WO1988002789A1 - An apparatus for dip-coating objects - Google Patents

An apparatus for dip-coating objects Download PDF

Info

Publication number
WO1988002789A1
WO1988002789A1 PCT/FI1987/000135 FI8700135W WO8802789A1 WO 1988002789 A1 WO1988002789 A1 WO 1988002789A1 FI 8700135 W FI8700135 W FI 8700135W WO 8802789 A1 WO8802789 A1 WO 8802789A1
Authority
WO
WIPO (PCT)
Prior art keywords
basin
coating material
coating
rotation
motor
Prior art date
Application number
PCT/FI1987/000135
Other languages
French (fr)
Inventor
Reijo Silvonen
Johannes Sallinen
Original Assignee
Silmecon Oy
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 Silmecon Oy filed Critical Silmecon Oy
Publication of WO1988002789A1 publication Critical patent/WO1988002789A1/en
Priority to NO882700A priority Critical patent/NO882700L/en
Priority to DK332788A priority patent/DK332788A/en

Links

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
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/003—Apparatus
    • C23C2/0034—Details related to elements immersed in bath
    • 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
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/003—Apparatus
    • C23C2/0036—Crucibles

Definitions

  • the invention relates to an apparatus for dip coating objects, particularly for coating objects with a metal alloy such as a mixture of zinc and aluminium, comprising a body, a basin for a molten coating ma ⁇ terial and heating means positioned within the basin for keeping the coating material contained in the basin in a molten state.
  • a metal alloy such as a mixture of zinc and aluminium
  • This kind of devices for coating various objects are well-known and used very generally for coating steel objects liable to corrosion.
  • Hot galva ⁇ nizing in which the coating material is zinc, is a conventional and tried method. In recent years, the use of and experimenting with new materials, such as mixtures of zinc and aluminium, have become more and more general.
  • Coating appar ⁇ atuses typically comprise a fixedly mounted basin of steel or a ceramic material, and the coating material contained therein is kept in a molten state by means of oil energy, gas energy or electric energy. Electric systems are heated either by induction or resistance heating. In most cases resistance-heated solutions with a fixed basin are based on radiation heating; however, experiments have been made recently with so called immersion heaters which comprise electric re- sistances mounted within a cover pipe and and which are immersed in zinc or aluminium or a mixture there ⁇ of.
  • the fixed vessel solution has certain major drawbacks - whatever the heating energy source.
  • So called hard zinc mainly a compound of zinc and steel in the form of a slime or a bottom deposit and usually containing 2.5 to 4% iron, is formed in the basins.
  • the iron contained in the bottom deposit orig ⁇ inates from the basin walls and/or the object to be coated.
  • the formation of hard zinc increases consider ⁇ ably the consumption of zinc in hot galvanizing (about 25 to 35%), because it is accumulated at certain points of the basin, especially on the bottom thereof, and it has to be removed therefrom at determined intervals.
  • the deposit formation is further increased.
  • Another problem with coating mixtures is often that they consist of components which are more or less un- mixable with each other: the weight differences of the components may vary greatly and the so called liquidu- s-solidus range formed is often large.
  • the dipping of room temperature objects to be coated in the basin causes a considerable decrease in the temperature of the coating material contained therein.
  • the volume of fixed basins has to be dimension ⁇ ed so as to be approximately 20 x the dipping capacity per hour, which increases the cost of investment.
  • the use and preparation of different coating material mixtures e.g. zinc-aluminium
  • the mixing is difficult to arrange.
  • the basin/immersion heater solution according to the invention enables a decisive improvement to be achieved with respect to the above drawbacks.
  • the apparatus according to the in ⁇ vention is characterized in that the basin is arranged to be rotatable with respect to the heating means.
  • the bottom of the basin is preferably round and supported agaisnt the body solely by means of 3 to 6 rubber- coated supporting wheels so arranged in the vicinity of the periphery of the bottom that the rotation axes thereof project towards the central shaft of the basin.
  • the heating means function as mixers, thus effecting a forceful mixing of the coating material contained in the basin.
  • the invention is advantageous mainly in that the rotatable basin solution provides an extremely even temperature of the coating material as well as an efficient mixing, by virtue of which properties the volume of the basin can be decreased as a result of the mixing effect so as to be 5 to 15 x the dipping capacity per hour; furthermore, the apparatus is ex ⁇ tremely suitable for examining different kinds of coating material mixtures (e.g. zinc-aluminium) .
  • coating material mixtures e.g. zinc-aluminium
  • the amount of the so called hard zinc formed in hot galvanizing is estimated to decrease by half, which results in material savings and reduces the need of maintenance.
