Patent Description:
The term "NOx" refers to mono-nitrogen oxides, in particular NO (nitric oxide) and NO2 (nitrogen dioxide). NOx is produced during combustion, especially at high temperatures, and is known to cause a variety of environmental problems. In the past NOx emissions in heavy-duty diesel-powered vehicles, for example diesel trucks, have been reduced by techniques such as selective catalytic reduction (SCR).

SCR of NOx is normally used for lean burn engine exhaust and involves the addition of reducing agents, such as urea. This technique is undesirable for luxury yachts since it requires large sacrifices of valuable space and utilizes dangerously high temperatures. The optimum temperature ranges for SCR vary from <NUM>°F to <NUM>°F (<NUM> to <NUM>) and are not effective at lower temperatures, e.g. at temperatures below <NUM>. Such high temperatures are potentially dangerous in engine rooms of marine vessels where space is confined and limited. Constant air flow is necessary with SCR because of the heat. In addition, reducing agents such as urea need to be stocked in sufficient amounts, which increases the weight of the ship considerably and results in higher emissions, including higher CO<NUM> emissions, which are not addressed by SCR and is undesirable from an environmental point of view. SCR is also prohibitively expensive with the additional cost for an average <NUM> foot luxury yacht with twin engines and two generators being estimated by the National Marine Manufacturer's Association at $<NUM>,<NUM> per engine, plus another $<NUM>,<NUM> per generator, i.e. over $<NUM>,<NUM> when installed.

In larger ships, such as those disclosed in <CIT>, typically greater than <NUM> feet, stacked scrubbers are utilized to reduce NOx emissions, but these are not suitable for smaller ships, i.e. vessels under <NUM>'/<NUM> such as luxury yachts, ferries, and other commercial vessels. One type of stacked scrubber is a wet scrubber. Inside an open-loop wet scrubber, the scrubbing liquid used is generally sea water with chemical additives. The most commonly used additive is caustic soda. Scrubbing liquid is sprayed into the exhaust gas stream through nozzles to distribute it effectively. In most scrubbers the design is such that the scrubbing liquid moves downstream, however, scrubbers with an upstream movement of scrubbing liquids are available as well. One such stacked wet scrubber is illustrated in <FIG> Prior Art. As will be appreciated, such scrubbers or too large for use in yachts under approximately <NUM> feet because of their size and the amount of chemical additives needed to make the system work effectively.

Other techniques, such as those disclosed in <CIT> and <CIT> utilize an ozone reaction as an oxidizing compound to reduce NOx emissions. However, the use of Ozone carries its own ramifications as ozone is known to be harmful to humans, animals and the environment. As a result, there are many restrictions regarding the use of Ozone, which can make it difficult to produce and utilize in a safe and cost-effective manner.

Another known NOx abatement technique comprises exhaust gas recirculation (EGR). This requires modifications of the engines and corresponding extensive development and testing. These EGR modified engines are not generally suitable for acceptable NOx reduction to meet current and new NOx emissions regulations and require additional SCR exhaust treatment to be compliant. The use of EGR in luxury yachts and similar size vessels, where space is confined and limited, along with the cost of replacing existing engines makes it an impracticable choice.

As a result, these prior art techniques have not been successfully applied for the treatment of exhaust gases from marine engines, specifically commercial vessels and yachts that are too small to utilize stacked scrubbing.

The International Maritime Organization (IMO), an agency of the United Nations which was formed to promote maritime safety, has developed new regulations to reduce NOx emissions. The NOx emission limits of Regulation <NUM> of MARPOL Annex VI apply to each marine diesel engine with a power output of more than <NUM> kW installed on a vessel. NOx emission limits are set for diesel engines depending on the engine maximum operating speed (n, rpm). In recent years the maximum allowable NOx emissions have been gradually decreased from Tier I (for ships constructed after <NUM> January <NUM>): <NUM> NOx per kWh, via Tier II (for ships constructed after <NUM> January <NUM>): <NUM> NOx per kWh, to Tier III (for ships constructed after <NUM> January <NUM>): <NUM> NOx per kWh. Tier IV legislation is expected, in which the maximum emission is as low as <NUM> NOx per kWh. The indicated maximum emissions are for engines operating at <NUM> rpm. Furthermore Regulation (EU) <NUM>/<NUM> imposes new emissions limits, referred to as "Stage V," to reduce the emissions of air pollutants, including NOx.

