Abstract:
A system for producing a gas includes a pressure vessel containing in its interior a feedstock and at least one set of electrodes in which an electric arc is formed between the electrodes. The system includes a mechanism for passing of the feedstock through a plasma of the electric arc thereby converting at least some of the feedstock into a gas. The system has a way to controlling the electric arc by, for example, a controller adjusting the position of the electrodes of the arc and/or voltage applied to those electrodes. The system collects the gas and during the production of the gas, the system measures at least one of a conductance of the feedstock and a viscosity of the feedstock and, based on this/these measurements, the system introduces a material into the pressure vessel such as fresh feedstock, a solvent, tap water, distilled water, etc.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. provisional application No. 62/026,096 filed on Jul. 18, 2014, the disclosure of which is incorporated by reference. 
     
    
     FIELD 
       [0002]    This invention relates to the field of gas production and more particularly to a system, method and apparatus for controlling the feedstock during production of a gas here within referred to as Magnegas. 
       BACKGROUND 
       [0003]    It has been demonstrated that, by exposing and/or flowing certain fluids through the plasma of a submerged electric arc, a unique gas is produced. The composition of the produced gas is dependent upon the feedstock in use, but the family of gases produced by exposing and/or flowing certain fluids through the plasma of an electric arc are herein referred to as Magnegas®. Various types and sources of feedstock have been used to produce Magnegas®. The resulting gas burns clean and at higher temperatures than gases occurring in nature or gases produced in different ways. 
         [0004]    In general, the feedstock is presented into a reaction chamber, in which a submerged electric arc is formed. As the feedstock is exposed to the arc, the arc releases gases from the feedstock which are captured and stored for future uses. 
         [0005]    In various systems, different methods have been anticipated to form the arc, control the electrodes, replenish/replacing the electrodes, capture the gas, capture heat produced, etc. Examples of fully operational systems for the production of Magnegas® can be found in U.S. Pat. No. 7,780,924 issued Aug. 24, 2010, U.S. Pat. No. 6,183,604 issued Feb. 6, 2001, U.S. Pat. No. 6,540,966 issued Apr. 1, 2003, U.S. Pat. No. 6,972,118 issued Dec. 6, 2005, U.S. Pat. No. 6,673,322 issued Jan. 6, 2004, U.S. Pat. No. 6,663,752 issued Dec. 16, 2003, U.S. Pat. No. 6,926,872 issued Aug. 9, 2005, and U.S. Pat. No. 8,236,150 issued Aug. 7, 2012, all of which are incorporated by reference. 
         [0006]    In many of the systems for generation of Magnegas®, the reactor (or chamber) is filled with the feedstock and then the feedstock if pumped into and/or around the plasma of the arc, producing the gas which is then collected. As time goes by, as portions of the feedstock change into gas, dissolved and/or suspended particles within the feedstock change the properties of the feedstock. For example, consider flowing salt water through such an arc over a period of time. As the water (H 2 O) is transformed into hydrogen (H) and Oxygen (O 2 ), the salt content of the remaining salt water increases. If such a process is allowed to continue, eventually the only material left in the reactor will be salt, though before that point, a very viscous liquid containing small amounts of water and large amounts of salts will be present. 
         [0007]    Likewise, in examples where the feedstock is, for example, used vegetable oils (e.g. oils previously used to cook food), as the vegetable oils transform into a gas, dissolved and/or suspended particles within the feedstock remain, again changing the properties of the feedstock such as increasing the viscosity of the feedstock and/or changing the electrical conductance of the feedstock. 
         [0008]    What is needed is a way to determine the instantaneous properties of the feedstock and introduce materials into the reactor to mitigate such changes to the properties. 
