JP3974611B2 - Container inner surface cleaning apparatus and inner surface cleaning method - Google Patents

Description

  The present invention relates to industrial equipment, and more particularly to detonative cleaning of industrial equipment.

Surface fouling is a significant problem in industrial equipment. Such equipment includes furnaces (such as coal, petroleum, waste), boilers, gasifiers, reactors, heat exchangers, and the like. Typically, industrial equipment includes a vessel with an internal heat exchange surface on which fouling and slag due to deposition of particles of ash, minerals and other combustion products and combustion by-products and soot More concentrated deposits such as fouling are likely to occur. Such particle deposition can gradually hinder the operation of the facility, reducing efficiency and throughput and causing damage. Thus, cleaning equipment is highly desirable, but with some associated problems. In many cases, direct access to the fouling surface is difficult. Furthermore, it is desirable to minimize the downtime and cleaning costs associated with industrial equipment to maintain revenue. Various techniques have been proposed so far. As examples, Patent Documents 1 to 3 describe various techniques. Another technique is disclosed in Non-Patent Document 1. Non-Patent Documents 2 and 3 describe specific explosion wave techniques. Such an apparatus is also described in US Pat. These devices are often referred to as “soot blowers” after the exemplary application of this technology.
US Pat. No. 5,494,004 US Pat. No. 6,438,191 US Patent Application No. 2002/0112638 Yugoslavia Patent No. P1756 / 88 Specification Yugoslavia Patent No. P1728 / 88 Specification Hugh zet. (Huque, Z.), "Experimental Investigation of Slag Removal Using Pulse Detonation Wave Technique, 19th Annual DOE / HBCU / Miami 19th Annual Symposium". March 16-18 Hanjalic Kay. (Hanjalic, K.) and Samajevik Eye. (Smajevic, I.), Cleaning of boiler heating surfaces using detonation waves (Further Experience Waves for Cleaning Boiler Heating Surfaces), International Energy Research Journal Vol. 17 (International Journal of Renewal Energy). 1993, p. 583-595 Hanjalic Kay. (Hanjalic, K.) and Samajevik Eye. (Smajevic, I.), “Detonation-Wave Technology for On-load Deposition of Surfaces Exposed to Foaling I, II to remove deposits from fouling surface during loading. , Gas Turbine and Power Engineering Journal, ASME Bulletin Vol. 1 (Journal of Engineering for Gas Turbines and Power, Transactions of the ASME, Vol. 1), January 1994, p. 223-236

  Regardless of the technology described above, further improvements are sought in the art.

  One aspect of the present invention includes a container internal surface cleaning apparatus. An elongate combustion line extends from the upstream end to the downstream end associated with the opening in the vessel wall and is arranged to direct a shock wave toward the surface. The elastic member elastically restrains the combustion pipeline against reaction force.

  In various embodiments of the present invention, the resilient member may connect the combustion line to the wall. The elastic member may include a metal coil spring. The elastic member may include a tension spring. The apparatus of the present invention may further comprise a plurality of movable supports, which support the weight of the combustion line at a plurality of locations along the length of the combustion line. The support may accommodate expansion and / or contraction in the longitudinal direction of the combustion line. The support can include a plurality of trolleys each having a wheel that engages a track on the support surface. The combustion line may include a plurality of separable segments. Each of these segments may be supported on one associated trolley. The support may include a plurality of hangers.

  Another aspect of the present invention includes a method for cleaning the internal surface of a container that is part of an industrial facility. Fuel and oxidant are charged into the pipeline. The reaction of fuel and oxidant is initiated to generate a shock wave that collides with the above surface. The reaction force applied to the pipe line is substantially absorbed by the elastic member.

  In various embodiments of the present invention, the elastic member can accumulate reaction energy as the pipe moves from the initial position to the reaction position and return the pipe to the initial position. This movement may be at least 0.01 m (for example, 0.03 to 0.1 m). The user can move the pipeline as a unit along the support mechanism to separate the downstream end of the pipeline from the container.

  The details of one or more examples of the invention are set forth in the accompanying drawings and the embodiments below. Other features, objects, and advantages of the invention will be apparent from the embodiments and drawings, and from the claims.

