Measuring and testing – Sampler – sample handling – etc. – Flow divider – deflector – or interceptor
Reexamination Certificate
1998-02-25
2001-01-30
Larkin, Daniel S. (Department: 2856)
Measuring and testing
Sampler, sample handling, etc.
Flow divider, deflector, or interceptor
C073S863810, C073S023310
Reexamination Certificate
active
06178830
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to the field of particle size distribution analysis and more particularly to a device for the in-line extraction and dilution of a representative sample of a processed medium for examination by a particle size distribution measurement instrument.
BACKGROUND OF THE INVENTION
Particle size distribution is an important parameter in many processes and its accurate measurement is required for the precise and cost-effective control of the process. The measurement of particle size distribution in order to accurately control a process finds importance in industries that manufacture cement, cosmetics, pharmaceuticals and the like. A number of instruments are presently used in industry that use angular light scattering or dynamic light scattering techniques to measure particle size distribution in a liquid medium. These instruments analyze and measure the concentration of particles suspended in the liquid medium and provide a measurement that is used to adjust the process in order to correct for any irregularities in the final processed product. One such angular light scattering measurement instrument is taught in U.S. Pat. No. 5,416,580, to Trainer et al, issued May 16, 1995.
In order for these aforementioned instruments to measure correct particle size distribution, an extracted sample representative of the processed medium must be conditioned for measurement. Conditioning disperses the particles within the suspension into a concentration value that is within the concentration requirements of the measurement technique being utilized. The concentration of particles within a typical process is generally higher than is allowed by the measurement technique being utilized and the aforementioned conditioning introduces some form of dilution to disperse the concentration. For example, in the case of instruments that employ angular light scattering techniques, multiple scattering limits the concentration to less than 0.1% of particles in suspension. In the case of dynamic light scattering, particle-to-particle interactions limit concentration to less than 3%. Particle concentrations in a processed medium, however, can be as high as 50% by volume.
One method presently employed that overcomes these limitations is to deliver an extracted sample representative of the processed medium to a conditioning instrument, which works in association with the measurement instrument and dilutes, disperses and finally circulates the conditioned sample to the measurement instrument for analysis. After analysis, the diluted sample is discarded and the cycle repeated. Such conditioning instruments are taught in U.S. Pat. No. 4,496,244, to Ludwig et al, issued Jan. 29, 1985, and U.S. Pat. No. 5,439,288, to Hoffman et al, issued Aug. 8, 1995.
These arrangements have shortcomings in the need to transport a concentrated sample from the process location to the conditioning instrument, the time involved in the conditioning-circulating-flushing cycle and the final discarding of the dilute sample in preparation for the next sample extraction. Such conditioning instruments also suffer from poor reliability and excessive maintenance due inherently to the mechanical actions and motions of the multiple seals, valves, and conduits that are required to extract the sample from the processed medium, condition the extracted sample, and finally deliver the sample to the measurement instrument.
SUMMARY OF THE INVENTION
Therefore, there is provided by the present invention a device for the extraction and delivery of a diluted representative sample of a processed medium flowing in a process stream within a pipe or conduit to a particle measurement instrument for analysis. The device of the present invention includes an extraction conduit that includes a probe end which has an opening extending through an exterior surface of the conduit into an interior cavity. The probe end is arranged to be inserted into a pipe with the opening facing the flow of the process stream.
A diluent delivery conduit connected to a source of diluent medium is substantially housed within the extraction conduit cavity in coaxial alignment with the extraction conduit. A sample delivery passage is formed between the extraction conduit and the diluent delivery conduit. The sample delivery passage connects the device of the present invention to a sampling chamber or cell of a particle measurement instrument. The diluent delivery conduit further includes an opening in direct face-to-face alignment with the extraction conduit opening. Diluent medium flows out of the diluent delivery conduit opening in proximity to said extraction conduit opening.
Responsive to the impact force of the process stream, processed medium enters the extraction conduit opening and mixes with the diluent medium emitted by the diluent delivery conduit opening, thereby forming a stream of diluted processed medium samples. The diluted processed medium samples flow through the sample delivery passage to the sampling chamber of the particle measurement instrument, where they are analyzed.
Accordingly, it is an object of the present invention to provide a diluting and extraction device that delivers to a measurement instrument a conditioned sample representative of the particles present in a processed medium for the real-time, in-situ measurement analysis of the particle size distribution present in the processed medium without the time limitations imposed by the prior art systems.
It is another object of the present invention to provide a diluting and extraction device that requires no mechanical pumping, seals, mixers, gate valves, or mechanically-driven recirculating systems and, therefore, requires a minimal effort to operate and to maintain.
It is still another object of the present invention to provide an effective and simple diluting and extraction device that can be used with any number of particle size distribution measurement instruments to effect the precise and cost-effective control of a processed medium.
REFERENCES:
patent: 3803921 (1974-04-01), Dietrich
patent: 4385910 (1983-05-01), Eilers et al.
patent: 4700560 (1987-10-01), Hoffa et al.
patent: 5033318 (1991-07-01), Wendt
patent: 5596154 (1997-01-01), Baughman
patent: 5753830 (1998-05-01), Sundh
Larkin Daniel S.
Microtrac, Inc.
Wood Herron & Evans LLP
LandOfFree
In-line diluting extractor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with In-line diluting extractor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and In-line diluting extractor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2441480