Electrolysis: processes – compositions used therein – and methods – Electrolytic synthesis – Utilizing fused bath
Reexamination Certificate
2001-09-28
2003-11-18
Valentine, Donald R. (Department: 1742)
Electrolysis: processes, compositions used therein, and methods
Electrolytic synthesis
Utilizing fused bath
C205S386000, C423S297000, C423S439000, C423S440000
Reexamination Certificate
active
06649040
ABSTRACT:
TECHNICAL FIELD
This invention relates to carbon-composite materials, particularly of the type used to form cathodes or cell linings of electrolysis reduction cells, especially those used for the production of aluminum metal, as well as parts of such cathodes and linings, and related products. More particularly, the invention relates to carbon composite materials that are erosion/oxidation-resistant and, desirably, that are wettable by molten aluminum.
BACKGROUND ART
The cathodes of cells used for the production of aluminum generally take the form of a lining made of carbon blocks, or the like, positioned along the bottom wall and sides of an electrolysis cell. A typical electrolysis cell
10
is shown in
FIGS. 1 and 2
of the accompanying drawings. Where the surface
11
of the molten electrolyte
12
contacts the sidewalls
14
of the cell, the cathode
15
is often sloped as shown (this usually being referred to as the “monolithic slope” of the cell lining) to reduce cell erosion caused by magneto-hydrodynamic (MHD) effects that may create excessive metal motion. Conductive anodes (not shown) dip into the molten electrolyte from above to complete the electrode combination required for electrolysis. The cathodic lining
16
is conductive and contacts the molten electrolyte
12
and also the pool
17
of molten metal as it is formed. Gaps
18
between the Spacers, in the form of short cylindrical stubs or buttons, are arranged in three groups spaced about the heat transfer basin and projecting into the heat transfer basin interior to maintain a prescribed space between the two basins. During use, that space contains a thermal transfer liquid, such as alcohol or glycol, serving as a thermal transfer medium between the two basins. A sterile drape, impervious to the thermal transfer medium, is disposed between the product basin exterior and the liquid thermal transfer medium to preserve the sterile nature of the product basin. Surgically sterile liquid, such as sodium chloride solution, is placed in the product basin and congeals on the side of that basin when the refrigeration unit is activated. A scraping tool is utilized to remove congealed sterile material from the product basin side to thereby form a slush of desired consistency within the product basin. Some users of the system employ the scraping tool to chip the solid pieces from the basin side.
As noted in the above-referenced Templeton patent (U.S. Pat. No. 4,934,152), the Keyes et al system has a number of disadvantages. In particular, the separate product basin must be removed and re-sterilized after each use. Additionally, the glycol or other thermal transfer medium is highly flammable or toxic and, in any event, complicates the procedure. The Templeton patent (U.S. Pat. No. 4,934,152) discloses a solution to these problems by constructing an entirely new apparatus whereby the product basin is eliminated in favor of a sterile drape impervious to the sterile surgical liquid, the drape being made to conform to the basin and directly receive the sterile liquid. Congealed liquid is scraped or chipped from the sides of the conformed drape receptacle to form the desired surgical slush.
The Faries, Jr. et al patent (U.S. Pat. No. 5,163,299) notes that scraping congealed liquid from the drape is undesirable in view of the potential for damage to the drape, resulting in a compromise of sterile conditions. As a solution to the problem, the Faries, Jr. et al patent (U.S. Pat. No. 5,163,299) proposes that the drape be lifted or otherwise manipulated by hand to break up the congealed liquid adhering to the drape. Although this hand manipulation is somewhat effective, it is not optimal, and often is inconvenient and constitutes an additional chore for operating room personnel. Accordingly, several of the Faries, Jr. et al patents (e.g., U.S. Pat. Nos. 5,331,820; 5,400,616; 5,457,962; 5,502,980; 5,653,938; 5,809,788; 5,857,467; 5,950,438; 6,003,328; and 6,035,855) resolve the problem of manual drape manipulation by disclosing various techniques and/or dislodgment mechanisms to automatically remove the congealed liquid adhering to the drape without endangering the integrity of the drape.
