US2248662A - Apparatus for treating solid materials with volatile organic solvents - Google Patents

Description

July 8, 1941.

G. EDHOFER EI'AL APPARATUS FOR TREAiING SOLID MATERIALS WITH VOLATILE ORGANIC SOLVENTS Filed Feb. 8, 1938 INVENTORS Gevfiaib/ro/ s/z G'ao/PaWoz/ r KM ALA z ATTO Y Patented July 8, 1941 UNITED STATES PATENT OFFICE APPARATUS FOR TREATING SOLID MATE- RIALS WITH -VOLATILE ORGANIC SOL- VENTS Georg Edhofer and Georg Wolfl, Munich, Germany, 'assignors to Dr. Alexander Wacker .Ges.

fiir elektrochemische Industrie in. Munich, Germany,- a corporation Application February s, 1938, Serial No. 189,412 In Germany May 4, 1937 8 Claims. (01.202-169) The present invention relates to a method and apparatus for treating solid material with volatile organic solvents.

It is well known to clean articles made of metal 'or other solid materials which are covered with grease by treatment with organic volatile solvents such as trichlorethylene, perchlorethylene, carbon-tetrachloride, benzine, benzol, and the like, and to use for this purpose a cleaning vessel which is filledwith cold, heated or vaporized solvent and which may be divided into a plurality of subchambers-into which the materials to be a preand after-cleaning treatment. It is also well known to use immersing chambers which are filled with solvents of difierent temperature or of diiferent aggregate state, sothat, for example, pre-cleaning may be carried out in a solvent having a temperature which is below its boiling point, and after-cleaning is .carried out in vaporized of an apparatus suitable to carry out our present invention.

Figure 2 shows adetail of the apparatus shown in Figure 1, and

Figure 3 shows a modification of .the'detail shown in Figure 2.

- Figure 4 shows a modification of the detail shown in Figure 3.

. treated are immersed consecutively for obtaining solvent whereby it cannot be avoided that some I of the solvent adhering to the articles vaporizes when the articles are thansferred from one immersing chamber to the other whereby the goods are completely or partially dried.

Experience has shown that for certain kindsof goods it is of advantage to prevent any drying, if only partial, of the goods in between the individual treating steps and it is an object of the present invention to provide a method and means whereby the goods are at first immersed in aliquid solvent, the temperature of which is below the boiling point, whereby the articles are pre-cleaned and then directly transferred into a chamber fed with solvent in vapor state, which chamberis sealed at the bottom with the'same.

solvent in liquid state, so that at the transition of the goods from the first to the second chamber,

no contact of the goods with air takes place. Only" after the goods have further been cleaned by the solvent condensed on the goods are they brought into a cooled air zone where the rest of the solvent still adhering to the goods vaporizes and the goods are quickly dried. With this method the vapor of the solvent is in direct communication with the liquid solvent so that the latter may graduallybe heated up to the boiling point, ,which is not desired, and means are therefore provided, according to the present invention, to cool the .liquid and maintain its temperature below the boiling point.

Further and other objects of the present invention will be hereinafter set forth in the accompanylng specification and claims and shown in the drawing which, by way-of illustration, shows what we now consider to be. a preferred embodiment of our invention.

In the drawing- Figure 1 is a diagrammatic cross sectional view Like parts are designated by like numerals in all figures of the drawing.

i represents a cleaning vessel, which is com- I pletely closed with the exception of a lateral opening 2 for the insertion of the goods and the lower part 3 of'which is filled with a liquid solvent. By means of the vertical partition 4', a

shaft-like chamber 5 is formed, the bottom of which is sealed by the liquid cleaning solvent. A tube 6 terminates into the lower part of chamber 5, through which tube solvent vapor is introduced which is produced in a heated evaporator l which is partly filled with a liquid solvent. The height of the vapor zone in chamber 5 is defined by the position of the cooling coils 8 located adjacent to the walls of chamber 5, because excess vapor con-- pass thereby the loading opening 2 through which the goods to be treated are introduced and filled into and taken out of the baskets; the filled baskets are immersed and taken through the lower part 3, which is filled with cleaning fluid and conducted underneath the partition 4 and upwardly into shaft 5. In this shaft, after leaving the cleaning liquid, the baskets pass first through a zone III which is filled with vaporized solvent whereby an after-cleaningeflect is obtained by said vapor which condenses on the surfaces of the goods, and then through a cooled air zone which is located above'the vapor zone. In

- .said air zone the heated goods are cooled and dried, whereafter they are brought back over the top of the partition 4 into the neighborhood of the opening 2 where they are taken from the baskets, fully cleaned. The baskets are then re-.

filled with new and unclean goods.

