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Title:
SYSTEM AT A FURNACE INCLUDING AT LEAST ONE LIQUOR GUN
Document Type and Number:
WIPO Patent Application WO/2015/199597
Kind Code:
A1
Abstract:
System (1) at a furnace, where combustible media such as liquor is dispersed into the furnace and burned, including at least one liquor gun (2) and at least one subsystem (3) with which the liquor gun's position in relation to the furnace is controlled and at least one control system with which at least one of the system's (1) functions are controlled. The liquor gun (2) is comprised of at least one elongated tubular body (7) which at its one end is connected to a nozzle (5) with an associated valve and control equipment and at its other end is connected to a feed of liquor and that the valve, controlling the flow through the nozzle, is comprised of at least one control body and at least one valve seat whose mutual positions are controlled via at least one axle that is affected by at least one actuator (10), whose rod's, axle's direction essentially corresponds with the nozzle's axial direction. The system (1) is comprised of at least one subsystem (4) with which vapor/steam condensate, if necessary, via at least one spray nozzle (20), spray jet or the like, positioned at the outside (12) of the nozzle (5), is applied to the entire or parts of the nozzle's (5) outside (12).

Inventors:
JOHANSSON SUNE (SE)
Application Number:
SE2015/000040
Publication Date:
December 30, 2015
Filing Date:
June 22, 2015
Export Citation:
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Assignee:
SUPPLY Ö VIK AB (SE)
International Classes:
F23G7/04; D21C11/12; F23G5/44
Foreign References:
JPH0688611A1994-03-29
JPH01229890A1989-09-13
US20050263108A12005-12-01
US20100139580A12010-06-10
SE524274C22004-07-20
Attorney, Agent or Firm:
JOHANSSON, Urban (Själevad, SE)
Download PDF:
Claims:
Claims

1. System (1) at a furnace, where combustible media such as liquor is dispersed into the furnace and burned, including at least one liquor gun (2) and at least one subsystem (3) with which positioning of the liquor gun in relation to the furnace is controlled and at least one control system with which at least one of the system's (1) functions are controlled, whose liquor gun (2) is comprised of at least one elongated tubular body (7) which at its one end is connected to a nozzle (5) with an associated valve and control equipment and at its other end is connected to a feed of liquor and that the valve, controlling the flow through the nozzle, is comprised of at least one control body and at least one valve seat whose mutual positions are controlled via at least one axle that is affected by at least one actuator (10), whose rod's, axle's direction essentially corresponds with the nozzle's axial direction and that the system (1) is comprised of at least one subsystem (4) with which vapor/steam condensate, if necessary, via at least one spray nozzle (20), spray jet or the like, positioned at the outside (12) of the nozzle (5), is applied to the entire or parts of the nozzle's (5) outside (12) characterized in that

the subsystem (4) is comprised of at least one connection device (14) with which at least one of the positions of the nozzles, relative to the nozzle's (5) outside (12), may be adjusted,

the subsystem (4) includes at least one condenser (21) for condensing steam to condensate,

the subsystem (3) is comprised of at least one stand (26) that includes a connector (27) to the furnace in the form of a frame structure (28), at least one protective lid (29) which is operated with at least one control device 30, at least one carriage (33), to which the liquor gun (2) is connected, which may be positioned relative the slide (32) with at least one control device,

the stand (26) is comprised of at least one first height adjusting device (37) and at least one second height adjusting device (38), with which the position of the liquor gun is controlled.

2. System (1) at a furnace in accordance with claim 1 characterized in that the system includes at least one actuator for controlling and indicating the position of the liquor nozzle.

3. System (1) at a furnace in accordance with at least one of the previous claims

characterized in that the liquor gun's spray lip (9) is arranged to be rotatable around at least one axis of rotation.

4. System (1) at a furnace in accordance with at least one of the previous claims

characterized in that the nozzle (5) has a cylindrical-shape which facilitates removal of deposits from the surface of the nozzle (5).