  FIG. 1 illustratively shows a furnace 20 having three associated soot blowers 22. In the illustrated embodiment, the furnace vessel is in the shape of a cuboid and the soot blowers are all associated with a single common wall 24 of the vessel and are arranged at a similar height along the wall. Other configurations are possible (such as a single soot blower, one or more soot blowers each provided at multiple heights).

  Each soot blower 22 includes an elongated combustion line 26 extending from an upstream distal end 28 remote from the furnace wall 24 to a downstream proximal end 30 proximate the wall 24. However, the end 30 can also be provided completely inside the furnace. During the operation of each soot blower 22, the combustion of the fuel / oxidant mixture in line 26 begins near the upstream end (within 10% from the upstream of the line length), and the surface within the internal volume of the furnace is A detonation wave is generated that is released as a shock wave along with the associated combustion gas from the downstream end for cleaning. Each soot blower 22 can be associated with a fuel / oxidant source 32. Such a source, or one or more parts thereof, can be shared between separate soot blowers 22. The exemplary source 32 includes a liquefied or pressurized gaseous fuel cylinder 34 and an oxygen cylinder 36 provided in corresponding containment structures 38, 40. In an exemplary embodiment, the oxidant is a first oxidant such as substantially pure oxygen. The second oxidant may be factory air supplied from a central air supply 42. In the exemplary embodiment, air is stored in the air accumulator 44. The expanded fuel from the cylinder 34 is generally stored in a fuel accumulator 46. The exemplary sources 32 are each connected to the associated conduit 26 by appropriate piping located below. Similarly, the soot blowers 22 each include an ignition box 50 that initiates combustion of the fuel oxidant mixture, which is controlled by a control and monitoring device (not shown) along with the supply source 32. FIG. 1 shows that the wall 24 includes several ports for inspection and / or measurement. Exemplary ports include an optical monitoring port 54 and a temperature monitoring port 56 associated with each soot blower 22, which are infrared and / or for observation of the surface to be cleaned and internal temperature monitoring. Accepts a visible light video camera and a thermocouple probe, respectively. Other probes / monitoring / sampling may be utilized for pressure monitoring, composition sampling, and the like.

FIG. 2 shows other details of an exemplary soot blower 22. An exemplary detonation conduit 26 includes a series of conduit portions or conduit segments 60 with flanges on both sides arranged from upstream to downstream, and a downstream portion 64 extending through a wall opening 66. And a downstream nozzle line portion that terminates at the downstream outlet 30 that is exposed to the interior 68 of the furnace, that is, a downstream nozzle line segment 62. The term nozzle is widely used and does not require the presence of aerodynamic contraction, expansion, or a combination thereof. An exemplary conduit segment material is a metal (such as stainless steel). An outlet 30 can be provided deeper in the furnace if adequate support and cooling is provided. FIG. 2 further shows tube bundles 70 inside the furnace, and fouling is likely to occur on the outer surface of these tube bundles. In the exemplary embodiment, the conduit segments 60 are each supported on an associated trolley 72 and the wheels of the trolley 72 engage a track device 74 provided along the floor 76 of the facility. The exemplary track device 74 includes a pair of parallel rails that engage the concave peripheral surface of the wheel of the trolley 72. Exemplary segment 60 is similar in length L _1, and is bolted in series by columns of the corresponding corresponding bolt provided on the bolt holes in the flange. Similarly, the downstream flange of the most downstream segment 60 is bolted to the upstream flange of the nozzle 62. In an exemplary embodiment, a reaction strap 80 (e.g., cotton or a thermally / structurally rugged synthetic material) includes one or more metal coil reaction springs 82 and a last coupled flange pair. Environmental structures such as combustion lines and furnace walls that are connected in series and elastically absorb reaction forces associated with the discharge of the soot blower 22 and are accurately positioned in the next ignition. And connect. Further, an additional attenuation means (not shown) can be provided. The reaction strap / spring combination can be configured in series or as a loop. In the exemplary embodiment, the overall length of the combined downstream section is L _2. Another elastic recoil absorbing means may include a non-metallic or non-coiled spring or rubber or other elastic element, at least partially by tension, compressive force, and / or shear force, such as a pneumatic recoil absorber. It is advantageous to be elastically deformed.

