US3238065A - Method and apparatus for maintaining a constant boiling liquid level in vapor solvent degreasing operation - Google Patents

Method and apparatus for maintaining a constant boiling liquid level in vapor solvent degreasing operation Download PDF

Info

Publication number
US3238065A
US3238065A US194270A US19427062A US3238065A US 3238065 A US3238065 A US 3238065A US 194270 A US194270 A US 194270A US 19427062 A US19427062 A US 19427062A US 3238065 A US3238065 A US 3238065A
Authority
US
United States
Prior art keywords
bath
boiling
level
vapor
maintaining
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US194270A
Inventor
Jr Lawrence Fullhart
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EIDP Inc
Original Assignee
EI Du Pont de Nemours and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by EI Du Pont de Nemours and Co filed Critical EI Du Pont de Nemours and Co
Priority to US194270A priority Critical patent/US3238065A/en
Priority to BE631669D priority patent/BE631669A/xx
Priority to DK214163AA priority patent/DK119339B/en
Priority to DE19631546176 priority patent/DE1546176B1/en
Priority to NL63292666A priority patent/NL140014B/en
Priority to CH596863A priority patent/CH483282A/en
Application granted granted Critical
Publication of US3238065A publication Critical patent/US3238065A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/02—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using non-aqueous solutions
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
    • C23G5/02—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents
    • C23G5/04—Apparatus
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F43/00—Dry-cleaning apparatus or methods using volatile solvents
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/7287—Liquid level responsive or maintaining systems
    • Y10T137/7498—Barometric

