CA2184776A1 - Chevron mist eliminator wash apparatus, and method and system employing the apparatus - Google Patents
Chevron mist eliminator wash apparatus, and method and system employing the apparatusInfo
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- CA2184776A1 CA2184776A1 CA 2184776 CA2184776A CA2184776A1 CA 2184776 A1 CA2184776 A1 CA 2184776A1 CA 2184776 CA2184776 CA 2184776 CA 2184776 A CA2184776 A CA 2184776A CA 2184776 A1 CA2184776 A1 CA 2184776A1
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- mist eliminator
- stream
- wash
- wash water
- downstream
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Abstract
The invention relates to a mist eliminator wash system, typically with chevron-type blades, employed with a horizontally flowing gas stream, and to an improved method of washing the mist eliminator, and to a mist eliminator system employing the mist eliminator and washing method. A bladed, chevron-type mist eliminator apparatus removes or reduces said entrained liquid and particles from the gas stream; wash streams upstream of the blades providing wash water to remove solids from the upstream portions of the chevron blade surfaces, the wash water initially flowing co-current with the horizontal flow path of the gas stream; and wash streams downstream of the blades directing wash water countercurrent to the gas stream flow, to remove solids from the downstream portions of the chevron blades. The method of the invention includes directing a plurality of concentrated wash streams from concentrated wash nozzles to provide flat wash streams against the downstream end of the mist eliminator, the streams in a non-overlapping arrangement, to remove solids from the downstream portions of the chevron blades, and reducing the entrainment of such wash liquid in the clean gas. The flat stream nozzles may be arranged to move vertically and also to arcuately rotate to cover selected areas of the downstream blade surfaces, which action of the stream nozzles may be used alone, in combination, or sequentially as desired.
Description
2t8~77~
~ . . .
Chevron Mist Eliminator Wash Apparatus, and Method and Sy~tem Employing th~ Apparatus De3cription Reference to Prior Applications 6 This application is based on and claims the benefit of the filing dates of provisional patent applications U.S. S.N.
60/003,192, filed September 5, 1995, and U.S. S.N. 60/003,681, filed September 11, 1995, both hereby incorporated by reference.
Background of the Invention Chevron-type mist eliminators comprise a plurality of generally spaced-apart, usually uniformly arranged chevron blades, and are employed to remove entrained liquid and mist from a gas stream. Such mist eliminator6 may be employed with vertical flow gas streams or with horizontal flow gas streams. Quite often, with ~5 chevron-type mist eliminators, horizontal flow is preferred, since there is less likelihood that the liquid in the gas streams would be re-entrained when the collected liquid falls from the chevron-type mist eliminator, while in the vertical flow mist eliminators, the collected liquid flows downwardly into the upwardly flowing gas stream. While some of the following comments may also apply to vertical flow arrangements, this application is specific to horizontal f low arrangements where the long dimension of the chevron blades is vertical.
Mist eliminators are often employed with horizontally flowing acid-c~nt~nin~ gases, particularly acid-containing gases derived from a furnace or other type chemical operation, wherein the -... . ~ 2184776 .
emitted gas would contain, in particular, oxides of sulfur, sueh as sulfur dioxide. Acid-containing gas streams usually must have the acid gases removed, and such gases are typically removed by treating, e.g. spraying, or otherwise eontaeting, the aeid-S r~lnte~in;n~ gas stream with a reactant liquid or slurry, sueh as analkaline earth salt-water slurry, which is used to eontaet the aeid-containing gas stream, and to cause the reaction of the reaetant with the acid gases, thereby reducing substantially the amount of acid gas in the gas stream and providing an aeid-alkali lO reaction product. The reactant slurry, sueh as a ealeium-salt water slurry, is then, after the reaetion, removed, while a gas stream, with the reduced acid gas content, and containing some entrained water, and often minor amounts of solid slurry-reaetion partieles, e.g. calcium sulfate, is then sent to a chevron-type l5 horizontal mist eliminator, to remove the entrained slurry liquid and the solid particles entrained with the liquid.
Solid particles from the slurry in the gas stream tend to build up on the blades of the chevron-type mist eliminator. Wash systems located upstream and/or downstream of the mist eliminator 2C have been devised to wash with water the chevron-type blade surfaces, to remove the buildup of solid slurry particles thereon, and to remove the particles, with the wash liquid, to a sump. The liquid from the wash stream then drains downwardly from the sùrfaces of the chevron blades into the sump. The horizontal flow-25 type mist eliminator reduces the problems concerning re-entrainment of the liquid wash water into the gas stream in comparison to a -` 218~776 vertical mist eliminator, however 60me liquid wash water is i.n fact entrained in the horizontally flowing gas stream. Despite the washing process, however, often some solids build up on the chevron blades, and periodic mechanical or chemical cléaning is still 6 re~uired. Periodically, the operation must be stopped and the chevron blades physically or chemically cleaned to remove the solid particles .
Generally, the wash nozzles used are a plurality of wash nozzles, in which the wash nozzles are disposed to spray generally between, e.g., intermediate the chevron-type blades, and to spray each opposing surface of the blades. The wash nozzles are arranged to be operated intermittently in a desired sequence during the - washing process. At any one time only a small portion of the mist eliminator is being washed. The wash nozzles are generally ~5 disposed toward the upstream end of the mist eliminator and toward the downstream end of the mist eliminator. The upstream end wash nozzles spray a wash liquor between the blades co-current with the horizontal flow of the gas stream. The downstream end wash nozzles spray wash water at the downstream end of the mist eliminator, i.e., spray the wash water countercurrent to, or into the generally horizontally flowing gas stream. The wash nozzles generally are placed 80 that the wash water will spray against all surfaces of the chevron blades, and the accumulated liquid with the collected solid reactant particles i8 directed into the sump.
26 In current practice, the spray nozzles are arranged both on the upstream end and downstream end, and are employed so as to -218477~
cover and overlap the entire exposed surface area of the upstream end and downstream end surfaces of the mist elimlnator. The nozzles generally comprise what is known as a full cone nozzle, i.e., provide a full conical spray pattern. The full cone nozzles 6 are 80 spaced as to cover all or substantially all of the entire area of that part of the chevron mist eliminator at which they are directed, and generally provide overlapping coverage, and generally are operated intermittently in a timed, controlled manner, 80 that a fraction of the spray nozzles are in operation at any one time.
Horizontal flow mi6t eliminators, because the captured liquid falls away from the gas stream rather than back through it, as in a vertical flow mist eliminator, can be operated at substantially higher velocities than vertical flow units, for example, velocities up to and exceeding 18-20 ft/sec. New high performance chevron ~5 mist eliminators will be permitting even higher velocities. This has created a problem with the use of traditional wash systems.
