Church Dwight & Co., Inc.

Other

William E Spears, Jr

Lawrence Kirschner

Michael S Lajoie

Benny S Yam

Robert C Jorgensen

James D Shank, Jr

Andrew M Taylor

Arthur C Rubey, Iii

Michael E Miner

A method of cleaning a solid surface which is particularly effective for a surface having a complicated structure including slots and holes comprises immersing the solid surface in a cleaning slurry comprising a cleaning liquid and abrasive particles which are soluble in the cleaning liquid, the cleaning liquid comprising a saturated solution so as to greatly reduce the dissolution of the abrasive particles in the cleaning liquid.

Slurry cleaning process

Blast cleaning with at least two types of abrasives employing a blasting apparatus having at least a first and a second closed blasting pot connected to a conveying line and the conveying line and each blasting pot are connected to a source of compressed gas by a differential pressure metering system. The differential pressure metering system provides a differential pressure between each blasting pot and the conveying line enabling blasting media in each pot to pass from each pot through a variable size orifice to the conveying line. Each blasting pot can be operated independently of each other enabling varying proportions of different types of blast media to be released in the conveying line and blasted from a nozzle to clean a solid surface.

Blasting apparatus and method for blast cleaning a solid surface

Cleaning method and apparatus utilizing sodium bicarbonate particles

An improved slurry blasting process is disclosed wherein a liquid carrier medium such as water contains a dispersed water-soluble particulate abrasive to enhance blast cleaning efficiency and wherein the liquid carrier comprises a saturated solution such as the dissolved particulate abrasive so as to minimize the dissolution of the particulate abrasive therein. Slurry blasting at relatively low pressures below 500 psi and at room temperature provides effective and cost efficient cleaning of substrates. The slurry can be recovered and continuously reused. A recrystallization agent can be added to the slurry to increase abrasive particulate growth in the saturated solution.

Slurry blasting process

To reduce dust and improve the productivity of wet blasting, a blast nozzle and a method of using same are provided for directing a stream of abrasive particles entrained in compressed air to a targeted surface and for injecting a pressurized water stream into the stream of abrasive particles at a point downstream of the orifice of the blast nozzle and in the expansion portion of the nozzle. At the injection point, the velocity of the entrained abrasive particles is substantially equivalent to the velocity of the injected water stream.

Blast nozzle for water injection and method of using same for blast

A media control valve used to dispense and meter an amount of abrasive media from a supply pot to a compressed air line for blast cleaning comprises a vertical discharge passage and an air flow tube communicating with the vertical discharge passage, a media control sleeve placed in an inclined bore in the valve body and disposed between the vertical discharge passage and air flow tube, the media control sleeve comprising a plurality of spaced orifices which allow communication between the vertical discharge passage and the air flow tube, the media control sleeve being rotatable in place within the valve body bore so as to present a different orifice in communication with the discharge passage.

Media control valve

Improvements to blast cleaning apparatus, and particularly to a media control device which contains a fixed orifice placed between the abrasive supply pot and a media outlet to the compressed air line to meter the media flow into the air line and means to maintain a positive pressure differential between the supply pot and the air line further includes a means to equalize the pressure between the air line and a media passage immediately below the orifice. An additional improvement comprises adding a flow straightening device upstream of a bend in the air line so as to reduce back-mixing in the bend and consequently the turbulence of air downstream of the bend and across the media outlet into the air line.

Differential pressure metering and dispensing system for abrasive media

An improved wet blasting process is disclosed wherein the liquid carrier medium contains a dispersed particulate abrasive to enhance the blast cleaning efficiency and wherein the particulate abrasive is soluble in the carrier liquid. To minimize dissolution of the soluble particulate abrasive, the liquid carrier comprises a saturated solution such as the dissolved particulate abrasive in the liquid.

Water blasting process

A conventional blasting apparatus is modified to provide a separate source of line air to a blast pot through a pressure regulator to provide a greater pressure in the blast pot than is provided to the conveying hose. This differential pressure is maintained by an orifice having a predetermined area situated between the blast pot and the conveying hose. This orifice provides an exit for the blast medium and a relatively small quantity of air from the blast pot to the conveying hose, and ultimately to the nozzle and finally the workpiece. The differential air pressure, typically operating between 1.0 and 15.0 psi with an orifice having an appropriate area, yields acceptable media flow rates in a controlled manner.

Blasting apparatus and method

Blasting media for removing coatings from sensitive metal and composite surfaces, and a process useful therewith, wherein the blasting media comprise mixtures of water-soluble crystalline sodium bicarbonate particles having average particle sizes of from 100-500 microns.

Process for removing coatings from sensitive substrates, and blasting

Conventional industrial pressure blasting apparatus is modified to allow a controlled pressure on the blast pot that is greater than the pressure on the line where less aggressive abrasive media and air are mixed for conveying the mixture to the nozzle and then to the workpiece. A media control device, with a fixed but readily variable area, is placed between the blast pot and the media/air mixing line to meter the media flow and maintain a positive pressure differential between the blast pot and the line. Adjusting the pressure differential allows control of the weight ratio of the media-to-air flow to between about 0.05 to 0.25.

Blasting apparatus

Conventional industrial pressure blasting apparatus is modified to allow a controlled pressure on the blast pot that is greater than the pressure on the line where the media and air are mixed for conveying the mixture to the nozzle and then to the workpiece. A media control device, with a fixed but readily variable area, is placed between the blast pot and the media/air mixing line to meter the media flow and maintain the pressure differential between the blast pot and the line. This allows control of the media flow when low flow rates, below about 10 pounds per minute, are required.

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Lawrenceville, NJ, United States of America

William E Spears, Jr