Predetonator conduit section / segment 84, from the upstream end portion 28 extends downstream, it is possible also in this predetonator Todorokikanro segment comprising a flange on both sides, it has a length L _3. The pre-explosive soot line segment 84 is smaller than the characteristic internal cross-sectional area (eg, average, median, mode, etc.) of the downstream portions 60, 62 of the combustion line (line axis / centerline of the line) Characteristic internal cross-sectional area (crossing 500). In an exemplary embodiment that includes a circular cross-section conduit segment, the pre-explosion cross-sectional area is characterized by a diameter of 8-12 cm and the downstream portion is characterized by a diameter of 20-40 cm. Thus, an exemplary cross-sectional area ratio of the downstream portion to the pre-detonation segment is 1: 1 to 10: 1, more narrowly 2: 1 to 10: 1. The total length L between the end portions 28 and 30 can be 1 to 15 m, and more narrowly 5 to 15 m. In the exemplary embodiment, transition line segment 86 extends between pre-detonation segment 84 and most upstream segment 60. Segment 86 has upstream and downstream flanges that are sized to mate with the corresponding flanges of segments 84, 60 and has an interior surface that provides a smooth transition between the internal cross-sections of these segments 84, 60. Exemplary segment 86 has a length L _4. An exemplary spread half angle of the inner surface of the segment 86 is ≦ 12 °, more narrowly 5-10 °.

  The fuel / oxidant charge can be introduced into the detonation line in various ways. There may be one or more different fuel / oxidant mixtures. Such a mixture can be premixed outside the detonation line or mixed during or after introduction into the line. FIG. 3 shows segments 84 and 86 configured to separately charge two different fuel / oxidizer formulations, a pre-detonation formulation and a main formulation. In the exemplary embodiment, in the upstream portion of the segment 84, a pair of pre-explosive fuel injection lines 90 are connected to a port 92 provided in the segment wall that defines the fuel injection port. Similarly, a pair of pre-explosive oxidant lines 94 are connected to the oxidant inlet port 96. In the exemplary embodiment, these ports are provided in the upstream half of the length of segment 84. In the exemplary embodiment, each fuel injection port 92 is paired with an associated oxidant port 96, at the same axial position as the associated oxidant port, and opposed injection mixes of fuel and oxidant. (Provided by way of example as 90 °, but other angles including 180 ° are possible). As will be described in more detail below, a purge gas line 98 is connected to the purge gas port 100 located further upstream. An end plate 102 bolted to the upstream flange of the segment 84 seals the upstream end of the combustion line and has an operative end 108 inside the segment 84 (such as a spark plug). Passes through the end plate 102.

  In the exemplary embodiment, main fuel and main oxidant are input to segment 86. In the illustrated embodiment, main fuel is carried by several main fuel lines 112 and main oxidant is carried by several main oxidant lines 110. Each main oxidant line 110 has a termination that concentrically surrounds the associated fuel line 112 so that main fuel and main oxidant are mixed at the associated inlet 114. In the exemplary embodiment, the fuel is a variety of hydrocarbons. In a particular exemplary embodiment, both fuels are the same and are drawn from the same fuel source, but with different oxidizers or substantially pure oxygen for a pre-detonation mixture and air for the main mixture, respectively. Mixed. An exemplary fuel useful in this case is propane, MAPP gas, or a mixture thereof. Other fuels including ethylene and liquid fuels (such as diesel oil, kerosene, and jet flight fuel) can also be used. The oxidant may comprise a mixture, such as an air / oxygen mixture in a ratio suitable to obtain the desired main detonation and / or pre-detonation charge chemistry. In addition, a monopropellant fuel having a molecularly combined fuel and an oxidant component may be an option.