5. System (1) at a furnace in accordance with at least one of the previous claims

characterized in that the condenser (21) consist of a double-sheathed condenser.

6. System (1) at a furnace in accordance with at least one of the previous claims

characterized in that the connection device (14) is comprised of at least one first bracket (15) for at least one first tube (16) equipped with at least one first spray nozzle and at least one second bracket (17) for at least one second tube (18) equipped with at least one second spray nozzle.

7. System (1) at a furnace in accordance with at least one of the previous claims

characterized in that the system is suitable for connection to at least one external control system.

8. System (1) at a furnace in accordance with claim 7 characterized in that the external control system consists of system for controlling the functions of a recovery boiler.

Description:
SYSTEM AT A FURNACE INCLUDING AT LEAST ONE LIQUOR GUN

Field of the Invention

The present invention concerns a device and a system at a furnace (boiler) in accordance with the claims. Background of the Invention

Devices for supplying and burning liquor and the like in furnaces, such as recovery boilers, are previously known. For example, such devices are described in SE361731 and SE529081. The described designs include an essentially straight tube part, which is passed through the furnace wall and has a curved portion located inside the furnace, wherein one, in the curved portion arranged control body is essentially axially movable in relation to one at the tube's orifice arranged stricture, wherein the control body is arranged to be affected by a mechanism which is adjustable by a device, arranged outside the furnace. There are several problems in conjunction with the combustion of for example liquor and similar substances, with the above mentioned designs and other known devices for similar purposes. One of the problems with known designs is that deposits (coatings) are formed on the outside of the burner nozzle or nozzles. The coatings on the outside of the nozzle or nozzles, carries an increased risk of various types of failures occurring such as that the liquor dispersion pattern deteriorates with a lower result of combustion as a result. Another problem with coatings is that the deposit corrodes, for example on the spoon-shaped part so that its area shrinks, which in turn results in a degraded dispersion of the liquor with lower combustion as a result.

The design described in SE529081 also has the problem that there is a risk of burning through the hardware on the mentioned "pipe stub" and at the top side of the curved section (positions X in the shown Fig. 1). A similar problem of burn-through is also present in the design described in SE361731 at the curved portion. The problem is caused by the curvature angle and also because of other reasons.

Known designs of control equipment for the aforementioned control body which regulates the flow of fluid through the nozzle, has a complicated design with many components. For example, these components consist of angle joints and several other components. The mentioned control equipment therefore becomes complicated and expensive.

In order to reduce the problems of deposits (coatings) on nozzles, designs have been developed which are designed to eliminate or at least limit the effects of these coatings. For example, US8163137 and US7988820 by the applicant Andritz describe variants of devices for the cleaning, flushing (rinsing) of nozzles from the nozzle's exterior. This

flushing/cleaning of nozzles occurs by a pressurized emul sion of water and steam being discharged out through the apertures in the nozzle's walls. The designs and methods according to their descriptions differ substantially from the design and method in accordance with the present patent application. For instance, cleaning, removal of coatings (deposits), in US8163137 and US7988820 does not occur by steam and/or steam condensate being applied to the nozzle from the nozzle's outside.

A further variant of prior art for cleaning/flushing nozzles for e. g. liquor burning are described in JP20000256979, that describes techniques that use pressurized steam for flushing/cleaning nozzles that burn liquor. This design differs substantially from the present invention. For example, the design in accordance with its description lacks a number of the present invention's functions.

In JP401229890 A is described a method to prevent material deposits accumulating on the outside of a liquor gun. The design uses a mixture of steam and water, whose mixture ratio is controlled by a valve which is moved towards the outside of the liquor gun via a nozzle. This design differs substantially from the design in accordance with the present patent application. For example, it does not consists of a system in accordance with the present patent application. The design also has the disadvantage of the risk of accidents in case of failure of the valve that regulates the mixture of steam and water. If only water is added, there is a risk of explosion.

