US2254538A - Still - Google Patents

Description

Sept. 2, 1941.

A. I. NEWMAN STILL Filed July 13, 1939 Patented Sept. 2, 1941 STILL Alexander I. Newman, Chicago, lil., assignor to Precision Scientiiic Company, Chicago, Ill., a corporation of Illinois Application July 13, 1939, Serial No. 284,310

(Cl. ZIB-189) 4 Claims.

The invention relates -to improvements in stills and finds particular utility as applied to apparatus for distilling water.

'Ihe general aim of the invention is to provide' an improved still which is small and compact in size so as to be readily. portable, is entirely automatic in operation, includes no moving parts which are likely to wear and get out of order, can be readily cleaned, and which, thoughrugged in construction and efficient in operation, is low in cost.

Another object of the invention is to provide Further objects and advantages of the inveh tion will become apparent as the following description proceeds, taken in connection with the accompanying drawing, in which:

Figure 1 is a general perspective view of a still embodying the invention.

Fig. 2 is a vertical sectional view, on a somewhat reduced scale, of the still of Fig. 1.

Fig. 3 is an exploded perspective view, on a reduced scale, of the still of Fig. 1.

By way of exemplication the invention has been shown herein as embodied in a small portable water still adapted for laboratory or industrial use in instances where a capacity of about a quart per hour is adequate. It will be obvious, however, to those skilled in the art that various features of the invention are applicable to other forms or sizes of stills. Accordingly, even though one particular embodiment of rthe invention has been shown and described in some detail there is no intention to thereby limit the invention to such embodiment, but, on the other hand, I intend to cover all modications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

In the illustrative construction (Fig. 1) the still shown is of generally cylindrical shape, being compact and easily portable. Raw water for distillation as well as for condenser cooling is supplied through a single inlet I0 by a suitable hose (not shown) and the distilled water is bled of! through an outlet spout II.

In brief, the raw water from the inlet I0 is discharged to a condenser cooling waterchamber I2 (Fig. 2) where it cools the surface of the condenser. From this chamber I2 water is overflowed through a pipe I3 to a cup I4 from which it passes into an evaporating chamber I5. In this latter chamber the water is boiled and the vapor passes into a condensing chamber I6 where it is condensed and the distillate Il collected. Finally, this distillate is Vdrawn oil through the outlet II.

In order to facilitate cleaning of the stilis active surfaces it is made up in a series lof separable units or sections, here shown (Figs. 2 and 3) as three in number and designated generally by the letters A, B and C. In general the lower section A embodies a vessel defining the evaporating chamber I5 and also includes a heating unit for this vessel; the intermediate unit B comprises a vessel fashioned to receive the distillate I1; and the upper section C embodies a water cooled condenser unit. By simply separating these three sections all of the active surfaces of the still are exposed for cleaning as will hereinafter appear in greater detail.

The lower unit A includes an outer cylindrical sheet metal casing I8 (Fig. 2) in the upper portion of which is removably mounted a cupshaped metal evaporating pan I9, defining the evaporating chamber I5. Any suitable heating unit may be located beneath the evaporator pan I9, this unit, in the present instance, being illustrated as a resistance type electrical heater 20 controlled by a switch 2|. The cup I4 is fixed on the side of the unit A by an inlet nipple 22 through which it communicates-with the evaporator pan I9. 'I'his nipple 22 is fixed to the cup I4 and is threaded in the side of the removable pan I9 to hold the latter in lplace. A vertical overow pipe 23, which may be connected with a waste drain through a rubber hose (not shown), sserves to regulate automatically the level of raw water 2l in the evaporator pan I9. Water enters the cup I4 from the pipe I3 and nils the cup` and evaporating pan I9 until it reaches the top of the overflow pipe 23. Upon reaching this level any excess water is drained on through the pipe.23.k

The intermediate unit B includes a cylindrical sheet metal casing 25 dimensioned to telescope within the top of -the lower unit casing I0. An.

titions 21 and 2l are flxedinthe intermediate casing 2l. The lower partition 2l has a flanged edge 2l which is press-fitted about the lower edge of the casing 2l while the peripheral edge of the upper partition 2l is fastened to the inner wall of the casing. Ihe lower partition or dome 2'l constitutes a top wall for the evaporating chamber il. and the upper dome 22 cooperates with the casing 2l to deilne aV vessel for collecting the distillate i1. A channel through which vapormayrisefromtheevaporating chamber Il to the condensing 4chamber it is formed by a vertical metal tube tl projecting through kthe centersofthepartitions 2l, 2Iandfixedtothem.