The removal of environmental pollutants from marine exhaust of diesel engines is an ongoing challenge in the maritime industry. As the adverse effects of contaminants such as NOx and CO<NUM> become more well know and widespread, emissions regulations in the maritime industry are becoming more restrictive. For luxury yachts and other vessels of a certain length, where space is at a premium and stacked SCR scrubbers are not a realistic solution, the reduction of NOx emissions and other pollutants in a practical and cost-effective manner has been challenging. A method and system for reducing pollutants in marine diesel exhaust to meet more stringent standards, which is economical, can interface with existing diesel engines, compact, and readily customized to any space is therefore desirable.

A modular reactive-cyclic induction ("RCI") system that connects to the exhaust of a conventional diesel marine engine, without modification to the engine or the use of ozone, which uses air pressure and the sodium chloride in seawater to create a molecular reaction to break down Nitrogen Oxide into Nitrogen is disclosed herein.

The system connects directly to the exhaust of existing engines that activates the system and includes controls to prevent back pressure from building, pressurized air is utilized within the system, including an air pressurized filter device to remove Sulfur Oxides ("SOx"), Hydrogen Carbons ("HC"), and Particulate Matter ("PM"), and at least one induction apparatus which cycles and emulsifies the exhaust fumes therethrough to expose toxic NOx to seawater to break down the molecular structure of NOx into harmless nitrogen (NO). The system is modular, so that it can be readily customized to the configuration of an engine room, such as those found in commercial vessels and luxury yachts, without sacrificing space. In one embodiment, the induction apparatus utilized provides static mixing of the seawater and NOx.

In one embodiment, the at least one induction apparatus is also utilized to reduce CO<NUM> emissions from the exhaust either contemporaneously or asynchronously with the breakdown of the NOx. The induction apparatus includes an electrolyzer having an anode and cathode along with calcium oxide and other compounds mixing with seawater as the electrolyte through which the CO<NUM> is passed.

If the induction apparatus is utilized to reduce CO<NUM>, an exhaust manifold with a heating coil may be provided in one embodiment to heat the seawater that is circulated through the manifold to increase the temperature of the seawater above about <NUM>°F when it enters the induction apparatus. Alternately, or in addition to an exhaust manifold, the induction apparatus itself may include a manifold to heat the seawater circulating therein, whether for NOx or CO<NUM> reduction. The induction apparatus may also include loop recirculation to insure full cycle exposure.

Various aspects of at least one embodiment are discussed below with reference to the accompanying figures, which are not necessarily drawn to scale, emphasis instead being placed upon illustrating the principles disclosed herein.

As also used herein, the term "NOx" refers to mono-nitrogen oxides, in particular NO (nitric oxide) and NO2 (nitrogen dioxide). As also used herein, certain terminology such as for example saltwater and seawater, may be used interchangeably to refer to the same thing. As also used herein, the reference to "sufficient" as it relates to a reduction in NOx emission reduction, means a reduction that meets the standards set by IMO, as set forth in the background, or by approximately <NUM>-<NUM>% of the emissions from the diesel engine, whichever is lesser.

Referring initially to <FIG>, the present disclosure is directed to a modular, reactive-cyclic induction method and system <NUM> for breaking down NOx pollutants from a marine exhaust diesel engine <NUM> into Nitrogen for discharge back into the sea. The system utilizes a combination of pressurized seawater, air pressure and a churning induction apparatus in order to break down the NOx. In the present embodiment, the system <NUM> connects to the exhaust <NUM> of the diesel engine <NUM> and includes a shuttle mechanism <NUM> that operates to prevent back pressure within the system, an air pressurized filter unit <NUM>, and an induction apparatus <NUM> that mixes the seawater with exhaust fumes and cycles the two by churning. Air compressor <NUM> driven by motor <NUM> pumps pressurized air through the system through a plurality of air lines <NUM> in order to drive the exhaust. Seawater is introduced into system <NUM> via inlet tube <NUM> and by pump <NUM>, which pumps the seawater through one or more water lines <NUM>. A tank <NUM> holds the seawater while a pressure/volume regulator <NUM> monitors the seawater pressure within the system <NUM> for distribution from the tank <NUM>, as needed.

