Methods and systems for controlling operation of a smelt dissolving tank receiving a flow of smelt and having a vent stack in fluid communication are provided. A dissolving liquid is injected into the smelt dissolving tank at a predetermined injection rate. A temperature of a flow of vapour in the vent stack is measured with a sensor. The injection rate of the dissolving liquid is controlled based on the temperature of the flow of vapour.

The specification relates to a method and a system for adjusting pH of green liquor dregs. The method comprises contacting a slurry containing green liquor dregs (100, 200, 300, 400, 500) with flue gas (101, 201, 301, 401, 501). The system comprises a recovery boiler (105) configured to burn black liquor to produce smelt, a smelt dissolving tank (107) configured to dissolve the smelt to produce green liquor comprising green liquor dregs, and a green liquor clarifier/filter (103) and/or a dregs filter (104) configured to separate a slurry containing green liquor dregs (100, 200, 300, 400, 500) from the green liquor. The system further comprises a vessel (102, 202, 302, 402) configured to receive a slurry containing green liquor dregs (100, 200, 300, 400, 500) and a gas inlet (210, 310, 410, 510) configured to convey flue gas (101, 201, 301, 401, 501) to be contacted with the slurry containing green liquor dregs (100, 200, 300, 400, 500).

A disruptor adjustment system comprising: a disruptor assembly configured to disrupt a volume of smelt flowing from a smelt spout into a dissolving tank, wherein the disruptor assembly comprises an actuator operatively engaged to a disruptor, a sensor configured to record process data from the recovery boiler; and a control system configured to receive a sensor output signal from the sensor, wherein the sensor output signal indicates the process data at a measured time, wherein the control system is further configured to compare the sensor output signal to a programmed operation range, and to send a disruptor input signal to the disruptor assembly to adjust a disruptor operating condition if the process data of the sensor output signal is outside of the programmed operation range. In certain exemplary embodiments, the sensor is an image capture device. In certain exemplary embodiments, the disruptor assembly can be adjusted remotely.

A disruptor adjustment system comprising: a disruptor assembly configured to disrupt a volume of smelt flowing from a smelt spout into a dissolving tank, wherein the disruptor assembly comprises an actuator operatively engaged to a disruptor, a sensor configured to record process data from the recovery boiler; and a control system configured to receive a sensor output signal from the sensor, wherein the sensor output signal indicates the process data at a measured time, wherein the control system is further configured to compare the sensor output signal to a programmed operation range, and to send a disruptor input signal to the disruptor assembly to adjust a disruptor operating condition if the process data of the sensor output signal is outside of the programmed operation range. In certain exemplary embodiments, the sensor is an image capture device. In certain exemplary embodiments, the disruptor assembly can be adjusted remotely.

A method and apparatus for cleaning a black liquor recovery boiler, where a furnace floor of the boiler is washed by mixing wash water in a wash water pool formed on the floor by at least one mixing device in the wash water pool, and by jetting wash water towards the floor by at least one pressure washer installed into the furnace through an opening in the furnace wall.

An apparatus comprising a cleaning rod driven in reciprocating, axial extension (y) and retraction (x) movements upon cleaning a smelt discharge opening of a chemicals recovery boiler, wherein a linear actuator is controllable for driving the cleaning rod in the axial movements. A pivot actuation means is controllable for pivoting the cleaning rod about an axis (S) upon cleaning a smelt spout associated with the smelt discharge opening, wherein one or more sensors are arranged to provide control basis for correlation of the axial movements (x; y) with the change in pivot angle (φ) during pivoting of the cleaning rod. A method to be performed in use of the apparatus is likewise disclosed.

A smelt shattering apparatus includes an inlet orifice, an outlet orifice, and a fluidic pathway between the inlet orifice and the outlet orifice. A convergence divergence zone is located between the inlet orifice and the outlet orifice. In one illustrative construction, a first separable section includes the inlet orifice, and a second separable section includes the outlet orifice and a divergence zone of the convergence divergence zone. In some constructions, there may be a second outlet orifice in fluidic communication with the inlet orifice. To provide uniformity over the multiple shatter jets, the first outlet orifice may have a cross-sectional dimension and the second outlet orifice is located a distance of between about 4 and about 10 times of the cross-sectional dimension from the first outlet orifice.

A startup burner assembly for a recovery boiler, the startup burner assembly includes a housing having a burner end and a second end distal to the burner end; a main fuel conduit disposed within the housing; and high-pressure air conduits disposed within the burner end of the housing. The high-pressure air conduits include angled air injection nozzles configured to direct high-pressure air exiting the burner end of the startup burner assembly in a rotational direction.

There is described a process for the recovering of inorganic chemicals of pulp and paper making processes (IC) and the production of biochemicals from black liquor (BL) using microwaves (MW) comprising: (a) filtration of BL to produce filtered BL, in a media, (b) drying of said filtered BL with MW in said media to produce dried BL, (c) pyrolysis of said dried BL with MW in said media to produce bio-oil, biogas, and solid residue, (d) recovering of said bio-oil, and (e) recovering of IC and biocarbon from said solid residue. The disclosed process does not require chemical additives compared to processes rely on precipitation of lignin to recover said IC. The disclosed process supports efficient, direct, and long-lasting reductions in greenhouse gas emissions and local air pollutants resulting from the current processes rely on burning BL in recovery boilers to recover said IC.

There is described a process for the recovering of inorganic chemicals of pulp and paper making processes (IC) and the production of biochemicals from black liquor (BL) using microwaves (MW) comprising: (a) filtration of BL to produce filtered BL, in a media, (b) drying of said filtered BL with MW in said media to produce dried BL, (c) pyrolysis of said dried BL with MW in said media to produce bio-oil, biogas, and solid residue, (d) recovering of said bio-oil, and (e) recovering of IC and biocarbon from said solid residue. The disclosed process does not require chemical additives compared to processes rely on precipitation of lignin to recover said IC. The disclosed process supports efficient, direct, and long-lasting reductions in greenhouse gas emissions and local air pollutants resulting from the current processes rely on burning BL in recovery boilers to recover said IC.