The subject of this disclosure may relate generally to systems, devices, and methods for facilitating the injection of various compounds into a utility furnace.
Utility furnaces are used in various industries for a variety of different purposes. Common issues associated between these various industries include the handling of the byproducts created by the combusted fuel. These byproducts can decrease the utility furnace efficiency and pose other pollution problems.
In one example, the pulverized coal, used in various types of boilers, burns in a combustion chamber. The hot gaseous combustion products then follow various paths, giving up their heat to steam, water and combustion air before exhausting through a stack. The boiler is constructed mainly of interconnected elements such as cylinders such as the super heater tubes, water walls, various larger diameter headers, and large drums. Water and steam circulate in these elements, often by natural convection, the steam finally collecting in the upper drum, where it is drawn off for use. Water/steam tubes typically almost completely cover the walls of the passage so that they efficiently transfer heat to the water/steam. As the coal is burned, ash and/or other products of combustion build-up on the tubes.
Presently sootblowers are available to aid in the removal of these build-ups. Soot-blowers are mechanical devices used for on-line cleaning of ash and slag deposits on a periodic basis. They direct a pressurized fluid through nozzles into the soot or ash accumulated on the heat transfer surface of boilers to remove the deposits and maintain the heat transfer efficiency. The soot and dust generated in combustion get deposited on outer tube surfaces. This adds to the fuel requirements to maintain heat transfer into the water/steam heated by the utility furnace. Running with added fuel in turn increases deposition of byproducts of fuel burning and also increases the chances of the tubes failure by overheating. This eventually results in shutting down of the furnace for repairs. All this can be avoided by soot blowing. Regular soot blowing saves fuel and boiler downtime. In other words steam at constant parameters is available over a longer period of time. Numerous types of sootblowers exist including but not limited to wall sootblower, long retractable sootblower, rotating element sootblower, helical sootblower, and Rake-type blower. Under optimal conditions this ash is removed from the surface of the tubes by pressured fluid (typically air, saturated steam or super-heated steam) delivered from sootblowers. However under suboptimal conditions the ash melts due to reaching its fusion temperature and results in the formation of slag. Sootblowers are less effective at removing the slag.
The major problem with the formation of slag is that it insulates the elements, thus requiring the furnace to burn at a hotter temperature to create the same increase in water temperature. Excessive ash deposits on a coal-fired boiler's heat transfer surfaces will reduce its efficiency, and in extreme cases a boiler can be shut down by ash-related problems. Slagging incidents are a heavy drag on the global utility industry due to reduced power generation and equipment maintenance.
The changing electricity market and political pressures have pushed the use of fuels other than coal. For example, use of gas, biofuel, cofired fuel, etc has become widespread. These factors have led to coal-fired plants being operated under unusual loads. This change in operation has altered the effects of boiler slagging. The cofiring of other fuels with coal, especially biomass, represents a large challenge to utility furnace operation. The ash chemistry of these alternative fuels is often very different to that of the coals and has given rise to serious problems. The tendency of coal for slagging depends on its composition. The complex interaction between a boiler's operating conditions and the fuel chemistry makes the prediction of slagging difficult. Furthermore, the increasing pressure on coal-fired power stations to reduce emissions has led to the development of technologies for the abatement of specific pollutants that impact on ash slagging. The new generation of pulverized coal fired plant, designed for high efficiency through the use of high steam temperatures and pressures, present further challenges with respect to ash slagging and fouling.
Various methods of removing the slag other than with a sootblower are in use. For example in some power plants, engineers fire shotguns into the furnace to break the slag off of the pipes. Other methods require taking the furnace off line to deal with the problem. Other methods include a specialized system that is located to access flue gasses whereby the system uses a specialized pressure source (i.e. different from that used by the facility for the operation of the sootblowers) to force a fluid into a feed tube, which mixes the fluid with a chemical coming from atomizing nozzles. The fluid and chemical is then injected into the flue gas stream which may allow incidental contact with areas affected by slagging. However, this method requires enormous amounts of chemical to be dumped into the flue gas stream which is difficult if not impossible to understand as the flow dynamics in the furnace are constantly changing. For example, the buildup of slag between tubes redirects the flue gas away from those tubes preventing the slag from receiving the chemical. Furthermore, the specialized equipment and the special access for introducing the chemicals from a specialized system into the utility furnace substantially increases cost. Thus, these techniques are less than satisfactory.