Definitions

  • FIG. 2 METHOD AND APPARATUS FOR MAINTAINING A CONSTANT BOILING LIQUID LEVEL IN VAPOR SOLVENT DEGREASING OPERATION Filed May 14, 1962 FIG. 2
  • This invention relates to apparatus for use in the control of a process for the treatment of metals and other materials with a boiling chlorinated solvent composition. It relates particularly to an improved apparatus for maintaining a boiling treating bath comprising a chlorinated solvent composition at a substantially constant level and composition.
  • Chlorinated solvents are the major constituents of a variety of treating baths in which metals and other materials are cleaned, coat-ed or modified by immersion in the boiling bath. Such processes include degreasing and cleaning in which metals, cloth fabrics and other materials are dipped into a substantially pure solvent. Processes in which the material treated is modified include metal conversion coating in which the boiling chlorinated solvent treating bath contains chemical agents, such as phosphoric, chromic and/or oxalic acid in combination with various bath adjuvants. In all of these processes, small amounts of the treat-ing bath are continually removed with the treated materials by drag-out and by diffusion across the interface between the air and the vapor above the boiling bath since the treating vessel must be open for the addition and removal of the various materials to be treated.
  • the boiling bath level in the treating vessel drops off and the path composition must be replenished from time to time.
  • the level of the treating bath is constantly changing and it is sometimes too low and sometimes too high.
  • non-continuous addition of a maintenance solution impairs the uniformity of the treating process since, under these conditions, the concentration of the active treating agents varies between upper and lower extremes and is seldom .at the optimum value.
  • the boiling bath of this invention comprises as its major ingredient a chlorinated solvent whose vapors at the boiling point, which is preferably at least about 70 C., have a density at least about three times that of air at the same temperature.
  • Other bath constituents are present to the extent of not more than about 10% by weight. These include solvent stabilizers, chemical treating agents and various adjuvants, such as solvents, catalytic activators, etc.
  • the vapor level of the boiling bath vapors in the treating vessel is maintained at least one foot above the boiling liquid and is preferably about two to ten feet above this level.
  • the conduit leading from the reservoir into the treating vessel should preferably have a diameter ranging from about three quarters of an inch to about one inch although somewhat smaller and larger diameters are acceptable.
  • the conduit must lead downward from the reservoir and, though it may proceed on a level for short intervals, must never sink below the level at which the bath is to be kept in the treating vessel or have a reverse upwards curve which would impair the constant feed of solution from reservoir to bath.
  • the opening in the reservoir be at the bottom thereof and be located at a point higher than the level at which the boiling bath is to be maintained in the treating vessel. It should also be noted that since it is impossible to support liquid in a reservoir at level equivalent to a hydraulic head greater than atmospheric pressure, there is no advantage in a reservoir positioned higher than compatible with such a liquid level.
  • the hydraulic pressure head H in FIGURE 1 should not be more than about 50% of the maximal theoretical value.
  • This maximal value in feet can be calculated from the vapor pressure of the bath in millimeters of murcury at the reservoir temperature P and the density of the bath at reservoir temperature D by means of the following formula in which the maximal head in feet equals H
  • the figure 760 in this equation is the value for atmospheric pressure in millimeters of mercury and should be replaced by the actual barometer reading for accuracy.
  • the figure 13.55 is the density of mercury and the figure 305 is the conversion factor which converts millimeters to feet.
  • a value of approximately 2.1 feet is obtained when the bath consists of trichloroethylene at a reservoir temperature of 30 C. when the value for the vapor pressure of trichlorethylene P is mm. and its density is about 1.46. With trichlorethylene at 40 C. when its vapor pressure is 132 mm., the maximal head value would be 19 feet.
  • the preferred maximum head value for trichlorethylene at a reservoir temperature of 30 C. to 40 C. would be about 10 feet.
  • FIGURE 1 represents a vertical cross section of the apparatus combination of the invention.
  • FIGURE 2 is a vertical side view of the apparatus showing a modified form of the combination.
  • Both figures show the essential elements of the combination of this invention. These are treating vessel 1 in which the boiling bath is maintained, bath reservoir 16 and the conduit, comprising items 8, 13 and 15, through which the bath composition in the reservoir passes to the treating vessel as required to maintain the boiling bath at a constant level.
  • FIGURE 1 shows treating vessel 1 in vertical cross section.
  • Boiling treating bath is kept boiling by heating means 6 which may consist of electric heating elements, heating coils for the passage of steam or other hot fluid media, etc. with outlet pipes or power contacts '7. Alternatively these heating means may be replaced by external gas flames or other heating means.
  • Heating means 6 which may consist of electric heating elements, heating coils for the passage of steam or other hot fluid media, etc. with outlet pipes or power contacts '7. Alternatively these heating means may be replaced by external gas flames or other heating means.
  • cooling means 3 Above the surface of the boiling treating bath are cooling means 3 which may consist of cooling coils as shown with external inlet 4 and outlet 5. These may alternatively be replaced or supplemented by an external cooling jacket.
  • Vapor level 12 controlled by the cooling means is normally located 2 to 6 feet above the boiling bath level 20 but may be up 10 feet or more above the bath level in some equipment.
  • Trough 2 located below the cooling means is adapted to collect condensed fluid so that it may be removed and separated from trace contamination with water or otherwise purified for recovery. Conduits for removal of condensate from trough 2 and possible return to a point below the surface of the boiling bath are not shown. Presence or absence of a condensate trough system are not an essential part of the subject invention and may or may not be included in the treating vessel.
  • Bath reservoir 16 as shown may consist of a drum or tank mounted on a support so its fluid contents 18 are above the level 20 which is to be maintained in the treating vessel 1. It may be held by an independent support 17 as shown in FIGURE 1 or by a supporting arm or frame 20 on the side of the treating vessel 1 as shown in the modified combination in FIGURE 2.
  • the conduit for passage of the bath composition from the reservoir to the treating vessel normally consists of pipe with valve 14 leading from the bottom part of the reservoir, pipe 8 with valve 9 leading into the treating vessel at the level to be maintained by the boiling bath and flexible tube 13 connecting pipes 15 and 8.
  • the valves are kept open when the invention is in use and are useful for closing off the pipes when the reservoir is not attached to the treating vessel or when the bath has been allowed to cool down at times when the treating process is not in operation.
  • the invention is not limited to the specific apparatus shown in the figures but is limited only to the combination of a treating vessel containing a boiling chlorinated solvent bath, reservoir and conduit. Numerous variations in this combination will be readily apparent to anyone skilled in the art. As an example, it should be noted that instead of cutting through the wall of the treating vessel as shown in the figures, the conduit may enter the bath at the top or at any point above the boiling bath level and then proceed downward to the bath level. A pipe entering the bath through the open top can be adjusted to various bath levels when desired and has a flexibility not shown by the apparatus in FIG- URE 1.
  • the bath maintenance solution will not contain the same concentration of additives as the boiling bath itself.
  • concentration of these agents in a maintenance bath in such cases will be determined by the experimental study of the bath in question and is a function of the rate at which these constituents are lost under operating conditions.
  • the preferred chlorinated solvents for use in the bath of this invention are those which have a boiling point at least of about 70 C. and whose boiling vapor has a density of at least three times that of air at the same temperatures.
  • solvents include trichloroethylene, perchlorethylene, carbon tetrachloride, 1,1,1-trichlorethane and, ethylene dichloride.
  • an open-topped treating vessel adapted to contain said bath composition and equipped with heating means, whereby said bath composition may be maintained at a constant boil, and cooling means, whereby boiling bath vapor may be contained as a dense vapor zone extending from directly above said boiling bath to a controlled level well above the predetermined boiling bath level,
  • an enclosed reservoir adapted to contain a maintenance composition for said bath composition and having an opening positioned at a low level in said reservoir but above the predetermined boiling bath level in said heating vessel, and
  • MORRIS O. WOLK Primary Examiner. vapor level is kept 2 to 10 feet above the boiling bath level. 20 DONALL H. SYLVESTER, Examiner.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Textile Engineering (AREA)
  • Cleaning By Liquid Or Steam (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)