The high horizontal velocity makes the downstream wash difficult because the wash water must flow against the gas stream.
Increa~ingly, users are finding that the need to shut down to clean 20 mechanically the downstream portions of chevron bladeg ig bec 'n~
an operational and economic burden. Traditional systems employing full cone sprays are not proving totally adequate to meet the needs of horizontal flow chevron mist eliminators, more 80 than ever ~ecause of the willingness of operators to push all equipment to qS their limits. New high performance mist ~1 ~m~n~tors will exacerbate the situation.
. . 2184776 .
It is desirable to provide for a new and improved mist eliminator-wash apparatus, and for a method and system employing the wash apparatus, which apparatu6, method and system provides improved wash efficiency and efficient removal of solid particles 5 from the blade surfaces.
Su~ary of the Invention The invention relates to a mist eliminator wash system, typically including a mist eliminator with chevron-type blades employed with a horizontally flowing gas stream, and to an improved lO method of washing the mist eliminator, and to a mist ~1 ~m~n~tor system employing the mist eliminator and the washing method.
The invention comprises a bladed, generally a chevron-type mist eliminator and associated wash apparatus, for use with horizontal flow gas streams, and which apparatus comprises a 5 plurality of spaced-apart blades, e.g. chevron-type blades, having an upstream end and a downstream end, the blades arranged to be placed in the horizontal flow path of a gas stream, having entrained liquid and solid particles therein and arranged and constructed to remove or reduce said entrained liquid and particles 20 from the gas stream. An upstream wash means upstream of the blades is arranged and constructed to direct wash water to remove solids, against the upstream end of the mist eliminator, and directs the wash water generally co-current with the horizontal flow path of the gas stream. ~ downstream wash means at the down~tream end of 25 the mist eliminator is arranged and constructed to direct wash water countercurrent to the gas stream flow, and to remove or -.
reduce 801 ids .
The downstream wash means employs a plurality of nozzles, each of which emits a concentrated non-spray, generally flat, wash stream to provide a forceful wash stream against the downstream end S of the mist eliminator, generally in a non-overlapping aLLa~ly --t and countercurrent to the horizontal flow path of the gas stream, thereby removing solids accumulated on the downstream portions of chevron blades and reducing the entrainment of wash water into the gas stream from the mist eliminator. The downstream wash means has lO nozzles to provide a non-conical, fan-like horizontal line of wash li~uid, rather than a cone spray pattern against the downstream end of the mist eliminator.
- The method of the invention comprises directing, in place of the downstream prior art conical spray nozzles, a plurality of l6 concentrated wash streams from concentrated wash nozzles to provide f lat wash streams against the downstream end of the mist eliminator, the streams in a non-overlapping arrangement to remove solid particles from the downstream portion of the chevron blades and reducing the entrainment of such concentrated wash li~uid in 20 the clean gas.
The method of the invention comprises a combination of wash 3treams, conical and non-conical, for the feed gas stream. The method of the invention further includes directing the wash water from the upstream end in a conical spray, generally between 25 opposing, spaced-apart surfaces of the mist eliminator blades, and also directing a concentrated flat, non-conical wash stream onto --21~477~
.
the opposing surfaces at the downstream end. The method additionally includes controlling the sequence and timing of the conical and flat wash water injections.
The invention comprises a replacement of all or most of the 5 full cone spray nozzles of the downstream part of the wash system, and employing flat or concentrated, defined, stream nozzles, which generate a thin, concentrated, water wash stream, rather than a conical spray wash stream, which flat stream is directed in a stream countercurrent to the gas flow, and directed to the selected lO areas of the exposed surfaces of the chevron blades to ef fect washing. The liquid stream does not have to cover the entire surface of the blade surface to be washed, rather the concentrated - stream is relied on to dislodge particles from the surface and to form a concentrated, downwardly flowing wash stream on the blade l5 surface, which concentrated descending liquid wash stream dislodges solid particles on the blade surface and cleans the surface, and this increases the ef f iciency of the wash method and extends the time between shutdown for cleaning of the blade surfaces.
It has been found that the employment of concentrated stream 20 noz21es, and the use of a concentrated flat non-droplet liquid stream of the wash water provides, surprisingly and unexpectedly, for an efficient removal of particle buildup and has other advantages; for example, the concentrated stream does not encourage the pickup or entrainment of the wash water in the horizontal flow 25 gas stream, as would the use of a full conical spray made up of spray droplets, where much of the downstream wash liquid would be - ~ - ` 218g775 picked up and re-entrained in the horizontal gas stream before it went into the mi6t eliminator to be washed, which, in addition to reducing washing capability, may also necessitate the use of an additional mist eliminator. Further, the use of a concentrated 6 stream provides more direct power in the selected area for the dislodgement of adhering solid particles, with the liquid striking a solid blade surface area, and a lot more liquid wash water is provided to a smaller blade surface area. Also, the concentrated wash water stream more easily penetrates the counteL~uLL~ntly lO flowing horizontal gas stream.
A wide variety of chevron-type or bladed mist eliminators may be used, wherein the blades become encrusted with particles of debris from a gas stream, and may be employed in conjunction with the wash system of the invention. One type of a prior art 15 vertical-flow chevron-type mist eliminator is shown, for example, in USP4,601,731, issued July 22, 1986. For example, a mist eliminator may have a plurality of uniformly spaced-apart chevron blade about 12" deep and about 6 to 8 feet in length. While a concentrated stream may also be employed on the upstream end of the 20 chevron miat eliminator, this is not required and not necessarily preferred, thus it i8 desirable, where both upstream and downstream wash water is used, to maintain the present operation of using full cone, overlapping spray nozzles on the upstream chevron blade surfaces, while employing the concentrated stream nozzles with the 25 concentrated liquid stream in a non-overlapping aLLal~y~ - t against the downstream chevron blades.
-21~77 .
The prior art method comprises directing such water in conical sprays from full cone wash nozzles against the surfaces of the upstream ends of the chevron blades and the downstream ends, to provide the washing of 6ubstantially all of the surface~ of the 6 chevron blades to remove solid particles adhering to the chevron - blades, and directing entrained liquid, wash water and washed off solid particles to a sump; and removing from the mist eliminator and di6charging a clean gas.
