Abstract:
An internal combustion engine for converting energy released during the combustion of a fuel, in particular an H 2 -0 2  mixture, into mechanical work. The internal combustion engine includes at least one drive shaft connected to at least one chamber component that has at least one explosion chamber, at least one fuel supply for introducing fuel into the explosion chamber, and at least one ignition device for igniting fuel so introduced, The engine provides a relatively high torque at low engine speeds if the explosion chamber has at least one outlet through which ignited fuel is released to the surroundings, wherein the outlet is arranged such that the reaction generated by the escape of the ignited fuel exerts a torque on the at least one chamber component.

Description:
PRIORITY CLAIM 
       [0001]    This application is a continuation of pending International Application No. PCT/EP2010/057040 filed on May 21, 2010, which designates the United States and claims priority from German Patent Applications No. 10 2009 022 472.6 filed on May 25, 2009 and 10 2009 045 627.9 filed on Oct. 13, 2009, each of the above-mentioned applications is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a hydrogen engine, or, more generally: an internal combustion engine for conversion of energy released by the combustion of fuel, in particular a mixture of Hydrogene (H 2 ) and Oxygene (0 2 ), into mechanical work. In addition, this invention relates to a hydrogen generator, especially for supplying an internal combustion engine with an H 2 -0 2  mixture as fuel. The hydrogen generator has a generator chamber, in which at least two electrodes are arranged and fed with electric power, for splitting water in the generator chamber electrolytically into H 2  and O 2 . 
         [0004]    2. Description of Relevant Art 
         [0005]    Hydrogen is regarded as one of the most promising future sources of energy. Hydrogen has about 2.6 times as much energy density as petrol (based on the mass). Hydrogen can be electrolytically generated with very high efficiency out of nearly limitlessly available water or, by the Kvaerner process, out of biomass. Energy stored in hydrogen can be converted by internal combustion engines into mechanical work or by a fuel cell into electric power. 
         [0006]    French patent publication with the number FR 2 778 430 discloses a rotary engine. The rotary engine has a rotor with two explosion chambers. Each of the chambers has an outlet for ignited fuel. The ignited fuel escapes through the outlets and the recoil of the escaping fuel exerts a torque on the rotor. 
         [0007]    German Patent Publication DE 2 927 973 discloses a Wankel like hydrogen engine. 
         [0008]    U.S. Pat. No. 2,458,128 discloses a steam engine with a rotor. The rotor has plurality of curved steam exit slots or channels communicating with a steam receiving channel and ending in steam exit openings. Steam is expanded when leaving the steam openings. The recoil of the expanded steam exerts a torque on the rotor. 
       SUMMARY OF THE INVENTION 
       [0009]    The object of the invention is to provide an internal combustion engine for the conversion of chemical energy stored in hydrogen, into mechanical work. A further object is to provide an efficient hydrogen generator. 
         [0010]    The internal combustion engine according to an embodiment of the invention is suitable in particular for the conversion of energy that is released by the combustion of an H 2 -0 2  mixture into mechanical work. Of course, other fuels may also be burnt in the internal combustion engine—or, for short, the hydrogen engine, as it will be also called in the following. The internal combustion engine has at least one drive shaft which is connected to a chamber component so that it rotates with the chamber component. The chamber component includes at least one explosion chamber. The explosion chamber is at least partially filled with fuel by at least one fuel supply. Then, an ignition device ignites the fuel that was introduced into the explosion chamber. The explosion chamber has at least one outlet which releases ignited fuel into the environment. Escape of ignited fuel produces a recoil which exerts a torque on the chamber component and drives it thus. The outlet is preferably constructed like a nozzle. The chamber component transfers this torque to the drive shaft. After the fuel is burnt, the explosion chamber is at least partially refilled with fuel that may be ignited again. 
         [0011]    The fuel supply includes preferably at least one channel recess in the drive shaft. The channel recess may in particular include a blind hole that is axially driven from one end into the drive shaft. The channel recess communicates preferably with a fuel channel of the chamber component. Fuel can be very easily introduced by the channel recess and, if necessary, by the fuel channel into the rotating explosion chamber of the chamber component, because the channel recess may be connected via a rotating joint to a fuel reservoir. Thus there is no need for mounting a—much more complex—rotating joint to the chamber component. 