  • the apparatus shown in the figure intended e.g. for coating steel objects by dipping them in a molten coating material, such as a mixture of zinc and aluminium, comprises a body formed by beams and indi ⁇ cated generally with the reference numeral 1; a cylin- drically shaped basin 2 for a molten coating material 3; and three electric heating elements generally indi ⁇ cated with the reference numeral 4.
  • a molten coating material such as a mixture of zinc and aluminium
  • the basin 2 comprises a vessel having a steel frame.
  • the inner surface of the vessel may be coated with a ceramic material or masoned internally for reducing reactions between the coating material and the basin.
  • the basin 2 is arranged to be rotatable with respect to the body 1 by supporting the bottom thereof on the body in the vi- cinity of the periphery of the bottom by means of four rubber-coated supporting wheels 5 the rotation axes of which project towards the central axis of the basin 2 and on which the basin can be rotated. In this way the basin 2 is provided with a steady base which enables it to be rotated in a simple way.
  • a groove (not shown) is formed in the bottom of the basin 2 for the sup ⁇ porting wheels, which groove guides the basin during the rotation thereof in a simple and reliable way.
  • the wheel 5 is mounted on a bearing block 7 positioned at the upper portion of a vertical beam 6 integral with the body 1.
  • the structure so obtained is compact and can be displaced from one place to another if re ⁇ quired.
  • a broken line shows a tooth rim 8 provided for the rotation of the basin 2 on the periphery of the bottom of the basin, the tooth rim cooperating with a gear 10 operated by an electric motor 9 and indicated with a broken line.
  • the motor 9 is arranged in the body 1 of the apparatus below the basin 2, so that it does not take too much space and is easy to handle in case of service.
  • the speed of rotation of the motor 9 is continuously adjustable, and it is arranged to rotate the gear 10 selectively in both directions, which en- ables versatile mixing programmes in the basin 2.
  • a cover structure of the basin is secured to long vertical beams 12 of the body, and it is com ⁇ pletely separate from the rotatable basin 2. Conse ⁇ quently, no kind of bearings have to be arranged bet ⁇ ween the cover structure 11 and the basin 2.
  • Three electric heating elements 4 to be positioned vertical ⁇ ly in the basin 2 are attached to a top portion 13 of the cover structure, and each one of the heating ele ⁇ ments comprises a resistance wire 14 which is surrounded with a cover pipe 15 of silicon carbide. When the basin 2 is rotating and the top portion 13 is maintained in place, the heating elements 4 function as efficient mixers of the coating material.
  • the apparatus according to the invention may also comprise means for additionally moving the basin 2 up and down in the vertical direction, which would make the mixing effect even more efficient.
  • These means would preferably be formed by hy ⁇ draulic cylinders arranged at the bottom of the basin 2. This kind of arrangement would require that the means shown in the figure for rotating the basin should be constructed in a slightly different way: the gear 10 could e.g. be fitted at the end of a shaft en- abling movement in the vertical direction.
  • the coating ma ⁇ terial basin need not necessarily be supported on the body in the manner described; instead, it can e.g. be supported directly on the base.
  • the basin need not be cylindrically shaped, and the rotation of the basin need not be effected by means of a gear transmission.
  • the rotation can be alternatively effected in such a way that one of the supporting wheels positioned against the bottom of the basin is a driving wheel operated by a motor.
  • the rotation may also be effected by means of a chain transmission comprising a pinion arranged on the central axis of the coating basin.
  • the number of the heating elements may vary and the basin may be provided with additional mixing blades suspend ⁇ ed from the cover.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Coating With Molten Metal (AREA)
  • Coating Apparatus (AREA)

Abstract

Apparatus for dip-coating objects, particularly for coating objects with a metal alloy such as a mixture of zinc and aluminium, comprising a body (1), a basin (2) for a molten coating material and heating means (4) positioned within the basin for keeping the coating material (3) contained in the basin in a molten state. In order that the temperature of the coating material contained in the basin would be even and rapidly adjustable and in order that the apparatus would be relatively small in size in view of the capacity thereof and suitable for examining different kinds of coating material mixtures, the apparatus is characterized in that the basin (2) is arranged to rotate with respect to the heating means (4). The bottom of the basin (2) is preferably round and supported against the body (1) merely by means of three to six rubber-coated supporting wheels (5) so arranged in the vicinity of the periphery of the bottom that the rotation axes thereof project towards the centre of the bottom.