One key to successful washing of a horizontal flow chevron lO mist eliminator is getting wash water to all parts of the chevron, that is, to all or substantially all surfaces of each blade. Water enters from the front, or upstream end, and from the back, or - downstream end. Recent work has shown that an important action is the flushing action; there is value to impingement, but it is not l6 the only action. The full cone spray is effective when it does not have to move against an opposing gas stream; it provide6 relatively uniform coverage, and flushes well with some impingement. To date, this method has been considered the best for all washing applications of this type. The flat spray of this invention does 20 not provide a uniform initial distribution, and it was previously held that such poor initial distribution would result in poor washing. This, however, has not proven to true.
In the high velocity environments of today' 8 horizontal flow chevron mist eliminators, ~or downstream washing the high 26 penetration of the flat spray is proving to be more important and efficient than the uniform initial coverage provided by the full -. . . 218477 .
cone spray. For downstream washing, the flushing action of the descending water, if provided with adequate penetration into the body of the mist eliminator against the gas flow, approaches the cleaning efficiency of upstream washing. For most current needs, 5 downstream washing with appropriate fixed position flat sprays should prove very satisfactory, particularly in high wash liquor velocity wash systems. For~ especially difficult services, some washing enhancement can be provided by providing moveable f lat spray nozzles. This will permit greater uniformity of delivery of ~0 wash water to the chevron blade surfaces. The need for moveability must be balanced against its initial cost and the increased maintenance required.
In another embodiment of the invention, the flat concentrated downstream nozzles are made moveable to deliver wash water against 15 a greater selected area of the downstream end of the mist eliminator and against the high velocity gas stream. In one embodiment, the flat stream nozzles, in groups, may be vertically moved, i.e., up and down adjacent the downstream end of the mist eliminator to deliver the wash stream to a grèater selected blade 20 surface area to promote washing efficiency. For example, the flat spray nozzles may be positioned on an H-type ladder, with the spray nozzles on the cross bars, and the legs moveable vertically to deliver the wash stream up and down the downstream blade surfaces.
In another embodiment, the f lat spray nozzles may be rotated a 25 selected angle ; e . g ., 3 0 to 6 0 degrees , to provide the f lat wash spray against the downstream end of the mist eliminator.
` - . 218~776 .
In a further embodiment, the flat spray nozzle may rotate in a selected arc, and, in addition or separately, also move vertically to provide a vertically and rotatably moveable multiplicity of flat concentrated sprays of wash water against the 5 entire or substantially entire surface area of the downstream end of the mist eliminator.
Thus, the movement of one or more of the flat spray nozzles in various directions provides concentrated wash water over a greater selected spray surface area of the downstream end of the blades to ~0 improve wash efficiency.
After the processing of the gas stream through the wash system and the horizontal flow mist eliminator, the gas stream, representing a clean gas stream, is then directed to a stack and discharged, or if desired, may be subjected to other processing or 16 treatment, for example, the use of another mist eliminator to remove any additional water as required.
The invention will be described for the purposes of illustration only in connection with a preferred embodiment;
however, it is recognized that various changes, corrections, 20 additions, modifications and i ~ c,v~ -nts may be made to the illustrated embodiments by persons 3killed in the art, all falling within the spirit and ~cope of the invention.
Brief Description of the Dr~wings Fig. l is a schematic illustration of the mist eliminator 25 system of the invention in a side elevational view.
Fig. 2 is a schematic illustration of the mist eliminator -. - . 218~776 .
system shown in Fig. 1 in a top plan view.
Fig. 3 is a schematic illustration of another . ' -';.~nt of the mist eliminator system of the invention in a side elevational view .
s Flg. 4 is a schematic perspective illustration of the embodiment of Fig. 3 illustrating vertically moving wash nozzles.
Flg. 5 is a schematic perspective illustration of another embodiment of the mist eliminator illustrating a rotatable wash nozzle .
I0 Flg. 6 is a schematic perspective illustration of the embodiment of the mist eliminator of Fig. 5 illustrating a rotatable wash nozzle in a multiple, H-type ladder configuration.
Description of the r o~- t~
Flg. 1 is a schematic illustration of the mist eliminator S system including the invention 10 in a side elevational view. As shown, fuel 12, e.g. coal or a fluid hydrocarbon, enters a furnace 14, which produces an acid-containing exhaust gas 16 to be processed, e.g., a gas containing oxides of sulfur. The acid-containing gas 16 is reacted with an alkalinè salt-water slurry liquid 18, such as a limestone water slurry, and the reacted liquid slurry 20 is removed. The reacted gas with entrained liquid 22, said liquid having solids dissolved therein and/or carrying particulate solids, then passes to the chevron-type mist eliminator 26. The chevron-type mist eliminator 26 is shown having full cone 2s wash nozzles 24 upstream of the inlet end 27 and the flat c~nc-~n~rated stream wash nozzles 30 at the downstream of the outlet -end 29 of the mist eliminator. A wash control means 28, to control the timing and sequence of the spray nozzles 24 and 30, i8 6hown above the mist eliminator 26, and a sump 32 for collected liquid and particles is shown below. The clean gas 34 is then removed S from the chevron-type mist eliminator 26 and directed to a stack 36 for discharge.
F$g. 2 illustrates schematically a portion of the system of Fig. 1, that is, the mist eliminator wash apparatus of the invention, in a top plan view 40. As seen from above, the full 10 cone wash nozzles 24 provide a wash water on the upstream end 27 of the blades in a conical spray 44, while the flat stream wash nozzles 30 provide a flat, concentrated spray arc 42 directed toward the downstream end 29 of the blades.
Fig~. 3 and 4 illustrate another embodiment of the invention 15 50, wherein the flat concentrated downstream nozzles 58 are made moveable to deliver wash water 56 against a greater selected area of the downstream blade surface 29. Fig. 3 shows a side elevational view of a single wash nozzle pipe configuration 57, and as shown by arrows, the flat stream nozzles 5B may be vertically 20 moved, i.e., up and down, adjacent the downstream ends of the blades 29 to deliver the wash stream 56 to a greater selected blade surface area to promote washing efficiency. Fig. 4 shows the flat spray nozzles 58 positioned on an H-type ladder 48, with the spray nozzles 58 on the cross bars 46, and the legs 45 moveable 25 vertically to deliver the wash stream 56 up and down the downstream end of the mist eliminator 29. Other structural c~ ents are 1~
. . 21~477~
.
numbered and unction as described in Fig. 1.