         [0012]    At least one check valve is preferred to be integrated near the channel recess and/or the rotating joint, to prevent the explosion from provoking a light-back into the fuel reservoir. 
         [0013]    Before ignition, the fuel in the explosion chamber is preferably uncompressed, i.e. 0.85*p 0 &lt;p K (&lt;1.15*p 0 , with p S  indicating fuel pressure outside the explosion chamber and p K  signifying fuel pressure inside the explosion chamber. The explosion chamber features therefore before ignition at least about the same pressure level which is prevalent outside the explosion chamber. Thus the combustion temperatures may remain rather low, and the cooling expenditure will also remain low. 
         [0014]    The chamber component includes preferably at least one burst disk, which is situated coaxially on the drive shaft and has at least one recess, serving as an explosion chamber. An explosion chamber of this kind facilitates the introduction of fuel into the explosion chamber and its ignition there very much. The ignited fuel may escape e.g. by a lateral opening of the explosion chamber, so that its recoil generates a torque which is transferred to the drive shaft. 
         [0015]    Parallel to the axis, the explosion chamber is ideally sealed by at least one capping, preferably on both sides. Such a capping facilitates easy assembly and, if necessary, an inspection of the explosion chamber or the whole burst disk. 
         [0016]    In particular the capping(s) may include a fuel channel of the fuel supply and/or at least parts of the ignition device. This provides for a most robust and easy-to-service design of the chamber component. 
         [0017]    The fuel channel to the explosion chamber preferably has at least one valve which is closed at least during the combustion of the fuel, e.g., a check valve. This prevents light-back of the combustion into parts of the fuel supply that are found outside the chamber component. Thus it is possible to introduce by the fuel channel an ignitable fuel mixture into the explosion chamber. Consequently it is sufficient to provide for one fuel channel, possibly branching, and/or one fuel outlet per explosion chamber. 
         [0018]    The valve preferably includes a spring-loaded tappet which is shifted by at least one control cam to open and/or close the valve when the chamber component is rotating. The control cam is preferably installed at a housing of the internal combustion engine and is shaped like a ramp. The control cam may be driven out of a control disk which is connected to the housing. Preferably the position of the control cam is adjustable, so that the moment when the valve opens may be timed, i.e. the position of the valve relative to the housing towards which it is opened. The moment of opening can be timed most easily if the control cam is driven out of a control disk which may be turned relative to the housing. For example, the control disk may feature elongated holes, shaped like ring segments, through which at least one mounting bolt is driven, so that the control disk can be turned relative to the housing, if the mounting bolts are loosened, while, if the mounting bolts are tightened, the control disk will be fixed at the housing. 
         [0019]    For ignition, the ignition device includes preferentially at least one electric spark generator that rotates with the chamber component and is fed by at least one rotary joint. This allows for timing ignition almost arbitrarily. Of course the rotary joint can transfer the power required for ignition by sliding contacts and/or inductively from the non-rotating environment to the chamber component rotating inside of it, and/or to the ignition device. Since the spark generator is rotating with the chamber component, the explosion chamber can be very easily sealed. Otherwise, two mutually rotating parts would have to be sealed against each other in such a way that there was no appreciable pressure loss, even when the fuel was exploding in the explosion chambers. In addition, the sealing would have to permanently withstand explosive combustion of the fuel in the explosion chamber. 
         [0020]    The fuel supply includes preferentially at least one pipe and/or a section of a pipe, which near the chamber component is thermically insulated against the explosion chamber. This allows to transport an ignitable fuel mixture in this pipe or section without invoking spontaneous combustion of the fuel mixture inside the fuel supply, which would damage the fuel supply. Thermally insulated is supposed to mean here that there is e.g. an insulating layer between the explosion chamber and the fuel supply. The same effect can be achieved by active cooling of at least one part of the fuel supply. In particular the fuel supply can be coaxially enveloped with a cooling pipe. Of course, cooling and insulation may be also combined. 
