US 5,976,319 A · Disrupting the flow from the smelt spout of a recovery boiler

Abstract

The intensity of explosions as a result of hot (750-820 degrees C.) smelt from a pulp mill recovery boiler impacting cool (70-100 degrees C.) liquid in a dissolving tank is minimized by more effectively disrupting the flow of smelt from a spout free end tip into the tank. First and second nozzles which issue jets of disrupting fluid (such as steam or green liquor) are positioned on opposite sides of the center line of the spout, and are positioned and spaced from the spout tip and each other so that the jet emanating from at least one of the nozzles always intersects the flow of smelt from the spout even though the smelt flow path varies during normal operation of the recovery boiler. The first and second nozzles are preferably each spaced from the spout free end tip a distance of between about 300-700 mm, but different by at least 50 mm from the other nozzle, and are positioned downwardly and obliquely at an angle to the vertical so that the jets move downwardly and obliquely making an angle of between about 20-40 degrees with respect to the vertical. Other nozzles--e. g. in front of the smelt flow--can also be provided within a hood covering the spout area.

Claims20

Dependent claims

A method of dissolving smelt to form green liquor while minimizing explosions as a result of hot smelt contacting cool liquid, using:

a recovery boiler having a smelt spout extending outwardly from a bottom portion thereof;
the smelt spout having a free end tip, and a center line, fluid smelt downwardly flowing along the center line from the free end tip of said spout;
and a dissolving tank positioned below the spout and having cool liquid therein;
said method comprising the steps of:
(a) causing fluid smelt to flow downwardly from the free end tip of the spout toward the dissolving tank, the smelt flow path inherently varying during normal operation of the recovery boiler;
and
(b) before the smelt impacts the liquid in the dissolving tank, directing a disrupting medium in first and second distinct jets from opposite sides of the center line of the smelt flow toward the smelt flow to impact the smelt and break the smelt into smaller flows, droplets, or pieces;
and
wherein step (b) is practiced so that the distinct jets are differently directed so that, in combination, the disrupting medium from at least one of the jets intersects the smelt flowing downwardly from the smelt spout free end tip during normal operation even though the flow path of the smelt varies.

6 more elements

Dependencies are inferred from the claim text.

Disrupting the flow from the smelt spout of a recovery boiler

Life of this patent

Disrupting the flow from the smelt spout of a recovery boiler

Life of this patent

Abstract

Claims20