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AssigneePulp and Paper Research Institute of Canada
InventorAndrew Garner
Estimating the term…
A monitor assembly for monitoring the effectiveness of a method and apparatus for electrochemical crevice corrosion protection by electrochemical potential control of a stainless steel vessel containing a corrosive washing solution, e.g. bleach plant washer equipment used in the pulp industry.
A monitor assembly for monitoring the effectiveness of cathodic crevice corrosion protection of a stainless steel member, comprising:
In combination, a stainless steel bleach plant washer perforated or foraminous drum, and welded to one end face thereof adjacent to the circumferential wall, a monitor assembly comprising:
Dependencies are inferred from the claim text.
No related US applications are recorded in the indexed filing history.
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Cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions: controlling or regulating…
Investigating resistance of materials to the weather, to corrosion, or to light: electrochemical measuring systems for weathering, corrosion or…
Non-mechanical removal of metallic material from surface
Investigating or analysing materials by determining their chemical or physical properties
Term ended 20 Mar 2000 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
(i) Field of the Invention
This invention relates to a monitor assembly for monitoring a method and apparatus for corrosion protection by electrochemical potential control of a stainless steel vessel containing a corrosive washing solution. More particularly, it is directed to such a monitor assembly for use in a method and apparatus for protecting stainless steel bleach plant washer equipment, used in the pulp industry, from corrosion.
(ii) Description of the Prior Art
In the accompanying drawings,
FIG. 1 is an exploded elevational view of the components of the monitor of an aspect of this invention;
FIG. 2 is an elevational view of an alternative mount which may be used in the monitor shown in FIG. 1;
As seen in FIGS. 1 and 4, the monitor 10 includes a mount 11 having an exposed threaded end 12. The mount 11 in FIG. 1 is shown welded to the end face of a stainless steel bleach plant washer drum 100. The mount 11 may be made of any metal which has sufficient mechanical and chemical stability to withstand the corrosive environment and to withstand mechanical stress, and which can be electrically and mechanically connected to the protected equipment. It may be a stainless steel, e.g., the same as that of the drum 100, but preferably it is HASTELLOY C-276, the Trade Mark of a nickel-based alloy of Cabot Corporation.
As shown more fully also in FIG. 3, a non-electrically conducting sleeve 15 is disposed on the mount 11. While the sleeve may be any electrically non-conducting material having sufficient mechanical and chemical stability to withstand the corrosive environment and the mechanical stress, it preferably is glass-filled TEFLON (the Trade Mark for polytetrafluoroethylene of DuPont).
A first frusto-conical centrally apertured metal spacer 16 is disposed on the sleeve 15 to be in electrical contact with mount 11. The larger diameter end of the spacer 16 is disposed in such contact with the mount 11. The spacer 16 may be made of any metal having sufficient mechanical and chemical stability to withstand the corrosive environment and the mechanical stress, and can be electrically and mechanically connected to the protected equipment. It may be a stainless steel, e.g., the same as that of the drum 100, but preferably it is HASTELLOY C-276.