CA2059100A1 - Agitator protected against corrosion and having a separable blade unit - Google Patents
Agitator protected against corrosion and having a separable blade unitInfo
- Publication number
- CA2059100A1 CA2059100A1 CA002059100A CA2059100A CA2059100A1 CA 2059100 A1 CA2059100 A1 CA 2059100A1 CA 002059100 A CA002059100 A CA 002059100A CA 2059100 A CA2059100 A CA 2059100A CA 2059100 A1 CA2059100 A1 CA 2059100A1
- Authority
- CA
- Canada
- Prior art keywords
- agitator
- electrically conducting
- blade unit
- enamel
- metallic
- 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.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/20—Investigating the presence of flaws
- G01N27/205—Investigating the presence of flaws in insulating materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
- B01F27/05—Stirrers
- B01F27/07—Stirrers characterised by their mounting on the shaft
- B01F27/071—Fixing of the stirrer to the shaft
Abstract
ABSTRACT OF THE INVENTION
Described is an agitator protected against corrosion and having a separable blade unit, comprising a metallic shaft provided with a corrosion resistant enameling on its outer surface, whereby at least one blade unit having a corrosion resistant enameling is provided, and whereby in the mounted condition of the agitator a plug-in connection is provided in an interference fit region 7 having complementary fitting surfaces out of adjacent worked surfaces of the coatings. In the interference fit region 7 in each of the two fitting surfaces a central partial region out of electrically conducting material is formed, of which the one partial region 3 is connected with the metallic body of the agitator shaft 1 and the other partial region 6 is connected in an electrically conducting manner with the metallic body of the blade unit. In the mounted condition the outer surfaces of the two partial regions are at least partially overlapping each other arranged in such a manner, that an electrically conducting connection is provided between the metallic body of the agitator shaft and the metallic body of the blade unit.
The assembly of the agitators is made preferably by means of a shrinking techniques by supercooling of the agitator shaft with liquid nitrogen introduced into the inside thereof.
Described is an agitator protected against corrosion and having a separable blade unit, comprising a metallic shaft provided with a corrosion resistant enameling on its outer surface, whereby at least one blade unit having a corrosion resistant enameling is provided, and whereby in the mounted condition of the agitator a plug-in connection is provided in an interference fit region 7 having complementary fitting surfaces out of adjacent worked surfaces of the coatings. In the interference fit region 7 in each of the two fitting surfaces a central partial region out of electrically conducting material is formed, of which the one partial region 3 is connected with the metallic body of the agitator shaft 1 and the other partial region 6 is connected in an electrically conducting manner with the metallic body of the blade unit. In the mounted condition the outer surfaces of the two partial regions are at least partially overlapping each other arranged in such a manner, that an electrically conducting connection is provided between the metallic body of the agitator shaft and the metallic body of the blade unit.
The assembly of the agitators is made preferably by means of a shrinking techniques by supercooling of the agitator shaft with liquid nitrogen introduced into the inside thereof.
Description
Novernber 20, 1~0 ~A~
~1~ file: ~-5637E gitator protected against corrosioll alld havillg a separable blade unit = = = = = = = = = = = = . = = . = = = = = = = = = = = = _ = = = = = = = _ _ =, . . = = = = = = = = = = = = = = = =
The invention is related to an especially enameled agitator having a separable blade unit in accordarlce with the pre-amble of claim 1.
Enameled agitators of this type are known from DE 29 51 937 C2 and from DE 30 07 718 Al. Such agitators can be made by means of a so-called cryo-lock connection techniques (press fit techniques) as known from US-Patent 4 221 488. This techniques allows to manufacture agitators consisting oE a completely enameled agitator shaft and an also fully enameled hub with the agitator blades hy shrinking. By supercooling of tile agitator shaft endWithliquid nitrogen introduced into the hollow shaft shrinking of the shaft can be achieved. ~ter performing such shrinking it is possible to provide a plug-in connection between the shaft and the hub of the agitator.
Upon heating the connection to room temperature a good connection is achieved between the worked enamel surfaces. Proper tole-rances and surface properties of the connecting press fit region are achieved by honing of the end of the shaft and of the hub of the agitator.
With such a techniques blade units with a single hub and several impeller blades can be manufactured, which can be inserted through the man hole of a vessel having the man hole as largest opening. Because of different forms of the impeller blades and in the caC;e of u.C~ing spl;t hubs agi-tators of various forms can be designed for various agitation tasks.