Description

An apparatus for dip-coating objects
The invention relates to an apparatus for dip coating objects, particularly for coating objects with a metal alloy such as a mixture of zinc and aluminium, comprising a body, a basin for a molten coating ma¬ terial and heating means positioned within the basin for keeping the coating material contained in the basin in a molten state. This kind of devices for coating various objects are well-known and used very generally for coating steel objects liable to corrosion. Hot galva¬ nizing, in which the coating material is zinc, is a conventional and tried method. In recent years, the use of and experimenting with new materials, such as mixtures of zinc and aluminium, have become more and more general. As to the coating procedure and the ap¬ paratus required therefor, the use of such new ma¬ terials and material mixtures as a coating material is more problematic than the use of zinc. Coating appar¬ atuses typically comprise a fixedly mounted basin of steel or a ceramic material, and the coating material contained therein is kept in a molten state by means of oil energy, gas energy or electric energy. Electric systems are heated either by induction or resistance heating. In most cases resistance-heated solutions with a fixed basin are based on radiation heating; however, experiments have been made recently with so called immersion heaters which comprise electric re- sistances mounted within a cover pipe and and which are immersed in zinc or aluminium or a mixture there¬ of.
The fixed vessel solution has certain major drawbacks - whatever the heating energy source. So called hard zinc, mainly a compound of zinc and steel in the form of a slime or a bottom deposit and usually containing 2.5 to 4% iron, is formed in the basins. The iron contained in the bottom deposit orig¬ inates from the basin walls and/or the object to be coated. The formation of hard zinc increases consider¬ ably the consumption of zinc in hot galvanizing (about 25 to 35%), because it is accumulated at certain points of the basin, especially on the bottom thereof, and it has to be removed therefrom at determined intervals. When mixtures are used as coating mat¬ erials, the deposit formation is further increased. Another problem with coating mixtures is often that they consist of components which are more or less un- mixable with each other: the weight differences of the components may vary greatly and the so called liquidu- s-solidus range formed is often large.
The dipping of room temperature objects to be coated in the basin causes a considerable decrease in the temperature of the coating material contained therein. In order that the decrease would not be too great, the volume of fixed basins has to be dimension¬ ed so as to be approximately 20 x the dipping capacity per hour, which increases the cost of investment. In addition, the use and preparation of different coating material mixtures (e.g. zinc-aluminium) is difficult in fixedly mounted basins, because the mixing is difficult to arrange.
The basin/immersion heater solution according to the invention enables a decisive improvement to be achieved with respect to the above drawbacks. For the achievement thereof the apparatus according to the in¬ vention is characterized in that the basin is arranged to be rotatable with respect to the heating means. The bottom of the basin is preferably round and supported agaisnt the body solely by means of 3 to 6 rubber- coated supporting wheels so arranged in the vicinity of the periphery of the bottom that the rotation axes thereof project towards the central shaft of the basin. When the basin part is rotated, the heating means function as mixers, thus effecting a forceful mixing of the coating material contained in the basin.
The invention is advantageous mainly in that the rotatable basin solution provides an extremely even temperature of the coating material as well as an efficient mixing, by virtue of which properties the volume of the basin can be decreased as a result of the mixing effect so as to be 5 to 15 x the dipping capacity per hour; furthermore, the apparatus is ex¬ tremely suitable for examining different kinds of coating material mixtures (e.g. zinc-aluminium) . In addition, the amount of the so called hard zinc formed in hot galvanizing is estimated to decrease by half, which results in material savings and reduces the need of maintenance. In the following the invention will be de¬ scribed in more detail by means of one preferred embo¬ diment thereof with reference to the attached drawing in which the figure shows a general view of the ap¬ paratus. The apparatus shown in the figure, intended e.g. for coating steel objects by dipping them in a molten coating material, such as a mixture of zinc and aluminium, comprises a body formed by beams and indi¬ cated generally with the reference numeral 1; a cylin- drically shaped basin 2 for a molten coating material 3; and three electric heating elements generally indi¬ cated with the reference numeral 4.