In JP40608861 1 A5, by the applicant Mitsubishi, is disclosed a variant of an injection device for the combustion of black liquor in a recovery boiler. The design is comprised of a nozzle that includes a valve body which may be operated towards and from a valve seat. This design comprises in one of the embodiments a similar operating device as in the present patent application. Even so this design differs substantially from the design in accordance with the present patent application. For example, it does not consist of a system in accordance with the present patent application.

SE52474 discloses a variant of a cleaning device for cleaning liquor guns in a recovery boiler. This design is comprised of one or more channels around the shaft of the injector which eject steam around the shaft of the liquor gun. This design in accordance with its description differs substantially from the design in accordance with the present patent application.

Known types of liquor nozzles also have problems with blockage forming inside the channels or the like, through which liquor is supplied to the spoon-shaped part.

Purpose of the Invention The main purpose of the present invention is to create a system which solves or reduces at least one of the above mentioned problems. This purpose is achieved by a system in accordance with the claims.

Brief Description of the Drawings

In the following detailed description of the present invention, reference and references to the following figures will occur. These figures are briefly described in the following figure list.

Fig. 1 shows an example of prior art.

Fig. 2 shows principally a first embodiment of a device/system in accordance with the present invention.

Fig. 3 shows the principle elements included in the system according to Fig. 2. Fig. 4 shows a liquor gun with its associated control equipment and exemplifying flushing system.

Fig. 5 shows an exemplifying embodiment of the included stand. Fig. 6 shows the first height adjusting device in more detail. Fig. 7 shows the second height adjusting device in more detail. Detailed Description of the Invention

Referring to Figs. 2 and 3, a system/device 1 is shown at the burner for a furnace, where the combustible medium is supplied to the furnace via at least one liquor gun 2 with its associated control systems. In the exemplifying preferred embodiment, the combustible medium consists of liquor or the like. In alternative embodiments it is conceivable that something other than liquor is burned.

The system includes at least one liquor gun 2 with its associated control equipment, at least one subsystem 3 for positioning the liquor gun in relation to the furnace, and a control system 4 for controlling the system's 1 functions. The liquor gun 2 with its associated components may alternatively be defined as a subsystem.

The liquor gun 2 is fed with liquor from at least one supply unit which supplies the combustible medium to the liquor gun 2, or liquor guns. The feed of liquor to the liquor gun is accomplished with previously known technology and this is why this technology is not described in more detail in this patent application. Referring to Fig. 4, an exemplifying embodiment of the liquor gun 2 is shown. The liquor gun 2, according to the present invention, has at least one first function and at least one second function. The first function is achieved with a device or subsystem, which is suitable for dispersing the combustible medium in the furnace during combustion. The second function is achieved with a device or subsystems, with which existing coatings (deposits) from the nozzle's (burner's) outside fully or partially are removed.

The liquor gun 2 in accordance with the exemplifying embodiment includes at least one nozzle 5. The nozzle 5 is comprised of or is provided with at least one dispersion member 6 or the like. The liquor gun is further comprised of at least one tubular (pipe-shaped) body 7 which in its one end is connected to the nozzle 5. The nozzle 5 and the tubular body 7 include at least one through channel through which liquor is supplied via the nozzle 5 in the direction of the dispersion member 6. In its other end the tubular body is directly or indirectly connected to the supply device for the liquor. The connection may for example be