Also other methods for making such agitators with one or several separable blade units are possible, whereby each ,biade member may include a blade portion and an arm, provided with a surface having a constant taper complementary to a shaft bore, so that a plug-in connection can be obtained by a relative movement under an assembling force in order to achieve the press fit (EP-Bl-0 145 370).
~1~ file: ~-5637E gitator protected against corrosioll alld havillg a separable blade unit = = = = = = = = = = = = . = = . = = = = = = = = = = = = _ = = = = = = = _ _ =, . . = = = = = = = = = = = = = = = =
The invention is related to an especially enameled agitator having a separable blade unit in accordarlce with the pre-amble of claim 1.
Enameled agitators of this type are known from DE 29 51 937 C2 and from DE 30 07 718 Al. Such agitators can be made by means of a so-called cryo-lock connection techniques (press fit techniques) as known from US-Patent 4 221 488. This techniques allows to manufacture agitators consisting oE a completely enameled agitator shaft and an also fully enameled hub with the agitator blades hy shrinking. By supercooling of tile agitator shaft endWithliquid nitrogen introduced into the hollow shaft shrinking of the shaft can be achieved. ~ter performing such shrinking it is possible to provide a plug-in connection between the shaft and the hub of the agitator.
Upon heating the connection to room temperature a good connection is achieved between the worked enamel surfaces. Proper tole-rances and surface properties of the connecting press fit region are achieved by honing of the end of the shaft and of the hub of the agitator.
With such a techniques blade units with a single hub and several impeller blades can be manufactured, which can be inserted through the man hole of a vessel having the man hole as largest opening. Because of different forms of the impeller blades and in the caC;e of u.C~ing spl;t hubs agi-tators of various forms can be designed for various agitation tasks.
Also other methods for making such agitators with one or several separable blade units are possible, whereby each ,biade member may include a blade portion and an arm, provided with a surface having a constant taper complementary to a shaft bore, so that a plug-in connection can be obtained by a relative movement under an assembling force in order to achieve the press fit (EP-Bl-0 145 370).
- 2 - 2~ 0 A use of such agitators for a great variety of production methods and agitatiO~ tasks is - however - limited insofar as it is not possible to perform a continuous monitoring during the production by means of known test methods allowing to detect damages of the enamel coatlngs occuring at one of the attached blade units. If damages of the enamel coating are not detected substantia:Lly immediately upon occurrence not only substantial repair costs and longer interruption~ of the production may be caused but al o very disadvantageous metal.l.ic poll.uti.ons oE tl~e product may be caused. ~notiler di.fficulty i.s to be seen in the fact that in the case of changes of the pro-duction or in tile case of optimizing production methods separable enameled agitators of the mentioned type often cannot be used if continuous monitoring with proper methods (DE 12 93 478 DE 22 59 492 C3 and DE 24 15 317 C2) becomes necessary since such monitoring is quite important for the operational safety of enameled apparatus. ~ continuous moni-toring during production which is possible with such methods does request that the steel elements of all enameled parts to be monitored are connected in an electrically conducting manner with eacil other.
It is therefore the major object of tile invention to improve agitators of the described kind having a corrosion resistant coating and at least one separable blade unit in such a manner that by means of knot~n test methodsfthe mentioned type a continuous monitoring during the production can be performed.
This object is achieved in the case of separable agitators of the described kind by the features of claim 1. Advantageous more specific features of the invention are subject of the subclaims.
Since in the case of such a separable agitator all enameled steel e].ements can be connected with each other i.n an electrically conducting manner the mentioned known teSt methods can be used allowing a continuous monitoring during the operation without causing difficulties of the mentioned 2 ~ o kind. In the case of such a construction furthermore the posslbi]ity e~ists to test already during manufactllre of separable enameled agitators if in the enameled press fit region in t.~hich an additional seallng is not provided a sufficient sealing is acllieved. Such tests cannot be performed with usual high voltage test devices normally used in this field .
~escription of the drawin~s:
Fig. 1 shows a view in section of a first embodiment of the invention in which embodiment two annular building-up weldings are used Eig. 2 shows a view correspondirlg to Fig. 1 of anot~er embodiment of the invention in whicll two annular regions out of electrically conducting enamel are provided Fig. 3 shows a partial section through the agitator shaft or the hub - resp. - in a third embodiment of the in-vention and ~ ig. 4 shows a partial section through the agitator shaft in a fourth embodiment of the invention.