In order to prevent raw water from reaching the condensing chamber il even during violent boilinginthee'vaporatingchamberiiabaille plate 3i is located at the lower or inlet end of the tube tl. 'Ihis baille may be square inshape and fastened at its corners to the dome 21. Consequently, water vapor rising in the evaporating chamber il passes around the marginal edges of the baille 2l and thence into the tube 2l which is of somewhat smaller cross section than the Dame.' 5

The upper section C includes a cup-shaped .sheet metal casing 32 on the outerwall of which is welded an annular plate 22 for supporting rit on the top of the intermediate casing section 25. A depending flange 34 on'the plate t3 is telescoped over and ilts' snugly about therolled edge on the upper rim of the casing 2l. The center of thermal conductivity. Also, the active inner surfaces of the still are preferably coated with pure block tin so as eifectually to prevent corrosionv and contaraination of the distilled water produced. j p

With the arrangement described above it is but the work'of a moment to take the still apart so as to exposeall of its-active surfaces in order that they can.be' scrubbedclean (see lig. 3). For thispurpose the intermediate section B is lifted oi! of the lower section A, the upper section C pulled on of the intermediate section B and the covertl` removed. It will be noted that the lower end of the feed-water supply tube i2 exi tends loosely into the open topcof the cup il (Fig. il) so that these parts offer no impediment to the separation of the still sections or units.

When the still has been pulled apart in the man? ner noted the evaporator pan il is entirely open for cleaning. If desired it can be removed entirely from the base casing il by simply unscrewingthenipple22inthecupll,whichisnormally the casing 22 is deeply dished to form a dome SI defining the condenser chamber it. With the casing so fashioned the condenser cooling water chamber l2 has a lower annular portion i2Il which chamber il.

The casing 22 is dimensioned so that the lower portion of the annular cooling chamber i2* projects below the distillate outlet ii .and into .the body of distillate Il. The cooling water entercompletely surrounds the condensing.

threaded into the evaporator pan to hold it in place. In the same way the active lower and upper surfaces of the domes 2l` and 2l are exposed at the opposite ends of the intermediate section 2l. In the case of the upper section C'the entire lower surface of the case 22 and dome Il is ex- Alivosed at the lower end of the section while removal 'of the cover Il givesaccess to the inteing thechamber i2 is directed from the inlet s il down through a pipe 26 into the bottom of the annular chamber i2.. In this `way the distillateV i1 is eifectually cooled by the entering cooling water, and the degree of cooling for the distillate can be regulated by varying the amount of the cooling water which is supplied the condenser. The top of the condenser is closed bya removable sheet metal cover 3l telescoped within the top of the casing 22.

To utilize a maximum amount of the surface of the casing 22 for condensing purposes, one or more equalizing tubes 22l (Fig. 2) are arranged to establish communication between the chamber il and the space or chamber lying between the outer wall or jacket portion of the casing I2 and inner wall of the casing 25.v In this way water vapor passes out to this latter space through the.

volatile gases, such as carbon dioxide,-chlorine and ammonia, provision is made for expelling these gases from the top of the still before the vapors are condensed, thereby rendering the distilled water gas-free. For this purpose a vertical tube 3l islet into the top of the condenser dome g Y distilled water can be rior of the cooling water chamber. Consequently, all of the parts can be thoroughly flushed out, scmbbedandinspectedsoastoinsurecomplete purityof vthe distilled water made inthe still.

In the operation of the still described above, a suitable source of raw water is connected to the inlet i0 and the heater 2l turned on by the switch 2|. The raw water entering at the inlet' Il iills the cooling waterl chamber i2 and flnally'over-` Y, nows through the pipe i3 through which it passes into the cup il. This water entering the cup il nlls the cup and the communicatingevaporating pan il to the top of the overilow tube 2l. Thereafter any excesswater is drained off through the overflow tube 2l. 'I'he water 24 in the evaporating pan il is boiled and the water vapor produced passes upward around the edges of the baille 2l into the tube 3l an'd thence into the condensing chamber i6. 'I'here the water vapor impinges against the water cooling dome 3l and is thus condensed so that'it drains down to form a pool i1 in the distillate collecting vessel formed by the partition 28 andy casing 25. Upon reaching the level of the outlet il the distilledwater flows of! f through this outlet into a suitable receptacle (not shown). s

Since the condenser cooling water jacket de-v nned by the casing 22 extends down into the pool of distillate I1, the latter is cooled by an amount depending upon the temperature of the cooling water, which iny turn depends to some extent upon the rate of supply of the cooling water. Consequently, the temperature of the outgoing regulated by va n t quantity of cooling water supplied. I'.Iyilheg stlillle permits of a large degree of flexibility in this respect since even if the amount of cooling water the pipe 23 as heretofore explained. The operation described continues entirely automatically and without the necessity of supervision. Furthermore, it will be noted that there are no float valves or other moving parts required. As a consequence the still is not subject to wear, nor does it require frequent readjustment.