The system <NUM> is connected to the exhaust <NUM> of diesel engine <NUM> by one end of flexible hose <NUM> and includes engine seawater cooling discharge <NUM> tube. The engine does not need to be modified in any way and there is no connection into any of the engine systems, only to the exhaust. The other end of flexible hose <NUM> is connected to shuttle mechanism <NUM> in the present embodiment. Upon exiting the engine, the exhaust and any engine seawater cooling discharge travel through flexible hose <NUM> and enter shuttle mechanism <NUM>.

As best shown in <FIG>, shuttle mechanism <NUM> may include a switch or valve <NUM> movable between closed (off) position and an open (on) position. An exemplary butterfly valve or switch is shown, but could be replaced with any of a variety of valves, as would be known to those of skill in the art. When the engine <NUM> is operating and the pressure from the exhaust is high enough, the valve <NUM> moves into the open position as shown in <FIG>. Also included in shuttle mechanism <NUM> are pressure monitors <NUM> and gauge <NUM> that monitor the air and seawater pressure within the system. When the pressure monitor is below a certain acceptable level it signals the valve <NUM> to close as shown in <FIG>. Closing valve <NUM> prevents back pressure from building within the system that could damage the engine through the introduction of seawater into the engine. Gauge <NUM> provides a visual indication of the pressure in the system in case manual intervention becomes necessary. After exiting the engine, the exhaust enters filter unit <NUM>.

Referring now to <FIG>, a pressurized filter unit <NUM> is provided in the present embodiment in order to remove secondary pollutants such as Sulfur Oxides ("SOx"), Hydrogen Carbons ("HC"), and Particulate Matter ("PM") from the exhaust. The exhaust enters a first enclosure <NUM> of filter unit <NUM> through hose <NUM>. Likewise, pressurized air is pumped through an air pressure regulator <NUM> via air lines <NUM> into the first enclosure <NUM> and through a dispersal nozzle <NUM> supported by the first enclosure for circulation therein. The pressurized air then forces the exhaust containing pollutants through the one or more filters <NUM> and into a second enclosure <NUM>. The one or more filters may be replaceable flow/pass through filters chosen to remove common pollutants found in diesel exhaust, including but not limiting, SOx, HC, and PM including soot, as would be known to those of skill in the art. Referring now to <FIG>, first enclosure <NUM> also supports a pressure monitor <NUM> and gate valve <NUM> attached to hose <NUM> that acts as a bypass mechanism for the exhaust in case the one or more filters <NUM> become clogged. This bypass mechanism aids in preventing engine manifold back pressure.

Referring again to <FIG>, a trap <NUM> may additionally be supported by enclosure <NUM> to catch any debris not cleared out by the one or more filters <NUM>. For maintenance of the pressurized filter unit <NUM>, periodic flushing may be desirable. In order to flush the pressurized filter unit <NUM>, including the first and second enclosures <NUM>, <NUM> and filters <NUM>, freshwater may be introduced through an inlet <NUM> having a fitting for receiving a hose, for example a conventional garden hose, and expelled through outlet <NUM>. Once the exhaust has passed through the pressurized filter unit <NUM> and the secondary pollutants have been reduced, it passes through hose <NUM> connected at a first end to the second enclosure <NUM> and at a second, opposing end to tank <NUM> of induction apparatus <NUM>.

As best shown in <FIG>, in addition to tank <NUM>, induction apparatus <NUM> also includes mixing component <NUM> supported by the tank, which operates to mix saltwater <NUM> with the exhaust. Because tank <NUM> is filled with saltwater it is watertight, except for the water entering and leaving the system through pipes, such as feed pipe <NUM> (<FIG>) that is used to fill the tank, bypass recirculating pipe <NUM> to recirculate the mixture of seawater and exhaust through the tank until such time as the NOx emission is sufficiently reduced, and saltwater reserve feed pipe <NUM>. The saltwater reserve feed pipe <NUM> is for adding salt in brackish and low sodium chloride seawater areas (bays, rivers, etc.) into the tank <NUM> from the sodium chloride reserve tank <NUM>, as described below.