  In operation, the combustion line is emptied with the exception of air (or other purge gas) at the beginning of the use cycle. Next, pre-detonation fuel and pre-depletion oxidant are injected via the associated ports, filling segment 84 and partially extending into segment 86 (eg, near midpoint), advantageously Spreads just beyond the fuel / oxidant port. Subsequently, the flow of pre-explosive fuel and pre-explosive oxidant is stopped. An exemplary volume that is filled by the pre-detonation fuel and pre-detonation oxidant is 1-40% of the volume of the combustion line, more narrowly 1-20%. Next, the main fuel and the main oxidant are charged so as to substantially fill a part (for example, 20 to 100%) of the remaining volume of the combustion line. Subsequently, the flow of main fuel and main oxidant is stopped. Pre-loading the pre-explosive fuel and pre-explosive oxidant across the main fuel / oxidant port may result in the formation of air or other non-combustible slag between the pre-explosive charge and the main charge Almost disappears. Such slag can interfere with the movement of the combustion surface between the two charges.

  With the charge applied, the ignition box is activated to provide a spark discharge for the igniter and a pre-detonation charge is ignited. The pre-detonation charge is selected such that the combustion has a very fast chemistry, and the initial deflagration rapidly changes to detonation within segment 84 to generate detonation waves. When such detonation waves occur, they effectively pass through the main charge, which may have a sufficiently slow chemistry in the pipeline to not detonate itself. The detonation wave travels longitudinally downstream and emerges from the downstream end 30 as a shock wave inside the furnace, typically impinging on the surface to be cleaned so as to at least loosen contamination (contaminants), Give mechanical shock. Following the detonation wave, pressurized combustion products are released from the detonation line, and the released products emerge from the downstream end 30 as a jet (such as by removal of loose material) cleaning process. Finish further. After or simultaneously with the release of such combustion products, a purge gas (eg, air from the same source supplying the main oxidant and / or nitrogen) is introduced through the purge port 100 and finally The pre-detonation line is filled with purge gas in preparation for repeating the cycle (with immediate or next regular or irregular intervals, according to manual or automatic decisions by the control and monitoring device) as well as expelling fresh combustion products. Also, the basic flow of purge gas can be maintained between fill / discharge cycles to prevent gas and particles from entering upstream from inside the furnace and to assist in cooling the detonation line. .

  In various embodiments, the internal surface reinforcement may substantially increase the internal surface area beyond the internal surface area of the substantially cylindrical and frustoconical segments. Such an enhancement may be effective in sustaining a change from deflagration to detonation or detonation waves. FIG. 4 shows an inner surface reinforcing portion provided inside one main segment 60. An exemplary reinforcement is substantially a chin spiral, but other reinforcements such as a Schelkin spiral or a Smirnov cavity can also be used. This spiral is constituted by a spiral member 120. The exemplary member 120 is formed as a metallic element having a circular cross section with a diameter of about 8-20 mm. Other cross sections may be used. The exemplary member 120 is held apart from the interior surface of the segment by a plurality of longitudinal elements 122. This exemplary longitudinal element 122 is a rod of cross-section and material similar to member 120 and is welded to the inner surface of member 120 and associated segment 60. Such enhancements can be utilized to provide pre-detonation instead of or in addition to the techniques described above for different charges and different combustor cross-sectional areas.

  The apparatus of the present invention can be used in a wide range of applications. For example, in a typical coal-fired furnace, the apparatus of the present invention comprises a pendant or secondary superheater, a convection flow path (temporary superheater and economizer bundle), an air preheater, a selective catalyst remover (SCR) scrubber, a bug It can be applied to houses or electrostatic precipitators, economizer hoppers, ash or other thermal deposits on heat transfer surfaces or other surfaces. The applicability of the present invention also exists in other applications such as oil burning furnaces, black liquor recovery boilers, biomass boilers, waste recycling burners (garbage burners).

  FIG. 6 shows an exemplary trolley 72 and track device 74 in more detail. The exemplary track device includes a pair of parallel right-angle channel elements 140 with apexes (eg, steel) located above the mounting plate 142, such as by welding. The mounting plate is fixed to the floor 76 by bolts (not shown) provided in the bolt holes 144. The exemplary trolley includes a structural frame 150 having a pair of left and right longitudinal members 152 and front and rear transverse members 154. Wheels 156 are attached to the hanging bracket 158 on the left and right sides of each transverse member. The perimeter of the wheel has a recess (such as a right-angled V-shaped groove 160) and accepts the apex of the right-angle channel element 140. The exemplary trolley has means for supporting the associated conduit segment and means for securing the segment in place. Exemplary support means includes a pair of front and rear conduit / tube fasteners 170 that are respectively disposed and supported by nuts 172 on left and right threaded shafts 174 secured to the frame at the lower ends. Has been. Fastener 170 has a concave surface 176 that is complementary to the body outer surface of the associated conduit segment to support the segment from below. The securing means includes similar top brackets 180 that are also attached to the shaft 174 and are held downwards in place so as to be in compression engagement with the segments by nuts 182.

