Device for determining and/or monitoring the density and/or the level of a filling material in a container

• US 6,879,425 B2
• Filed: 08/23/2001
• Issued: 04/12/2005
• Est. Priority Date: 09/01/2000
• Status: Expired due to Term

• Current Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Original Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Inventors: Kämereit, Wolfgang, Damm, Hartmut, Neuhaus, Joachim
• Primary Examiner(s): Ben, Loha
• Application Number:
  US10/362,523
• Publication Number:
  US 20040025569A1
• Time in Patent Office: 1,328 Days
• Field of Search: 359/272, 250/357.1, 250/252.1, 250/258, 250/339.12, 250/383, 378/52, 378/54, 164/454, 164/455, 340/635
• US Class Current: 359/272
• CPC Class Codes: G01F 23/288 X-rays; Gamma rays or other forms of ionising radiation
• CPC Class Codes: G01F 23/2885 for discrete levels
• CPC Class Codes: G01N 23/22 by measuring secondary emission from the material
• CPC Class Codes: G01N 9/24 by observing the transmission of wave or particle radiation through the material

Abstract

The invention relates to a device for determining and/or monitoring the density and/or the level (L) of a filling material in a container. A transmitting unit which emits radioactive radiation and a receiving unit which is arranged in such a way that it receives the radioactive radiation or the secondary radiation that is produced by the interaction of the radioactive radiation with the filling material are provided. A regulating/evaluating unit which determines the density and/or the level of the filling material in the container using the measuring data that is supplied by the receiving unit is also provided. The aim of the invention is to provide a device which enables the level or the density of a filling material in a container to be measured reliably. To this end, the receiving unit consists of individual detector units. These detector units are positioned at different distances from the floor of the container, so that each detector unit directly or indirectly, essentially detects the proportion of radiation that passes.

Claims

1. A device for determining and/or monitoring the density and/or the level of a filling material in a container, the container defining a floor, comprising:

a transmitting unit that transmits radioactive radiation;

a receiving unit that is disposed such that it receives the radioactive radiation, or the secondary radiation generated by interaction of the radioactive radiation with the filling material; and

a regulating/evaluating unit, which from the measurement data furnished by said receiving unit determines the density and/or the level of the filling material in the container, wherein;

said receiving unit comprises individual detector units, said detector units are positioned at different distances from the floor of the container, so that each detector unit directly or indirectly detects essentially the proportion of radiation that passes through a defined partial area of the container or is generated in a defined partial area of the container.

2. The device of claim 1, wherein:

one detector unit of said detector units is a solid detector and/or a liquid detector.

3. The device of claim 1, wherein:

one detector unit of said detector units is one of;

a plastic scintillator, a crystal scintillator with a downstream photomultiplier, and a downstream PIN diode.

4. The device of claim 1, wherein:

one detector unit of said detector units is a semiconductor detector, including a CdZnTe detector.

5. The device of claim 1, wherein:

said detector units comprise a single detector, and an assembly formed of a plurality of individual detectors that are disposed such that they form a detector array.

6. The device of claim 1, wherein:

said receiving unit further comprises at least one first additional detector unit, which is disposed above a predetermined maximum level (H) of the filling material in the container, said first additional detector unit receives essentially only the radioactive radiation emitted by said transmitting unit that has not entered into interaction with the filling material.

7. The device of claim 6, further comprising:

at least one second additional detector unit, which is disposed such that it detects essentially only the radioactive background radiation in the immediate vicinity of the container.

8. The device of claim 1, further comprising:

a pressure sensor that is disposed above a maximum level (H) of the filling material in the container.

9. The device of claim 1, wherein:

the distance between two successive detector units is designed variably, and the distance is adapted to whatever the desired local resolution is.

10. The device of claim 1, wherein:

said receiving unit further comprises a retaining element, and wherein said detector units are disposed in a predetermined number on said retaining element, said retaining element is embodied flexibly.

11. The device of claim 1, wherein:

for the case where said detector units have a temperature dependency, each detector unit is assigned a temperature sensor, which determines the temperature at the measurement site; and

wherein said regulating/evaluating unit takes the temperature prevailing at the measurement site into account in evaluating the measured level or density data.

12. The device of claim 1, further comprising:

a bus line by way of which said detector units and said regulating/evaluating unit communicate with a remote control point.

13. The device of claim 1, further comprising:

an input/output unit, by way of which the operator can select an arbitrary detector unit to secure against overfilling; and

wherein said regulating/evaluating unit, via said input/output unit, outputs a report accordingly as soon as the predetermined level (L) is reached.

14. The device of claim 1, wherein:

said regulating/evaluating unit determines the measurement data of the individual detector units with the container empty and sets up a corresponding empty profile;

said regulating/evaluating unit determines the measurement data of the individual detector units with the container full and sets up an actual measurement profile; and

said regulating/evaluating unit, by comparison of the measurement profile with the empty profile, furnishes information about the formation of foam above the filling material or the formation of scale on the container wall.

15. The device of claim 1, said regulating/evaluating unit sets up a density profile of the filling material disposed in the container;

and, taking the density profile into account, said regulating/evaluating unit determines the level (L) of the filling material in the container.

16. The device of claim 1, wherein:

said regulating/evaluating unit sets up a density profile of the filling material disposed in the container; and

, taking the density profile into account, said regulating/evaluating unit makes the density profile available to the operator for the sake of process analysis and/or for regulating purposes.

17. A device for determining and/or monitoring the density and/or the level of a radioactive filling material in a container, the container defining a floor, comprising:

a receiving unit which is disposed such that it receives the radiation of the radioactive filling material; and

a regulating/evaluating unit, which from the measurement data furnished by said receiving unit determines the density and/or the level of the filling material in the container, wherein;

said receiving unit comprises individual detector units, said detector units being positioned at different distances from the floor of the container, so that each detector unit directly or indirectly detects essentially the proportion of radiation that passes through a defined partial area of the container or is generated in a defined partial area of the container.

18. A device for determining and/or monitoring the density of a medium in a container, comprising:

a transmitting unit that transmits radioactive radiation;

a receiving unit that is disposed such that it receives the radioactive radiation or the secondary radiation generated by interaction of the radioactive radiation with a filling material; and

a regulating/evaluating unit being provided which from the measurement data furnished by said receiving unit determines the density of the medium in the container, wherein;

said receiving unit comprises two detector units, and said detector units are positioned in different positions along the container;

each detector unit directly or indirectly detects essentially the proportion of radiation that passes through a defined partial area of the container; and

from the differing extinction of the proportions of radiation that are detected in said two detector units, said regulating/evaluating unit determines the density of the medium in the container.