In the embodiment of <FIG>, mixing component <NUM> is a rotating screw style helix that is turned by shaft <NUM>, which is driven by a motor <NUM> that turns the helix at relative low number of revolutions per minute "rpms," for example between approximately <NUM>-<NUM> rpms. It is contemplated that other types of mixing components <NUM> may readily be utilized, including static mixing that does not have a moving/motorized component, provided that it sufficiently blends the exhaust with the saltwater, as would be known to those of skill in the art. Upon blending the exhaust with the saltwater a molecular reaction to break down Nitrogen Oxide into Nitrogen is produced. In order to create the molecular reaction a sufficient amount of sodium chloride must be utilized. To ensure the salt content is sufficient a PH meter <NUM> is provided to measure the sodium chloride in the seawater in tank <NUM>.

Referring still to <FIG>, an electric operated valve <NUM> in communication with feed pipe <NUM> opens when low salinity seawater is registered by PH meter <NUM>. Air pressure valve <NUM> uses low air pressure to help move salt from feed pipe <NUM> into induction unit <NUM>. This addition of sodium chloride aids the molecular reaction by ensuring that the levels of sodium are enough to break down the NOx emission even in brackish water. Likewise, a diverter valve <NUM> may also be provided to allow the exhaust/seawater mixture to recirculate and loop back through the induction unit <NUM> if the NOx emissions have not been sufficiently reduced to insure full cycle exposure. A gauge <NUM> may be utilized to determine the NOx emissions and signal the diverter valve to remain open as shown in <FIG> for discharge through pipe <NUM> overboard if the NOx emissions have been met, and to close so that the exhaust/seawater mixture is sent through recirculating pipe <NUM> if the NOx emissions have not been sufficiently reduced. Instead of recirculating through the same tank <NUM>, multiple tanks may be utilized.

As shown in the embodiment of <FIG>, which is substantially the same in all aspects as the embodiment of <FIG> with the exception that multiple, vertical induction apparatus <NUM> are provided. The tanks are positioned such that the shaft of the mixing component <NUM> (i.e. an auger type screw in the present embodiment) is vertically disposed, while connecting the more than one tanks 50a, 50b, 50c, and 50d are recirculating pipes <NUM>. The remaining components of <FIG> are substantially the same as of the embodiment of <FIG>, except they may be multiples, in order to account for the multiple tanks. For example, there may be multiple feed pipes <NUM> provided as well as more than one PH meter <NUM> (not shown). Regardless of the number of induction apparatus <NUM>, the combination of the seawater, air pressure and exhaust work together to create a molecular reaction to break down Nitrogen Oxide into Nitrogen. In order to increase the reactivity, electrolysis may be added to the system <NUM>.

Referring again to <FIG>, an alternate embodiment of induction apparatus <NUM> is illustrated. In this embodiment, induction apparatus <NUM> also includes an electrolysis accelerator <NUM>. The embodiment of <FIG> is substantially the same in all aspects as the embodiment of <FIG> but additionally includes the electrolysis accelerator <NUM> that has a positive (anode) <NUM> and negative (cathode) <NUM> DC current created by battery <NUM>, for example a <NUM>/24v battery operated by an amperage controller <NUM>, to generate electrolysis to accelerate molecular transformation of the NOx into NO. In creating the reaction, the seawater acts as the electrolyte. The cathode <NUM> may be made of a less noble, sacrificial metal such as zinc, while the anode <NUM> may be made of a metal such as copper or magnesium, or the like. If electrolysis is utilized for the molecular transformation of NOx into NO, it is also possible to utilize the induction apparatus <NUM> to reduce CO<NUM> from the exhaust.