  There are several options for using the trolley. The individual segments can be pre-assembled into the associated trolley and rolled along the track device to a predetermined position, where the segments can be secured together via end flanges. Degradation may reverse this process. The combustion line may be moved as a unit by trolley (if it is not desirable to always insert the downstream part of the line into the furnace). In addition, as described above, movement associated with longitudinal thermal expansion and / or recoil during the discharge cycle can be absorbed as a unit while maintaining alignment of the line segments.

  FIG. 7 shows another apparatus 200 in which the combustion line 202 is suspended by a bracket 204 (eg, provided as part of a separate support structure or secured to the ceiling or roof 206 of the facility). Yes. Such a device may be particularly useful when the conduit 202 is located high on the facility floor. The exemplary apparatus 200 guides a conduit 202 around environmental obstacles outside the furnace. Exemplary obstacles include upper and lower tube bundles 210, 212 between which the conduit passes. In the exemplary embodiment, a conduit is provided to bypass the tube bundle so that the outlet 214 can be located at a location on the furnace wall corresponding to one of the two tube bundles. In such a situation, the straight line is obstructed by the bundle. Therefore, one or a plurality of curved portions 216 are provided in the pipe line corresponding to the tube bundle.

  An exemplary support device includes upstream and intermediate spring hangers 220, 222 connected from upstream to downstream by turnbuckle devices 224, 226 to associated line segments. Exemplary spring hangers are available from LISEGA, Inc., Newport, Tennessee. In the exemplary embodiment, spring hanger 222 may have a substantially higher allowable load due to the relatively high static load at that location. The particular combination of hanger sizing is along the pipeline, taking into account the mass parameters (such as the center of gravity and mass distribution) of the pipeline, the strength parameters (such as various factors) of the pipeline, and additional support positions. Can be affected by the relative position of the hangers. The exemplary spring hanger functions as a substantially constant load hanger and has a substantially constant support tension over a range of operation. One function of the vertical compliance provided by the hanger is to accommodate vertical position changes related to the heat of the outlet 214 relative to the ceiling surface 206 or other combustion line support structure. For example, thermal expansion of the furnace wall can change the vertical position of the outlet in hot and cold conditions of the furnace (such as during operation and shutdown). In the embodiment of FIG. 2, an unsecured vertical connection between the conduit and the wall provides sufficient vertical play to the conduit within the excessive wall opening to accommodate such expansion. is doing. However, when the connecting part is fixed, if the constant load hanger is not provided, the larger part of the mass of the pipe will be the wall of the furnace when the height of the pipe outlet is raised by the heat of the furnace. And a smaller part is placed on the upstream support part. This leads to shear force / bending force / moment and associated deformation. However, spring hangers tend to shrink and do not raise the attached segment to substantially increase the mass supported on the furnace wall, and in conjunction with increasing outlet height. Reduce / prevent at least some, preferably most, of the stresses that may occur. Accordingly, these hangers maintain the direction of the conduit substantially constant (eg, the main portion upstream of the conduit in a substantially horizontal direction).

  In the exemplary embodiment, a support structure 240 external to the combustion line further reinforces the associated segments combined. Such reinforcement advantageously addresses structural stresses associated with impact reflection occurring within the curved segment. In the illustrated embodiment, the structure further secures the downstream portion of the conduit to the furnace wall. In the exemplary embodiment, turnbuckle 226 is connected to fixture 242 by its lower threaded rod, and fixture 242 is secured to the upstream end of the support structure and is generated by the combustion process. It has a snubber 244 that attenuates it in response to possible lateral movement. In an exemplary embodiment, the fixed connection of the support structure to the furnace wall absorbs reaction forces and substantially prevents reaction. As long as the longitudinal thermal expansion of the conduit is an issue, the hanger with the associated conduit engaging fixture located at the bottom (e.g., relative to the coupling location 246 and the coupling point 248 to the bracket 204 located at the top). ) Such expansion can be dealt with by providing it rotatably. In other embodiments, the fixed connection of the conduit to the wall can be eliminated and an elastic or damped connection can be provided.

