FI117636B - Cleaning device for cleaning the air sprayers in a soda boiler - Google Patents

Description

117636 I

: 1 ..1

Purifier for cleaning the lye sprays of the recovery boiler

Background of the Invention

The present invention relates to a cleaning device for cleaning lye sprays from a recovery boiler from material falling on them.

5 The boiler feeds the combustible material, ie the liquor from the pulp making process, by means of lye syringes, from which the lye injects into droplets and returns to the furnace. The problem is that as a result of the flows generated by the combustion process on the shaft or in the nozzle portion of the syringe, the liquor or combustible carbon builds up, which in time burns a hole in the nozzle. The material accumulated on the nozzle-10 arm receives combustion air through the nozzle mounting opening, which enhances combustion and thereby accelerates the destruction of the nozzle arm. At its worst, the nozzle can be destroyed out of service for up to 24 hours. When multiple syringes, often a dozen or so, are needed in a single recovery boiler, repairing or replacing lye syringes is quite a job, requiring staff and cost.

Manual maintenance of the syringes has been attempted by keeping the syringes clean, with the use of brushes or other cleaning devices designed for the purpose by the operating personnel to remove any accumulated material from the syringe stems. Some types of mechanical cleaning equipment have also been tested, but the benefits thereof have not, at least so far, proved very significant. Liquid sprays and their mounting opening have also been purged: ***; • by blowing steam or air into the installation port of the lye syringe, which has not • · · been shown to be of significant benefit, and. has recently been abandoned. With the knowledge that plant automation will reduce continuous * * * 25 personnel, it will not be possible in the future to keep purge syringes manually • and, as a result, problems caused by burns of syringes may just increase. .

:: *: Brief Description of the Invention It is an object of the present invention to provide a device whereby the lye syringe shaft can be kept cleaner and thus more usable than the present solutions. The cleaning device according to the invention is characterized in that it comprises one or more steam pipes mounted around the arm of the lye syringe, which can be fed so that steam flows from the liquid nozzle side 1 of the ': 1

Ian around the handle of the lye nozzle in the furnace, protecting the arm of the lye.

It is an essential idea of the invention that one or more passageways are provided on the arm of the lye syringe, at one end of which steam is conducted so as to flow along the passageway of the lye syringe arm to create a flow around it that blows material off and not even grasping the handle, because the flow pushes the material falling at the handle to the side. Further, the steam will inert the combustion sensitive area of the shaft, whereby any material that has been splashed on the shaft will not receive oxygen and thereby prevent combustion to that extent.

An advantage of the cleaning device according to the invention is that it is easy to install in both existing and new lye syringes. A further advantage of the invention is that it can be operated continuously when necessary without its use disrupting the actual combustion process of the recovery boiler. A further advantage of the invention is that the lifetime of li-15 mini-syringes is significantly increased compared to current solutions. $

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail in the accompanying drawings, in which Fig. 1 schematically shows a cross-section of a conventional soda boiler, Figs. 2a and 2b schematically show a side view of a liquefied syringe equipped with a cleaning device according to the invention; 3a and 3b schematically illustrate a side spray and a side view of a lye spray having an embodiment of the purifier according to the invention, and 25 on the side of the furnace of the recovery boiler, and f · ·

Figures 4a and 4b show schematically a side view, partially in section, and a side view of a furnace spray of a third embodiment of a purifying device of the invention according to the invention.

• · · • * · • · «

DETAILED DESCRIPTION OF THE INVENTION Fig. 1 shows a recovery boiler 1 with a furnace 2. At the bottom of the furnace 2 is a salt cavity 3 formed when the lye is injected into the furnace furnace as droplets in a manner known per se. The primary nozzles, secondary nozzles, and tertiary nozzles 5a through 7b, through which the combustion air for liquor combustion is fed to the recovery boiler, are known in the art, as shown in the figures.

'3' I

for example, the secondary as well as the tertiary nozzles may be two overlapping planes J

or another structural solution known per se for supplying air to the recovery boiler. Since such various air supply solutions are generally well known to those skilled in the art, and as such are not substantially related to the present invention, there is no need to explain these different air supply alternatives in more detail.

The flue gases from the liquor combustion inside the recovery boiler flow into the upper part of the recovery boiler, which has heating surfaces known per se, such as superheaters 8, which are heated by the hot flue gases 10. The structure and function of all of these are well known to those skilled in the art and, as they are not substantially related to the actual invention, need not be further elucidated herein.

Fig. 2a is a schematic representation of a conventional lye syringe having a cleaning device according to the invention in partial section.