Description

March 1, 1966 FULLHART, JR 3,238,065
METHOD AND APPARATUS FOR MAINTAINING A CONSTANT BOILING LIQUID LEVEL IN VAPOR SOLVENT DEGREASING OPERATION Filed May 14, 1962 FIG. 2
INVENTOR LAWRENCE FULLHART, JR.
AGENT United States Patent 3,238,065 METHOD AND APPARATUS FOR MAINTAINING A CONSTANT BOILING LIQUID LEVEL IN VAPOR SOLVENT DEGREASLNG OPERATION Lawrence Fullhart, Jr., Newark, Dcl., assignor to E. I. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware Filed May 14, 1962, Ser. No. 194,270 4 Claims. (Cl. 13411) This invention relates to apparatus for use in the control of a process for the treatment of metals and other materials with a boiling chlorinated solvent composition. It relates particularly to an improved apparatus for maintaining a boiling treating bath comprising a chlorinated solvent composition at a substantially constant level and composition.
Chlorinated solvents are the major constituents of a variety of treating baths in which metals and other materials are cleaned, coat-ed or modified by immersion in the boiling bath. Such processes include degreasing and cleaning in which metals, cloth fabrics and other materials are dipped into a substantially pure solvent. Processes in which the material treated is modified include metal conversion coating in which the boiling chlorinated solvent treating bath contains chemical agents, such as phosphoric, chromic and/or oxalic acid in combination with various bath adjuvants. In all of these processes, small amounts of the treat-ing bath are continually removed with the treated materials by drag-out and by diffusion across the interface between the air and the vapor above the boiling bath since the treating vessel must be open for the addition and removal of the various materials to be treated. As a result, the boiling bath level in the treating vessel drops off and the path composition must be replenished from time to time. When this procedure is followed, the level of the treating bath is constantly changing and it is sometimes too low and sometimes too high. In the case of solvent compositions containing treating agents which are lost differentially due to their action on the materials treated, non-continuous addition of a maintenance solution impairs the uniformity of the treating process since, under these conditions, the concentration of the active treating agents varies between upper and lower extremes and is seldom .at the optimum value.
Methods for level maintenance in liquid baths wherein the gas above the liquid is a permanent gas at the ambient temperature are Well known. A device of this type is commonly employed for watering poultry. However, these methods have not been adapted to maintaining the level of a boiling bath in which the gas phase over the liquid consists of vapors which undergo substantially complete condensation at ambient temperatures and have a specific gravity of about three or greater with respect to air.
It is an object of this invention to provide an apparatus for maintaining a boiling treating bath comprising a chlorinated solvent at a substantially constant level below an atmosphere consisting substantially of said boiling bath vapor.
It is a further object to provide an apparatus for maintaining a boiling bath comprising a chlorinated solvent in combination with a minor proportion of treating agent at a substantially constant level and composition.
Still other objects of the invention will become apparent from the following description.
The above-mentioned objects are accomplished by means of an apparatus for the treatment of articles with a boiling bath comprising a chlorinated solvent by the improvement comprising the combination of:
(1) A treating vessel in which a chlorinated solvent composition is maintained at a constant boil and the vapors are kept at a controlled level well above the bath level,
(2) An enclosed reservoir, in which liquid solvent bath maintenance composition is kept at a temperature below its boiling point, said reservoir having an opening positioned below the liquid level in said reservoir but above the boiling bath level in the treating vessel, and
(3) A conduit leading downwards from the opening in the reservoir into the treating vessel to the level at which it is desired to maintain the boiling liquid treating bath.
The boiling bath of this invention comprises as its major ingredient a chlorinated solvent whose vapors at the boiling point, which is preferably at least about 70 C., have a density at least about three times that of air at the same temperature. Other bath constituents are present to the extent of not more than about 10% by weight. These include solvent stabilizers, chemical treating agents and various adjuvants, such as solvents, catalytic activators, etc.
The vapor level of the boiling bath vapors in the treating vessel is maintained at least one foot above the boiling liquid and is preferably about two to ten feet above this level. The conduit leading from the reservoir into the treating vessel should preferably have a diameter ranging from about three quarters of an inch to about one inch although somewhat smaller and larger diameters are acceptable. The conduit must lead downward from the reservoir and, though it may proceed on a level for short intervals, must never sink below the level at which the bath is to be kept in the treating vessel or have a reverse upwards curve which would impair the constant feed of solution from reservoir to bath.
