US-12617565-B2 - Method for producing individual dosing quantities via a drum dosing device

US12617565B2US 12617565 B2US12617565 B2US 12617565B2US-12617565-B2

Abstract

A method is for producing individual dosing quantities of a powdered product via a drum dosing device. A dosing drum has a dosing opening on its circumference. In an ejection position, an ejection process is effected, the dosing opening being subjected to a positive pressure and the dosing quantity being thereby ejected from the opening, and an associated ejection reference time-point being determined. The individual mass of an ejected dosing quantity and an associated measurement reference time-point are determined via the measuring device. An actual time period is ascertained from the difference between the measurement reference time-point and the ejection reference time-point and compared with a specified time period. In dependence on the comparison, an adaptation of the positive pressure for a subsequent ejection process is performed such that the level of the positive pressure is increased if the actual time period is too great.

Inventors

Bernhard HANDEL

Assignees

HARRO HOEFLIGER VERPACKUNGSMASCHINEN GMBH

Dates

Publication Date: 20260505
Application Date: 20240806
Priority Date: 20230817

Claims (8)

1 . A method for producing individual dosing quantities of a powdered product via a drum dosing device, the drum dosing device having a product feeder, a dosing drum, and a capacitive measuring device for determining a mass of the dosing quantities, the dosing drum defining a circumference and a dosing opening on the circumference, the dosing opening being delimited on an inner side via a filter element and being configured to be subjected to a negative pressure through the filter element, the method comprising: rotating the dosing drum until the dosing opening is in a filling position; in the filling position, effecting a filling process in which the dosing opening is filled from the product feeder with a sub-quantity of the powdered product, the dosing opening being subjected to negative pressure through the filter element, and a dosing quantity of the powdered product forming in the dosing opening; rotating the dosing drum until the dosing opening filled with the dosing quantity is in an ejection position; in the ejection position, effecting an ejection process, the dosing opening being subjected to a positive ejection pressure through the filter element and the dosing quantity being thereby ejected from the dosing opening, and an associated ejection reference time-point being determined; determining an individual mass of an ejected dosing quantity and an associated measurement reference time-point via the capacitive measuring device; ascertaining an actual time period from the difference between the measurement reference time-point and the ejection reference time-point and comparing the actual time period with at least one specified time period; and, in dependence on the comparison of the actual time period with the at least one specified time period, performing an adaptation of the positive ejection pressure for a subsequent ejection process in that a level of the positive ejection pressure is increased if the actual time period is too great.
2 . The method of claim 1 further comprising: recording, via the capacitive measuring device, a time characteristic of a measuring signal as the dosing quantity passes through; determining a maximum value with an associated maximum value time-point from the time characteristic of the measuring signal; and, setting the measurement reference time-point equal to the maximum value time-point.
3 . The method of claim 1 , wherein a first specified time period is formed by an upper limit time period, and, if the actual time period exceeds the upper limit time period, the positive ejection pressure is increased.
4 . The method of claim 1 , wherein, in dependence upon the comparison of the actual time period with the at least one specified time period, the adaptation of the positive ejection pressure for a subsequent ejection process is performed such that the level of the positive ejection pressure is reduced if the actual time period is too short.
5 . The method of claim 4 , wherein a second specified time period is formed by a lower limit time period, and, if the actual time period falls below the lower limit time period, a reduction of the positive ejection pressure is effected.
6 . The method of claim 1 , wherein the adaptation of the positive ejection pressure is effected incrementally in predefined pressure steps.
7 . The method of claim 1 , wherein the adaptation of the positive ejection pressure is effected in proportion to a deviation of the actual time period from the at least one specified time period.
8 . The method of claim 1 , wherein the actual time period is formed by an average value of a plurality of measured differences between the measurement reference time-point and the ejection reference time-point; and, the average value is compared with the at least one specified time period.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority of European patent application no. 23191975.4, filed Aug. 17, 2023, the entire content of which is incorporated herein by reference. TECHNICAL FIELD The disclosure relates to a method for producing individual dosing quantities of a powdered product via a drum dosing device. BACKGROUND In the field of pharmaceuticals, for example, but also in the field of food supplements or the like, powders are processed that have to be provided in precisely measured sub-quantities, or dosing quantities, for the intended form of administration. Target containers, for example in the form of blisters, two-part capsules or the like, are filled with such measured dosing quantities of a powdered product, such that the consumer has available and can consume the corresponding unit doses. Such powdered products are converted, in particular on so-called drum dosing devices, into individually measured dosing quantities, which are then filled into respectively assigned target containers. Such a drum dosing device includes a dosing drum, which is provided on its circumference with at least one dosing opening, usually a plurality thereof, and the dosing openings are delimited on the inside via a filter element and can be subjected to a negative pressure through the filter element. Under the effect of the negative pressure, powder is drawn into the dosing openings, forming dosing quantities of the powder, the volume of which corresponds to the volume of the respective dosing opening. The dosing quantities formed in this way are then ejected from the dosing openings via positive pressure and forwarded to the target container. It is clear from the above explanations that dosing via a drum dosing device is a volumetric dosing process. As a rule, however, it is sought to achieve dosing in which the measured dosing quantity has a determined mass within a permissible tolerance range. For volumetric dosing, it is therefore important that there is as repeatable a relationship as possible between the measured volume and the actual mass achieved. So-called “Advanced Mass Verification” (AMV) systems are increasingly being used to check the actual dosing accuracy achieved, with a capacitive measuring device being used. The dosing quantity ejected from the dosing opening falls through a capacitive measuring section of the AMV system and thereby generates a capacitive measuring signal. When correctly calibrated, this measuring signal provides information about the mass of the dosing quantity and allows random or even 100% checking of the dosing process. Known from US 2020/0047926 is a method in which a continuous determination of mass is performed with the aid of such an AMV system. Averaging is used to effect tendency closed-loop control of the negative suction pressure in order to achieve the most uniform possible filling of the dosing openings. Nevertheless, such a method is not without its difficulties. For example, it has been shown that the dosing quantities are not always ejected uniformly. The dosing quantities in the form of a powder plug do not always dislodge uniformly when being ejected, which can result in different fall speeds and also in tumbling motions as they fall. As a consequence, this can falsify the measurement results of the AMV system or even result in faults in the dosing process as a whole. SUMMARY It is an object of the disclosure to specify a method via which the individual masses produced by a drum dosing device can be ejected and verified in a simple and controlled manner. This object is, for example, achieved by a method for producing individual dosing quantities of a powdered product via a drum dosing device, the drum dosing device having a product feeder, a dosing drum, and a capacitive measuring device for determining a mass of the dosing quantities, the dosing drum defining a circumference and a dosing opening on the circumference, the dosing opening being delimited on an inner side via a filter element and being configured to be subjected to a negative pressure through the filter element. The method includes: rotating the dosing drum until the dosing opening is in a filling position; in the filling position, effecting a filling process in which the dosing opening is filled from the product feeder with a sub-quantity of the powdered product, the dosing opening being subjected to negative pressure through the filter element, and a dosing quantity of the powdered product forming in the dosing opening; rotating the dosing drum until the dosing opening filled with the dosing quantity is in an ejection position; in the ejection position, effecting an ejection process, the dosing opening being subjected to a positive ejection pressure through the filter element and the dosing quantity being thereby ejected from the dosing opening, and an associated ejection reference time-point being determined; determining an individual mass of an ejected dosing qua