Dispensing – Weighing
Reexamination Certificate
2002-02-23
2004-03-09
Kaufman, Joseph A. (Department: 3754)
Dispensing
Weighing
C222S413000
Reexamination Certificate
active
06702152
ABSTRACT:
TECHNICAL FIELD
The present invention relates, in general, to equipment for feeding bulk materials in metered amounts and, in particular, to the control of dosing of such equipment and to a method for the operation of such equipment.
In the conveying of bulk materials using an extraction helix, the volumetric dosing principle or the more precise gravimetric principle can be used. In the latter, the mass m(t) of an extraction equipment, a supply container and the bulk material present in it are weighed together, whereby the difference of mass per unit of time, namely the mass flow {dot over (m)}(t) dependent on the time t, is continuously detected electronically. The actual value is compared to a desired target value and regulated by a known dosing controller to the desired value.
In practice, the mass flow {dot over (m)}(t), dependent on the time t, is, however, not constant, but fluctuates periodically at a frequency which equals the speed of revolution of the extraction helix or is a whole harmonic of it. The dosing controller is generally not arranged to even out these periodic deviations from the desired constant value.
In addition, the difficulty exists that different extraction helices, and also different bulk materials, or the same bulk materials with slightly different or changing flow parameters, lead to completely other fluctuations of the mass flow {dot over (m)}(t).
The objective which is addressed by the present invention, is to provide a device for dosing control of helical dosing equipment as well as a method for the operation of such devices, which are immediately and always ready, and with which the above mentioned periodic fluctuations arising in the mass flow {dot over (m)}(t) of such devices can be essentially eliminated, independent of the characteristics of the extraction helix used and independent of the characteristics of different bulk materials.
SUMMARY OF THE INVENTION
In accordance with the present invention, bulk material, stored in a container, is received by a feeder, driven by a motor, and delivered, in metered amounts, to utilization equipment by the feeder. The actual mass flow rate of the bulk material delivered by the feeder to the utilization equipment is measured and the difference between the actual flow rate of the bulk material delivered to the utilization equipment and a desired flow rate of the bulk material delivered to the utilization equipment is determined. Periodic deviations of the actual mass flow rate of the bulk material delivered to the utilization equipment from the desired flow rate of the bulk material delivered to the utilization equipment are quantitatively analyzed and a modulation signal, representative of the quantitative analysis, is generated. The modulation signal is processed into a modulated position signal that controls the motor that drives the feeder to modulate the speed of the motor with the modulated position signal.
REFERENCES:
patent: 4272824 (1981-06-01), Lewinger et al.
patent: 4320855 (1982-03-01), Ricciardi et al.
patent: 5184754 (1993-02-01), Hansen
patent: 5423456 (1995-06-01), Arendonk et al.
patent: 6060667 (2000-05-01), Pollock
patent: 6168305 (2001-01-01), Marmsater
patent: 2903259 (1980-07-01), None
patent: 1491034 (1977-11-01), None
patent: 57028217 (1982-02-01), None
“Schuttgutmechanische Auslegung von Dosierdifferential waagen mit Schneckenaustrag”, G. Vetter et al., Wagen und Dosieren, DE, Verlagsgesellschaft, Keppler, Mainz, vo. 24, No. 4, Jul. 1, 1993, pp. 3-16.
International Search Report of PCT/CH00/00656 dated Mar. 14, 2001.
K-Tron Technologies Inc.
Kaufman Joseph A.
RatnerPrestia
LandOfFree
Dosing control for helical dosing equipment does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dosing control for helical dosing equipment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dosing control for helical dosing equipment will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3219972