It is preferable for the operation of the invention that the opening in the reservoir be at the bottom thereof and be located at a point higher than the level at which the boiling bath is to be maintained in the treating vessel. It should also be noted that since it is impossible to support liquid in a reservoir at level equivalent to a hydraulic head greater than atmospheric pressure, there is no advantage in a reservoir positioned higher than compatible with such a liquid level. Preferably, the hydraulic pressure head (H in FIGURE 1) should not be more than about 50% of the maximal theoretical value. This maximal value in feet can be calculated from the vapor pressure of the bath in millimeters of murcury at the reservoir temperature P and the density of the bath at reservoir temperature D by means of the following formula in which the maximal head in feet equals H The figure 760 in this equation is the value for atmospheric pressure in millimeters of mercury and should be replaced by the actual barometer reading for accuracy. The figure 13.55 is the density of mercury and the figure 305 is the conversion factor which converts millimeters to feet. A value of approximately 2.1 feet is obtained when the bath consists of trichloroethylene at a reservoir temperature of 30 C. when the value for the vapor pressure of trichlorethylene P is mm. and its density is about 1.46. With trichlorethylene at 40 C. when its vapor pressure is 132 mm., the maximal head value would be 19 feet. As can be seen from these figures, the preferred maximum head value for trichlorethylene at a reservoir temperature of 30 C. to 40 C. would be about 10 feet.
The success of this invention is far from obvious in that the level of the boiling bath is maintained in spite of the fact that the gas over the boiling liquid is substantially completely condensable at ordinary temperatures and there is no apparent way in which any quantity of permanent gas could replace the chlorinated solvent bath maintenance composition in the reservoir. The apparatus combination of this invention including a treating vessel in which the bath is maintained at a constant boil was at first believed by many skilled technical personnel to be obviously inoperative and yet was found to work in a satisfactory manner. This is particularly surprising in View of the fact that the vapor layer over the boiling bath has a density much greater than air. The leveling device operates even when the bath is held in the boiling state and no articles are added and withdrawn for treatment so that the only bath loss is by gradual diffusion of bath vapor into the air. Accordingly, the disturbing effect on the vapor phase of the movement of articles being treated has apparently no part in determining the operability of the invention.
The apparatus improvement of the invention is illustrated schematically by the figures.
FIGURE 1 represents a vertical cross section of the apparatus combination of the invention.
FIGURE 2 is a vertical side view of the apparatus showing a modified form of the combination.
Both figures show the essential elements of the combination of this invention. These are treating vessel 1 in which the boiling bath is maintained, bath reservoir 16 and the conduit, comprising items 8, 13 and 15, through which the bath composition in the reservoir passes to the treating vessel as required to maintain the boiling bath at a constant level.
FIGURE 1 shows treating vessel 1 in vertical cross section. Boiling treating bath is kept boiling by heating means 6 which may consist of electric heating elements, heating coils for the passage of steam or other hot fluid media, etc. with outlet pipes or power contacts '7. Alternatively these heating means may be replaced by external gas flames or other heating means. Above the surface of the boiling treating bath are cooling means 3 which may consist of cooling coils as shown with external inlet 4 and outlet 5. These may alternatively be replaced or supplemented by an external cooling jacket. Vapor level 12 controlled by the cooling means is normally located 2 to 6 feet above the boiling bath level 20 but may be up 10 feet or more above the bath level in some equipment. Trough 2 located below the cooling means is adapted to collect condensed fluid so that it may be removed and separated from trace contamination with water or otherwise purified for recovery. Conduits for removal of condensate from trough 2 and possible return to a point below the surface of the boiling bath are not shown. Presence or absence of a condensate trough system are not an essential part of the subject invention and may or may not be included in the treating vessel.
Bath reservoir 16 as shown may consist of a drum or tank mounted on a support so its fluid contents 18 are above the level 20 which is to be maintained in the treating vessel 1. It may be held by an independent support 17 as shown in FIGURE 1 or by a supporting arm or frame 20 on the side of the treating vessel 1 as shown in the modified combination in FIGURE 2. The conduit for passage of the bath composition from the reservoir to the treating vessel normally consists of pipe with valve 14 leading from the bottom part of the reservoir, pipe 8 with valve 9 leading into the treating vessel at the level to be maintained by the boiling bath and flexible tube 13 connecting pipes 15 and 8. The valves are kept open when the invention is in use and are useful for closing off the pipes when the reservoir is not attached to the treating vessel or when the bath has been allowed to cool down at times when the treating process is not in operation. Since the bath level drops when it is cooled or even when it is not boiling, at least one of the valves is closed so that when it is desired to start operating, the bath will not be too high as would be the case if it were allowed to come to the desired level when the bath was cold. The liquid head from the top of the reservoir at bath level 19 to the boiling bath level 20 is indicated by the dotted line H in FIGURE 1.