In dealing with the byproducts released into the environment (pollution), various systems associated with the utility furnaces process the byproducts before their release. However, better methods of chemical processing of these byproducts are constantly sought after. New utility furnaces are almost certain to be required to operate under conditions that facilitate carbon capture and storage, for compliance with climate change driven requirements. While such requirements are frequently sought in relation to coal fired furnaces they could also apply to a variety of fuel types.
While the problems and limitations of utility furnaces are clear, there are few solutions. The presence of certain compounds in the utility furnaces have been experimented with and resulted in improved abilities to deal with slag and pollution. While the specific compounds vary across the board depending on the specific chemistry of the fuel and problem to be addressed, one uniform problem exists, there is no adequate delivery mechanism to inject the compounds into targeted spots in the furnace.
A solution to the problem of delivering various compounds to targeted locations of a utility furnace is needed. As such a solution to the delivery of compounds into a utility furnace is presented herein.
In accordance with various aspects of the present invention an apparatus comprises a mixing chamber configured to receive a compound for improving environmental and/or efficiency conditions in a utility furnace, wherein the mixing chamber is further configured to mix the compound with a fluid which is in a pressurized fluid system in place with the utility furnace and configured to inject the fluid and compound into a utility furnace.
In another exemplary embodiment, a system comprises a fluid supply configured to deliver a fluid; a valve connected to the fluid supply wherein the valve is operable to control the fluid from the fluid supply; a feed tube configured to connect to the valve and transport the fluid; a delivery device configured to connect to the feed tube and configured to eject the fluid into a utility furnace; a compound capable of improving the efficiency of the utility furnace; a hopper configured to hold a quantity of the compound; an delivery system connected to the hopper and operable to transfer compound from the hopper; and a mixing chamber operable to receive the compound from the delivery system and combine the compound with the fluid supply wherein, the mixing chamber is configured to be removably connected to the valve.
In another exemplary embodiment, a system comprises a fluid supply configured to deliver a fluid; a valve connected to the fluid supply wherein the valve is operable to control the fluid from the fluid supply; a delivery system configured to connect to the fluid supply; a compound capable of improving the efficiency of the utility furnace; a mixing chamber operable to receive the compound from the delivery system and combine the compound with the fluid supply; the mixing chamber located in line with the fluid supply; the fluid supply delivering a mixture of fluid and compound to the air blowers of a burner, the air blowers connected in line to the fluid supply configured to relapse the mixture into the furnace.
Furthermore, in an exemplary embodiment a method comprises attaching a mixing chamber inline with a fluid supply; delivering a compound to the mixing chamber mixing the compound with the fluid supply forming a mixture; delivering the mixture to a utility furnace through a manufactured sootblower; covering areas of the furnace accessible by sootblowers; and impregnating the compound to affected slagging areas regardless of changing flue gas flow dynamics.
Furthermore, in an exemplary embodiment a method comprises attaching a mixing chamber inline with a fluid supply; delivering a compound to the mixing chamber mixing the compound with the fluid supply forming a mixture; delivering the mixture to a utility furnace through a burner; covering areas of the furnace accessible by the furnace; and impregnating the compound to affected slagging areas.
These and other features, aspects, and advantages will become better understood with reference to the following description, claims and accompanying drawings where:
In accordance with an exemplary embodiment of the present invention, systems, devices, and methods are provided, for among other things, facilitating the injection of various compounds into a utility furnace. The following descriptions are not intended as a limitation on the use or applicability of the invention, but instead, are provided merely to enable a full and complete description of exemplary embodiments.
In accordance with various exemplary embodiments of the present invention, a compound may be injected into a utility furnace by mixing with a pressurized fluid going into the utility furnace. In various examples the compound may be merely injected under pressure into the pressurized fluid. In various embodiments the system may be configured to pull the compound into the fluid. These examples may be combined as well. As will be discussed herein the terms nozzles and/or mixing chambers may be used to describe the devices, locations and situations in which compound and the pressurized fluid are mixed. While each term may be discussed in various examples and embodiments it is noted that either term may be used without excluding the other from application in the examples and embodiments.
