Patents by Inventor Yao Tzu Li

Yao Tzu Li 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: 5971061
    Abstract: A tube-type heat exchanger has a low wear support and drive for a whip rod that orbits over the inner surface of the heat transfer tube to spread a process liquid into a thin falling film. The support and drive includes a conical thrust bearing near the upper end of the rod. An edge of the thrust bearing engages and rolls over a circular rim bearing surface. A stem pin axially aligned with the rod extends upwardly over the rod and through a circular hole in an orbiting drive plate. In one form, the rim bearing surface is formed on the upper edge of the tube, or on the upper edge of a generally cylindrical bearing secured on or over the tube. The thrust bearing is secured between the rod and the stem. A stop disc carried on the stem pin limits the fall of the rod in the tube when the orbiting stops.
    Type: Grant
    Filed: September 21, 1998
    Date of Patent: October 26, 1999
    Assignee: Y.T. Li Engineering, Inc.
    Inventor: Yao-Tzu Li
  • Patent number: 5953924
    Abstract: An apparatus, thermal storage system and method for heat exchange using a tube-type heat exchanger. A rod or rods are propelled to moves over the inner surface of the tube. The moving rod is in contact with a first process liquid which is adjacent the inner surface as a falling film or by flooding the interior of the tube. The flooded mode is particularly useful where the tube is non-vertical or the heat exchanger is used to make an ice slurry for HVAC systems serving high-rise buildings. Multiple such rod and tube assemblies are operated simultaneously using a drive plate powered to execute an orbital motion in a plane generally orthogonal to the rods. In one form the plate is coupled via a crank to equiangularly space spaced rods in each tube. This form of orbital drive allows the use of a device to develop an auxiliary radial force, such as spring mounts extending between a central, rotating shaft mounted in each tube and the rod or rods for that tube.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: September 21, 1999
    Assignee: Y. T. Li Engineering, Inc.
    Inventors: Yao Tzu Li, Albert Yundt, Jr., I-Chien Ho, Hong Ding Huang
  • Patent number: 5768894
    Abstract: An apparatus, thermal storage system and method for heat exchange using a tube-type heat exchanger. A rod (24) or rods (24, 24') are propelled to move over the inner surface (7) of the tube (1). The moving rod (24) is in contact with a first process liquid which is adjacent the inner surface (7) as a falling film or by flooding the interior of the tube (1). The flooded mode is particularly useful where the tube (24) is non-vertical or the heat exchanger is used to make an ice slurry for HVAC systems serving high-rise buildings. Multiple such rod (24) and tube (1) assemblies are operated simultaneously using a drive plate (22) powered to execute an orbital motion in a plane generally orthogonal to the rods (24, 24'). In one form the plate (22) is coupled via a crank (40) to equiangularly spaced rods (24, 24') in each tube (1).
    Type: Grant
    Filed: December 19, 1995
    Date of Patent: June 23, 1998
    Assignee: Y.T. Li Engineering, Inc.
    Inventors: Yao Tzu Li, Albert Yundt, Jr., I-Chien Ho, Hong Ding Huang
  • Patent number: 5385645
    Abstract: A heat transfer apparatus for processing a liquid continuously has a positive mechanical drive for a set of vertical whip rods each disposed in a vertical heat transfer tube. Each whip rod is free-standing on its lower end and is sufficiently flexible to conform closely to the inner surface of the tube as it orbits. The orbital drive propels the whip rod directly through a pair of horizontal, vertically spaced plates that engage the rods in loose openings that serve as fluid inlets from the drive plate. A motor rotates a drive shaft coupled to at least one of the drive plates through at least one eccentric crank. Each plate can be an opposed pair of plates with a separate eccentric drives 180.degree. out of phase with one another for a self balancing. Another form of drive plate uses a rigid circular ring that mounts rod-engaging sleeves via a network of wires supported by the ring.
    Type: Grant
    Filed: June 22, 1993
    Date of Patent: January 31, 1995
    Assignee: Y. T. Li Engineering, Inc.