In another embodiment of the mist eliminator of the invention 60 shown in Figs. 5 and 6, the flat spray nozzle 62 may be rotated a selected angle, e.g., 30 to 60 degrees, to provide the flat wash 5 apray 64 against the downstream end of the blades 29. Fig. 5 shows one pipe 68 with the wash water 65 entering the pipe at one end, and the pipe rotating i 30 to rotat~e the flat spray nozzles 62 to provide wash water 64 to directly wash a wider area of the downstream blades 29. In Fig. 6, multiple flat spray nozzles 62, ~0 positioned on a series of pipes 68 in the H-type ladder of Flg. 4, rotate in a selected arc of i30. In addition or separately, the pipes 68 also may move vertically, to provide a vertically and rotatably moveable multiplicity of flat spray nozzlea 62 to provide flat concentrated sprays of wash water 64 against the entire or 15 substantially entire surface area of the downstream end of the mist el iminator 2 9 .
The invention thus comprises an improvement in the removal of acid gases from an acid gas-containing feed gas stream, and also has advantages for use with other mist eliminators, where gas 20 streams tend to build up particles on the blades of the mist eliminator. The invention also is directed to a chevron mist eliminator and wash apparatus for use with the horizontal f low gas stream, particularly an acid gas-containing stream which haa been treated prior to introduction into the mist eliminator, with a 26 reactant slurry, such as, for example, an alkaline slurry like a lime or limestone, to react with the acid gases.
21~776 The method of the invention provides for removal of acid gases from an acid gas-containing feed gas stream, which method comprises treating the feed gas stream with an alkaline reactant containing liquid slurry to provide a gas stream with reduced amounts of acid 5 gases and entrained liquid and solid particles, and passing the gas stream, with generally horizontal flow, through a blade-type mi8t eliminator comprising a plurality of spaced-apart, generally vertically arranged blades having a front and back end, to provide a clean gas.
~0 The method comprises directing wash water in a conical spray from full cone wash nozzles against the upstream end of the mist eliminator and directing wash water in a flat stream spray from flat wash nozzles against the downstream end, to provide the washing of substantially all of the surfaces of the chevron blades l6 to remove solid particles adhering to the chevron blades, and directing entrained liquid, wash water and washed off solid particles to a sump; and removing from the mist eliminator and discharging a clean gas.
The composition o~ the wash water sprayed from the nozzles may 20 vary as required for the specific cleaning process; however, ~t may be comprised of detergents, surfactants, chelating agents, or acid-alkaline slurries or other combinations thereof. The temperature of the wash water may also vary, for example, from between 500C and 100C, and the pressure of the wash water to the nozzles may be in 26 the range of 15 to 60 psig.
In another embodiment of the invention, the flat concentrated _ . . 2184~76 .
downstream nozzles are made moveable to deliver wash water against a greater selected area of the down6tream surface of the mist eliminator and against the high velocity gas stream. In one t, the flat stream nozzle may be vertically moved, i.e., S up and down adj acent the downstream ends of the blades to deliver the wash stream to a greater and selected blade surface area to promote washing efficiency. For example, the flat spray nozzle may be positioned on an H-type ladder, with the apray nozzle on the cross bars, and the legs moveable vertically to deliver the wash ~0 atream up and down the downstream end of the mist eliminator. In another embodiment, the flat spray nozzle may be rotated a selected angle; e.g., 30 to 60 degrees, to provide the flat wash spray against the downstream ends of the blades.
Thus, the ~ ,v~ - t of one or more of the flat spray nozzles in ~s various directions provides greater concentrated wash water over a selected spray surface area of the downstream end of the blades to improve wash efficiency.
_
~ . . .
Chevron Mist Eliminator Wash Apparatus, and Method and Sy~tem Employing th~ Apparatus De3cription Reference to Prior Applications 6 This application is based on and claims the benefit of the filing dates of provisional patent applications U.S. S.N.
60/003,192, filed September 5, 1995, and U.S. S.N. 60/003,681, filed September 11, 1995, both hereby incorporated by reference.
Background of the Invention Chevron-type mist eliminators comprise a plurality of generally spaced-apart, usually uniformly arranged chevron blades, and are employed to remove entrained liquid and mist from a gas stream. Such mist eliminator6 may be employed with vertical flow gas streams or with horizontal flow gas streams. Quite often, with ~5 chevron-type mist eliminators, horizontal flow is preferred, since there is less likelihood that the liquid in the gas streams would be re-entrained when the collected liquid falls from the chevron-type mist eliminator, while in the vertical flow mist eliminators, the collected liquid flows downwardly into the upwardly flowing gas stream. While some of the following comments may also apply to vertical flow arrangements, this application is specific to horizontal f low arrangements where the long dimension of the chevron blades is vertical.
Mist eliminators are often employed with horizontally flowing acid-c~nt~nin~ gases, particularly acid-containing gases derived from a furnace or other type chemical operation, wherein the -... . ~ 2184776 .
emitted gas would contain, in particular, oxides of sulfur, sueh as sulfur dioxide. Acid-containing gas streams usually must have the acid gases removed, and such gases are typically removed by treating, e.g. spraying, or otherwise eontaeting, the aeid-S r~lnte~in;n~ gas stream with a reactant liquid or slurry, sueh as analkaline earth salt-water slurry, which is used to eontaet the aeid-containing gas stream, and to cause the reaction of the reaetant with the acid gases, thereby reducing substantially the amount of acid gas in the gas stream and providing an aeid-alkali lO reaction product. The reactant slurry, sueh as a ealeium-salt water slurry, is then, after the reaetion, removed, while a gas stream, with the reduced acid gas content, and containing some entrained water, and often minor amounts of solid slurry-reaetion partieles, e.g. calcium sulfate, is then sent to a chevron-type l5 horizontal mist eliminator, to remove the entrained slurry liquid and the solid particles entrained with the liquid.
Solid particles from the slurry in the gas stream tend to build up on the blades of the chevron-type mist eliminator. Wash systems located upstream and/or downstream of the mist eliminator 2C have been devised to wash with water the chevron-type blade surfaces, to remove the buildup of solid slurry particles thereon, and to remove the particles, with the wash liquid, to a sump. The liquid from the wash stream then drains downwardly from the sùrfaces of the chevron blades into the sump. The horizontal flow-25 type mist eliminator reduces the problems concerning re-entrainment of the liquid wash water into the gas stream in comparison to a -` 218~776 vertical mist eliminator, however 60me liquid wash water is i.n fact entrained in the horizontally flowing gas stream. Despite the washing process, however, often some solids build up on the chevron blades, and periodic mechanical or chemical cléaning is still 6 re~uired. Periodically, the operation must be stopped and the chevron blades physically or chemically cleaned to remove the solid particles .