In the embodiment shown in Fig. 1 an agitator shaft 1 is provided having a closed end. ~t the outer surface of the agitator sllaft 1 and over the closed end a corrosion re-sistant enamel coating 2 is provided wllich consistC out of several enamel layers as conventional in the art.
The agitator shaft 1 is surrounded by the hub 4 of a blade unit provided with a bore. The blade unit comprises at least one blade 10 shaped in accordance with the agitator task of the agitator system e.g. like the impeller agitator as known from US-Patent 4 221 488. Alons the outer surface of the blade unit and along the surface of the bore defining the inner diameter also a corrosion resistant enamel coating is provided.
In accordance with the invention in thé case of this embodi-ment a building-up welding is provided on the shaft of the agitator surrounding the shaft in an annular manner. The building-up welding consists out of a material which can be enameled and 2 i~ 0 and has a corro~ioll resistance WhiCil is clS ~r as possible as good as the corrosion reslstance of the enamel. Materials usable for this purpose are e.g. ~lastelloy or Inconel. Further-more, at the metallic body of the hub ~ also a building-up welding 6 is formed, which is provided in a central partial region of the bore. The annular building-up weldings 3 and 6 at the agitator shaft and in the bore of the hub 4 of the blade unit,resp., are having preferably the same width. In the mounted condition of the agitator the two surfaces of the two partial regions can be arranged at least partially over-lapping in such a manner, that an electrically well conducting connection exists between the metallic body of the agitator shaft 1 and the metallic body of the hub 4 of the blade unit.
In order to form an appropriate interference fit region 7, the surfaces of the enamel coatings 2 and 5 fitting in the mounted condition of the agitator as well as the two building-up weldings 3 and 6 are worked e.g. by honing.
During manufacturing of such an agitator at first the building-up welding 3 can be applied along the circumference of the metallic body of the agitator shaft 1 with a sufficient thick-ness, as well as the building-up welding 6 along the central region of the inner circumference of the hub 4 of the blade unit. Upon depositing of the two building-up weldings 3,6 the surfaces thereof are formed and the enamel coatings 2,5 are deposited a.s layers in the usual manner and then fired.
Then the enamel surfaces in -the interference fit region 7 are turned true, so that upon working the outer surfaces of the enamel coating and of the building-up welding are flush in the interference fit region 7. Thereafter mounting of the agitator can be performed by means of the described known cryo-lock techniques in such a manner, that the outer surfaces of the two building-up weldings 3,6 are connected in an electrically conducting manner.
In the embodiment shown in Fig. 2 corresponding parts are provided with the same reference numerals. Instead of the building-up weldings 3,6 in Fig. 1 in this embodiment in the two fitting partial regions annular enamel coatings 8 and 9, resp., out of electrically conducting enamel are provided in - s~ o the centrcll partial region of the intel^fere1lce f:it regioll 7.
The electrical conductivity of the enamel for the two partial regions 8,9 can be achieved by adding electrically conducting particles to tile frit, which particles may consist e.g. out of silver. The worked surfaces of the interference fit region 7 with the two annular central partial regions 8 and 9 are in contact upon shrinking, so that therewith the electrically conducting connection has been made.
In the embodiment in Fig. 3 only a steel body 11 is shown, whicll may be the steel body of the agitator shaft 1 or the hub 4 in Fig. 1 and 2, since the princïple construction of the meal-s providing the electrically cond~lcting connection may be the same at both steel bodies. In the embodiment as shwon in Fig. 3 a ground enamel coating 12 is provided consisting out of normal and therefore electrically insulating enamel.
Furthermore, a cover coating 13 out of insulating enamel is provided and an annular partial region 14 out of electrically conducting cover enamel. The electrical connection between the steel body 11 and the annular partial region 14 out of electrically conducting cover enamel is achieved by means of an electrically conducting band 16, which e.g. may consist out of platinum. The one end of -this band 16 is connected by spot welding 15 with the steel body 11 and the band 16 is embedded in such a manner into the ground enamel coating 12, that it is possible after applying of the ground enamel to e~pose the end of the band before the electrically conducting cover enamel is deposited and fired.