         [0021]    Not only ignitable fuel may be filled into the explosion chambers, but preferably also a liquid which evaporates at least in parts, when exposed to the heat generated by fuel combustion, and also escapes by the outlet. Evaporation of the liquid profoundly increases the volume, so that the liquid, now turned gaseous, is pressed through the outlet, intensifying the recoil and thus the torque on the drive shaft. 
         [0022]    Also, the evaporating liquid reduces the heat that is generated by the explosion, and therefore, efficiency is increased. The liquid may be water, in particular, which is preferably injected into the explosion chamber so that it obscures the chamber at least partially. Most preferably, the liquid is first introduced into the explosion chamber, e.g., as a fog, and only after that, fuel is filled into the explosion chamber. This facilitates cooling of the explosion chamber before introducing fuel so much that spontaneous fuel combustion at hot residuals of the preceding combustion or at the hot chamber walls is prevented. Then, during the next combustion of the fuel, the liquid evaporates with all the above-mentioned advantages. 
         [0023]    The internal combustion engine accordingly includes preferably at least one coolant pipe with at least one outlet in the explosion chamber, introducing a liquid into the explosion chamber. At least a part of this liquid will evaporate during the combustion of the fuel. Efficiency can thus be increased, as described above. 
         [0024]    The outlet of the coolant pipe which is leading into the explosion chamber is preferentially designed as an atomisation nozzle. The surface of the liquid in the explosion chamber is thus increased, and the liquid will evaporate quickly and evenly. 
         [0025]    Besides, the coolant pipe contains preferably at least one coolant valve, e.g., a coolant check valve, so that any pressure developing in the coolant pipe from combustion will not vent off by the outlet but by the coolant pipe. In addition, the coolant valve allows to control timing and amount of liquid entering the explosion chamber. 
         [0026]    In particular the coolant pipe can be designed in such a way that a column of liquid will remain between the outlet leading into the explosion chamber and the coolant valve after the introduction of liquid is finished. This column of liquid is positioned in front of the valve, seen from the perspective of the explosion chamber, and will protect the coolant valve and any components behind the valve from high thermal load by heat produced by the exploding fuel. 
         [0027]    The coolant pipe is preferably installed inside the chamber component. For example, the coolant pipe may feature a U-shaped segment in the chamber component, with the lower part of the U-segment pointing radially outwards. This way, a column of liquid will remain in the U-segment when the chamber component rotates, shielding any components in that leg of the coolant pipe which is turned away from the coolant pipe&#39;s outlet—as for example a coolant check valve or any components connected to it, such as a coolant pump—against high thermal load by the heat of the exploding fuel. The explosion heats up that part of the liquid which is kept in that section of the coolant pipe which is leading towards the coolant pipe*s outlet. Then at least a part of this preheated liquid is introduced into the explosion chamber. Since it is already warmed up, less power is required to evaporate it. Efficiency can thus be further increased, while the chamber component is cooled by the inflowing liquid. 
         [0028]    Electrolytic production of hydrogen out of water was till now achieved by using metallic electrodes which are very expensive. Most astonishingly, tests have shown that carbon electrodes, which are substantially cheaper, also enable highly efficient electrolytic splitting of water. The hydrogen generator, which is in particular suitable for supplying the above described internal combustion engine with a H2-02 mixture, accordingly features a generator chamber, in which at least two carbon electrodes are arranged and connected to a power supply to be fed with electric power. 
         [0029]    When operating the hydrogen generator, the active surface of the carbon electrodes decreases in the course of time. Using in addition to the carbon electrodes at least one auxiliary metal electrode on each side, e.g., made of stainless steel, provokes a layer of coal to accumulate on the metal electrodes, so that the active surface of the electrodes will be preserved. To clean the auxiliary metal electrodes, it is enough to switch off the carbon electrodes briefly and to reverse the polarity of the auxiliary metal electrodes, e.g., only for the fraction of a second. The amassed coal dust will then fall to the ground, and the auxiliary electrodes may again accumulate fresh carbon. The voltage applied to the auxiliary metal electrodes when reversing polarity should preferably be lower than the minimum voltage required for the electrolysis of water. This facilitates the separate collection of highly purified gases (H 2  and O 2 ). 