It should be noted that the invention is not limited to the specific apparatus shown in the figures but is limited only to the combination of a treating vessel containing a boiling chlorinated solvent bath, reservoir and conduit. Numerous variations in this combination will be readily apparent to anyone skilled in the art. As an example, it should be noted that instead of cutting through the wall of the treating vessel as shown in the figures, the conduit may enter the bath at the top or at any point above the boiling bath level and then proceed downward to the bath level. A pipe entering the bath through the open top can be adjusted to various bath levels when desired and has a flexibility not shown by the apparatus in FIG- URE 1.
It should be noted that when the bath is operated with a chlorinated solvent containing treating agents which are lost differentially by their action on the materials treated which tends to exhaust them from the bath, the bath maintenance solution will not contain the same concentration of additives as the boiling bath itself. The concentration of these agents in a maintenance bath in such cases will be determined by the experimental study of the bath in question and is a function of the rate at which these constituents are lost under operating conditions.
As previously stated, the preferred chlorinated solvents for use in the bath of this invention are those which have a boiling point at least of about 70 C. and whose boiling vapor has a density of at least three times that of air at the same temperatures. Such solvents include trichloroethylene, perchlorethylene, carbon tetrachloride, 1,1,1-trichlorethane and, ethylene dichloride.
I claim:
1. In an apparatus of the type used for the treatment of articles with a boiling treating bath composition comprising a chlorinated solvent, whose vapor at the boiling point has a density of at least three times that of air at the same temperature, the improvement whereby such a boiling bath may be maintained automatically at a predetermined and substantially constant level below a dense atmosphere of bath vapor, said improvement comprising, in combination,
(a) an open-topped treating vessel adapted to contain said bath composition and equipped with heating means, whereby said bath composition may be maintained at a constant boil, and cooling means, whereby boiling bath vapor may be contained as a dense vapor zone extending from directly above said boiling bath to a controlled level well above the predetermined boiling bath level,
(b) an enclosed reservoir adapted to contain a maintenance composition for said bath composition and having an opening positioned at a low level in said reservoir but above the predetermined boiling bath level in said heating vessel, and
(c) a conduit leading downwards from said reservoir opening into said treating vessel at the predetermined level at which it is desired to maintain said boiling bath composition.
2. The apparatus of claim 1 wherein the vertical distance between the point at which the said conduit enters the treating vessel and the controlled level at which said cooling means are adapted to maintain the top of the dense vapor zone is in the range of 2 to 10 feet.
3. In a process for treating articles with a boiling liquid comprising a chlorinated solvent whose vapor at the boiling point has a density of at least three times that of air at the same temperature, the improvement for maintaining said boiling path at a substantially constant level below an atmosphere of bath vapor by continuous addition of a solvent maintenance composition, comprising the steps of:
(a) maintaining said chlorinated solvent bath composition at the boiling point in a treating vessel while maintaining the bath vapor at a controlled level well above the boiling hath,
(b) providing liquid chlorinated solvent maintenance composition for said chlorinated solvent bath in an enclosed reservoir having an opening positioned below the liquid level in said reservoir but above the boiling bath level in said treating vessel, and
(c) allowing said liquid maintenance composition to pass from said reservoir to said treating vessel by means of a conduit leading downwards from said opening in said reservoir to the level at which it is desired to maintain said boiling liquid in said treating vessel.
4. The process of claim 3 in which the boiling bath References Cited by the Examiner UNITED STATES PATENTS 1/1914 Biddle 134453 X 6/1934 Savage 13411 4/1938 Dinley 134l1 11/1940 Seaton 13411 11/ 1942 Rubinstein 137454 X 8/1951 Pitney 137454 3/1956 McGillis et al 137454 FOREIGN PATENTS 3/ 1929 France. 11/1942 France. 11/ 1887 Great Britain. 11/ 1938 Great Britain.
2/1938 Switzerland.
MORRIS O. WOLK, Primary Examiner. vapor level is kept 2 to 10 feet above the boiling bath level. 20 DONALL H. SYLVESTER, Examiner.

