Inline particle size analyzing device for continuous measurement of particle sizes of a continuously taken measurement sample of a bulk material, mill, method for controlling a mill for grinding bulk material to be ground in dependence on measurement results of an inline particle size analyzing device, computer program product and non-transitory computer-readable storage medium

An inline particle size analyzing device for continuous measurement of particle sizes of a continuously collected measurement sample of a free-flowing bulk material ground by a mill, the inline particle size analyzing device comprising:

• a main conduit having a main conduit inlet opening and a main conduit outlet opening which are fluidically connected for transporting the bulk material via a main conduit channel from the main conduit inlet opening to the main conduit outlet opening;
• a bypass conduit having a bypass conduit inlet opening and a bypass conduit outlet opening that are fluidically connected for continuously transporting the continuously collected measurement sample of the bulk material via a bypass conduit channel from the bypass conduit inlet opening and to the bypass conduit outlet opening, wherein the bypass conduit is fluidically connected to the main conduit channel via the bypass conduit inlet opening for conveying the measurement sample taken from the bulk material to the bypass conduit;
• a measurement sampling unit adapted to continuously collect the continuously collected measurement sample of the bulk material transported in the main conduit channel and to continuously supply the continuously collected measurement sample to the bypass conduit channel via the bypass conduit inlet opening;
• and
• a particle measuring device provided in the bypass conduit channel adapted for the continuous measurement of particle sizes of the continuously collected measurement sample, and including a measurement sample inlet, through which the continuously collected measurement sample can be continuously fed to the particle measuring device, and including a measurement sample outlet arranged downstream of the particle measuring device and fluidically connected to the particle measuring device, through which the continuously collected measurement sample detected by the particle measuring device in the bypass conduit channel can leave the particle measuring device in the direction of the bypass conduit outlet opening;
• wherein the measurement sampling unit has an adjustable sampling inlet, the inlet opening size of which is adjustable between a first inlet opening size and a second inlet opening size different from the first inlet opening size, the second inlet opening size being larger than the first inlet opening size.

A mill for grinding bulk material to be ground, the mill comprising:

• a grinding chamber enclosed by a grinding chamber housing with a grinding device for grinding bulk material to be ground, which grinding device is arranged within the grinding chamber so as to be rotatably drivable by a grinding drive unit;
• a bulk material inlet for feeding bulk material to be ground into the grinding chamber and a bulk material outlet for discharging bulk material ground by the grinding device from the grinding chamber;
• and
• an inline particle size analyzing device for continuous measurement of particle sizes of a continuously collected measurement sample of a free-flowing bulk material ground by a mill, the inline particle size analyzing device comprising:
• a main conduit having a main conduit inlet opening and a main conduit outlet opening which are fluidically connected for transporting the bulk material via a main conduit channel from the main conduit inlet opening to the main conduit outlet opening;
• a bypass conduit having a bypass conduit inlet opening and a bypass conduit outlet opening that are fluidically connected for continuously transporting the continuously collected measurement sample of the bulk material via a bypass conduit channel from the bypass conduit inlet opening and to the bypass conduit outlet opening, wherein the bypass conduit is fluidically connected to the main conduit channel via the bypass conduit inlet opening for conveying the measurement sample taken from the bulk material to the bypass conduit;
• a measurement sampling unit adapted to continuously collect the continuously collected measurement sample of the bulk material transported in the main conduit channel and to continuously supply the continuously collected measurement sample to the bypass conduit channel via the bypass conduit inlet opening;
• and
• a particle measuring device provided in the bypass conduit channel adapted for the continuous measurement of particle sizes of the continuously collected measurement sample, and including a measurement sample inlet, through which the continuously collected measurement sample can be continuously fed to the particle measuring device, and including a measurement sample outlet arranged downstream of the particle measuring device and fluidically connected to the particle measuring device, through which the continuously collected measurement sample detected by the particle measuring device in the bypass conduit channel can leave the particle measuring device in the direction of the bypass conduit outlet opening;
• wherein the measurement sampling unit has an adjustable sampling inlet, the inlet opening size of which is adjustable between a first inlet opening size and a second inlet opening size different from the first inlet opening size, the second inlet opening size being larger than the first inlet opening size;
• and
• wherein the inline particle size analyzing device is arranged downstream of the bulk material outlet for continuously measuring particle sizes of the continuously collected measurement sample of the bulk material ground by the grinding device, and wherein the main conduit is fluidically coupled to the bulk material outlet via the main conduit inlet opening.

A method for controlling a mill for grinding bulk material to be ground in dependence on measurement results of an inline particle size analyzing device for continuous measurement of particle sizes of a continuously collected measurement sample of a free-flowing bulk material ground by a mill, the inline particle size analyzing device comprising:

• a main conduit having a main conduit inlet opening and a main conduit outlet opening which are fluidically connected for transporting the bulk material via a main conduit channel from the main conduit inlet opening to the main conduit outlet opening;
• a bypass conduit having a bypass conduit inlet opening and a bypass conduit outlet opening that are fluidically connected for continuously transporting the continuously collected measurement sample of the bulk material via a bypass conduit channel from the bypass conduit inlet opening and to the bypass conduit outlet opening, wherein the bypass conduit is fluidically connected to the main conduit channel via the bypass conduit inlet opening for conveying the measurement sample taken from the bulk material to the bypass conduit;
• a measurement sampling unit adapted to continuously collect the continuously collected measurement sample of the bulk material transported in the main conduit channel and to continuously supply the continuously collected measurement sample to the bypass conduit channel via the bypass conduit inlet opening;
• and
• a particle measuring device provided in the bypass conduit channel adapted for the continuous measurement of particle sizes of the continuously collected measurement sample, and including a measurement sample inlet, through which the continuously collected measurement sample can be continuously fed to the particle measuring device, and including a measurement sample outlet arranged downstream of the particle measuring device and fluidically connected to the particle measuring device, through which the continuously collected measurement sample detected by the particle measuring device in the bypass conduit channel can leave the particle measuring device in the direction of the bypass conduit outlet opening;
• wherein the measurement sampling unit has an adjustable sampling inlet, the inlet opening size of which is adjustable between a first inlet opening size and a second inlet opening size different from the first inlet opening size, the second inlet opening size being larger than the first inlet opening size;
• the method comprising the steps of:
• detection of an ACTUAL grain spectrum of a measurement sample by means of a particle measuring device;
• analysis of the detected ACTUAL grain spectrum;
• define a TARGET grain spectrum;
• comparison of the detected ACTUAL grain spectrum with the defined TARGET grain spectrum;
• and
• setting of one or more of the following mill parameters in dependence on the result of the comparison of the detected ACTUAL grain spectrum with the defined TARGET grain spectrum:
• speed of a rotor of the mill,
• amount of an air volume flow that flows through the mill, and/or
• feed quantity of the bulk material to be ground.