         [0030]    Preferably, at least one of the metal auxiliary electrodes should surround one of the carbon electrodes. E.g., a cylindrical carbon electrode may be coaxially placed inside a tubular auxiliary metal electrode. 
         [0031]    The hydrogen generator includes preferably at least one emergency outlet, which is closed by at least one pressure relief valve. If the production of gases generates a pressure which is higher than the opening pressure of the pressure relief valve, then the pressure will be drained through the emergency outlet. In particular, water can be drained through the emergency outlet, for then there is no increased risk of fire or explosion, other than with the blowing off of one or both gases. At the latest when the water was completely drained, electrolysis is interrupted, i.e. no more gas is produced and thus no more pressure develops in the hydrogen generator. 
         [0032]    The hydrogen generator preferably includes at least one fan, to rapidly and thoroughly dilute any gas which was released to the environment by the emergency outlet in housing of overpressure, so that the risk of fire or explosion is reduced. The fan may be driven in particular by a brushless electric motor. Such a motor generates no sparks which could cause a fire or an explosion. 
         [0033]    The hydrogen generator preferably includes at least one pressure switch to interrupt the electrolytic splitting of water into H 2  and O 2  if the pressure in the hydrogen generator should rise above a predetermined value. In particular the pressure switch may separate electrodes from the power supply, e.g., all cathodes and/or all anodes. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]    In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment and with reference to the drawings. 
           [0035]      FIG. 1 : an internal combustion engine 
           [0036]      FIG. 2 : an drive shaft 
           [0037]      FIG. 3 : a side view of a housing 
           [0038]      FIG. 4 : a front view of the housing 
           [0039]      FIG. 5 : a burst disk 
           [0040]      FIG. 6 : a front view of the internal combustion engine (partially disassembled) 
           [0041]      FIG. 7 : a lateral cover 
           [0042]      FIG. 8 : a slip ring disk 
           [0043]      FIG. 9 : a front view of the internal combustion engine with slip ring disk, and 
           [0044]      FIG. 10 : a detail of  FIG. 9  in section, 
           [0045]      FIG. 11 : a hydrogen generator. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0046]      FIG. 1  is depicting an internal combustion engine. The internal combustion engine has a housing  50 . A side and a front view of the housing  50  are depicted in  FIG. 3  and  FIG. 4  respectively. The housing  50  supports a drive shaft  10 . The drive shaft is depicted in  FIG. 2 . The drive shaft protrudes on both sides from the housing  50  and may rotate in the housing  50  (cf.  FIG. 1 ). On one side of the housing  50 , the drive shaft features a keyway  11 , to connect e.g. a pulley, a clutch plate, a gearwheel or a similar element to rotate with the drive shaft  10 . Inside of the housing  50 , a chamber component  60  is fixed to the shaft  10  and rotating with it. The chamber component  60  includes a first cover  20  and a second cover  40 . A burst disk  30  is arranged between both of them. The drive shaft  10  has a channel recess  12  (cf.  FIG. 1 ) which is shaped like a coaxial blind hole and serving as a part of a fuel supply. The channel recess  12  communicates with a fuel channel  42  in the second lateral cover  40 . The fuel channel  42  has two branches which are leading radially outward, each issuing into a valve housing  44 . In the valve housing is a valve tappet  46  which is charged with a valve spring  48 . The valve housing  44 , the valve tappet  46  and the valve spring  48  combine into a check valve (cf.  FIG. 1 ). 
         [0047]    An injector  80  is located in the channel recess  12  of the drive shaft, conducting an ignitable fuel mixture through the channel recess  12  and the fuel channel  42  to the two valves and from there on into each one of two explosion chambers  32  of the burst disk  30 . The injector  80  is mounted swivelling in the shaft, i.e. it does not rotate with the shaft but serves as a connection for a fuel pipe. The injector possesses a check valve (not shown) which safely prevents any light-back of an explosion into the fuel pipe. The fuel duct from the injector  80  to the recesses  32  is in  FIG. 1  indicated by a line with directional arrows. 