The space 3 communicates with the evaporator 1 through the conduit H whereby the liquid level in the cleaning vessel and in the evaporator are maintained alike. The solvent carries out a complete cycle; it enterschamber 5 in vapor state,

is condensed, and the condensate returned to the evaporator. I

In order to obtain efllcient' condensation of the vapor on the goods, it is desirable thatthe latprocess, design, scribed, for obvious modifications will occur to ter enter the .vapor zone at low temperature and the temperature of the goodsis not increased while passing through the liquid. Since continuously hot condensate drips into the liquid from the vapor'zone II and the cooling tubes I therein, the heat so introduced must be removed;

this is done by means of cooling tubes |2 located and a light draft'of air into the vessel through opening 2 is created. The tube connection I is widened out to a funnel shaped inlet IS, the upper wide opening of which funnel includes a platform means which is located beneath the basket standing at the opening 2 so that vapor adhering to said basket and goods-therein is completely removed. I

The chains 9 and 9 are moved by connecting a crank to be operated by. hand or, as shown, a motor 20, to one of the rollers IS. The operation of the motor is preferably automatically stopped when a basket filled with cleaned goods reaches the loading opening 2, and is started by the operator when the basket is refilled with new, unclean goods. In case motor is an electric motor, this may be done by arranging a switch 2|: located at one end of a two arm lever 22 which is turned clockwise when a basket ll contacts its free end 23; thereby switch 2| is opened and the current for operating the motor 2|! interrupted. To lever 22' also'a foot pedal 25 is connected by means of a connecting rod 24. Upon depression of said pedal by the operator, the switch 2| is closed and current is admitted to the motor 20.

Instead of baskets having cross bars which connect chains 9 and 9' as shown in Figures 1 and Z, baskets H! as shown in Figure 3 may be used having lateral shafts 26 and 21 whereby one of said shafts, for example 21, is provided with a crank adapted to contact a stationary abutment 28 in the vessel I. Whenever said abutment is contacted, the basket I0 is revolved about the axis 26-21 whereby the cleaning action is increased and also quick and complete drying of the goods, particularly goods of hollow construction, is assured. Provisions for revolving the baskets may be situated at any point of the apparatus, for example, in the liquid zone and/or in the vapor zone and/or in the drying zone.

Insteadof providing a crank and abutment a pinion 29 and a rack 30 may be used as shown in Figure 4 whereby the baskets are revolved all the way while they travel through the solvent in liquid state, in vapor state and through the drying zone or, if the racks are arranged at certain parts only of the path of the baskets the baskets are continuously revolved while they travel through said parts.

While we believe the above-described embodiments of our invention to be preferred embodiments, we wish it-to beunderstood that we do not desire to be limited'to the exact details of and construction shown and dea person skilled in the art. For example, the opening 2 may the wall; a plurality of immersion chambers be arranged on top instead of on filled with cleaning liquid may be arranged in the lower part of vessel l and passed by the goods to be cleaned consecutively before they are taken into the vapor zone.

We claim:

1. The apparatus for treating solid goods with a volatile solvent comprising, in combination, a

vessel having a lower portion which is filled with said solvent in liquid state, a partition in said vessel, said partition having a lower part immersed in said solvent in liquid state and forming a loading chamber and a treating chamber within said vessel, the lower parts of said chambers being sealed from one another by means 0! said liquid solvent, an evaporator for said solvent, said evaporator having a vapor space, a conduit connected to and connecting said vapor space and said treating chamber and terminating in said treating chamber in a mouth which is positioned above the level of the solvent in liquid state, cooling means in said treating chamber and being positioned above the mouth of said conduit whereby solvent vapor condenses on said cooling means, an opening in said loading chamber for introducing into and removing the goods to be treated from said vessel, conduits terminating into said vessel adjacent to said opening and means producing in said conduits a pressure which is lower than the pressure prevailing in said vessel, one of said second-mentioned conduits terminating below said opening in said vesse'l and having a furmel configuration flaring out into said loading chamber.

2. The apparatus for treating solid goods with a volatile solvent comprising a vessel having a lower portion filled with said solvent in liquid state, a partition in said vessel, said partition having a lower part immersed in said solvent in liquid state and forming shaftlike chambers within said vessel, the lower parts of said chambers being sealed from one another by means of said liquid solvent, an evaporator for said solvent, said evaporator having a vapor space, a conduit connected to and connecting said vapor space and one of said chambers and terminating in said chamber in a mouth positioned above the level of the solvent in liquid state, cooling means in that one of said chambers to which said conduit is connected, said cooling means being positioned above the mouth of said conduit whereby solvent adapted to temporarily cooperate with said contact means, whereby upon contact of said contact means and said abutting means said containers are temporarily moved with respect to said conveyor means and the position of the goods in said containers is changed.