The lye syringe 4 has a nozzle 11 from which lye fed through the lye syringe inlet duct 12 * and the arm 13 is injected into the furnace of the recovery boiler. Around the shaft 13 is an annular steam passage 14, which is most preferably in the form of a circular tube 20. The steam channel 14 is otherwise closed at one end, but is led by a steam supply channel 15 through which steam is supplied to the steam channel 14. The steam flows between the steam channel 14 and the arm 13 in an annular |

flow and continue after the end of the steam passage 14 around the shaft 13 forward

towards. This vapor flow blows away the lye-carbon material that has fallen onto the boiler side of the recovery boiler, which is schematically dropped from the wall 13 shown schematically in Fig. 16, and prevents falling material. * ··. from falling onto the shaft 13, since the vapor flow causes the material to be ejected away. Further, the absence of oxygen in the vapor prevents combustion of material already adhered to the shaft, since this would require the presence of oxygen "f 30 around this material.

The vapor channel cross-section may vary depending on, among other things, the shape of the liquor nozzle and the desired vapor flow form. The vapor flow may be either symmetrically cross-sectioned about the shaft 13 or be positioned, for example, so that there is a greater vapor flow above the shaft, since the material will fall on the shaft closest to the upstream direction. Depending on the operation characteristics of the recovery boiler, the steam may be either continuous or suitably intermittent and the steam used for cleaning may be taken at any convenient point in the process from which steam of suitable temperature and pressure can advantageously be obtained.

Fig. 2b shows an embodiment according to Fig. 2a, viewed from the side of the fire-housing 5 of the recovery boiler. As shown in the figure, there is an annular steam passageway around the lye arm 13, to which the vapor supply passage 15 leads.

From this the steam comes out as an annular jet around the shaft 13.

Fig. 3a schematically shows a lye syringe with another embodiment of a cleaning device according to the invention. In this embodiment, there are a plurality of separate steam supply tubes 14 'around the lye syringe barrel spaced at appropriate intervals around the lye syringe barrel so that the jets of steam flowing out of them together form a protective and purifying steam of the lye syringe 4. In this embodiment, the steam supply channel 15 is connected to an annular distribution chamber 17 to which the steam supply pipes 14 'are connected at one end so that steam can flow into each of the steam supply pipes 14'. Fig.

3b illustrates this embodiment of the invention, respectively, viewed from the furnace side of the recovery boiler.

Fig. 4a shows a partially sectioned side view of a lye syringe with another embodiment of the cleaning device 20 according to the invention.

As shown in this embodiment, there is a steam tube 14 around the handle of the lye syringe, which is closed at its end, as shown in Fig. 2a, by the steam supply channel • · · ϊ.,. However, in this embodiment, there is also a wall on the side of the lye syringe, which is formed with holes 14a at suitable intervals: * ·. · 25. From these holes 14a, the steam can be discharged out of each other in the form of * * jets of steam at appropriate intervals which, on the other hand, blow when flowing. • the falling material and also the material that has fallen off the spray gun and the • • dense enough to form an inert protective environment around the shaft. Figure 4b, in turn, shows the solution of Figure 4a viewed from the furnace side of the soda-30 boiler, whereby the holes 14a are clearly visible around the rod of the syringe.

··· The invention is set forth above in the description and in the drawings only in an indicative manner, and is not limited thereto. It is essential that • · · .. * steam is sprayed around the arm of the lye syringe in one or more * * \ "35 pan jets so that a protective vapor is formed on the side of the lye syringe on the side of the recovery boiler. material 5. ^ 117636, preventing it from sticking to the syringe barrel while inertizing the environment to reduce or completely prevent combustion conditions of material that has fallen onto the syringe 1 ··· * · 1 · 1 m • ♦ • «· * · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 1

Mtt * · Φ • • «1 1 1 * 1 · * 1 1 * * 1 1 2 *

Claims (7)

A cleaning device for cleaning liquor syringes of a recovery boiler from material falling thereon, characterized in that it comprises one or more steam tubes mounted around the shaft of the syringe syringe, which can be fed so that the steam flows from the liquid end of the around the stem protecting the syringe arm. A cleaning device according to claim 1, characterized in that the steam is connected to flow through the steam pipe in a substantially continuous manner. A cleaning device according to claim 1, characterized in that the steam is connected to flow through the steam pipe at predetermined intervals for a predetermined length. A cleaning device according to any one of the preceding claims, characterized in that the vapor tube is a tube mounted around the lye syringe, whereby an annular channel is formed around the steam tube and the lye syringe shaft. ; A cleaning device according to claim 4, characterized in that the steam pipe is open at its end on the recovery boiler side, so that the steam 20 flows around the shaft of the lye syringe in the recovery boiler as an annular flow: 1 2 ϊ. ···: 3: A cleaning device according to claim 4, characterized in that a wall is formed at the end of the steam pipe's recovery boiler: ···· ': a plurality of spaced-apart holes are formed so that steam flows from the inside of the steam pipe through the holes in showers around the syringe arm • · 4 ... #. ** · 1 A cleaning device according to any one of claims 1 to 3, characterized in that it comprises a plurality of spaced-apart steam tubes arranged around the shaft of the syringe syringe, from which the flowing jets 30 form the steam stream of the liquefied jet boiler liquor. - around the arm of the lye syringe on the weather side. • · · · • ♦ · 1 ···. ♦ · ♦ · 2 •; · 3 • · · • · · • '' 7 117636