         [0048]      FIG. 5  depicts the burst disk  30  in the front view (left) and the side view (right). The burst disk has two recesses  32 , being the explosion chambers. These, when mounted, are laterally closed by the first and second lateral covers  20  and  40  (cf.  FIG. 1 ). The explosion chambers  32  each have a nozzle-shaped outlet  34  (cf.  FIG. 5 ). The symmetric axes (not shown) of the nozzle-shaped outlets  34  of the explosion chambers  32  are secants of the radius of the burst disk  30  (as far as  FIG. 5  is concerned; three-dimensionally, they are in fact symmetry planes intersecting the enveloping cylindrical surface of the chamber component  60 ). If an ignitable fuel, e.g., a H 2 -O 2  mixture, is ignited in the explosion chambers  32 , then the developing heat causes the ignited fuel to expand in all directions, so that at least a part of the ignited fuel escapes by the outlets  34  from the explosion chamber  32 . This causes a recoil which exercises a torque on the burst disk  30 , driving the drive shaft  10  which is mounted co-rotating with the burst disk  30 . 
         [0049]    The valves have to be opened to fill the explosion chamber  32 . For this purpose there is a control disk  53  in a recess of the housing, featuring two control cams  54  which are shaped like ramps. While the chamber component is rotating with the shaft  10  inside the housing, the tappets  46  are shifted by the control cams  54  against the force of the valve springs  48 . This opens the valves, and fuel may flow into the explosion chambers  32 . The valves close shortly before the outlets  34  of the explosion chamber  32  start to communicate with the environment via housing outlets  52 . After that, i.e. when the outlets  34  are communicating via the housing outlets  52  with the environment, the fuel in the explosion chambers  32  is ignited by an ignition device  22  (only to some extent shown) which is integrated into one in the first lateral cappings, and an explosion is triggered. 
         [0050]    At least a part of the combustion product is now squeezed out of the explosion chambers via the outlets  34  of the explosion chambers  32  and the housing outlets  52 . Each explosion chamber  32  is filled and ignited twice during each full rotation of the drive shaft  10 . In the illustrated example, the internal combustion engine has therefore two power strokes per rotation. Of course the number of the housing outlets and valves can be changed, so that the internal combustion engine may feature only one or more than two power strokes per rotation. 
         [0051]    In front of the first lateral capping  20  there is a slip ring disk  70  (cf.  FIG. 8  to  FIG. 10 ). The slip ring disk  70  includes an outer rim  72 , which is connected rigidly with the housing, and an inner rim  74 , which is connected rigidly with the first lateral cover  20 . A sliding contact  76  is provided (cf.  FIG. 10 ) to electrically connect the outer and the inner rim of the slip ring. The inner rim  74  is connected to the ignition devices  22 . The ignition devices  22  are controlled by a transistor igniter (not shown) which uses at least one measuring sensor  78  to register the position of the chamber component  60  relative to the housing  50 . Using this information, the igniter controls the spark timing. 
         [0052]      FIG. 9  and  FIG. 10  indicate how the injector  80  is connected by a conduit  82  with a fuel source, e.g., a fuel tank or a hydrogen generator, feeding the internal combustion engine with fuel. The illustrated internal combustion engine is designed for operation with a H 2 -O 2  mixture (in a ratio of 2 mol of H 2  VS. 1 mol of O 2 ). For safety reasons it is useful if hydrogen and oxygen are conducted by separate pipes to the injector and mixed only as closely as possible to the explosion chamber or even inside of it. In the illustrated example the mixing takes place inside the injector. 