Claims (1)

  1. 3. IN A PROCESS FOR TREATING ARTICLES WITH A BOILING LIQUID COMPRISING A CHLORINATED SOLVENT WHOSE VAPOR AT THE BOILING POINT HAS A DENSITY OF AT LEAST THREE TIMES THAT OF AIR AT THE SAME TEMPERATURE, THE IMPROVEMENT FOR MAINTAINING SAID BOILING PATH AT A SUBSTANTIALLY CONSTANT LEVEL BELOW AN ATMOSPHERE OF BATH VAPOR BY CONTINUOUS ADDITION OF A SOLVENT MEAINTENANCE COMPOSITION, COMPRISING THE STEPS OF: (A) MAINTAINING SAID CHLORINATED SOLVENT BATH COMPOSITION AT THE BOILING POINT IN A TREATING VESSEL WHILE MAINTAINING THE BATH VAPOR AT A CONTROLLED LEVEL WELL ABOVE THE BOILING BATH, (B) PROVIDING LIQUID CHLORINATED SOLVENT MAINTENANCE
US194270A 1962-05-14 1962-05-14 Method and apparatus for maintaining a constant boiling liquid level in vapor solvent degreasing operation Expired - Lifetime US3238065A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US194270A US3238065A (en) 1962-05-14 1962-05-14 Method and apparatus for maintaining a constant boiling liquid level in vapor solvent degreasing operation
BE631669D BE631669A (en) 1962-05-14 1963-04-29
DK214163AA DK119339B (en) 1962-05-14 1963-05-06 Method for maintaining the surface height of a boiling treatment bath and apparatus for performing the method.
DE19631546176 DE1546176B1 (en) 1962-05-14 1963-05-09 DEVICE FOR TREATMENT OF OBJECTS IN A BOILING TREATMENT BATH
NL63292666A NL140014B (en) 1962-05-14 1963-05-13 PROCEDURE FOR MAINTAINING THE LEVEL OF A COOKING TREATMENT BATH.
CH596863A CH483282A (en) 1962-05-14 1963-05-13 Method of treating materials with a boiling bath

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US194270A US3238065A (en) 1962-05-14 1962-05-14 Method and apparatus for maintaining a constant boiling liquid level in vapor solvent degreasing operation

Publications (1)

Publication Number Publication Date
US3238065A true US3238065A (en) 1966-03-01

Family

ID=22716940

Family Applications (1)

Application Number Title Priority Date Filing Date
US194270A Expired - Lifetime US3238065A (en) 1962-05-14 1962-05-14 Method and apparatus for maintaining a constant boiling liquid level in vapor solvent degreasing operation