Fig. 4 shows a further embodiment, in which at the steel body of the agitator shaft 1 in Fig. 1 or 2 a plug or pin 20 is fastened by hard soldering, by means of an interference fit or by another known fastening techniques allowing to provide for an electrically conducting connection. The connecting body 20 may also be provided by building-up welding. The material of the pin-type connecting body is preferably platinum, though also other metals like Inconel may be used, which can be enameled and which are corrosion resistant. Upon fastening of the connecting body ground enamel 22a is deposited in several layers and fired, whereafter several layers out of cover enamel 22b 2 ~ 0 are deposited alld fired. Thereafter t~e surface of the cover enamel 22b and the surface of the pin- or button-type connecting body will be ground and holled to the required dimension. Whell complete, the surfaces of the pin- or button-type connecting body 20 and of the surrounding cover enamel coating will be flush.
As indicated in Fig. 4, the pin~type connecting body 20 can also be connected upon depositing a coating out of ground enamel with a plate 23 out of platinum or the like material, ir~ ~ r-.1er 1:-) n(-llieve nn el.ecl-ric;llly con(lucl-in9 conrl-~ct:i.on, before the cover coating 22b is fired, so that after firing and working by grinding and honing flush sitting surfaces for the interference fit region 7 can be achieved. Instead of a metallic plate 23 also electrica]ly conducting enamel can be used as described in the embodiment of Fig. 3.
In the enamel coating along the inner surface of the bore of the hub 4 in Fig. 1 and 2 a band or a spot out of electrically conducting enamel can be provided, which is directly connected with the metallic body of the hub as shown in Fig. 2, or which is connected indirectly througll a metallic conductor as in the embodiments shown in Fig. 3 or in Fig. 4,resp. The spot out oF electric.ll1y conductirlg material needs only to be c~s large as required to insure that the pin-type connecting body out of platinum or the like material can be aligned in such a manner, that an electrical contact and therewith an electrically conducting connection with the metallic body of the agitator shaft can be achieved.
If another pin or plug out of platinum or the like corrosion resistant material is present or specifically provided, which is in a conducting connection Wit}l the metal body of the hub and accessible from the outside of the hub, by applying a voltage a test can be performed, if the metallic body of the hub is in an electrically conducting connection with the metal]ic body of the agitator shaft.
It is furthermore advisable to form the outer surfaces of the electrically conducting regions within the interference fit region 7 with a surface size as small as possible, if the used electrically conducting material does no-t have a corrosion - 7 - 2~
resistance whieh is not as good as the corrosion resistanee of the enamel surface, since generally by the shrinking techniques a hermetic sealing between the outer surface of the agitator shaft and the inner surface of the hub eannot be achieved with eertainness.
In the described embodiments the two electrieally eonducting partial regions at the agitator shaft and at the hub of the blade unit can prineipally be formed in a similar manner.
The described embodiments, however, can also be combined in a different manner, so that it is possible to seleet the optimum eonstruetion at the agitator shaft or the hub of the blade unit,resp., in view of the costs and possibilities for the manufaeture.
It is therefore the major object of tile invention to improve agitators of the described kind having a corrosion resistant coating and at least one separable blade unit in such a manner that by means of knot~n test methodsfthe mentioned type a continuous monitoring during the production can be performed.
This object is achieved in the case of separable agitators of the described kind by the features of claim 1. Advantageous more specific features of the invention are subject of the subclaims.
Since in the case of such a separable agitator all enameled steel e].ements can be connected with each other i.n an electrically conducting manner the mentioned known teSt methods can be used allowing a continuous monitoring during the operation without causing difficulties of the mentioned 2 ~ o kind. In the case of such a construction furthermore the posslbi]ity e~ists to test already during manufactllre of separable enameled agitators if in the enameled press fit region in t.~hich an additional seallng is not provided a sufficient sealing is acllieved. Such tests cannot be performed with usual high voltage test devices normally used in this field .
~escription of the drawin~s:
Fig. 1 shows a view in section of a first embodiment of the invention in which embodiment two annular building-up weldings are used Eig. 2 shows a view correspondirlg to Fig. 1 of anot~er embodiment of the invention in whicll two annular regions out of electrically conducting enamel are provided Fig. 3 shows a partial section through the agitator shaft or the hub - resp. - in a third embodiment of the in-vention and ~ ig. 4 shows a partial section through the agitator shaft in a fourth embodiment of the invention.
In the embodiment shown in Fig. 1 an agitator shaft 1 is provided having a closed end. ~t the outer surface of the agitator sllaft 1 and over the closed end a corrosion re-sistant enamel coating 2 is provided wllich consistC out of several enamel layers as conventional in the art.