    Inventor: Yao-Tzu Li
  • Patent number: 5363660
    Abstract: A machine for freezing or chilling a liquid continuously to produce a slurry of the liquid and frozen crystals feeds the liquid into a vertically oriented heat transfer tube at its upper end. A refrigerant flow at the outer tube surface evaporates in a vapor/foam stream causing the liquid to freeze at the inner tube surface. A whip rod, preferably one that is free-standing, revolves over the inner surface to dislodge the frozen crystals mechanically and to distribute the liquid. An additive to the liquid such as ethylene glycol (in water) aids the dislodging. In one form, a mechanical flow guide surrounding the outer surface produces a thin, high velocity upward flow of the boiling refrigerant to increase the heat transfer. An orbital drive propels the whip rod. In one form the orbital drive includes a pair of horizontal plates coupled between the whip rod and at least one eccentric crank.
    Type: Grant
    Filed: June 22, 1993
    Date of Patent: November 15, 1994
    Assignee: Y. T. Li Engineering, Inc.
    Inventors: Yao-Tzu Li, Albert P. Yundt, Jr., I-Chieng Ho, Henry Huang
  • Patent number: 5221439
    Abstract: An orbital evaporator has a vertical heat transfer tube or tubes mounted in a container driven in an orbital motion. A stiff whip rod is freely movable within the tube. Its lower end rests on a horizontal plate. The orbital motion causes the rod to roll over the interior surface of the tube to distribute the liquid in a thin film and to control fouling. A set of fins is mounted on the exterior of the tube to collect and channel the condensate to improve heat transfer through the tube. The fins are preferably longitudinal and the whip rod is preferably hydrophobic. Operating the evaporator with boiling temperatures substantially below 100.degree. C. in combination with the fins and a rolling whip rod allows operation as a desalinization unit for an indefinite period of time with a high total heat transfer coefficient. The evaporator preferably also includes a degasser to control the formation of a gas barrier at the exterior surface of the tube.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: June 22, 1993
    Assignee: Y. T. Li Engineering, Inc.
    Inventors: Yao-Tzu Li, Henry Huang, I-Chieng Ho, Albert P. Yundt, Jr.
  • Patent number: 5013446
    Abstract: A gel contactor receives a fluid media produced in a bio-reactor and containing a product to be extracted, cells and other particles. The gel contactor has a cylindrical container with a cylindrical filter mounted inside the container. A freely rotatable wiper blade sweeps the upstream side of the filter in a closely spaced relationship. The container holds a supply of beads of an absorptive chromatography media such as an ion-exchange or affinity type gel, that selectively bond to the product. An orbital drive causes the blade, process fluid and gel to revolve. The rotation of the blade depolarizes the filter and circulates the process fluid process fluid and gel within the container so that they are well mixed, with substantially no dead spots. After mixing and filtration an elution buffer solution strips the product from the gel. There are no rotary seals connecting to the container.
    Type: Grant
    Filed: April 25, 1990
    Date of Patent: May 7, 1991
    Assignee: Y. T. Li Engineering, Inc.
    Inventors: Yao-Tzu Li, Brad Yundt
  • Patent number: 4075846
    Abstract: A thermal engine with entrapped working medium is a device with a principle element in the form of a continuous yieldable belt whose tension and length are responsive to temperature due to the property of the working medium entrapped by the belt. This yieldable belt is then wrapped in sequence over several rollers which are coupled together rigidly by suitable mechanical means to give differential speeds among the rollers. Driven in this manner the yieldable belt will undergo cyclic change in tension and stretch while passing over the rollers in sequence. When heat is applied and removed in proper phasing with the cyclic variation of the mechanical properties exhibited by the belt and the entrapped working medium, the device will act as an engine with adequate power output at the shaft coupled to one of the rollers.
    Type: Grant
    Filed: May 4, 1976
    Date of Patent: February 28, 1978
    Assignee: Massachusetts Institute of Technology
    Inventor: Yao Tzu Li
  • Patent number: 4000659
    Abstract: A taut ribbon rotary suspension system is constructed with ribbons stretched inside a case over a set of ribbon planes intersecting the pivot axis of the suspended member. The ribbons are wrapped over a set of rod segments attached to the suspended member so that the line of departure of the ribbons from the rod coincides with the pivot axis. The ribbons pertaining to each ribbon plane at one side of the pivot axis are rigidly attached to the case to provide positive geometric positioning. The ribbons of the same ribbon plane at the other side of the pivot axis are anchored elastically to minimize effect due to dissimilar coefficient of expansion. Configuration may vary from using single ribbon plane to two orthogonal planes for single axis application and four ribbon planes for two orthogonal axis adaptation.
    Type: Grant
    Filed: February 25, 1975
    Date of Patent: January 4, 1977
    Inventor: Yao Tzu Li