The basin 2 comprises a vessel having a steel frame. The inner surface of the vessel, indicated with broken lines, may be coated with a ceramic material or masoned internally for reducing reactions between the coating material and the basin. The basin 2 is arranged to be rotatable with respect to the body 1 by supporting the bottom thereof on the body in the vi- cinity of the periphery of the bottom by means of four rubber-coated supporting wheels 5 the rotation axes of which project towards the central axis of the basin 2 and on which the basin can be rotated. In this way the basin 2 is provided with a steady base which enables it to be rotated in a simple way. A groove (not shown) is formed in the bottom of the basin 2 for the sup¬ porting wheels, which groove guides the basin during the rotation thereof in a simple and reliable way. The wheel 5 is mounted on a bearing block 7 positioned at the upper portion of a vertical beam 6 integral with the body 1. The structure so obtained is compact and can be displaced from one place to another if re¬ quired. A broken line shows a tooth rim 8 provided for the rotation of the basin 2 on the periphery of the bottom of the basin, the tooth rim cooperating with a gear 10 operated by an electric motor 9 and indicated with a broken line. This solution enables a reliable and durable transmission to be provided from the motor 9 to the basin 2. The motor 9 is arranged in the body 1 of the apparatus below the basin 2, so that it does not take too much space and is easy to handle in case of service. The speed of rotation of the motor 9 is continuously adjustable, and it is arranged to rotate the gear 10 selectively in both directions, which en- ables versatile mixing programmes in the basin 2.
This is important for finding out an advantageous "ro¬ tation programme" for use with each particular coating material contained in the basin.
A cover structure of the basin, generally in- dicated with the reference numeral 11, is secured to long vertical beams 12 of the body, and it is com¬ pletely separate from the rotatable basin 2. Conse¬ quently, no kind of bearings have to be arranged bet¬ ween the cover structure 11 and the basin 2. Three electric heating elements 4 to be positioned vertical¬ ly in the basin 2 are attached to a top portion 13 of the cover structure, and each one of the heating ele¬ ments comprises a resistance wire 14 which is surrounded with a cover pipe 15 of silicon carbide. When the basin 2 is rotating and the top portion 13 is maintained in place, the heating elements 4 function as efficient mixers of the coating material. When charging the basin 2 with room temperature objects to be coated, these objects cool the molten coating a- terial contained in the basin. By virtue of the rota¬ tion of the basin 2, no major temperature differences can be formed nor can the temperature of the coating material drop to any greater degree, because the basin is provided with temperature sensors (not shown) which rapidly register the temperature decrease caused by the charging, and this causes electric power to be supplied to the resistance wires 14. A discharge pipe 16 is provided in the bottom of the basin 2 for empty¬ ing the basin by discharging the coating material 3 through a chute 17.
The apparatus according to the invention may also comprise means for additionally moving the basin 2 up and down in the vertical direction, which would make the mixing effect even more efficient. These means (not shown) would preferably be formed by hy¬ draulic cylinders arranged at the bottom of the basin 2. This kind of arrangement would require that the means shown in the figure for rotating the basin should be constructed in a slightly different way: the gear 10 could e.g. be fitted at the end of a shaft en- abling movement in the vertical direction.
The invention has been described above merely by means of an example. It is obvious that the details of the invention can be effected in various ways with- in the scope of the attached claims: the coating ma¬ terial basin need not necessarily be supported on the body in the manner described; instead, it can e.g. be supported directly on the base. The basin need not be cylindrically shaped, and the rotation of the basin need not be effected by means of a gear transmission. The rotation can be alternatively effected in such a way that one of the supporting wheels positioned against the bottom of the basin is a driving wheel operated by a motor. The rotation may also be effected by means of a chain transmission comprising a pinion arranged on the central axis of the coating basin. The number of the heating elements may vary and the basin may be provided with additional mixing blades suspend¬ ed from the cover.