The agitator shaft 1 is surrounded by the hub 4 of a blade unit provided with a bore. The blade unit comprises at least one blade 10 shaped in accordance with the agitator task of the agitator system e.g. like the impeller agitator as known from US-Patent 4 221 488. Alons the outer surface of the blade unit and along the surface of the bore defining the inner diameter also a corrosion resistant enamel coating is provided.
In accordance with the invention in thé case of this embodi-ment a building-up welding is provided on the shaft of the agitator surrounding the shaft in an annular manner. The building-up welding consists out of a material which can be enameled and 2 i~ 0 and has a corro~ioll resistance WhiCil is clS ~r as possible as good as the corrosion reslstance of the enamel. Materials usable for this purpose are e.g. ~lastelloy or Inconel. Further-more, at the metallic body of the hub ~ also a building-up welding 6 is formed, which is provided in a central partial region of the bore. The annular building-up weldings 3 and 6 at the agitator shaft and in the bore of the hub 4 of the blade unit,resp., are having preferably the same width. In the mounted condition of the agitator the two surfaces of the two partial regions can be arranged at least partially over-lapping in such a manner, that an electrically well conducting connection exists between the metallic body of the agitator shaft 1 and the metallic body of the hub 4 of the blade unit.
In order to form an appropriate interference fit region 7, the surfaces of the enamel coatings 2 and 5 fitting in the mounted condition of the agitator as well as the two building-up weldings 3 and 6 are worked e.g. by honing.
During manufacturing of such an agitator at first the building-up welding 3 can be applied along the circumference of the metallic body of the agitator shaft 1 with a sufficient thick-ness, as well as the building-up welding 6 along the central region of the inner circumference of the hub 4 of the blade unit. Upon depositing of the two building-up weldings 3,6 the surfaces thereof are formed and the enamel coatings 2,5 are deposited a.s layers in the usual manner and then fired.
Then the enamel surfaces in -the interference fit region 7 are turned true, so that upon working the outer surfaces of the enamel coating and of the building-up welding are flush in the interference fit region 7. Thereafter mounting of the agitator can be performed by means of the described known cryo-lock techniques in such a manner, that the outer surfaces of the two building-up weldings 3,6 are connected in an electrically conducting manner.
In the embodiment shown in Fig. 2 corresponding parts are provided with the same reference numerals. Instead of the building-up weldings 3,6 in Fig. 1 in this embodiment in the two fitting partial regions annular enamel coatings 8 and 9, resp., out of electrically conducting enamel are provided in - s~ o the centrcll partial region of the intel^fere1lce f:it regioll 7.
The electrical conductivity of the enamel for the two partial regions 8,9 can be achieved by adding electrically conducting particles to tile frit, which particles may consist e.g. out of silver. The worked surfaces of the interference fit region 7 with the two annular central partial regions 8 and 9 are in contact upon shrinking, so that therewith the electrically conducting connection has been made.
In the embodiment in Fig. 3 only a steel body 11 is shown, whicll may be the steel body of the agitator shaft 1 or the hub 4 in Fig. 1 and 2, since the princïple construction of the meal-s providing the electrically cond~lcting connection may be the same at both steel bodies. In the embodiment as shwon in Fig. 3 a ground enamel coating 12 is provided consisting out of normal and therefore electrically insulating enamel.
Furthermore, a cover coating 13 out of insulating enamel is provided and an annular partial region 14 out of electrically conducting cover enamel. The electrical connection between the steel body 11 and the annular partial region 14 out of electrically conducting cover enamel is achieved by means of an electrically conducting band 16, which e.g. may consist out of platinum. The one end of -this band 16 is connected by spot welding 15 with the steel body 11 and the band 16 is embedded in such a manner into the ground enamel coating 12, that it is possible after applying of the ground enamel to e~pose the end of the band before the electrically conducting cover enamel is deposited and fired.