In accordance with an exemplary embodiment, with reference to
The nozzle may also have a compound entrance 408. In an exemplary embodiment, the compound may be brought into nozzle 400a via compound entrance 408. Nozzle 400a may also have a compound exit 406 (also referred to herein as chemical injection port). In an exemplary embodiment the compound exits nozzle 400a via compound exit 406a. In accordance with an exemplary embodiment of the present invention, nozzle 400a may be configured for mixing a compound with a pressurized fluid stream.
In accordance with various embodiments, nozzle 400a may be merely a mixing chamber. For example, 400a may be configured for mixing a compound with a pressurized fluid stream. This mixing occurs in response to the compound coming into contact with the fluid being carried within the fluid supply.
In accordance with various embodiments, a mixing chamber may be employed to mix a compound and a pressurized fluid stream. With reference to
The mixing chamber may also have a compound entrance 408. In an exemplary embodiment, the compound may be brought into mixing chamber 400b via compound entrance 408. Mixing chamber 400b may also have a compound exit 406b (also referred to herein as chemical injection port). In an exemplary embodiment the compound exits mixing chamber 400b via compound exit 406b. In accordance with an exemplary embodiment of the present invention, mixing chamber 400b may be configured for mixing a compound with a pressurized fluid stream.
In various embodiments, a mixing chamber may comprise a point where a compound supply line and a fluid supply line intersect. In one example a mixing chamber may be a distinct separate part added to a fluid supply line. For example, mixing chamber 400b may be added in-line. In another example, a fluid supply line may be tapped into directly with a second line. Compound may be delivered under pressure through the second line into the fluid supply line. In this embodiment, the mixing chamber may be the point or region of the system where the pressurized fluid and the compound intersect. Any of variety of fluid supply lines on a utility furnace may be accessible for incorporating a mixing chamber, including plant instrument air, service air, primary air into the furnace, secondary air into the furnace, and/or tertiary air into the furnace.
In various embodiments of the present invention, the nozzle may further comprise a valve 410. One exemplary embodiment, valve 410 may be a ball valve. In another exemplary embodiment, valve 410 may be a gate valve. Valve 410 may control the flow of the compound. In accordance with various embodiments of the present invention, the flow of the incoming compound may be stopped and started by opening and closing valve 410. In other exemplary embodiments, valve 410 may prevent the compound from flowing away from nozzle 400a and only allow the compound to flow into nozzle 400a. For example, valve 410 may be a check valve.
In accordance with an exemplary embodiment of the present invention, an apparatus for mixing a compound with a pressurized fluid stream comprises a mixing chamber, a valve, and a feed tube. In this embodiment, referring to
In various exemplary embodiments nozzle/mixing chamber 500a/b may include features which allow for the connection of nozzle/mixing chamber 500a/b to valve 506 or to feed tube 504. Such features might include any of a variety of fasteners known in the industry e.g. bolts, weld, pressure fittings, bracketed flanges, etc. In other various embodiments nozzle/mixing chamber 500a/b may be an integral or integrated part of valve 506 or feed tube 504. For example, nozzle/mixing chamber 500a/b and feed tube 504 may be manufactured as one piece. In an alternate example valve 506 and nozzle/mixing chamber 500a/b maybe manufactured as one piece. Likewise, all three elements may be manufactured as one piece.
In one exemplary embodiment, valve 506 is a poppet valve. In other embodiments valve 506 is any of a variety of valves include but not limited to diaphragm valves, pressure regulator valves, check valves, etc. In various embodiments of the present invention valve 506 can be any of a variety of valves used in the art whereby the valve controls the flow of fluid. Furthermore, valve 506 may be configured to adjust the pressure of the fluid passing through.
