Multistage screen sorting device

Patent metadata

Field	Value
Publication number	US-12239997-B2
Application number	US-202318502607-A
Country	US
Kind code	B2
Filing date	Nov 6, 2023
Priority date	May 12, 2021
Publication date	Mar 4, 2025
Grant date	Mar 4, 2025

Abstract

A screen sorting device for cleaning a fibrous stock suspension includes: an inlet for the fibrous stock suspension; a first sorting stage, which includes a first accepts discharge; at least one second sorting stage, which includes a second accepts discharge; and a fill level detection way, which is configured for detecting an accumulation height in the at least one second sorting stage and is assigned to the at least one second sorting stage.

First claim

What is claimed is:

1. A screen sorting device for cleaning a fibrous stock suspension, the screen sorting device comprising:
an inlet for the fibrous stock suspension;
a first sorting stage, which includes a first accepts discharge;
at least one second sorting stage, which includes a second accepts discharge;
a fill level detector, which is configured for detecting an accumulation height in the at least one second sorting stage and is assigned to the at least one second sorting stage; and
an orifice plate, which is arranged between the first sorting stage and the at least one second sorting stage and includes a side facing the at least one second sorting stage, wherein the screen sorting device is configured such that a pressure acquisition for a detection of a prevailing pressure is provided on the side of the orifice plate facing the at least one second sorting stage.

2. A screen sorting device for cleaning a fibrous stock suspension, the screen sorting device comprising:
an inlet for the fibrous stock suspension;
a first sorting stage, which includes a first accepts discharge;
at least one second sorting stage, which includes a second accepts discharge;
a fill level detector, which is configured for detecting an accumulation height in the at least one second sorting stage and is assigned to the at least one second sorting stage; and
a rinsing water inlet; and
a screen, wherein the rinsing water inlet is provided for an inflow of a rinsing water for diluting the fibrous stock suspension entering the screen, wherein the rinsing water inlet includes a pressure sensor.

3. The screen sorting device according to claim 2 , wherein the pressure sensor is configured for detecting a plurality of negative pressures.

4. The screen sorting device according to claim 2 , wherein the pressure sensor is configured for detecting a plurality of pressures in a range of −0.5 bar to 0.5 bar.

5. The screen sorting device according to claim 2 , wherein the pressure sensor has a measuring accuracy of at least less than 0.2%.

6. The screen sorting device according to claim 1 , further comprising a housing and a temperature sensor configured for detecting a temperature profile, the first sorting stage and the at least one second sorting stage being arranged in the housing, wherein for the fill level detector the temperature sensor configured for detecting a temperature profile is assigned to the at least one second sorting stage.

7. The screen sorting device according to claim 6 , wherein the temperature sensor is configured for two-dimensional detection of a temperature distribution of the housing surrounding the at least one second sorting stage.

8. The screen sorting device according to claim 6 , wherein the temperature sensor is provided inside the housing or integrated in the housing.

9. The screen sorting device according to claim 6 , wherein the at least one second sorting stage includes a cooling system for at least partially cooling the housing which surrounds the at least one second sorting stage.

10. The screen sorting device according to claim 6 , wherein at least a partial region of housing surrounding the at least one second sorting stage consists of a non-ferromagnetic material, wherein the fill level detector includes a capacitive sensor.

11. The screen sorting device according to claim 1 , further comprising a common housing, wherein the first sorting stage and the at least one second sorting stage are arranged in the common housing, wherein at least the first sorting stage is a screen sorting stage.

12. The screen sorting device according to claim 11 , wherein the at least one second sorting stage is a screen sorting stage.

13. A method for operating a screen sorting device for cleaning a fibrous stock suspension, the method comprising the steps of:
providing that the screen sorting device includes:
an inlet for the fibrous stock suspension;
a first sorting stage, which includes a first accepts discharge;
at least one second sorting stage, which includes a second accepts discharge; and
a fill level detector, which is configured for detecting an accumulation height in the at least one second sorting stage and is assigned to the at least one second sorting stage;

assigning a control unit to the screen sorting device;
controlling a supply of the fibrous stock suspension into the screen sorting device by the control unit;
feeding data of a sensor assigned to the at least one second sorting stage to the control unit for the fill level detector;
storing a desired fill level in the control unit and, in an event of a detected fill level falling below the desired fill level, increasing at least one of an inflow volume and an inflow pressure of the fibrous stock suspension entering the screen sorting device; and
reducing, in an event of a detected high fill level exceeding the desired fill level which is stored, an inflow of the fibrous stock suspension that is incoming.

14. The method according to claim 13 , wherein, during a fill level detection, a dynamic pressure component associated with an inflow volume of a rinsing water is determined by way of a pressure detection in the rinsing water that is inflowing, and the dynamic pressure component is taken into account in determining the accumulation height.

15. The method according to claim 13 , wherein, during determination of the fill level for eliminating a pulsating signal due to a rotation of an at least one rotor of the screen sorting device, a smoothing of a plurality of signals is carried out.

Assignees

• Voith Patent Gmbh

Inventors

• Jaschek Thomas

Classifications

• B08B3/06

  using perforated drums in which the article or material is placed {(B08B3/042 takes precedence)} · CPC title

• B03B5/48

  by mechanical classifiers · CPC title

• D21D5/04

  Flat screens · CPC title

• D21D5/026

  with rotating cleaning foils · CPC title

• B03B13/00 Primary

  Control arrangements specially adapted for wet-separating apparatus or for dressing plant, using physical effects · CPC title