Generally, the wash nozzles used are a plurality of wash nozzles, in which the wash nozzles are disposed to spray generally between, e.g., intermediate the chevron-type blades, and to spray each opposing surface of the blades. The wash nozzles are arranged to be operated intermittently in a desired sequence during the - washing process. At any one time only a small portion of the mist eliminator is being washed. The wash nozzles are generally ~5 disposed toward the upstream end of the mist eliminator and toward the downstream end of the mist eliminator. The upstream end wash nozzles spray a wash liquor between the blades co-current with the horizontal flow of the gas stream. The downstream end wash nozzles spray wash water at the downstream end of the mist eliminator, i.e., spray the wash water countercurrent to, or into the generally horizontally flowing gas stream. The wash nozzles generally are placed 80 that the wash water will spray against all surfaces of the chevron blades, and the accumulated liquid with the collected solid reactant particles i8 directed into the sump.
26 In current practice, the spray nozzles are arranged both on the upstream end and downstream end, and are employed so as to -218477~
cover and overlap the entire exposed surface area of the upstream end and downstream end surfaces of the mist elimlnator. The nozzles generally comprise what is known as a full cone nozzle, i.e., provide a full conical spray pattern. The full cone nozzles 6 are 80 spaced as to cover all or substantially all of the entire area of that part of the chevron mist eliminator at which they are directed, and generally provide overlapping coverage, and generally are operated intermittently in a timed, controlled manner, 80 that a fraction of the spray nozzles are in operation at any one time.
Horizontal flow mi6t eliminators, because the captured liquid falls away from the gas stream rather than back through it, as in a vertical flow mist eliminator, can be operated at substantially higher velocities than vertical flow units, for example, velocities up to and exceeding 18-20 ft/sec. New high performance chevron ~5 mist eliminators will be permitting even higher velocities. This has created a problem with the use of traditional wash systems.
The high horizontal velocity makes the downstream wash difficult because the wash water must flow against the gas stream.
Increa~ingly, users are finding that the need to shut down to clean 20 mechanically the downstream portions of chevron bladeg ig bec 'n~
an operational and economic burden. Traditional systems employing full cone sprays are not proving totally adequate to meet the needs of horizontal flow chevron mist eliminators, more 80 than ever ~ecause of the willingness of operators to push all equipment to qS their limits. New high performance mist ~1 ~m~n~tors will exacerbate the situation.
. . 2184776 .
It is desirable to provide for a new and improved mist eliminator-wash apparatus, and for a method and system employing the wash apparatus, which apparatu6, method and system provides improved wash efficiency and efficient removal of solid particles 5 from the blade surfaces.
Su~ary of the Invention The invention relates to a mist eliminator wash system, typically including a mist eliminator with chevron-type blades employed with a horizontally flowing gas stream, and to an improved lO method of washing the mist eliminator, and to a mist ~1 ~m~n~tor system employing the mist eliminator and the washing method.
The invention comprises a bladed, generally a chevron-type mist eliminator and associated wash apparatus, for use with horizontal flow gas streams, and which apparatus comprises a 5 plurality of spaced-apart blades, e.g. chevron-type blades, having an upstream end and a downstream end, the blades arranged to be placed in the horizontal flow path of a gas stream, having entrained liquid and solid particles therein and arranged and constructed to remove or reduce said entrained liquid and particles 20 from the gas stream. An upstream wash means upstream of the blades is arranged and constructed to direct wash water to remove solids, against the upstream end of the mist eliminator, and directs the wash water generally co-current with the horizontal flow path of the gas stream. ~ downstream wash means at the down~tream end of 25 the mist eliminator is arranged and constructed to direct wash water countercurrent to the gas stream flow, and to remove or -.
reduce 801 ids .
The downstream wash means employs a plurality of nozzles, each of which emits a concentrated non-spray, generally flat, wash stream to provide a forceful wash stream against the downstream end S of the mist eliminator, generally in a non-overlapping aLLa~ly --t and countercurrent to the horizontal flow path of the gas stream, thereby removing solids accumulated on the downstream portions of chevron blades and reducing the entrainment of wash water into the gas stream from the mist eliminator. The downstream wash means has lO nozzles to provide a non-conical, fan-like horizontal line of wash li~uid, rather than a cone spray pattern against the downstream end of the mist eliminator.
- The method of the invention comprises directing, in place of the downstream prior art conical spray nozzles, a plurality of l6 concentrated wash streams from concentrated wash nozzles to provide f lat wash streams against the downstream end of the mist eliminator, the streams in a non-overlapping arrangement to remove solid particles from the downstream portion of the chevron blades and reducing the entrainment of such concentrated wash li~uid in 20 the clean gas.
The method of the invention comprises a combination of wash 3treams, conical and non-conical, for the feed gas stream. The method of the invention further includes directing the wash water from the upstream end in a conical spray, generally between 25 opposing, spaced-apart surfaces of the mist eliminator blades, and also directing a concentrated flat, non-conical wash stream onto --21~477~
.
the opposing surfaces at the downstream end. The method additionally includes controlling the sequence and timing of the conical and flat wash water injections.
The invention comprises a replacement of all or most of the 5 full cone spray nozzles of the downstream part of the wash system, and employing flat or concentrated, defined, stream nozzles, which generate a thin, concentrated, water wash stream, rather than a conical spray wash stream, which flat stream is directed in a stream countercurrent to the gas flow, and directed to the selected lO areas of the exposed surfaces of the chevron blades to ef fect washing. The liquid stream does not have to cover the entire surface of the blade surface to be washed, rather the concentrated - stream is relied on to dislodge particles from the surface and to form a concentrated, downwardly flowing wash stream on the blade l5 surface, which concentrated descending liquid wash stream dislodges solid particles on the blade surface and cleans the surface, and this increases the ef f iciency of the wash method and extends the time between shutdown for cleaning of the blade surfaces.
It has been found that the employment of concentrated stream 20 noz21es, and the use of a concentrated flat non-droplet liquid stream of the wash water provides, surprisingly and unexpectedly, for an efficient removal of particle buildup and has other advantages; for example, the concentrated stream does not encourage the pickup or entrainment of the wash water in the horizontal flow 25 gas stream, as would the use of a full conical spray made up of spray droplets, where much of the downstream wash liquid would be - ~ - ` 218g775 picked up and re-entrained in the horizontal gas stream before it went into the mi6t eliminator to be washed, which, in addition to reducing washing capability, may also necessitate the use of an additional mist eliminator. Further, the use of a concentrated 6 stream provides more direct power in the selected area for the dislodgement of adhering solid particles, with the liquid striking a solid blade surface area, and a lot more liquid wash water is provided to a smaller blade surface area. Also, the concentrated wash water stream more easily penetrates the counteL~uLL~ntly lO flowing horizontal gas stream.