As discussed above, the apparatus may further comprise feed tube 504. In various embodiments of the present invention, feed tube 504 may be configured to attach directly to either valve 506 or nozzle/mixing chamber 500a/b. In an exemplary embodiment feed tube 504 may be configured to be detached from valve 506 and attached to nozzle/mixing chamber 500a or 500b inserted between feed tube 504 and valve 506. In this manner, an existing device may be retrofitted to include the nozzle/mixing chamber 500a/b. As discussed above the feed tube may also be integrated with nozzle/mixing chamber 500a/b and/or valve 506. In various embodiments, feed tube 504 maybe configured to withstand the pressure and corrosion caused by any material flowing through it. In various examples, fluid may flow through the feed tube at 300 SCFM to 1000 SCFM. However, depending on the application smaller or larger rates may be used. The feed tube may be comprised of hardened steel that is capable of withstanding the mixture of the high pressure fluid and also the compound introduced at nozzle/mixing chamber 500a/b. Further, other various materials may be used depending on the intended use of the system. In some instances the feed tube may be a component already installed in a facility incorporating the apparatus.
In one exemplary embodiment of the present invention, the compound introduced at nozzle/mixing chamber 500a/b may be any of a variety of solids, liquids, or gases that may beneficially be injected into a utility furnace. Furthermore, the compounds should be configured such that they are capable of being transported in line through a pressure system. In various examples the compound may be caused to move through the system via a positive pressure or a negative pressure.
In accordance with an exemplary embodiment, a compound in solid form may be sufficiently granular that it can pass through various types of tubing. In one exemplary embodiment, the compound may be a solid agent or a dry compound, being a substantially dry, granular solid having insignificant levels of humidity or liquid. In various exemplary embodiments, the compound is delivered as a slurry, liquid, or gas. For example, delivering the compound as a slurry, liquid, or gas may be beneficial where pumping is incorporated. This may be especially true where there are high pressures to overcome at the nozzle. In another example, delivering the compound as a solid may be beneficial when the compound is delivered by transport air created by a vacuum. Various examples of compounds used in the system may include, but are not limited to, magnesium hydroxide, potassium hydroxide, sodium hydroxide, aluminum hydroxide, magnesium, kaolin, mullite, trona, sodium bromide, potassium bromide, magnesium carbonate, magnesite, micronized limestone, and/or urea-based solids delivered dry or wet. Any such compound that may be desirable for a variety of chemically reactive, cleaning, processing or other beneficial purposes inside of a utility furnace may also be incorporated.
In one exemplary embodiment of the present invention, the fluid comprises pressurized air. In other various embodiments the fluid might comprise steam. Moreover, the fluid may comprise any compressed or pressurized fluid capable of being injected into the system.
In accordance with an exemplary embodiment of the present invention, the apparatus for mixing a compound with a pressurized fluid stream (comprising a nozzle, a valve, and a feed tube) may be used or adapted to a utility furnace. In an exemplary embodiment, and with reference to
The fluid, as contemplated in an exemplary embodiment of the system, may comprise any of a steam, air or other compressed gasses or fluids typically released in a utility furnace. In accordance with an exemplary embodiment the fluid supply may be an air compressor, steam recirculation system, pump, pressure vessel etc. Furthermore, the fluid supply may be any commercially available mechanism capable of creating, maintaining, or adjusting these pressures as contemplated herein. The fluid supply may be positioned and/or coupled to valve 324 directly or by means of other connections and/or devices.
In accordance with an exemplary embodiment of the present invention, referring to
In one exemplary embodiment, lance 718 may be capable of being inserted partially or fully into a utility furnace. The lance tube is what is carried and rotated into the furnace by a gearbox/motor attached to the sootblower. The lance tube may surround the stationary feed tube and is sealed by a gland. In another exemplary embodiment, injection nozzle 720 is configured to deliver the fluid supply and/or the fluid supply compound mixture to specific locations inside the utility furnace, such as to a wall as depicted in
With reference to the compound, as discussed above, the compound may be received by the nozzle. This compound may be stored in any of a variety devices connected to the nozzle. In accordance with an exemplary embodiment, and with reference to
Various quantities of this compound may be incorporated in the use and functionality of the system herein discussed. In one exemplary embodiment, upwards of 1000 lbs of compound per cleaning cycle may be injected into a utility furnace for the removal of soot. However, the quantities can vary depending on the size of the utility furnace and purpose for which the compound is being injected.
