Abstract: The present invention is directed to methods for preparing quaternary ammonium salts, particularly pyridinium and quinolinium salts. By preparing these salts in a solvent selected from the group consisting of propylene glycols, propylene glycol ethers and mixtures thereof, the production of undesirable by-products and contamination of the product with undesirable solvents are minimized, if not eliminated. Using the preparation methods of the present invention low hazard corrosion inhibitors and aqueous cleaning solutions using these inhibitors may be prepared. In fact, by preparing dodecyl pyridinium bromide in dipropylene glycol methyl ether as the solvent, a particularly desirable corrosion inhibitor characterized by a low toxicity and a high flash point has been prepared. The present invention thus provides the safer corrosion inhibitors and cleaning solutions long sought by industrial cleaning services.

Abstract: The present invention is directed to methods for cleaning films and particulates from the compressor section and combustion contaminants from the combustion and turbine sections of a combustion turbine. Particulate films and contaminants adhering to the internal components of the compressor section of a turbine are readily removed by forcing a mist comprising a cleaning solution such as an aqueous surfactant solution through the compressor section. Contaminants resulting from fuel combustion and deposited in the combustion and turbine sections are removed by forcing a mist comprising a second cleaning solution through those sections. The second solution typically comprises an aqueous acid solution optionally including a corrosion inhibitor. The compressor section must be isolated from such acid solutions, e.g. by continuing to force the misted surfactant solution through the compressor section prior to and simultaneously with forcing the misted acid solution through the combustion section.

Abstract: The present invention is directed to a manifold for temporarily blocking the air intake of the compressor section of a combustion turbine to facilitate cleaning. A manifold suitable for providing a temporary seal about the air intake of the compressor section and through which a foamed cleaning solution can be pumped is disclosed. The manifold is conveniently provided as a flexible manifold body having an inflatable tubular member along the periphery thereof for sealing with the air intake and a plurality of hose connections through which a foamed cleaning solution can be delivered to the compressor section of the combustion turbine. Particulate films and contaminants adhering to the internal components of the compressor section of a turbine are readily removed by pumping a foamed cleaning solution such as a foamed, aqueous surfactant solution through the manifold and into the compressor section.

Abstract: The present invention is directed to methods for cleaning films and particulates from the compressor section and combustion contaminants from the combustion and turbine sections of a combustion turbine. Particulate films and contaminants adhering to the internal components of the compressor section of a turbine are readily removed by pumping a foamed cleaning solution such as a foamed, aqueous surfactant solution through the compressor section. Contaminants resulting from fuel combustion and deposited in the combustion and turbine sections are removed by pumping a second, foamed cleaning solution through those sections. The second solution typically comprises a foamed, aqueous acid solution optionally including a corrosion inhibitor. The compressor section must be isolated from such acid solutions, e.g. by pumping the foamed surfactant solution through the compressor section prior to and simultaneously with pumping the foamed acid solution through the combustion section.

Abstract: The present invention is directed to methods for preparing quaternary ammonium salts, particularly pyridinium and quinolinium salts. By preparing these salts in a solvent selected from the group consisting of propylene glycols, propylene glycol ethers and mixtures thereof, the production of undesirable by-products and contamination of the product with undesirable solvents are minimized, if not eliminated. Using the preparation methods of the present invention low hazard corrosion inhibitors and aqueous cleaning solutions using these inhibitors may be prepared. In fact, by preparing dodecyl pyridinium bromide in dipropylene glycol methyl ether as the solvent, a particularly desirable corrosion inhibitor characterized by a low toxicity and a high flash point has been prepared. The present invention thus provides the safer corrosion inhibitors and cleaning solutions long sought by industrial cleaning services.

Abstract: The present invention is directed to methods and apparatus for cleaning industrial and commercial operations hard surfaces, e.g., concrete and asphalt slabs, walls, tanks, grates, and ship hulls, contaminated by oil and chemical spills or barnacles. The methods and apparatus of the present invention produce a high velocity airflow about only the periphery of the area being cleaned by the device to provide improved entrainment and removal of cleaning fluid and dislodged debris. High velocity streams of cleaning fluid are directed against the surface from nozzles disposed on rotating arms of a hub suspended within the portable housing of the slab cleaner. The spent cleaning fluid and dislodged debris are removed by the application of a vacuum to a chamber extending about the periphery of the housing to create the high velocity airflow. Thus, high velocity airflow is developed without fear that the slab cleaner will be sucked down and become temporarily stuck on the surface being cleaned.

Abstract: A method and solution for removing iron oxide-containing scale from the interior surfaces of steel vessels. During normal cleaning procedures for internal scale-encrusted steel surfaces of a utility boiler, a reducing atmosphere is maintained, and an aqueous solution containing an about 4:1 to about 9:1 weight ratio of formic acid and citric acid, is placed in dissolving relation to the scale. The high F/C ratios hold more iron in solution than low F/C ratios, especially if the iron is kept in the 2+oxidation state. The ability of the solution to hold dissolved iron is only slightly dependent on pH, so long as pH is maintained below 7.0. An oxidation stage is not required to remove dissolved iron to below 1 ppm from the solution, during waste treatment procedures using lime and NaOH.

Abstract: Methods and solutions useful for removing iron oxide-containing scale from the interior surfaces of steel. An aqueous cleaning solution containing formic acid and at least one carboxylic acid having at least two carbon atoms wherein the weight ratio of formic acid to higher carboxylic acid is greater than about 4:1 is contacted with the scale in the absence of an oxidizing agent. Preferred carboxylic acids are the mono-, di-, hydroxy-, and polyhydroxy-carboxylic acids having from two to six carbon atoms. More preferrably, the aqueous solution includes about 0.5-10.0 percent-by-weight in total of such acids wherein the weight ratio of formic acid to higher carboxylic acid is from about 4:1 to about 9:1, together with an effective amount of an organic acid corrosion inhibitor and, optionally, a scale dissolution accelerating agent. Preferrably, contact is under a reducing atmosphere, at a temperature in the range of about 150.degree.-200.degree. F. and a pH less than 7.

Abstract: Disclosed is a method to remove heavy metals from amino-carboxylic acid chelate solutions comprising adding nitrous acid to lower the pH of the aqueous solution sufficient to destroy the chelate bonds and release the metal ions and thereafter adding an appropriate strong base and optionally a sulfide salt to precipitate the liberated heavy metals.

Abstract: In accordance with illustrative embodiments of the present invention, the existing valves in a crude oil, gas, or other product pipeline are positively sealed off to allow a pressure test to be made of a section or segment of the pipeline between the valves. The section is packed with a hydrocarbon or aqueous liquid. A mixture of a highly viscous hydrocarbon based gel material and a lost-circulation material are injected into the pipeline segment adjacent each valve to form plugs in the line. The gel plugs are squeezed under pressure against the internal components of each valve to cause all leakage paths therein to be bridged over and sealed off. The pipeline segment then is pressure tested to determine if there are any leaks therein, after which the gel is flushed out of the line and broken down into a linear pumpable state for disposal.