A wide variety of chevron-type or bladed mist eliminators may be used, wherein the blades become encrusted with particles of debris from a gas stream, and may be employed in conjunction with the wash system of the invention. One type of a prior art 15 vertical-flow chevron-type mist eliminator is shown, for example, in USP4,601,731, issued July 22, 1986. For example, a mist eliminator may have a plurality of uniformly spaced-apart chevron blade about 12" deep and about 6 to 8 feet in length. While a concentrated stream may also be employed on the upstream end of the 20 chevron miat eliminator, this is not required and not necessarily preferred, thus it i8 desirable, where both upstream and downstream wash water is used, to maintain the present operation of using full cone, overlapping spray nozzles on the upstream chevron blade surfaces, while employing the concentrated stream nozzles with the 25 concentrated liquid stream in a non-overlapping aLLal~y~ - t against the downstream chevron blades.
-21~77 .
The prior art method comprises directing such water in conical sprays from full cone wash nozzles against the surfaces of the upstream ends of the chevron blades and the downstream ends, to provide the washing of 6ubstantially all of the surface~ of the 6 chevron blades to remove solid particles adhering to the chevron - blades, and directing entrained liquid, wash water and washed off solid particles to a sump; and removing from the mist eliminator and di6charging a clean gas.
One key to successful washing of a horizontal flow chevron lO mist eliminator is getting wash water to all parts of the chevron, that is, to all or substantially all surfaces of each blade. Water enters from the front, or upstream end, and from the back, or - downstream end. Recent work has shown that an important action is the flushing action; there is value to impingement, but it is not l6 the only action. The full cone spray is effective when it does not have to move against an opposing gas stream; it provide6 relatively uniform coverage, and flushes well with some impingement. To date, this method has been considered the best for all washing applications of this type. The flat spray of this invention does 20 not provide a uniform initial distribution, and it was previously held that such poor initial distribution would result in poor washing. This, however, has not proven to true.
In the high velocity environments of today' 8 horizontal flow chevron mist eliminators, ~or downstream washing the high 26 penetration of the flat spray is proving to be more important and efficient than the uniform initial coverage provided by the full -. . . 218477 .
cone spray. For downstream washing, the flushing action of the descending water, if provided with adequate penetration into the body of the mist eliminator against the gas flow, approaches the cleaning efficiency of upstream washing. For most current needs, 5 downstream washing with appropriate fixed position flat sprays should prove very satisfactory, particularly in high wash liquor velocity wash systems. For~ especially difficult services, some washing enhancement can be provided by providing moveable f lat spray nozzles. This will permit greater uniformity of delivery of ~0 wash water to the chevron blade surfaces. The need for moveability must be balanced against its initial cost and the increased maintenance required.
In another embodiment of the invention, the flat concentrated downstream nozzles are made moveable to deliver wash water against 15 a greater selected area of the downstream end of the mist eliminator and against the high velocity gas stream. In one embodiment, the flat stream nozzles, in groups, may be vertically moved, i.e., up and down adjacent the downstream end of the mist eliminator to deliver the wash stream to a grèater selected blade 20 surface area to promote washing efficiency. For example, the flat spray nozzles may be positioned on an H-type ladder, with the spray nozzles on the cross bars, and the legs moveable vertically to deliver the wash stream up and down the downstream blade surfaces.
In another embodiment, the f lat spray nozzles may be rotated a 25 selected angle ; e . g ., 3 0 to 6 0 degrees , to provide the f lat wash spray against the downstream end of the mist eliminator.
` - . 218~776 .
In a further embodiment, the flat spray nozzle may rotate in a selected arc, and, in addition or separately, also move vertically to provide a vertically and rotatably moveable multiplicity of flat concentrated sprays of wash water against the 5 entire or substantially entire surface area of the downstream end of the mist eliminator.
Thus, the movement of one or more of the flat spray nozzles in various directions provides concentrated wash water over a greater selected spray surface area of the downstream end of the blades to ~0 improve wash efficiency.
After the processing of the gas stream through the wash system and the horizontal flow mist eliminator, the gas stream, representing a clean gas stream, is then directed to a stack and discharged, or if desired, may be subjected to other processing or 16 treatment, for example, the use of another mist eliminator to remove any additional water as required.
The invention will be described for the purposes of illustration only in connection with a preferred embodiment;
however, it is recognized that various changes, corrections, 20 additions, modifications and i ~ c,v~ -nts may be made to the illustrated embodiments by persons 3killed in the art, all falling within the spirit and ~cope of the invention.
Brief Description of the Dr~wings Fig. l is a schematic illustration of the mist eliminator 25 system of the invention in a side elevational view.
Fig. 2 is a schematic illustration of the mist eliminator -. - . 218~776 .
system shown in Fig. 1 in a top plan view.
Fig. 3 is a schematic illustration of another . ' -';.~nt of the mist eliminator system of the invention in a side elevational view .
s Flg. 4 is a schematic perspective illustration of the embodiment of Fig. 3 illustrating vertically moving wash nozzles.
Flg. 5 is a schematic perspective illustration of another embodiment of the mist eliminator illustrating a rotatable wash nozzle .
I0 Flg. 6 is a schematic perspective illustration of the embodiment of the mist eliminator of Fig. 5 illustrating a rotatable wash nozzle in a multiple, H-type ladder configuration.
Description of the r o~- t~
Flg. 1 is a schematic illustration of the mist eliminator S system including the invention 10 in a side elevational view. As shown, fuel 12, e.g. coal or a fluid hydrocarbon, enters a furnace 14, which produces an acid-containing exhaust gas 16 to be processed, e.g., a gas containing oxides of sulfur. The acid-containing gas 16 is reacted with an alkalinè salt-water slurry liquid 18, such as a limestone water slurry, and the reacted liquid slurry 20 is removed. The reacted gas with entrained liquid 22, said liquid having solids dissolved therein and/or carrying particulate solids, then passes to the chevron-type mist eliminator 26. The chevron-type mist eliminator 26 is shown having full cone 2s wash nozzles 24 upstream of the inlet end 27 and the flat c~nc-~n~rated stream wash nozzles 30 at the downstream of the outlet -end 29 of the mist eliminator. A wash control means 28, to control the timing and sequence of the spray nozzles 24 and 30, i8 6hown above the mist eliminator 26, and a sump 32 for collected liquid and particles is shown below. The clean gas 34 is then removed S from the chevron-type mist eliminator 26 and directed to a stack 36 for discharge.