While the compound can be delivered and/or received by the mixing chamber/nozzle in a variety of ways as discussed previously, the motivation of compound through the mixing chamber/nozzle can also occur in a variety of ways. In accordance with an exemplary embodiment of the present invention, a vacuum may be present on the second side of nozzle 400a which may create a force which may draw sufficient amounts of compound into the fluid stream to be delivered with the system. In one exemplary embodiment, nozzle 400a may cause 60 inches of vacuum (i.e. a drop in pressure expressed in inches of water). In various other embodiments the vacuum can be greater or less than 60 inches of water depending on the application. For example, there can be no vacuum at nozzle 400a but instead nozzle 400a may create a zone of static or low pressure compared to the fluids in the sootblower. Variations on the profile of the nozzle can be optimized to produce a sufficient vacuum and/or a maximum pressure drop. In other various embodiments, the compound may be pressurized by a pump or the like and introduced into the fluid stream under pressure. Such pressurization can occur in any way typical of the art including, but not limited to the forces created by the devices discussed above.
Referring again to
Referring to
In an exemplary embodiment of the present invention, and with reference to
In an exemplary embodiment, wall mounted soot blower 616 may comprise feed tube 604 and valve 606. In one exemplary embodiment nozzle 602 is inserted between feed tube 604 and valve 606. For example nozzle 602 may be retrofitted into wall mounted soot blower 616. In another example, wall mounted soot blower 616 may be originally constructed with nozzle 602 between feed tube 604 and valve 606. In various exemplary embodiments, nozzle 602 may be a component of a compound feed mechanism 600 which comprises valve 608, feed line 610, transport air valve 612 and compound storage 614. Valve 608 may be coupled to feed line 610. Feed line 610 may be coupled to transport air valve 612. Transport air valve 612 may be coupled to compound storage 614.
In an exemplary embodiment, nozzle 602 may receive the compound from compound storage 614 and mix the compound with fluid flowing through wall mounted sootblower 616. Wall mounted sootblower 616 may carry the compound to any of a variety of utility furnaces. Wall mounted sootblower 616 may also deliver the compound to wall 630 or any targeted area of the furnace reachable by wall mounted sootblower 616.
In various other embodiments, transport air valve 612 may also include components capable of attaching pressurized air to feed line 610. For example, transport air valve 612 may also include a flow regulator, an air pressure regulator, and/or a filter. These components may enable transport air valve 612 to function as an air pressure source so that it is possible to add additional transport air to move larger heavier quantities of the compound.
In an exemplary embodiment of the present invention, and with reference to
In an exemplary embodiment nozzle, 702 may receive the compound from compound storage 714 and mix the compound with fluid flowing through retractable sootblower 716. In various examples, the sootblower may be a Long Retract Diamond Power Model IK-525 or a Long Retract Clyde Bergemann Model US. Sootblower 716 may comprise any device configured to deliver fluid into the interior of any of a variety of utility furnaces. Specifically, lance 718 and injection nozzle 720 may extend into the interior of a utility furnace. Retractable sootblower 716 may then deliver the compound to, for example, the wall, superheat pipes, or any targeted area of the furnace reachable by retractable sootblower 716.
In various exemplary embodiments of the present invention, the nozzle can be placed in line with any commercially available or custom built soot blower including but not limited to a wall sootblower, long retractable sootblower, rotating element sootblower, helical sootblower, and rake-type blower. The nozzle may be included as a constituent piece of the valve, the feed tube, or a combination of either. Furthermore, the sootblowers may be installed on a furnace before adding the nozzle and compound feed. Alternatively a sootblower can be installed on a furnace after it has been retrofitted with a nozzle.
In accordance with various exemplary embodiments, an apparatus mixes a compound with a pressurized fluid to be delivered into a utility furnace. The mixture of the compound and the pressurized fluid may occur inside the body of the nozzle or may occur as the nozzle delivers the compound and pressurized fluid to the feed tube. The nozzle functions to mix the compound with the pressurized fluid stream. This mixture of pressurized fluid and compound is then delivered into a furnace, either by means of a custom apparatus or commercial apparatus. Any apparatus that functionally delivers the fluid compound mixture to the furnace is contemplated herein.