accomplished via a hose 8, tube (pipe) or the like. The nozzle 5 and the tubular body 7 are connected to each other with for the purpose previously known suitable technology. Pressurized liquor is supplied via the through channel in the direction of the distribution member 6, such as a spray lip 9 with which the dispersion of the liquor takes place during combustion. The spray lip (the spoon-shaped part) 9 in the exemplifying embodiment is angled relative to the through channel's axial direction. The regulation of the supply of liquor is accomplished via at least one valve. The valve may for example be comprised of at least one regulating body which engages with at least one valve seat in, or at, the through channel. The flow through the valve is operated manually or automatically by at least one control device. The control device in the exemplifying embodiment consists of at least one actuator motor (servo motor) 10 which via a rod, a strut, a shaft or the like affects the regulating body's position relative to the valve seat. In one preferred embodiment, the rod's axial direction essentially corresponds to the axial direction of the nozzle 5. The actuator motor is in the figure provided with at least one protective cover 11 (which in the figure hides the actuator motor). The dispersed (ejected) liquor creates a dispersion pattern. The dispersion pattern may be fixed or adjustably arranged. The control of the dispersion pattern in an alternative embodiment is accomplished by the spray lip's position relative to the nozzle (the nozzle's additional parts) being adjustable. This may for example be accomplished by the spray lip 9 being articulately or pivotally connected to the nozzle (other parts of the nozzle) via at least one joint (hinge) or pivot axis (not shown in the figures). The present design comprises an enhanced feature to operate the regulating body's position relative to the valve seat.

The system 1 also preferably includes at least one subsystem to remove all or part of the outside 12 of the nozzle 5 from deposits (coatings). The subsystem includes at least one device which supplies a medium to the nozzle's 5 outside. By applying medium to the outside of the nozzle, deposits (coatings) are fully or partially removed from it. In the exemplifying embodiment, the system 4 is suitable for removing parts of the tubular body from deposits.

In order to clean and/or flush (rinse) at least (remove coatings from) one nozzle 5 included in the liquor burner, subsystem 4 is comprised of at least one connecting device 13 with which the device is connected to the nozzle 5 or secured to at least one object in the stand, bracket or the like adjacent to the nozzle. In the exemplifying embodiment, subsystem 4 includes at least one connection device 14, pipe rack, cradle, with which the nozzle or nozzles positions relative to the liquor gun 2 may be controlled. The connecting device's (pipe rack's) 14 design may differ greatly within the scope of the present invention. In the exemplifying embodiment of the design, the connection device (pipe rack) 14 includes at least one bracket 15 for at least one first tube 16 and at least one second bracket 17 for at least one second tube 18. The first tube 16 and second tube 18 are each in their free ends 19 equipped with at least one spray nozzle 20, spray jet or similar each. The spray nozzles 20 may be of a fixed or adjustable type.

On removal of the deposits (coatings) from the burner's (nozzle's) outside surface, steam or steam condensate or alternatively a combination of steam and steam condensate are preferably used. The steam and/or condensate may be supplied to the cleaning system in a variety of different ways. For example, it is conceivable that the steam and/or condensate is supplied to the system 1 via at least one condenser 21 which condenses steam pressure. The condensate is then supplied to the subsystem. The advantage of using condensate of steam is that it is available in most common applications of the present invention.

Pressurized steam is supplied to the condenser 21 via supply such as via at least one hose 22, tube or the like. The condenser 21 may be double-sheathed or of another for the purpose suitable type. The condenser 21 includes a function to cool the steam, which in the exemplifying design takes place with cooling water. In order to supply cooling water, the condenser thus includes an inflow 23 and an outflow 24 of coolant such as cooling water.

The condensate is driven out by the steam pressure to the spray nozzles 20, spray jets or the like positioned at the nozzle 5. The regulation of the flow to the spray nozzles, spray jets or the like occurs via at least one valve 25 of a type suitable for the purpose. For example, the valves may be solenoid valves or other suitable for the purpose types of valves.

The nozzle (burner) 5 in accordance with the present invention also has an improved form (shape) which means that the function of the above described subsystem 4 to free the outside of the nozzle 5 and the spray lip 9 from deposits (coatings) has improved in relation to the designs of prior art. The present design forms a cylinder-shaped unit with a diameter that does not vary along the length of the part.