F$g. 2 illustrates schematically a portion of the system of Fig. 1, that is, the mist eliminator wash apparatus of the invention, in a top plan view 40. As seen from above, the full 10 cone wash nozzles 24 provide a wash water on the upstream end 27 of the blades in a conical spray 44, while the flat stream wash nozzles 30 provide a flat, concentrated spray arc 42 directed toward the downstream end 29 of the blades.
Fig~. 3 and 4 illustrate another embodiment of the invention 15 50, wherein the flat concentrated downstream nozzles 58 are made moveable to deliver wash water 56 against a greater selected area of the downstream blade surface 29. Fig. 3 shows a side elevational view of a single wash nozzle pipe configuration 57, and as shown by arrows, the flat stream nozzles 5B may be vertically 20 moved, i.e., up and down, adjacent the downstream ends of the blades 29 to deliver the wash stream 56 to a greater selected blade surface area to promote washing efficiency. Fig. 4 shows the flat spray nozzles 58 positioned on an H-type ladder 48, with the spray nozzles 58 on the cross bars 46, and the legs 45 moveable 25 vertically to deliver the wash stream 56 up and down the downstream end of the mist eliminator 29. Other structural c~ ents are 1~
. . 21~477~
.
numbered and unction as described in Fig. 1.
In another embodiment of the mist eliminator of the invention 60 shown in Figs. 5 and 6, the flat spray nozzle 62 may be rotated a selected angle, e.g., 30 to 60 degrees, to provide the flat wash 5 apray 64 against the downstream end of the blades 29. Fig. 5 shows one pipe 68 with the wash water 65 entering the pipe at one end, and the pipe rotating i 30 to rotat~e the flat spray nozzles 62 to provide wash water 64 to directly wash a wider area of the downstream blades 29. In Fig. 6, multiple flat spray nozzles 62, ~0 positioned on a series of pipes 68 in the H-type ladder of Flg. 4, rotate in a selected arc of i30. In addition or separately, the pipes 68 also may move vertically, to provide a vertically and rotatably moveable multiplicity of flat spray nozzlea 62 to provide flat concentrated sprays of wash water 64 against the entire or 15 substantially entire surface area of the downstream end of the mist el iminator 2 9 .
The invention thus comprises an improvement in the removal of acid gases from an acid gas-containing feed gas stream, and also has advantages for use with other mist eliminators, where gas 20 streams tend to build up particles on the blades of the mist eliminator. The invention also is directed to a chevron mist eliminator and wash apparatus for use with the horizontal f low gas stream, particularly an acid gas-containing stream which haa been treated prior to introduction into the mist eliminator, with a 26 reactant slurry, such as, for example, an alkaline slurry like a lime or limestone, to react with the acid gases.
21~776 The method of the invention provides for removal of acid gases from an acid gas-containing feed gas stream, which method comprises treating the feed gas stream with an alkaline reactant containing liquid slurry to provide a gas stream with reduced amounts of acid 5 gases and entrained liquid and solid particles, and passing the gas stream, with generally horizontal flow, through a blade-type mi8t eliminator comprising a plurality of spaced-apart, generally vertically arranged blades having a front and back end, to provide a clean gas.
~0 The method comprises directing wash water in a conical spray from full cone wash nozzles against the upstream end of the mist eliminator and directing wash water in a flat stream spray from flat wash nozzles against the downstream end, to provide the washing of substantially all of the surfaces of the chevron blades l6 to remove solid particles adhering to the chevron blades, and directing entrained liquid, wash water and washed off solid particles to a sump; and removing from the mist eliminator and discharging a clean gas.
The composition o~ the wash water sprayed from the nozzles may 20 vary as required for the specific cleaning process; however, ~t may be comprised of detergents, surfactants, chelating agents, or acid-alkaline slurries or other combinations thereof. The temperature of the wash water may also vary, for example, from between 500C and 100C, and the pressure of the wash water to the nozzles may be in 26 the range of 15 to 60 psig.
In another embodiment of the invention, the flat concentrated _ . . 2184~76 .
downstream nozzles are made moveable to deliver wash water against a greater selected area of the down6tream surface of the mist eliminator and against the high velocity gas stream. In one t, the flat stream nozzle may be vertically moved, i.e., S up and down adj acent the downstream ends of the blades to deliver the wash stream to a greater and selected blade surface area to promote washing efficiency. For example, the flat spray nozzle may be positioned on an H-type ladder, with the apray nozzle on the cross bars, and the legs moveable vertically to deliver the wash ~0 atream up and down the downstream end of the mist eliminator. In another embodiment, the flat spray nozzle may be rotated a selected angle; e.g., 30 to 60 degrees, to provide the flat wash spray against the downstream ends of the blades.
Thus, the ~ ,v~ - t of one or more of the flat spray nozzles in ~s various directions provides greater concentrated wash water over a selected spray surface area of the downstream end of the blades to improve wash efficiency.
_
Claims (29)
- Claim 1. In a method for the removal of solid particles from the surface of the blades of a mist eliminator, the mist eliminator having a plurality of spaced apart blades, the mist eliminator having upstream and downstream ends comprised of the upstream and downstream ends of the blades, the assembly adapted and arranged to remove entrained liquid and solid particles from a horizontally flowing gas stream, the improvement which comprises:
forcefully directing a plurality of generally fan-like, flat concentrated wash water streams from stream nozzles against selected areas of the downstream end of the mist eliminator to remove solids from the blade surfaces near the downstream end of the mist eliminator. - Claim 2. The method of claim 1 which includes arcuately rotating said stream nozzles to cover selected areas of the downstream blade surfaces.
- Claim 3. The method of claim 1 which includes vertically moving the stream nozzles to direct the wash water streams against selected areas of the downstream end of the blade surfaces.
- Claim 4. The method of claim 1 which includes;
a) arcuately rotating said stream nozzles to cover selected areas of the downstream blade surfaces; and b) vertically moving the stream nozzles to direct the wash water streams against selected areas of the downstream end of the blade surfaces. - Claim 5. The method of claim 1 which includes directing against the upstream end of the mist eliminator conical spray streams of the wash water from spray nozzles adjacent the upstream end of the mist eliminator.
- Claim 6. The method of claim 1 which includes forcefully spraying the wash water stream generally intermediate the spaced apart blades to cover selected surface areas of adjacent blades.
- Claim 7. The method of claim 1 wherein the mist eliminator comprises chevron blades, the solid particles are solid reactant particles from an acid gas and an alkaline wash stream, and the gas stream comprises an exhaust gas produced from burning a fuel.
