Fluid handling – Self-proportioning or correlating systems – Self-proportioning flow systems
Reexamination Certificate
1998-03-31
2001-08-07
Hepperle, Stephen M. (Department: 3753)
Fluid handling
Self-proportioning or correlating systems
Self-proportioning flow systems
C137S396000, C137S558000, C137S599040, C137S599050
Reexamination Certificate
active
06269831
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a precision apparatus for measuring and mixing volumes of two or more liquids.
2. Description of the Prior Art
In the manufacture of synthetic thermoplastic fiber materials, such as polyamides, polyesters, or polyolefins, it is common practice to apply a finish liquid (also known as a “spin finish”) to the surface of the fibers. The spin finish may be applied using any of a variety of mechanical expedients, such as a metered tip applicator, a rotary kiss roller, or a metered spray applicator.
The finish liquid is commonly formulated in an area remote from the area housing the fiber spinning machines. The finish liquid is formulated by measuring and them mixing a predetermined volume of each of several finish components in a preferred order, the last of these being a diluent liquid. For economy, one relatively large volume mixing tank is typically dedicated to the finish preparation for a plurality of spinning machines. This arrangement has certain disadvantages.
Storing a large volume of liquid material in a single mixing tank enhances the possibility of bacteria growth. In addition, since a single mixing tank is used to service a multiple number of spinning machines, each machine would receive a “standard” finish mixture as prepared in that tank. When, as occurs from time-to-time, changes are made to a given finish formulation, unused quantities of previously formulated finish mixtures may result. Moreover, if a mixture different from the standard would be preferable for a fiber being produced by a given spinning machine, a separate mixing tank would be dedicated solely to that different mixture. Owing to the size and space occupied by the mixing tanks it is believed to be economically impractical to allocate a finish mixing tank to a spinning machine on a one-to-one basis.
There have been attempts in the art to overcome these problems using a so-called “just-in-time” smaller-volume batch diluter apparatus that is located near a the spinning machine. Typical devices use spring-loaded flow regulators, such as the Kates Flow Regulator, manufactured by W. A. Kates Company, Ferndale, Mich. These spring-loaded devices are economical, but are subject to loss of accuracy should the supply pressures drop below a critical minimum, or if the supply stream viscosity changes so as to significantly affect the pressure drop through the device. A more elaborate and costly device, such as the Henkel In-line Mixer, manufactured by Henkel Corporation, Charlotte, N.C., uses another flow sensing and flow control valve scheme to reduce the sensitivity to supply pressure or viscosity changes.
In any case, devices which rely on flow measurement and control are subject to inaccuracies during start-up where flow phenomena, such as pressure transients and flow acceleration, create a non-steady-state condition. This disadvantage can be overcome by either diverting the start-up flow to waste, or by blending it with large quantities of accurately diluted finish. By using large volume tanks so that these diluter apparatus have longer steady-state run times, the inaccurately measured volumes of liquids during start-up transient periods are small in proportion to the more accurate volumes measured during steady-state running periods. Assuming good mixing in a sufficiently large tank, the average composition of the finish can be maintained within acceptable limits.
In view of the foregoing it is believed to be advantageous to provide a volumetric mixing apparatus adapted to prepare in a precision manner a finish liquid mixture particularized for an associated spinning machine.
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus for mixing a first liquid, such as a concentrated spin finish liquid material, with at least a second liquid, such as a diluent. The apparatus comprises a tank having a mixing chamber therein. Each of a first and a second liquid source is connected to the mixing chamber through a first and a second supply line. A gross control valve is disposed in each of the first supply lines and a fine control valve is disposed in each of the second supply lines. An outlet conduit having a drain valve therein emanates from the mixing chamber. A liquid level detector, such as an ultrasonic liquid level detector of the noncontacting type, measures the total volume of liquid present in the mixing chamber. A controller, operable in response to signals output from the detector representative of the total volume within the mixing chamber, actuates the gross and the fine control valves in the respective first and second supply lines from each source in accordance with a predetermined sequence. The controller also actuates the drain valve in the outlet conduit when the volume of liquid in the mixing chamber as measured by the detector equals a predetermined liquid volume.
Following the termination of the actuation sequence for the gross and fine control in the respective first and second supply lines, the controller may (prior to actuation of the drain valve) operate to monitor for a predetermined time delay period the volume of liquid in the mixing chamber as measured by the detector and to generate an alarm signal if the measured volume of the liquid deviates from a predetermined reference liquid volume.
REFERENCES:
patent: 3705598 (1972-12-01), Ray
patent: 3963146 (1976-06-01), Esbjornsson
patent: 4362033 (1982-12-01), Young
patent: 4374785 (1983-02-01), Wyatt
patent: 4633413 (1986-12-01), Caveney et al.
patent: 4650339 (1987-03-01), Chetcuti et al.
patent: 5203504 (1993-04-01), Frost et al.
patent: 5207251 (1993-05-01), Cooks
patent: 5288145 (1994-02-01), Mackey et al.
patent: 5329965 (1994-07-01), Gordon
patent: 5339854 (1994-08-01), Leith
patent: 5346302 (1994-09-01), Ryu
patent: 5558435 (1996-09-01), Marjo
patent: 42 01 811 A1 (1992-01-01), None
patent: 0 589 053 A1 (1992-04-01), None
patent: 1124502 (1965-09-01), None
patent: Toku Kai Hei 5-64734 (1993-03-01), None
patent: Toku Kai Hei 5-64733 (1993-03-01), None
patent: WO98/31862 (1998-07-01), None
Blair, Jr. Howard
Dickert John Michael
Mahoney, Jr. Clarence Bernard
E. I. Du Pont de Nemours and Company
Hepperle Stephen M.
LandOfFree
Precision volumetric measuring and mixing apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Precision volumetric measuring and mixing apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Precision volumetric measuring and mixing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2465628