         [0053]      FIG. 11  shows a hydrogen generator with a generator housing  113 . Water was filled by an intake  114 , which is not shown, into the generator housing  113 . The generator housing  113  is closed by a generator housing cover  110  which may be removed for purposes of inspection. In the generator housing  113  there are two stainless steel electrodes  101 ,  112  and two coal electrodes  102 ,  111 . Each of the stainless steel electrodes  101 ,  112  is paired with one of the coal electrodes  102 ,  111 , to create an electrode couple. The generator housing  113  is divided by a partition  106  into two parts, so that on both sides of the partition  106  there is one electrode couple, combined out of either of the stainless steel electrodes  101 ,  112  and either of the coal electrodes  102 ,  111 . The partition hangs down from the generator housing cover  110  between the two electrode couples to at least the level of the lower ends of the electrode couples, so that both parts of the generator housing  113  may communicate below the partition with each other. 
         [0054]    To generate H 2  and O 2 , the stainless steel electrode  101  and the coal electrode  102 , combined into one electrode couple, are attached by connections  104 ,  105  in parallel to a pole of a power source (not shown), and the stainless steel electrode  112  and the coal electrode  111 , combined into the other electrode couple, are connected to the other pole of the power source. The voltage between both electrode couples is set on a value which is at least equal to that voltage which is needed to split water electrolytically. Accordingly, the water is split electrolytically into H 2  and O 2 . The gases rise to the generator housing cover  110 , and the two gases H 2  and O 2 , separated by the partition  106 , accumulate below the generator housing cover  110 . There they are separately drained by outlets  103  and  109 . 
         [0055]    During electrolysis, a layer of coal accumulates on the stainless steel electrodes  101 ,  112 . For removing the coal layer from the stainless steel electrodes  101 ,  112 , the coal electrodes will be separated from the power supply, and the polarity of the two stainless steel electrodes is reversed. When reversing the polarity of the stainless steel electrodes  101 ,  112 , the applied voltage should preferably be lower than the minimum voltage required to split water electrolytically, so that no O 2  and no H 2  are produced while the polarity of the stainless steel electrodes  101 ,  112  is reversed. This way, mixing of the gases is avoided. By reversing the polarity of the voltage applied between stainless steel electrodes  101 ,  112 , the coal layer comes loose of the stainless steel electrodes  101 ,  112  and drops to the floor of the generator housing  113 . There it can be sucked off. After at least of the coal layer has dropped down, the polarity of the voltage at the stainless steel electrodes  101 ,  112  is reversed back, and the coal electrodes  102 ,  111  are reconnected to the power supply. Now the voltage applied to the electrodes is set again on a level which is sufficient for the electrolytic splitting of water into O 2  and H 2 , so that the production of gas is continued. 
         [0056]    While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. 
         [0057]    It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide a hydrogen engine and a hydrogen generator. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
           10  Drive shaft 
           11  Keyway 
           12  Channel recess 
           13  Key 
           20  Lateral capping (first one) 
           22  Ignition device 
           30  Burst disk 
           32  Explosion chamber 
           34  Outlet of the explosion chamber  32 , here shaped like a nozzle 
           36  Central recess for drive shaft  10   
           38  Holes for bolts to brace the burst disk  30  between the cappings  20 . 40   
           40  Lateral capping (second one) 
           42  Fuel channel 
           44  Valve housing 
           46  Tappet 
           48  Valve spring 
           50  housing 
           52  Case outlet for combustion products 
           53  Control disk 
           54  Control cam 
           56  Case recess for drive shaft, support, etc. 
           58  Fastening for silencer 
           60  Chamber component 
           70  Slip ring disk 
           72  Outer slip ring rim 
           74  Inner slip ring rim 
           76  Sliding contact 
           78  Measuring sensors 
           79  Ignition timer 
           80  Injector 
           90  Pulley 
           101  Stainless steel electrode (e.g., anode) 
           102  Coal electrode (e.g., anode) 
           103  Outlet 
           104  Connection coal electrode 
           105  Connection stainless steel electrode 
           106  Partition 
           107  Connection stainless steel electrode 
           108  Connection coal electrode 
           109  Oxygen outlet 
           110  Generator housing cover 
           111  Coal electrode (e.g., cathode) 
           112  Stainless steel electrode (e.g., cathode) 
           113  Generator case 
           114  Water