The ornamental design of the still illustrated herein forms no part of the present invention, but is described and claimed in my copending application for a design patent Serial No. 86,001, filed July 13, 1939, and subsequently issued on November 21, 1939, as Design Patent No. 117,756.

I claim as my invention:

l. The combination of a generallyicup shaped distillate collecting vessel having an outlet in its side wall located substantially above the bottom thereof to trap distillate in the vessel to a normal liquid level in the latter equal to the height of n said outlet from the vessel bottom, a generally cup shaped sheet metal condenser of substantially lesser diameter than the interior of said vessel nested in the latter and having a deeply concaved bottom forming a dome overlying the central portion of the bottom of said vessel, an annular lower edge portion of said condenser projecting down into the vessel below said normal liquid level so as to be immersed in the distillate trapped in the vessel below said outlet, means for supplying cooling waterto said condenser, means above said normal liquid level for conveying vapor between a first chamber defined between the dome and vessel bottom and a second chamber defined between the side walls of the condenser and vessel for condensation of such vapor on both the water cooled outer` side wall and inner dome of the condenser, and means for admitting condensable vapor to the central portion of said first chamber.

2. The combination of a generally cup shaped distillate collecting vessel having an annular side wall and( a bottom wall humped in its central portion and sloped outward `and downward toward its juncture with the side wall, an upstanding conduit projecting through the center of said bottom wall for conveying vaporizing liquid therethrough, a condenser unit removably seated in the top of said cup shaped vessel and including a central upwardly concaved dome disposed to overlie the mouth of said conduit and also including an annular jacket encircling said dome and joined to it at its lower edge to define an annular cooling water chamber about the dome, means for supplying cooling water to said chamber to cool both the dome and jacket, said vessel having an outlet located above the lower edge of the dome and jacket assembly of the condenser unit so that the llatter is immersed in the liquid distillate trapped in the vessel below said outlet to cool such distillate, said jacket being disposed in spaced relation to the vessel side wall to denne a chamber therebetween, and means dening a cross-over passage through the condenser unit for conveying vapor from the interior of the dome to the chamber between the jacket andvessel side walls for condensation of the same on the water cooled jacket.

3. In a device of the type described, the combination of an upright cylindrical sheet metal casing section having a distillate collecting pan therein, said pan being apertured for the upward passage therethrough of vapor, a condenser unit lcomprising an annular sheet metal member dimensioned to be received in the upper portion of said casing section in spaced relation to the side Wall of the latter and also including a dome wall closing the top of the open center of said annular member, said annular member dening interiorly thereof a cooling water chamber with an opening in the top thereof into the interior of s'aid annular member, an annular ilange encircling said annular member and xed thereto, said ilange extending laterally of said member and removably seated on the upper edge of said casing to support said member therefrom, and a removable lid for closing said opening in the top' of said annular member.

4. A still comprising, in combination, three generally tubular casing sections removably supported one on-another in superimposed and axially alined relation, the upper casing section being of lesser cross sectional area than the intermediate section and nested down into the interior of the latter, the lower section having an evaporating pan therein, the intermediate section having vertically spaced upper and lower transverse partitions therein constituting respectively a distillate collecting pan and atop wall of an evaporating chamber above .said evaporatevaporating pan to a point above said distillate collecting pan, an upwardly concaved dome overlying the mouth of said conduit and joined at its lower edge to the lower edge of said upper casing section to define an annular cooling water chamber about said dome, means for supplying cooling water to said annular chamber, said intermediate casing section having a. distillate outlet therein located above the lower edge of said annular water chamber so that the latter is immersed in liquid distillate trapped in the distillate collectmg pan below said outlet to cool such trapped distillate, the exterior of said upper casing section being spaced from the interior of the intermediate casing section, and means delining a cross-over passage through said dome and upper casing assembly for conveying vapor from the interior of the dome to the space between the walls of said upper and intermediate casing sections at a level above said distillate outlet.

Y ALEXANDER I. NEWMAN.

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