Fig. 4 shows a further embodiment, in which at the steel body of the agitator shaft 1 in Fig. 1 or 2 a plug or pin 20 is fastened by hard soldering, by means of an interference fit or by another known fastening techniques allowing to provide for an electrically conducting connection. The connecting body 20 may also be provided by building-up welding. The material of the pin-type connecting body is preferably platinum, though also other metals like Inconel may be used, which can be enameled and which are corrosion resistant. Upon fastening of the connecting body ground enamel 22a is deposited in several layers and fired, whereafter several layers out of cover enamel 22b 2 ~ 0 are deposited alld fired. Thereafter t~e surface of the cover enamel 22b and the surface of the pin- or button-type connecting body will be ground and holled to the required dimension. Whell complete, the surfaces of the pin- or button-type connecting body 20 and of the surrounding cover enamel coating will be flush.
As indicated in Fig. 4, the pin~type connecting body 20 can also be connected upon depositing a coating out of ground enamel with a plate 23 out of platinum or the like material, ir~ ~ r-.1er 1:-) n(-llieve nn el.ecl-ric;llly con(lucl-in9 conrl-~ct:i.on, before the cover coating 22b is fired, so that after firing and working by grinding and honing flush sitting surfaces for the interference fit region 7 can be achieved. Instead of a metallic plate 23 also electrica]ly conducting enamel can be used as described in the embodiment of Fig. 3.
In the enamel coating along the inner surface of the bore of the hub 4 in Fig. 1 and 2 a band or a spot out of electrically conducting enamel can be provided, which is directly connected with the metallic body of the hub as shown in Fig. 2, or which is connected indirectly througll a metallic conductor as in the embodiments shown in Fig. 3 or in Fig. 4,resp. The spot out oF electric.ll1y conductirlg material needs only to be c~s large as required to insure that the pin-type connecting body out of platinum or the like material can be aligned in such a manner, that an electrical contact and therewith an electrically conducting connection with the metallic body of the agitator shaft can be achieved.
If another pin or plug out of platinum or the like corrosion resistant material is present or specifically provided, which is in a conducting connection Wit}l the metal body of the hub and accessible from the outside of the hub, by applying a voltage a test can be performed, if the metallic body of the hub is in an electrically conducting connection with the metal]ic body of the agitator shaft.
It is furthermore advisable to form the outer surfaces of the electrically conducting regions within the interference fit region 7 with a surface size as small as possible, if the used electrically conducting material does no-t have a corrosion - 7 - 2~
resistance whieh is not as good as the corrosion resistanee of the enamel surface, since generally by the shrinking techniques a hermetic sealing between the outer surface of the agitator shaft and the inner surface of the hub eannot be achieved with eertainness.
In the described embodiments the two electrieally eonducting partial regions at the agitator shaft and at the hub of the blade unit can prineipally be formed in a similar manner.
The described embodiments, however, can also be combined in a different manner, so that it is possible to seleet the optimum eonstruetion at the agitator shaft or the hub of the blade unit,resp., in view of the costs and possibilities for the manufaeture.
Claims (9)
1. An agitator protected against corrosion and having a separable blade unit, comprising:
a) a metallic shaft (1) provided with a corrosion resistant insulating electrically insulating enamel or the like.
b) a blade unit having at least one blade (10), which blade unit has a corrosion resistant electrically insulating enamel or the like coating on its surface, whereby c) in the mounted condition of the agitator a plug-in connection is provided in an interference fit region (7) having complementary fitting surfaces out of adjacent worked surfaces of the coatings, characterized in that:
d) in the interference fit region (7) in each of the two fitting surfaces a central partial region out of electrically conducting material is formed, that e) one such partial region is connected in an electrically conducting manner with the metallic body of the agitator shaft (1) and that the other partial region (6;9;14;23) is connected in an electrically conducting manner with the metallic body of the blade unit, and that f) in the mounted condition of the agitator the outer surfaces of the two partial regions are at least partially overlapping each other in such a manner, that an electrically conducting connection is provided between the metallic body of the agitator shaft (1) and the metallic body of the blade unit.
a) a metallic shaft (1) provided with a corrosion resistant insulating electrically insulating enamel or the like.
b) a blade unit having at least one blade (10), which blade unit has a corrosion resistant electrically insulating enamel or the like coating on its surface, whereby c) in the mounted condition of the agitator a plug-in connection is provided in an interference fit region (7) having complementary fitting surfaces out of adjacent worked surfaces of the coatings, characterized in that:
d) in the interference fit region (7) in each of the two fitting surfaces a central partial region out of electrically conducting material is formed, that e) one such partial region is connected in an electrically conducting manner with the metallic body of the agitator shaft (1) and that the other partial region (6;9;14;23) is connected in an electrically conducting manner with the metallic body of the blade unit, and that f) in the mounted condition of the agitator the outer surfaces of the two partial regions are at least partially overlapping each other in such a manner, that an electrically conducting connection is provided between the metallic body of the agitator shaft (1) and the metallic body of the blade unit.