Country Status (6)

Country Link
US (1) US3238065A (en)
BE (1) BE631669A (en)
CH (1) CH483282A (en)
DE (1) DE1546176B1 (en)
DK (1) DK119339B (en)
NL (1) NL140014B (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3329581A (en) * 1964-09-28 1967-07-04 Macnabb Engineering Co Inc Portable degreaser and distillation apparatus
US3491778A (en) * 1967-01-17 1970-01-27 Kabel Metallwerke Ghh Method and apparatus for cleaning and degreasing metal articles
US3881949A (en) * 1973-02-27 1975-05-06 Du Pont Vapor degreaser process employing trichlorotrifluoroethane and ethanol
US4356038A (en) * 1979-07-25 1982-10-26 Imperial Chemical Industries Limited Stabilization of chlorinated aliphatic hydrocarbons and use of stabilized composition in cleaning articles
US4537660A (en) * 1978-06-28 1985-08-27 Mccord James W Vapor generating and recovering apparatus
US5075982A (en) * 1990-09-25 1991-12-31 Allied-Signal Inc. Open top defluxer with improved solvent vapor recovery
US20090020175A1 (en) * 2007-03-08 2009-01-22 Jean Gehrig Device for regulation of a concentration for a product in a liquid

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3335266A1 (en) * 1983-09-29 1985-04-18 Chemische Werke Hüls AG, 4370 Marl METHOD FOR SURFACE TREATMENT OF METALS

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1083723A (en) * 1913-02-03 1914-01-06 George Lash Biddle Automatic water-supply for cooking utensils.
FR662742A (en) * 1928-06-15 1929-08-10 Chemische Werk Zurich Akt Ges Method and device for pickling metal articles
US1961867A (en) * 1926-12-16 1934-06-05 Castner Kellner Alkali Company Process for degreasing metallic articles
CH193935A (en) * 1937-01-19 1937-11-15 J Zucker Method and device for cleaning metal objects.
US2113129A (en) * 1934-05-15 1938-04-05 Solvent Machine Company Treatment of work with solvents
GB496357A (en) * 1937-05-04 1938-11-29 Wacker Chemie Gmbh Improvements relating to the treatment of rigid goods with volatile organic solvents and apparatus therefor
US2220125A (en) * 1940-04-02 1940-11-05 Westvaco Chlorine Products Cor Degreasing
US2302476A (en) * 1941-08-25 1942-11-17 Rubinstein Louis Electric iron
FR878808A (en) * 1941-02-03 1943-02-04 Alexander Wacker Dr Method and apparatus for treatment with solvent vapors
US2564230A (en) * 1948-03-05 1951-08-14 Earl H Pitney Liquid level maintainer
US2738802A (en) * 1953-04-13 1956-03-20 John J Mcgillis Liquid level maintenance apparatus

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE468772C (en) * 1927-04-22 1928-11-19 Wacker Chemie Gmbh Cleaning and degreasing device using liquid solvents
DE505980C (en) * 1927-07-19 1930-08-28 Wacker Chemie Gmbh Cleaning and degreasing device for objects made of rigid material using solvents with a high specific vapor weight
CH134375A (en) * 1929-07-05 1929-07-31 Chemisches Werk Zuerich Akt Ge Method and device for cleaning and degreasing metal objects.
US2153577A (en) * 1935-03-07 1939-04-11 Du Pont Process of degreasing
GB472342A (en) * 1935-05-22 1937-09-22 Ici Ltd Improvements in or relating to the cleaning and degreasing of materials
DE667379C (en) * 1937-05-05 1938-11-10 Wacker Chemie Gmbh Method and device for treating rigid material with a volatile organic solvent
US2447840A (en) * 1938-11-19 1948-08-24 Mabor Company Inc Vapor phase degreasing apparatus, including temperature control of vapor condensers
GB550703A (en) * 1941-07-18 1943-01-20 William Edward Booth Improvements in the degreasing of metal articles