Referring to Fig. 5, an exemplifying embodiment of subsystem 3 is shown for positioning the liquor gun relative to the furnace. The subsystem 3 includes at least one stand 26. The stand includes functions for positioning the liquor gun 2 and connecting the liquor gun 2 to the furnace. The stand 26 includes in the exemplifying embodiment, a connector 27 to the furnace. The connector includes in the exemplifying embodiment, at least one frame structure 28 with at least one opening. The opening may be closed by at least one protective lid

(shutter, hatch) 29 which in the exemplifying embodiment is operated with at least one control device 30. The control device consists in the exemplifying embodiment of at least one pressure cylinder 31. The stand 26 further includes at least one slide 32, after which at least one carriage 33 or the like is movably arranged. The carriage 33 is connected to the liquor gun 2 via brackets or similar. The carriage's 33 position along the slide is operated with at least one control device 34. The figure also shows a control device 35 for a cleaning rod. The system may be provided with or without control device 35 for a cleaning rod. The stand in the exemplifying embodiment includes at least one protective cage 36 which partitions the dangerous area around the liquor gun.

The stand includes a control function with which the position of the nozzle, with its associated liquor gun, may be positioned in both the vertical and horizontal directions. It is also possible to adjust the liquor gun's angle, direction or the like (the direction of the ejected flow). The adjustment of the height may for example be done via at least one first height adjusting device 37. An exemplifying first adjusting device 37 is shown in Fig. 6. It is comprised of at least one actuator for indicating and controlling the position of the nozzle and liquor gun and transmit this information to the control system. The position of the nozzle and liquor gun may be adjusted with the control system. In the exemplifying embodiment, the adjustment of the vertical height and direction is accomplished via at least one first height adjusting device 37 and at least one second height adjusting device 38. An exemplifying second adjusting device 38 is shown in Fig. 7. The second height adjusting device in the exemplifying embodiment includes at least one gear 39 and at least one toothed rack 40 whose mutual positions may be adjusted. The figure also shows screws 41 or the like. By way of this adjustment, the height of the liquor gun may be adjusted. The present system 1 includes at least one control system 4 which is comprised of at least one control unit, control box 42 or the like. The control system (control box) controls the stand's functions such as the liquor gun's horizontal position, the cleaning rod's function and the operation of the protective lid. The control system is preferably connected to at least one other external control system such as a boiler control system which controls other furnace functions or other types of control systems.

In the exemplifying embodiment of the present sub-method, for removal of deposits from the outside of the nozzle, steam or steam condensate is regularly applied to the outside of the nozzle. For example, steam and/or steam condensate is applied to the nozzles at intervals of regular time intervals where steam and/or steam condensate is applied to the nozzle and where steam and/or steam condensate is not applied to the liquor nozzle.

In the detailed description of the present invention, design details may have been omitted which are apparent to persons skilled in the art of the device. Such obvious design details are included to the extent necessary so that the proper and full performance of the present invention is achieved.

Even if certain preferred embodiments have been described in detail, variations and modifications within the scope of the invention may become apparent for specialists in the field and all such are regarded as falling within the scope of the following claims. It is thus conceivable that the system 1 be used to apply something other than liquor for combustion in some other type of furnace (furnace-like device). It is further conceivable in alternative embodiments that the system be defined to include several liquor nozzles than those in the exemplifying embodiment. The present system may alternatively be defined as a robotic system where all the recovery boiler's functions or parts of the recovery boiler's functions are controlled by the robotic system. With all the functions are meant such functions as air supply, air flow, air pressure, liquor pressure, liquor temperature, end combustion, boiler pressure, liquor levels in tanks (containers) and the like, and even electricity generation and so on. Advantages of the Invention

The present invention achieves several advantages. The key advantage is that at least one of the above mentioned disadvantages are eliminated or reduced. The system leads to fewer work steps needing to be performed in relation to known designs. The system also leads to improved safety and working environment. The system also saves time during load changes. Furthermore, the system entails lower emissions of undesirable substances in the flue gases thanks to more efficient combustion. A further advantage of the system is that fewer parts are required (liquor guns). The present system's liquor gun also has the advantage that it prevents the formation of blockages by obstructions being pushed out with the regulating body.