded an annular flange 113 to which is screwed a perforated circular plate 114. This plate supports a body 115 of fibrous cotton or the like and this body of fibrous cotton is held in a slightly compressed condition by another circular perforated plate 116 resting thereon. The desired pressure is obtained by means of a rod 117 which is threaded at both ends and extends through both plates 116 and 114 and through the body of cotton 115. To the lower end of this rod 117 and below the lower perforated plate 114 is secured a spider 118 the arms,

of which engage and support the lower face of the perforated late 114 and over the upper plate 116 an around the rod 117 is arranged an upper spider 119. A wing nut 120 is threaded onto the upper end of the rod 117 above the upper spider 119 so that upon tightening this wing nut 120 the two spiders 119 and 118 are drawn together and the fibrous body 115 compressed between the upper and lower perforated plates 116 and 114. The upper open end of the water separator 108 is closed by a loosely fitted cover 121, and to observe the level of the separated water in the lower part of the shell 111 a sight glass 122 is provided, the upper end of which communicates with the side of the shell 111 immediately below the body of fibrous material 115 and the lower end of which communicates with the bottom of the shell 111. The condensate consisting of both the condensed solvent and an amount of water is forced by the pump into the lower part of the shell 111 through the pipe 107 and up through the fibrous cotton body 115. In flowing through this fibrous body 115 the water is held back and collects in the bottom of the shell 111 where its amount is visible through the sight glass 122 but the pure distilled solvent passes up through the body of fibrous material 115 and out through the purified solvent outlet line 123 in a condition available for re-use.

During the start of the filtering operation, the condensate sometimes comes over cloudy and until the .system is operating at full efliciency and recovering a clear and pure solvent, it is desirable to bypass this cloudy product back to the main solvent supply tank for redistillation. For this purpose a bypass pipe 125 connects with the lower part of the separator 108 and at the start of the distilling operation the cloudy solvent, instead of being withdrawn through the outlet 123 by means of suitable valves, (not shown), is bypassed through the bypass pipe tank (not shown) for redistillation, When the solvent starts to come over clear, the bypass flow of solvent through the bypass pipe to the main solvent-supply 125 is out off and the dehydrated clear solvent asses out through the outlet 123, as descrilied.

From the foregoing it will be apparent that our invention provides a distilling apparatus which insures the complete separation of all foreign substances from a solvent such as dirt and water from gasoline in dry cleaning establishments. The equlpment is sturdy and compact and is extremely inexpensive and simple in both construction and operation. Provision is made throughout for the prevention of impurlties' passing through the still, preheater, condenser or separator so that the final product consists of entirely purified solvent. It will also be observed that the system can be readily cleaned at any time and is so designed that it requires cleaning or adjustment only at infrequent intervals.

We claim as our invention:

1. In an apparatus of the character described for removing foreign substances from a liquid, a preheater and a still, means for. conducting the liquid to be treated first through said preheater and thence to said still, means for heating said still, sald preheater comprising means forming an upper header chamber, means forming a lower header chamber arranged immediately be low said upper header chamber, means for conducting the liquid to be treated into one of said header chambers and out of the other header chamber, tubes connecting said chambers, means increasing the flow of liquid through said header chambers without increasing the flow of liquid through said tubes, comprising means forming a restricted by-pass directly connecting said header chambers and means for conducting the vapors from said still around said tubes to preheat the liquid flowing therethrough.

2. In an apparatus of the character described for removing foreign substances from a liquid, a preheater and a still, means for conducting the liquid to be treated first through said preheater and thence to said still, means for heating said still, said preheater comprising a tube sheet, a header enclosing one side of said tube sheet, a partition between said header and tube sheet and forming two header chambers, said partition being provided with a restricted by-pass opening connecting said chambers, tubes extending through said tube sheet and forming at least a part of meansfor connecting said chambers, means for conducting the liquid to be treated into one of said header chambers and out of the other header chamber and means for conducting the vapors from said still around said tubes to preheat the liquid flowing therethrough.

3. In an apparatus of the character described for removing foreign substances from a liquid, a preheater and a still, means still, means for heating-said still, said pre-' heater comprising a pair of tube sheets, a

shell connecting said tube sheets, tubes con-.

necting said tube sheets, a header enclosing the outer side of each of said tube sheets, a partition in one of said headersand form ing two chambers therein, said partition being provided with a restricted by-pass opening, means for conducting the liquid to be treated intoone of said header chambers and out of the other whereby the preponderance of said liquid flows through one of said chambers, a part of said tubes, theopposite header chamber, the remainder of said tubes and out through the other header chamber and a. limited amount of said liquid bypasses through said opening and means for conducting the vapor from said still through said shell to preheat the liquid as it flows through said tubes.

4. In an apparatus of the character described for removing foreign substances from a liquid, a still having a steam chest, means for conducting steam to said steam chest, means for conducting the liquid to be treated to said still, and a horizontal bafile of inverted cone form and having an outer reversely formed down turned rim opposing the flow of vapors, said bafile being suspended in said still immediately above said steam chest and spaced from the walls of said still to prevent the passage" of entrained liquid with the vapors generated by said steam chest and passing upwardly between the .walls of said still and said down turned rim.

5. In an apparatus of the character described for removing foreign substances from a liquid, a still having a steam chest, means for conducting steam to said steam chest, means for conducting the liquid to be treated to said still, and a horizontal baifle comprising an upper horizontal plate having a down-turned rim opposing the flow of the vapors and a conical lower plate con.- nected at its edges to and depending from said upper plate, said conical plate directing the vapors to said downturned rim and said baflle being suspended immediately above said steam chestto prevent the passage of entrained liquid with the vapors generated by said steam chest.

6. In an apparatus of the character described for removing foreign substances from a liquid, a still comprising a shell, a-

steam chest arranged in said she I and comprising upper and lower tube sheets, a sheet metal body connecting said tube sheets, tubes connecting said tube sheets within. the bod and adapted to contain the liquid to be treated, means for conducting the liquid to be treated to said shell and means for conducting steam to said steam chest comprisina a steam pipe entering said shell and having a vertical part arranged centrally above said steam chest and communicating with the chamber formed by said tube sheets, sheet metal body and tu es and a baflie supported in said vertical part of said steam pipe, said baflle. comprising a horizontal disk shaped member surrounding said pipe and supported thereby and having a downturned rim, said baflie being adapted to pre- 10 vent the passage of entrained liquid with the vapors generated by said steam chest.

In testimony whereof we hereby aflix our signatures.

WILLIAM F. BRACE. FERNAND E. BELUCHE.

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