3. The apparatus for treating solid goods with a volatile solvent comprising a vessel subdivided into a plurality of chambers, one of said chambers being partly filled with said solvent in liquid state, and partly with said solvent in vapor state, an endless conveyor means within said vessel and moving consecutively through said chambers and v tainers is changed.

through said solvent in liquid state and subsesaid treating chamber and terminating in said quently through said solvent in vapor state, con- I tainers for the goods toibe treated directly movably connected to said conveyor means, contact means connected to said containers, and abutting means spaced apart and being connected to a stationary part of said vessel and being adapted to temporarily cooperate with said contact means,

whereby, upon contact of said contact means and said abuttingmeans, said containers are temporarily moved withrespect to said conveyor means and the position of the goods in said con- 4. The apparatus for treating solid a volatile solvent comprising a vessel subdivided into a plurality of chambers, an endless conveyor means within said vessel and moving consecutively through said chambers, containers for the goods to be treated, a shaft-like member individually connectedto said containers and to said conveyor means for individually revolvably connecting said contalnerswith said conveyor means, a crank connected with said shaft-like member and crank actuating means spaced apart and being connected with said vessel and being adaptgoods with ing and extending into said vessel, an endless conveyor means within said vessel comprising containers for theagoods to be treated, and being adapted to transport the goods to be treated con-'- secutively over said platform means and through ed to temporarily actuate said crank, whereby said containers are temporarily revolved.

5. An apparatus for treating work with a, vola- V tile solvent, said apparatus comprising a vessel having a lower portion containing solvent in liquid state, a partition in' said vessel and having a lower part immersed in the liquid solvent, said said chambers, suction means connected with and terminating in said platform means and causing a suction efl'ect adjacent to said opening and on said containers and goods from below ing over'said platform means.

7. The apparatus. for treatingsolid goods with a volatile solvent comprising, in combination, a vessel having a lower portion filled with said solvent in liquidstate, a partition in said vessel, said partition having a, lower part immersed in said solvent in liquid state and forming. shaft-like chambers within said'vessel, the lower parts of said chambers being sealed from one another by -means of said liquid solvent, an evaporator for said solvent, said evaporator having a vapor space, a conduit connected to and connecting said vapor space andone of said chambers and terminating in said chamber in a mouth positioned above the level of the solvent in liquid state, cooling means in that one of said chambers to which said conduit is connected, said cooling means being positioned above the mouth of said conduit whereby solvent vapor condenses on said cooling means.

and a vapor filled zone is created in the chamber to which said conduit is connected between-the a liquid level and the mouth of said conduit, and

and preventing vaporisation in said intake chamber, solventvapor supply means terminating in said treating chamber, cooling means disposed in said treating chamber and above the surface of the liquid solvent and above said vapor supply means for condensing the vapor and dripping the hot condensate into the liquid solvent'in said treatingchamber and creating a vapor treating zone between the liquid surface and said cooling means and a substantially vapor free zone above said cooling means, and work conveyor means disposed completely in said vessel and extending a all around said portion for transporting the work 'a volatile solvent comprising a vessel having an opening for taking the goods to be treated into and removing same from said vessel, said vessel having a lower portion which is filled with said solvent in liquid state, a partition in said vessel,

said partition having a lower part immersed in said solvent in liquid state and forming a loading chamber and a treating chamber within said vessel, the lower parts of said chambers being an endless conveyor means disposed completely within said vessel and extending around said partition and being adapted to transport the oods to be treated consecutively from one of said chambers, through said solvent in liqi'iid state, underneath said partition, through said vapor zone, above-said partition, and back into 'the chamber from which they started.

8. The apparatus for treating solid goods with a volatile solvent comprising, in combination, a vessel having a lower portion filled with said solvent in liquid state, a partition in said vessel, said partition having a lower part immersed, in said solvent in liquid state and forming shaft-like chambers within said vessel, the lower parts of said'chambers being sealed from one another by, means of said liquid solvent, an evaporator for saidsolvent, said evaporator having .a vapor space, aconduit connected to and connecting said vapor space and one of said chambers and terminating in said chamber in a mouth positioned above the level of the solvent in liquid state, cooling means in that one of said chambers to which said conduit is connected, said cooling means being positioned above the mouth of said conduit whereby solvent vapor condenses on said cooling means, and an endless conveyor means disposed entirely within said Vessel-and around said partition for moving the goods to be treated sealed from one another by means of said liquid solvent, an evaporator for said solvent, said evaporator having a vapor space, a conduit con-, nected to and connecting said vapor space and around, saidpartition from one of said chambers into the. other and back into the first chamber.

" GEORG EDHOFER. cacao. wow.

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