- Claim 8. The method of claim 1 which includes forcefully spraying, at a water pressure of about 15 to 60 psig, a generally flat, concentrated, non-overlapping, fan-like wash water stream against the downstream end of adjacent blade surfaces.
- Claim 9. The method of claim 1 which includes controlling the timed operation of the wash water stream.
- Claim 10. The method of claim 1 which includes positioning a plurality of the stream nozzles on an H-type ladder configuration with legs and crossbars, arranging said nozzles on at least one crossbar of said ladder, and vertically moving in a reciprocating manner said ladder legs.
- Claim 11. In a method for removal of solid particles from an acid-gas containing feed gas stream, which method comprises:
a) treating the feed gas stream with an alkaline reactant containing-liquid slurry to provide a gas stream with reduced amounts of acid gases and entrained liquid and solid particles;
b) passing the reduced gas streams with generally horizontal flow through a chevron-type mist eliminator, comprising a plurality of spaced-apart, generally vertically arranged chevron blades, having a downstream end and an upstream end, to provide a clean gas;
c) directing wash water in conical sprays from full cone wash nozzles against the upstream end of the mist eliminator to provide the spraying of substantially the entire upstream portion of the surfaces of the chevron blades to remove solids adhering to the chevron blades;
d) directing entrained liquid, water wash and washed off solid particles to a sump; and e) removing from the mist eliminator and withdrawing a clean gas, the improvement which comprises;
forcefully directing a plurality of flat wash streams from wash nozzles against the downstream end of the mist eliminator, the flat streams arranged in a non-overlapping arrangement to remove solid particles from the downstream portions of the chevron blades and to reduce the re-entrainment of wash liquid in the clean gas. - Claim 12. The method of claim 11 wherein the feed gas stream is a combustion effluent and contains oxides of sulfur.
- Claim 13. The method of claim 11 wherein the reactant slurry comprises a water slurry of an alkaline salt.
- Claim 14. The method of claim 11 which includes directing the flat feed streams intermediate to and onto the opposing surfaces of downstream portion of adjacent chevron blades.
- Claim 15. The method of claim 11 which includes controlling the sequence and timing of the conical and flat streams.
- Claim 16. The method of claim 11 which includes arcuately rotating the flat stream nozzles to direct the flat wash water against selected surface areas of the blades.
- Claim 17. The method of claim 11 which includes moving the flat stream nozzles generally vertically relative to the downstream end of the mist eliminator to spray different parts.
- Claim 18. A mist eliminator system including a mist eliminator for use with a horizontal flow gas stream containing entrained liquid and solid particles to be removed by the mist eliminator, which system comprises:
a) a mist eliminator constructed and arranged to be placed in the horizontal flow path of a gas stream containing entrained liquid and solid particles to be removed by the mist eliminator, the mist eliminator having a plurality of spaced apart blades arranged generally parallel to the gas flow path and to provide blade impingement surfaces in the gas flow path, the mist eliminator having an upstream end and a downstream end;
b) a downstream wash stream means to direct forcefully a wash water against selected areas of the downstream blade surfaces, the wash water means comprising a plurality of flat stream nozzles to direct a generally flat concentrated, wash water stream, countercurrent to the gas flow and against the downstream portion of the blade surfaces, thereby removing solid particles from the downstream portions of the blade surfaces and reducing the re-entrainment of the wash water stream into the gas stream. - Claim 19. The system of claim 18 which includes an upstream wash water means to direct wash water against the upstream blade surfaces.
- Claim 20. The system of claim 19 wherein the upstream wash water means comprises a plurality of spray nozzles to direct conical sprays of wash water against the upstream blade surfaces.
- Claim 21. The system of claim 20 wherein the mist eliminator wash water means is intermediate the downstream blades to direct a flat wash water stream against adjacent and opposite blade surfaces.
- Claim 22. The system of claim 18 which includes means to rotate arcuately a selected amount the flat stream nozzles to cover selected areas of the downstream blade surfaces.
- Claim 23. The system of claim 18 which includes means to move vertically the flat stream nozzles to direct the flat wash water stream against selected areas of the downstream blade surface.
- Claim 24. The system of claim 18 which includes means to control the timed operation of the flat wash water stream.
- Claim 25. The system of claim 18 wherein the flat stream nozzle provides a generally flat, concentrated fan-like stream.
- Claim 26. A system for the treatment of a gas stream containing acid gas which system includes the mist eliminator wash system of claim 18.
- Claim 27. The system of claim 26, which system includes:
a) a furnace to produce an acid containing gas stream;
b) a means to treat the acid-containing gas stream with an alkaline reactive material to provide a gas stream containing entrained liquid and solid reactant particles;
c) a sump means to collect liquid and solid particles removed by the mist eliminator; and d) means to withdraw a clean gas from the mist eliminator. - Claim 28. The system of claim 27 which includes an upstream wash water means to dislodge solid particles form the upstream blade surfaces.
- Claim 29. The system of claim 27 wherein the upstream wash water means comprises a plurality of spray nozzles to provide a plurality of generally conical spray streams against the upstream blade surfaces.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US319295P | 1995-09-05 | 1995-09-05 | |
| US60/003,192 | 1995-09-05 | ||
| US368195P | 1995-09-11 | 1995-09-11 | |
| US60/003,681 | 1995-09-11 | ||
| US62741996A | 1996-04-04 | 1996-04-04 | |
| US08/627,419 | 1996-04-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2184776A1 true CA2184776A1 (en) | 1997-03-06 |
Family
ID=27357342
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2184776 Abandoned CA2184776A1 (en) | 1995-09-05 | 1996-09-04 | Chevron mist eliminator wash apparatus, and method and system employing the apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2184776A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112426841A (en) * | 2020-11-11 | 2021-03-02 | 昆岳互联环境技术(江苏)有限公司 | Digital desulfurization demister flushing control device and method |
| WO2023165129A1 (en) * | 2022-03-04 | 2023-09-07 | 华电电力科学研究院有限公司 | Demister blockage pre-control system and method, device, and medium |
-
1996
- 1996-09-04 CA CA 2184776 patent/CA2184776A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112426841A (en) * | 2020-11-11 | 2021-03-02 | 昆岳互联环境技术(江苏)有限公司 | Digital desulfurization demister flushing control device and method |
| WO2023165129A1 (en) * | 2022-03-04 | 2023-09-07 | 华电电力科学研究院有限公司 | Demister blockage pre-control system and method, device, and medium |
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