For convenience a number of pressures and relative pressures may be discussed herein. For example, a first pressure may be the pressure at the poppet valve. This pressure is what is being put through the sootblower in the absence of the present invention. This pressure may also vary greatly due to a number of factors such as plant system pressure, poppet valve setting, and/or sootblower type. A second pressure may be the pressure at the chemical injection port. The second pressure is a function of the pressure drop across the nozzle. A third pressure discussed may be the pressure required to push the compound into the fluid stream running through the sootblower. The third pressure may be formed on or behind the compound in order to deliver it to the sootblower. The third pressure may be created by a pump. In instances where there is a sufficient vacuum at the chemical injection port or the second pressure, there may not need to be a third pressure to deliver compound. The pressures discussed herein are relative to atmospheric pressures. In various examples, functionality of the system with various commercially manufactured sootblowers was tested as shown in table 1.
In various examples, such as the test performed on the Copes Vulcan T-40 (see Table 1), the pressure of the fluid at the poppet valve in a utility furnace may be maximized in an attempt to deal with extreme slagging. In some instances the fluid pressures at the poppet valves may be operated at higher pressures than the utility furnace manufacture recommended pressure settings. High poppet valve pressures may translate into high chemical injection port pressures. In such instances, a pump may be used to increase the compound pressure in order to overcome the pressure at the chemical injection port. Furthermore, depending on the situation and/or the type of mechanism used to overcome the chemical injection port pressures, the compound may be introduced as a wet slurry in order to ease introduction into the pressurized stream.
In other examples, such as the test performed on the Clyde Bergmann US Blower (see Table 1), lower fluid pressures at the poppet valve correspond to lower fluid pressures at the chemical injection port. In such instances, lower pressures from the pump may be used in order to overcome the pressure at the chemical injection port. Again, the compound may be introduced as a wet slurry in order to ease introduction into the pressurized stream.
In still other examples, such as the test performed on the Diamond Power IK-525 Blower (see Table 1), the still lower pressures at the poppet valve illustrate the vacuum that may be created at the nozzle allowing substantially easier introduction of the compound into the furnace regardless whether it is slurried or in dry form.
While the pressures at the poppet valve of the various sootblowers in the industry may vary greatly depending on the type and condition of the sootblowers or the conditions of the medium, utility furnace, or other factors, it should be noted that the systems, devices, and methods discussed herein are beneficial in adapting the sootblowers to receive and disperse various compounds in the utility furnace regardless of the countless variations.
In accordance with various aspects of the invention, as discussed above, the delivery mechanism may be any permanent or temporary fixture on the utility furnace. In various exemplary embodiments of the present invention, a delivery mechanism is any component capable of delivering the pressurized fluid and/or mix of compound and fluid into a utility furnace.
As may be typical of a burner in a utility furnace, the burner can be vertical or horizontal, having air blowers located around the burner. On the outlet of the air blower are devices with movable flaps or vanes that control the shape and pattern of the flame from the burner. These air blowers can be classified as primary secondary and tertiary depending on when the air is introduced into the furnace. Primary air is the first air introduced into the furnace. Primary air is the first combustion air added to fuel being carried into the burner. Secondary air is used to supplement and finely tune the primary air. Compound may be injected into the furnace by supplying compound via plant utility air to the burner front. Then by routing high temperature tubing (or similar material) from the burner front, outside the furnace, to the internal combustion air delivered by the air blower devices.