  While one or more embodiments of the invention have been described, various changes can be made without departing from the spirit and scope of the invention. For example, the present invention can be provided for use with various industrial equipment and various sootblower technologies. The form of a particular embodiment can be influenced by the form of existing equipment and technology. Accordingly, other embodiments are within the scope of the claims.

FIG. 3 is a perspective view of an industrial furnace provided in association with a plurality of soot blowers arranged for furnace cleaning. FIG. 2 is a side view of one soot blower of FIG. 1. It is a partial notch side view of the upstream edge part of the soot blower of FIG. FIG. 3 is a longitudinal sectional view of a main combustion segment of the soot blower of FIG. 2. FIG. 5 is an end view of the segment of FIG. 4. FIG. 2 is a perspective view of a conduit segment support trolley of the apparatus of FIG. It is a side view of another combustion pipeline.

Explanation of symbols

DESCRIPTION OF SYMBOLS 22 ... Soot blower 24 ... Furnace wall 26 ... Combustion line 28 ... Upstream distal end 30 ... Downstream proximal end 60 ... Pipe line segment 62 ... Downstream nozzle line segment 64 ... Downstream part 66 ... Wall opening Portion 68 ... Inside of furnace 70 ... Tube bundle 72 ... Trolley 74 ... Track device 76 ... Facility floor 80 ... Reaction strap 82 ... Metal coil reaction spring 84 ... Pre-explosion segment 86 ... Transition pipeline segment 500 ... Center of pipeline line

Claims (11)

A device for cleaning the inner surface of a container,
An elongate combustion line extending from an upstream end to a downstream end associated with an opening in the vessel wall and arranged to direct a shock wave toward the surface;
A plurality of wheeled movable supports that support the weight of the combustion line at a plurality of positions along the length of the combustion line;
A track that supports the wheels of the movable support;
An apparatus for cleaning an inner surface of a container, comprising: an elastic member that connects the combustion pipe to the wall and elastically restrains the combustion pipe against reaction force.   2. The container inner surface cleaning apparatus according to claim 1, wherein the elastic member includes a metal coil spring.   2. The container inner surface cleaning apparatus according to claim 1, wherein the elastic member includes a tension spring. Wherein the plurality of supports, said combustion conduit expansion and / or the internal surface cleaning apparatus container according to claim 1, characterized in that it corresponds to the shrinkage in the longitudinal direction of. Wherein the plurality of support internal surface cleaning device of a container according to claim 1, characterized in that it comprises a plurality of trolleys with wheels to track and engage on the support surface, respectively. The combustion line includes a plurality of separable segments;
6. The container inner surface cleaning apparatus according to claim 5 , wherein each of the segments is supported on one associated trolley among the plurality of trolleys. A method for cleaning an inner surface of a container that is part of an industrial facility and includes a wall having an opening,
Put fuel and oxidizer into the pipeline,
The reaction of the fuel and oxidant is initiated to generate a shock wave that collides with the surface, and the reaction force applied to the conduit is elastically absorbed by an elastic member connecting the conduit to the wall. , an inner surface of the container movement of the conduit is absorbed by movement along the track of the wheel with the supporting member for supporting the pipe line at a plurality of locations along the length of the conduit, characterized in Rukoto Cleaning method. 8. The method of cleaning an inner surface of a container according to claim 7 , wherein the elastic member accumulates reaction energy when the pipe moves from the initial position to the reaction position, and returns the pipe to the initial position. . 9. The method of cleaning an inner surface of a container according to claim 8 , wherein the movement is at least 0.01 m. The method for cleaning an inner surface of a container according to claim 7 , further comprising moving the pipe as a unit along a support mechanism to separate the downstream end of the pipe from the container. The apparatus for cleaning an inner surface of a container according to claim 1, wherein the elastic member includes a rubber tension element.

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