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1083723A (en) * 1913-02-03 1914-01-06 George Lash Biddle Automatic water-supply for cooking utensils.
US1961867A (en) * 1926-12-16 1934-06-05 Castner Kellner Alkali Company Process for degreasing metallic articles
FR662742A (en) * 1928-06-15 1929-08-10 Chemische Werk Zurich Akt Ges Method and device for pickling metal articles
US2113129A (en) * 1934-05-15 1938-04-05 Solvent Machine Company Treatment of work with solvents
CH193935A (en) * 1937-01-19 1937-11-15 J Zucker Method and device for cleaning metal objects.
GB496357A (en) * 1937-05-04 1938-11-29 Wacker Chemie Gmbh Improvements relating to the treatment of rigid goods with volatile organic solvents and apparatus therefor
US2220125A (en) * 1940-04-02 1940-11-05 Westvaco Chlorine Products Cor Degreasing
FR878808A (en) * 1941-02-03 1943-02-04 Alexander Wacker Dr Method and apparatus for treatment with solvent vapors
US2302476A (en) * 1941-08-25 1942-11-17 Rubinstein Louis Electric iron
US2564230A (en) * 1948-03-05 1951-08-14 Earl H Pitney Liquid level maintainer
US2738802A (en) * 1953-04-13 1956-03-20 John J Mcgillis Liquid level maintenance apparatus

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3329581A (en) * 1964-09-28 1967-07-04 Macnabb Engineering Co Inc Portable degreaser and distillation apparatus
US3491778A (en) * 1967-01-17 1970-01-27 Kabel Metallwerke Ghh Method and apparatus for cleaning and degreasing metal articles
US3881949A (en) * 1973-02-27 1975-05-06 Du Pont Vapor degreaser process employing trichlorotrifluoroethane and ethanol
US4537660A (en) * 1978-06-28 1985-08-27 Mccord James W Vapor generating and recovering apparatus
US4356038A (en) * 1979-07-25 1982-10-26 Imperial Chemical Industries Limited Stabilization of chlorinated aliphatic hydrocarbons and use of stabilized composition in cleaning articles
US5075982A (en) * 1990-09-25 1991-12-31 Allied-Signal Inc. Open top defluxer with improved solvent vapor recovery
US20090020175A1 (en) * 2007-03-08 2009-01-22 Jean Gehrig Device for regulation of a concentration for a product in a liquid
US7997298B2 (en) * 2007-03-08 2011-08-16 Special Coating Laboratory International Archamps Device for regulation of a concentration for a product in a liquid

Also Published As

Publication number Publication date
NL140014B (en) 1973-10-15
DE1546176B1 (en) 1971-12-16
BE631669A (en) 1963-11-18
DK119339B (en) 1970-12-14
CH483282A (en) 1969-12-31

Similar Documents

Publication Publication Date Title
US3957531A (en) Two tank cleaning process using a contaminated cleaning mixture capable of forming an azeotrope
US3238065A (en) Method and apparatus for maintaining a constant boiling liquid level in vapor solvent degreasing operation
US2310569A (en) Degreasing of metal articles
NO148386B (en) DEVICE FOR TRANSMISSION OF DUMPED FLOATS
EP0060225B1 (en) Process for the high-velocity dip-coating of filament like materials in a molten metal bath
US3661732A (en) Method and apparatus for electroplating
US4579566A (en) Process and apparatus for producing a gas of high purity by vaporization of a cryogenic liquid
GB471756A (en) Improvements in or relating to the degreasing of metallic articles
US3953381A (en) Composition containing diamide and halocarbon for treatment of surfaces
EP0017459B1 (en) Process for removing water from surfaces of articles and water removing bath for use in the process
US3491778A (en) Method and apparatus for cleaning and degreasing metal articles
KR920701501A (en) Method and apparatus for purification of liquid metal for hot-dip galvanizing
US2276232A (en) Metal coating process
US3828723A (en) Galvanizing apparatus for wire and the like
US3480420A (en) Process and apparatus for vacuum purification of the float glass bath
US3537843A (en) Process for recovering mercury from an inactive mercuric chloride/active carbon-catalyst
US2220125A (en) Degreasing
US2459550A (en) Destructive distillation of solids in a liquid bath
Campbell et al. Salt‐Bath Chromizing
US2047545A (en) Manufacture of stannic chloride
US1897360A (en) Manufacture of stannic chloride
US2005709A (en) Production of organic fluorine compounds
US2083731A (en) Absorbent article-saturating apparatus
GB796242A (en) Coating of strand-like metal bodies with molten metal
US160178A (en) Improvement in apparatus for pickling metal plates