The Templeton patent (U.S. Pat. No. 4,934,152) further discloses an electrical heater disposed at the bottom of the basin to convert the sterile slush to warmed liquid, or to heat additional sterile liquid added to the basin. Templeton describes the need for such warm sterile liquid as occurring after a surgical procedure is completed to facilitate raising the body cavity of the surgery patient back to its normal temperature by contact with the warmed liquid. However, there are a number of instances during a surgical procedure when it is desirable to have simultaneous access to both warmed sterile liquid and sterile surgical slush. Accordingly, several of the Faries, Jr. et al patents (e.g., U.S. Pat. Nos. 5,333,326; 5,429,801; 5,522,095; 5,524,643; 5,615,423; 5,653,938; 5,816,252; 5,862,672; 5,857,467; and 5,879,621) disclose a manner in which to simultaneously provide both surgical slush and warmed surgical liquid during a surgical procedure by utilizing a machine having plural basins with each basin either producing surgical slush or heating a sterile liquid. This machine typically utilizes a single surgical drape that forms a drape receptacle within each basin to collect sterile slush and heated sterile liquid produced by the machine in the respective basins.
In addition, several of the drapes and thermal treatment systems disclosed in the above-mentioned patents and copending applications include specialized features to enhance various aspects of thermal treatment system operation. For example, some of the specialized features may include: bladder drapes (e.g., as disclosed in U.S. Pat. Nos. 5,809,788; 5,950,438; and 6,003,328); drapes having plates or disks (e.g., as disclosed in U.S. Pat. Nos. 5,457,962 and 5,502,980); leak detection drapes (e.g., as disclosed in U.S. Pat. Nos. 5,524,643 and 5,816,252); reinforced drapes (e.g., as disclosed in U.S. Pat. No. 5,857,467); drape indicators and corresponding thermal treatment system detection devices to ensure sterility by enabling system operation in response to detecting a sterile drape placed on the system (e.g., as disclosed in U.S. Pat. Nos. 5,653,938 and 5,879,621); drapes having indicia to direct placement of the drapes on thermal treatment systems (e.g., as disclosed in U.S. Pat. No. 5,615,423); surgical drapes constructed of materials having a coefficient of friction in a particular range and/or drapes including attachment mechanisms such that a drape may withstand being drawn under a dislodgment mechanism (e.g., as disclosed in U.S. Pat. No. 6,035,855); and a stand to elevate objects within a heated basin above the basin floor (e.g., as disclosed in U.S. patent application Ser. No. 08/807,095) and/or a heater configured to cover a portion of the basin (e.g., as disclosed in U.S. patent application Ser. No. 09/046,090) to prevent the drape from overheating and puncturing when objects are placed within the basin.
The above-described apparatus may stand some improvement. In particular, thermal treatment systems or machines are generally utilized for certain aspects of a medical procedure. These machines are typically operated prior to or during the medical procedure to enable a sterile medium to attain a desired temperature and/or form suitable for that procedure. The machines are positioned within an operating room or other facility proximate the medical procedure site and patient. Since the machine treats sterile media in a sterile field, sterile personnel (e.g., personnel that have taken the necessary precautions enabling them to interact with objects in the sterile field without contaminating that field) are required to operate the machine to prevent contamination of the sterile field and injury to the patient. Thus, the machine either provides sterile personnel with an additional task of controlling and monitoring the machine, or requires additional sterile personnel to perform the
Bergeron Jules
Mirchi Amir A.
Alcan International Limited
Valentine Donald R.
LandOfFree
Wettable and erosion/oxidation-resistant carbon-composite... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Wettable and erosion/oxidation-resistant carbon-composite..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wettable and erosion/oxidation-resistant carbon-composite... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3178302