In accordance with various embodiments, as illustrated in
In accordance with various embodiments, a mixing chamber 802 may be located in the fluid supply 820. As may be typical of a utility furnace, the fluid supply 820, which may be instrument air and/or plant utility air, may be routed to the burner front. The compound may be delivered from the compound delivery device 814 through delivery tube 810 and valve 812 to the mixing chamber 802. In the mixing chamber the compound may be mixed with the plant utility air under pressure. The mixture of the compound and the pressurized fluid may then travel through the fluid supply 820 to the burner front 824. Fluid supply line 820 may have a valve 822 to shut off compound delivery and/or regulate supply air to the burner. From the burner front 824, high temperature line 840 may be routed to the air blowers 830 in the burner. As the high temperature line 840 between the burner front 824 and the air blowers 830 is likely not present on a commercial burner, the high temperature line 840 may need to be routed in the field on the burner. In one example, high temperature line 840 may deliver compound to the primary air. In one example, high temperature line 840 may deliver compound to the secondary air. In one example, high temperature line 840 may deliver compound to the tertiary air. In on example, high temperature line 840 may deliver compound to one or more of the primary, secondary, or tertiary air. The air from the air blowers carrying the compound exits the burner into the utility furnace.
The compound when introduced into the utility furnace adds a benefit over the already available pressurized fluid. In one exemplary embodiment, MgHO2 is the compound. In this example, MgHO2 may be delivered by sootblowers to slag coated steam/water pipes to aid in the removal of slag. In this example, the MgHO2 is suited specifically to breaking up a variety of slag accumulations caused by coal based fuels burned inside of the utility furnace.
In another exemplary embodiment, magnesium is added into a utility furnace to aid in the encapsulation of harmful by products. In other exemplary embodiments, magnesium, kaolin, mullite, and/or other beneficial agents or combinations of these agents can be introduced into the utility furnace. These agents can be introduced into the utility furnace, superheats, back pass, preheats, exhaust stream, or other location to aid in the encapsulation of SO2.
In another exemplary embodiment, multiple compounds can be injected into the sootblowers to deal with inclement conditions such as low temperature. Dry has its advantages in extreme cold temperatures in the sootblower in the furnace; dry injection is a good option for injecting in the ducts and the discharge of the air-preheaters. However due to difficulties in delivering dry compound at higher pressures, poly-ethylene glycol (PEG) mixed with other chemicals discussed above, for example, MgHO2, may be a good combination as a alternative to dry injection in extreme low temperature conditions. In accordance with one embodiment, the PEG can be effectively mixed with the compound at 55-60% solids by weight. Furthermore, the PEG is EPA compliant to inject in the furnace. In various other embodiments, the mixture of PEG and compound can be effective for dusting when transporting coal. Thus this combination functions as a dust inhibitor and slag suppressor.
In accordance with an exemplary embodiment and with reference to
In accordance with an exemplary embodiment, a user may retrofit the nozzle by installing it on an operational sootblower in use on any utility furnace (step 910). For example, the user may separate the poppet valve and feed tube in a sootblower (step 912) and insert a nozzle by removably connecting the nozzle between the valve and the feed tube (step 914). When separating the valve and the feed tube the fastening mechanism is removed. For example, in some commercially used sootblowers this mechanism is a 600 pound flange with four ½ in NPT studs. In accordance with various embodiments the user may need to replace the studs that originally held the feed tube and the poppet valve together. The new studs may need to be longer in order to make up the new distance added by the nozzle. For example when placing a nozzle inline with some commercial feed tubes and valves, 2 inch longer studs may be used. The user may reconnect the valve and the feed tube with the nozzle in between (step 916).
In accordance with and exemplary embodiment, the user may attach the nozzle to a compound feed mechanism (step 920). As discussed above the compound feed mechanism may deliver compound to the nozzle in a number of ways. In accordance with one embodiment of the present invention, the compound is drawn into the nozzle by a vacuum created at the nozzle. This vacuum may create a transport air stream. The compound may be inserted into the transport air stream in a variety of ways including but not limited to physical force (e.g. an auger), pressure, gravity, or vacuum. However, it may be possible to overload the transport air by introducing too much compound (i.e. extreme loading) or to heavy a compound. When extreme loading or moving very heavy solids occurs, additional transport may be needed. As such, in accordance with another embodiment, the transport air may be pressurized coming from the compound feed. For example, the pressurized feed can come from plant instrument air and connect at the transport air valve (612 of
In accordance with an exemplary embodiment, fluid may be supplied through a sootblower (step 930). In one example, the fluid supply may be initiated by opening the poppet valve. In accordance with various other exemplary embodiments, the fluid supply may be initiated according to the individual operation of the sootblower or other fluid supply and delivery device.
In accordance with one embodiment of the present invention, the compound may be mixed with the pressurized fluid (step 940). In one exemplary embodiment the compound may be combined with fluid supply into a laminar flow. The compound may be control fed into the transport flow stream. In one exemplary embodiment and with exemplary reference to
In accordance with one embodiment of the present invention, the mixture of pressurized fluid and compound may then be advantageously supplied to targeted portions of a utility furnace (step 950). Such locations may normally be accessible only by means of the sootblower. For example, referring to
In accordance with one embodiment of the present invention, the mixture may react with the targeted elements on the interior of the furnace (step 960). Introducing the compound into a utility furnace may improve the efficiency of the furnace. This is done by impregnating the compound to affected slagging areas and chemically altering the buildup of pollution, slag, or other deleterious elements in furnace. In an exemplary embodiment, the device is configured to more easily remove the slag after first chemically reacting with the slag. In one example, this may allow the furnace to function on less fuel while maintaining substantially similar operating parameters.
In accordance with one embodiment of the present invention, the nozzles may be removed from the sootblower when finished distributing the compound into the furnace (step 970). This will restore the sootblower to its original condition. Once removed the nozzle and compound feed mechanism may be stored for use on the same sootblower or they may be moved to another sootblower. In accordance with another embodiment of the present invention, the nozzle and/or compound feed mechanism may be left in place for future use.
It may be understood herein with regard to the various aspects, embodiments and examples of the present invention, that a compound, for providing environmental benefits to emissions gases, reducing slagging, and/or improving the overall efficiency of a utility furnace, may be injected into the utility furnace through preexisting fluid systems (e.g. compressed air systems) by mixing the compound with the fluid in the fluid systems. The mixture may be injected into the utility furnace through one more of preexisting devices on the furnace including burners, sootblowers, access panels, fuel delivery, etc.
In the following description and/or claims, the terms coupled and/or connected, along with their derivatives, may be used. In particular embodiments, connected may be used to indicate that two or more elements are in direct physical contact with each other. Coupled may mean that two or more elements are in direct physical contact. However, coupled may also mean that two or more elements may not be in direct contact with each other, but yet may still cooperate and/or interact with each other. Furthermore, couple may mean that two objects are in communication with each other, and/or communicate with each other, such as two pieces of hardware. Furthermore, the term “and/or” may mean “and”, it may mean “or”, it may mean “exclusive-or”, it may mean “one”, it may mean “some, but not all”, it may mean “neither”, and/or it may mean “both”, although the scope of claimed subject matter is not limited in this respect.
It should be appreciated that the particular implementations shown and described herein are illustrative of various embodiments including its best mode, and are not intended to limit the scope of the present disclosure in any way. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system.
While the principles of the disclosure have been shown in embodiments, many modifications of structure, arrangements, proportions, the elements, materials and components, used in practice, which are particularly adapted for a specific environment and operating requirements without departing from the principles and scope of this disclosure. These and other changes or modifications are intended to be included within the scope of the present disclosure and may be expressed in the following claims.
This application is a continuation of and claims priority to U.S. Ser. No. 13/492,479 filed on Jun. 8, 2012, and entitled SYSTEM AND METHOD FOR INJECTING COMPOUND INTO UTILITY FURNACE, which is a continuation-in-part of and claims priority to PCT App. No. PCT/US2010/059886 filed on Dec. 10, 2010, and entitled SYSTEM AND METHOD FOR INJECTING COMPOUND INTO UTILITY FURNACE, which designates the United States and is itself a PCT filing of and claims priority to, U.S. Ser. No. 12/636,446 filed on Dec. 11, 2009, and entitled SYSTEM AND METHOD FOR INJECTING COMPOUND INTO UTILITY FURNACE, all of which are incorporated herein by reference in their entirety.
Number | Date | Country | |
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Parent | 13492479 | Jun 2012 | US |
Child | 15089204 | US |
Number | Date | Country | |
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Parent | PCT/US2010/059886 | Dec 2010 | US |
Child | 13492479 | US | |
Parent | 12636446 | Dec 2009 | US |
Child | PCT/US2010/059886 | US |