If the induction apparatus is utilized to reduce CO<NUM>, in addition to the anode <NUM>, cathode <NUM>, and the seawater electrolyte, calcium oxide <NUM> in the form of lime may also be mixed with the seawater through which the CO<NUM> from the exhaust is passed, as shown in the embodiment of <FIG>. The embodiments of <FIG> are substantially the same in all aspects as the embodiment of <FIG> but additionally include calcium oxide <NUM>. The lime should be about <NUM>% calcium in order to react with the CO<NUM> to form calcium bicarbonate that can be safely pumped overboard. Such lime is available as a compressed block, as would be known to those of skill in the art. Referring to <FIG>, a block of lime <NUM> is secured by a mount <NUM> within tank <NUM> and in contact with the seawater <NUM>. As the mixing component <NUM> rotates and churns the seawater, the lime <NUM> dissolves and is emulsified as it is distributed into the seawater. A float (not shown) may be provided within tank <NUM> in order to maintain a level of seawater sufficient to contact and dissolve the lime <NUM>. Once the brick of lime is dissolved it may be replaced by simply opening the top of the tank <NUM> and mounting a new block.

Referring to <FIG>, an exhaust manifold <NUM> including at least one heating element <NUM> may be provided to heat the seawater that is discharged through tube <NUM> from the engine <NUM> to <NUM>°F in order to boil and create steam, to increase the temperature of the seawater above about <NUM>°F when in the induction apparatus <NUM> to enable the desired reaction. As shown in <FIG>, the exhaust is directed from the manifold <NUM> into the pressurized filter unit <NUM>, but the heated seawater is transferred via tube <NUM> directly to the tank <NUM> of the induction unit <NUM>. Alternately, or in addition to an exhaust manifold <NUM>, the induction apparatus itself may include a manifold <NUM> to heat the seawater circulating therein, whether for NOx or CO<NUM> reduction or both. By heating the seawater the reaction to turn the CO<NUM> into calcium bicarbonate is enhanced. Although illustrated as a single tank <NUM>, multiple tanks may be utilized with some having lime and others being used just for reduction of NOx. The reduction of the emissions of CO<NUM> and NOx through the use of the induction apparatus, high pressure air, and electrolysis as described herein is above about <NUM>% for CO<NUM> and about <NUM>% - <NUM>% for NOx.

Claim 1:
A system (<NUM>) for reducing pollutants from marine exhaust comprising:
a hose (<NUM>) including a first end configured and dimensioned to connect to the exhaust of a marine diesel engine (<NUM>) and a second end opposite the first end;
a plurality of air lines (<NUM>) configured and dimensioned to deliver compressed air therethrough;
an air compressor (<NUM>) operatively connected to one or more of the plurality of air lines (<NUM>);
an air pressurized filter unit (<NUM>) including a first enclosure (<NUM>) constructed and arranged to receive the second end of the hose (<NUM>), and including a cavity through which pressurized air is injected forcing the exhaust to flow through one or more filters (<NUM>) constructed and arranged to filter out one or more pollutants;
an inlet tube (<NUM>) configured to draw seawater from the sea and operatively connected to one or more water lines (<NUM>);
a pump (<NUM>) constructed and arranged to pump the seawater through the one or more water lines (<NUM>);
an induction apparatus (<NUM>) including a tank (<NUM>) configured and dimensioned to hold seawater and supporting a mixing component (<NUM>) selected from the group consisting of a static mixer and an active mixer constructed and arranged to mix the seawater with the exhaust, the induction apparatus (<NUM>) being operatively connected to the air pressurized filter unit (<NUM>);
a shuttle mechanism (<NUM>) including a valve (<NUM>) movable between a closed position and an open position operatively connected to the hose (<NUM>), and a pressure monitor (<NUM>) that monitors air pressure in the system, and wherein when the pressure from the exhaust of the engine reaches a sufficient level the valve opens and when the pressure is below a certain acceptable level the pressure monitor signals the valve to close in order to avoid back pressure building within the system that could damage the engine through the introduction of seawater into the engine;
and wherein during use the marine exhaust is routed through the system by the compressed air and is received within both the air pressurized filter unit (<NUM>) to remove a first set of pollutants selected from the group consisting of Sulfur Oxides, Hydrogen Carbons, and Particulate Matter, and is received within the induction apparatus (<NUM>) to remove a second set of pollutants including at least one of NOx and CO<NUM>.