US 12,134,859 B2Granted

Determining the reduction rate of a recovery boiler

AssigneeAndritz Inc.

InventorsHeikki Lappalainen, Juho Nurmi, Sauli Rissanen, Esa Vihavainen

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Abstract

A method to determine a reduction rate of a recovery boiler using optical information from a chemical smelt sample. A processor is used to read a digital frame at least part of which represents the chemical smelt sample of the recovery boiler. An area of interest is determined from the digital frame read comprising at least part of the area in the digital frame representing the chemical smelt sample. Of the pixel values of the area of interest, one or more spectral characteristic values correlating with the change of reduction rate are determined. The reduction rate of the recovery boiler is determined using a reduction rate function of one or more of the determined spectral characteristic values weighted at predetermined weights.

Claims12

Dependent claims

A method for determining a reduction rate of a recovery boiler comprising:

obtaining a chemical smelt sample from smelt that flows from the recovery boiler;
capturing a digital frame of an image of the chemical smelt sample;
reading with a processor the digital frame including an area within the image which represents the chemical smelt sample of the recovery boiler;
determining from the digital frame an area of interest within the image comprising at least part of the area in the digital frame representing the chemical smelt sample;
determining with the processor and from pixel values of the area of interest one or more spectral characteristic values;
determining with the processor a reduction rate of the recovery boiler based on the one or more spectral characteristic values and using a reduction rate function to correlate the one or more of the spectral characteristic values to corresponding predetermined weights used to determine the reduction rate, and
controlling the recovery boiler using the reduction rate.

4 more elements

A method to control a recovery boiler comprising:

obtaining a chemical smelt sample from smelt that flows from the recovery boiler;
capturing a digital frame of an image of the chemical smelt sample;
identifying an area of interest within the digital frame comprising at least part of an area in the digital frame representing the chemical smelt sample;
analyzing in the area of interest to determine a spectral characteristic value of the chemical smelt sample shown in the area of interest;
calculating a reduction rate of the chemical smelt sample by using the spectral characteristic and a reduction rate function that correlates spectral characteristic values or data representing spectral characteristic values to reduction rates of chemical smelt, and
controlling the recovery boiler based on the reduction rate.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/612,191Filed 15 May 2020
Priority: FI 2019541017 May 2019
Published: US 2022/0220671 A114 Jul 2022
Granted: 5 Nov 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

D21C 11/10
Regeneration of pulp liquors or effluent waste waters: concentrating spent liquor by evaporation
D21C 7/12
Digesters: devices for regulating or controlling
F23N 1/042
Conjointly with air supply and with draught: using electronic means
F23N 5/082
Using light-sensitive elements: using electronic means