2. An agitator as claimed in Claim 1, characterized in that at least one of the two partial regions has an annular shape.
3. An agitator as claimed in Claim 1 characterized in that at least one of the two partial regions is formed by building-up welding.
4. An agitator as claimed in Claim 1 characterized in that at least one of the two partial regions consists out of electrically conducting enamel.
5. An agitator as claimed in Claim 1 characterized in that at least one of the two partial regions is connected in an electrically conducting manner with the respective metallic body (11) through a plug-type metallic connecting body (20).
6. An agitator as claimed in Claim 6, characterized in that a layer out of electrically conducting enamel is provided over the connecting body (20).
7. An agitator as claimed in Claim 6, characterized in that a metallic plate (23) is provided over the connecting body (20).
8. An agitator as claimed in Claim 2, characterized in that the annular partial region has a cover coating (14) out of electrically conducting enamel over a ground coating (12) out of electrically insulating enamel, and that the electrically conducting cover coating (14) is connected in electrically conducting manner with the respective metallic body (11) through a metallic band (16) extending through the electrically insulating ground coating.
9. An agitator as claimed in Claim 1, characterized in that at least the outer surface of the two partial regions is formed by a corrosion resistant metal like tantal, inconel or hastelloy.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP91100349.9 | 1991-01-12 | ||
| EP91100349A EP0495133A1 (en) | 1991-01-12 | 1991-01-12 | Corrosion protected stirrer with removable agitating vane unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2059100A1 true CA2059100A1 (en) | 1992-07-13 |
Family
ID=8206292
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002059100A Abandoned CA2059100A1 (en) | 1991-01-12 | 1992-01-09 | Agitator protected against corrosion and having a separable blade unit |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0495133A1 (en) |
| JP (1) | JPH05192554A (en) |
| CA (1) | CA2059100A1 (en) |
| IE (1) | IE920081A1 (en) |
| MX (1) | MX9102809A (en) |
| ZA (1) | ZA9297B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108603855A (en) * | 2016-01-28 | 2018-09-28 | 腐蚀检测有限公司 | Corrosion detection system |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4420570A1 (en) * | 1994-04-02 | 1995-10-05 | Thale Eisen Huettenwerk | Stirrer with corrosion rate measurement and warning |
| DE60228680D1 (en) * | 2002-02-27 | 2008-10-16 | Pfaudler Werke Gmbh | A method of making an electrically conductive connection between metal components coated with non-conductive material |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2811339A (en) * | 1955-12-02 | 1957-10-29 | Pfaudler Co Inc | Separable glass coated agitators |
| NL272388A (en) * | 1960-12-16 | |||
| CH518732A (en) * | 1970-01-28 | 1972-02-15 | Fritz Dr Schneider | Composite stirrer in chemical apparatus |
| EP0393516B1 (en) * | 1989-04-17 | 1994-09-21 | TYCON Spa | An enamelled stirrer with paddles detachably fixed on the shaft in an enamel to enamel coupling without any gasket |
-
1991
- 1991-01-12 EP EP91100349A patent/EP0495133A1/en not_active Withdrawn
- 1991-12-26 MX MX9102809A patent/MX9102809A/en unknown
-
1992
- 1992-01-07 ZA ZA9297A patent/ZA9297B/en unknown
- 1992-01-09 CA CA002059100A patent/CA2059100A1/en not_active Abandoned
- 1992-01-10 IE IE008192A patent/IE920081A1/en unknown
- 1992-01-10 JP JP4002677A patent/JPH05192554A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108603855A (en) * | 2016-01-28 | 2018-09-28 | 腐蚀检测有限公司 | Corrosion detection system |
| US10809217B2 (en) | 2016-01-28 | 2020-10-20 | Cranfield University | Corrosion detection system |
| CN108603855B (en) * | 2016-01-28 | 2021-12-03 | 腐蚀检测有限公司 | Corrosion detection system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05192554A (en) | 1993-08-03 |
| IE920081A1 (en) | 1992-07-15 |
| ZA9297B (en) | 1992-10-28 |
| MX9102809A (en) | 1994-04-29 |
| EP0495133A1 (en) | 1992-07-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |