Patents by Inventor Ramsay Chang

Ramsay Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5948143
    Abstract: An apparatus and method are described for removing vapor phase contaminants from a gas stream by placing a porous tube having a sorbent material into ductwork through which the gas stream passes. In a first mode of operation, vapor phase contaminants are adsorbed by the sorbent. In a second mode of operation, the porous tube is cleaned of any accumulated deposits, for example fly ash, while in place without having to stop the gas flow. In a third mode of operation, the sorbent can be regenerated in place and without having to stop the gas flow by heating and collecting the desorbed contaminants. This invention is particularly suited for the removal of vapor phase mercury from flue gas generated by a combustion process.
    Type: Grant
    Filed: January 20, 1998
    Date of Patent: September 7, 1999
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Sharon Sjostrom, Ramsay Chang
  • Patent number: 5854173
    Abstract: A method for removing vapor phase contaminants from a gas stream. Sorbent particles are injected into the gas stream to react with vapor phase contaminants in the gas stream. Each sorbent particle is made from a support particle of a material coated with a layer of sorbent material different than the material of the support particle. The gas stream is directed through a particulate control device to remove the sorbent particles from the gas stream. A sorbent particle for use in the method and a method for manufacture of the sorbent particle are provided.
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: December 29, 1998
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Ramsay Chang, Massoud Rostam-Abadi
  • Patent number: 5827352
    Abstract: A method for removing mercury from a gas stream. In the method, sorbent is injected into the gas stream. Water is dispersed into the gas stream to create a cooled gas stream. The cooled gas stream is allowed to dwell with the sorbent in a chamber to remove mercury from the cooled gas stream. The cooled gas stream is passed through an electrostatic precipitator located above the chamber which collects water and recycles the collected water back into the chamber for cooling the gas stream in the chamber. An apparatus for removing mercury from a gas stream is also provided.
    Type: Grant
    Filed: April 16, 1997
    Date of Patent: October 27, 1998
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Ralph F. Altman, Ramsay Chang, Robert M. Henningsgaard, Ronald W. Elsner
  • Patent number: 5505766
    Abstract: A method for removing pollutants from a combustor flue gas. The method includes the steps of supplying sorbent to a baghouse having a filter bag therein until the filter bag is coated with a predetermined amount of sorbent and introducing the flue gas into the baghouse. Pollutants in the flue gas are sorbed by the sorbent on the filter bag. A system is provided for performing the method of the invention.
    Type: Grant
    Filed: July 12, 1994
    Date of Patent: April 9, 1996
    Assignee: Electric Power Research, Inc.
    Inventor: Ramsay Chang
  • Patent number: 5158580
    Abstract: A method and apparatus for efficient removal of particulates from a gas is described which incorporates a barrier filter (e.g. baghouse) internally of an electrostatic precipitator. An alternative embodiment is disclosed which incorporates an electrostatic precipitator and a barrier filter (i.e. baghouse) in series, with a pre-charger interposed therebetween. The series arrangement enables the barrier filter to operate at significantly higher filtration velocities than normal 4.06-20.32 cm/s (8-40 ft/min) versus 0.76-2.54 cm/s (1.5-5 ft/min) and reduces the size of the barrier filter significantly. The precharger adds an additional electrostatic charge to particulates exhausted from the electrostatic precipitator and replaces charge lost in lengthy and poorly insulated conduits.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: October 27, 1992
    Assignee: Electric Power Research Institute
    Inventor: Ramsay Chang
  • Patent number: 5024681
    Abstract: A method for removing particulates from a gas is described incorporating an electrostatic precipitator and a barrier filter in series, i.e. baghouse, downstream of the electrostatic precipitator. The series arrangement enables the barrier filter to operate at significantly higher filtration velocities than normal 4.06-20.32 cm/s (8-40 ft/min) versus 0.76-2.54 cm/s (1.5-5 ft/min) and reduces the size of the barrier filter significantly. The invention overcomes the problem of the sensitivity of electrostatic precipitator particulate collection efficiency to variations in particulate and flue gas properties and the alternative of having to substitute the electrostatic precipitator with large barrier filters in which its use would be prohibited by cost and space considerations.
    Type: Grant
    Filed: December 15, 1989
    Date of Patent: June 18, 1991
    Assignee: Electric Power Research Institute
    Inventor: Ramsay Chang