Claims

Claims :
1. An apparatus for dip coating objects, parti¬ cularly for coating objects with a metal alloy such as a mixture of zinc and aluminium, comprising a body (1) , a basin (2) for a molten coating material and heating means (4) positioned within the basin for keeping the coating material (3) contained in the basin in a molten state, c h a r a c t e r i z e d in that the basin (2) is arranged to be rotatable with respect to the heating means (4) .
2. An apparatus according to claim 1, c h a r ¬ a c t e r i z e d in that the bottom of the basin (2) is round and supported against the body (1) merely by means of three to six rubber-coated supporting wheels (5) so positioned in the vicinity of the periphery of the bottom that the rotation axes thereof project to¬ wards the central axis of the basin.
3. An apparatus according to claim 2, c h a r - a c t e r i z e d in that the bottom of the basin (2) is provided with a groove for the supporting wheels (5), which groove functions as a guide for the basin during the rotation thereof.
4. An apparatus according to claim 2 or 3, c h a r a c t e r i z e d in that each supporting wheel (5) is mounted on a bearing block (7) positioned at the upper portion of a vertical beam (6) integral with the body (1) .
5. An apparatus according to claim 1 or 4, c h a r a c t e r i z e d in that one of the support¬ ing wheels is a driving wheel operated by a motor and effects the rotation of the basin (2) around the axis thereof.
6. An apparatus according to claim 1, 2, 3 or 4, c h a r a c t e r i z e d in that a tooth rim (8) for rotating the basin (2) around the axis thereof is provided on the periphery of the bottom of the basin, which tooth rim cooperates with a gear operated by a motor (9) arranged within the body (1) of the appar- atus below the basin (2) .
7. An apparatus according to claim 5 or 6, c h a r a c t e r i z e d in that the speed of the motor (9) is continuously adjustable.
8. An apparatus according to any of the preced- ing claims, c h a r a c t e r i z e d in that a cover structure (10) of the basin (2) is attached to the body (1) of the apparatus and comprises three upright heating elements (4) operated electrically and attached to a top portion (13) of the cover structure, each heating element comprising a resistance wire (14) surrounded by a cover pipe (15) acting as a mixer during the rotation of the basin.
9. An apparatus according to any of the preced¬ ing claims, c h a r a c t e r i z e d in that the basin (2) is arranged to rotate up and down.
10. An apparatus according to any of the pre¬ ceding claims, c h a r a c t e r i z e d in that the basin is further arranged to move up and down in the vertical direction by means of hydraulic cylinders.
PCT/FI1987/000135 1986-10-20 1987-10-09 An apparatus for dip-coating objects WO1988002789A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
NO882700A NO882700L (en) 1986-10-20 1988-06-17 DEVICE FOR DEPARTMENT OF OBJECTS.
DK332788A DK332788A (en) 1986-10-20 1988-06-17 DEVICE COVERING DEVICE

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI864234 1986-10-20
FI864234A FI76121C (en) 1986-10-20 1986-10-20 Device for coating articles by immersion

Publications (1)

Publication Number Publication Date
WO1988002789A1 true WO1988002789A1 (en) 1988-04-21

Family

ID=8523348

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1987/000135 WO1988002789A1 (en) 1986-10-20 1987-10-09 An apparatus for dip-coating objects

Country Status (2)

Country Link
FI (1) FI76121C (en)
WO (1) WO1988002789A1 (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1440500A (en) * 1973-10-23 1976-06-23 Surfalloy Corp Rotary barrel diffusion coating in molten lead

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1440500A (en) * 1973-10-23 1976-06-23 Surfalloy Corp Rotary barrel diffusion coating in molten lead

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
DERWENT'S ABSTRACT, No. 07 402 D/05; & SU,A,737496. *
DERWENT'S ABSTRACT, No. 86-290633/44; & SU,A,1217922. *

Also Published As

Publication number Publication date
FI76121C (en) 1988-09-09
FI864234A0 (en) 1986-10-20
FI76121B (en) 1988-05-31

Similar Documents

Publication Publication Date Title
CA1256694A (en) Rotary device, apparatus and method for treating molten metal
US4673434A (en) Using a rotary device for treating molten metal
EP0151434B1 (en) Method of and apparatus for treating and breaking up a liquid with the help of centripetal force
US3792848A (en) Device for improving reactions between two components of a metallurgical melt
EP0000293A1 (en) Apparatus and method for anaerobic digestion of biodegradable waste material
DE68912461T2 (en) Device and method for melting and homogenizing a batch.
US4443004A (en) Device for the treatment of a stream of aluminum or magnesium-based liquid metal or alloy during its passage
WO1999003620A1 (en) Method for the directional solidification of molten metal and casting device for carrying out said method
WO1988002789A1 (en) An apparatus for dip-coating objects
SE461215B (en) GLASFEEDER
US8367163B2 (en) Enamel flow coating process and apparatus
US3091217A (en) Hot-dip coating apparatus
US3887721A (en) Metallic coating method
JP2003501611A (en) Method and apparatus for tilting and emptying a melting vessel for metallurgy
GB2109269A (en) Apparatus for the separation of metallic zinc from residues containing zinc
US4989666A (en) Process and device for electromagnetically casting metals
JP2000502654A (en) Rotary resistance melting furnace
US1189356A (en) Electric furnace.
CN1273247C (en) Tun dish and method for production of a metal strip of high purity
US4448822A (en) Apparatus and method for the production of gas filters
CN210512606U (en) Electric immersion type aluminum heating furnace
CA1193638A (en) Induction furnace
US3081988A (en) Furnace
SU831855A1 (en) Device for hot zinc-plating
JPS55165193A (en) Automatic control apparatus of float support of metal plate scale removing liquid vessel

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): DK NO SU US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LU NL SE