       SUMMARY 
       [0009]    A system for producing a gas including a pressure vessel containing in its interior a feedstock and at least one set of electrodes in which an electric arc is formed between the electrodes. The system includes a mechanism for passing of the feedstock through a plasma of the electric arc thereby converting at least some of the feedstock into a gas (e.g., a circulation system). The system has a way to controlling the electric arc by, for example, a controller adjusting the position of the electrodes of the arc and/or voltage applied to those electrodes. The system collects the gas (e.g. moves the gas to a storage tank). During the production of the gas, the system measures at least one of a conductance of the feedstock and a viscosity of the feedstock and, based on this/these measurements, the system introduces a material into the pressure vessel such as fresh feedstock, a solvent, tap water, distilled water, etc. 
         [0010]    In one embodiment, a system for producing a gas is disclosed. The system includes a pressure vessel containing in its interior a feedstock and at least one set of electrodes and an electric arc formed between the electrodes and within the feedstock. A device flows of the feedstock through a plasma of the electric arc thereby converting at least some of the feedstock into the gas. There is a mechanism for controlling the electric arc and a mechanism for collecting the gas. A mechanism measures at least one of a conductance of the feedstock and a viscosity of the feedstock and based upon the conductance of the feedstock and/or the viscosity of the feedstock, the mechanism introduces an amount of a material into the pressure vessel. 
         [0011]    In another embodiment, a system for producing a gas is disclosed. The system includes a pressure vessel containing in its interior a feedstock and at least one set of electrodes with a power supply electrically interfaced to the at least one set of electrodes such that an electric arc is formed between the electrodes. The electric arc is submerged within the feedstock. A circulation pump circulates the feedstock through a plasma of the electric arc where at least some of the feedstock is converted into the gas. A controller is interfaced to the power supply and controls an amount of the current provided to the electric arc. The controller also determines a viscosity of the feedstock by measuring a load on a motor driving the circulation pump and introduces a material into the pressure vessel based upon the viscosity of the feedstock. 
         [0012]    In another embodiment, a method for producing a gas is disclosed. The method includes containing a feedstock in a pressure vessel that has a set of electrodes submerged in the feedstock and controlling power that is interfaced to the electrodes, thereby forming an electric arc between the electrodes. The electric arc is also submerged within the feedstock. The feedstock is circulated through a plasma of the electric arc, thereby converting at least some of the feedstock into the gas. A viscosity of the feedstock is determined and a material is introduced into the pressure vessel based upon the viscosity of the feedstock. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
           [0014]      FIG. 1  illustrates a schematic view of an exemplary system for producing gas. 
           [0015]      FIG. 2  illustrates a second schematic view of the exemplary system for producing gas. 
           [0016]      FIG. 3  illustrates a third schematic view of the exemplary system for producing gas. 
           [0017]      FIG. 4  illustrates a fourth schematic view of the exemplary system for producing gas. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
         [0019]    Referring to  FIG. 1 , an exemplary system for the production of a combustible gas, which is typically in gaseous form as produced, but often compressed, at times, in to a liquid. This is but an example of one system for the production of such a gas, as other such systems are also anticipated. Examples of fully operational systems for the production of a gas using a submerged arc are be found in U.S. Pat. No. 7,780,924 issued Aug. 24, 2010, U.S. Pat. No. 6,183,604 issued Feb. 6, 2001, U.S. Pat. No. 6,540,966 issued Apr. 1, 2003, U.S. Pat. No. 6,972,118 issued Dec. 6, 2005, U.S. Pat. No. 6,673,322 issued Jan. 6, 2004, U.S. Pat. No. 6,663,752 issued Dec. 16, 2003, U.S. Pat. No. 6,926,872 issued Aug. 9, 2005, and U.S. Pat. No. 8,236,150 issued Aug. 7, 2012, all of which are incorporated by reference. 
         [0020]    As exemplified in  FIGS. 1-4 , the production of the gas  24  is performed within the plasma of an electric arc  18  submerged in a feedstock  22 . The electric arc  18  is formed by providing a flow of electrical current between an anode  14  and a cathode  16  that are of sufficient proximity to each other as to allow arcing between the anode  14  and the cathode  16 . A power supply  10  provides sufficient power (voltage and current) as to initiate and maintain the electric arc  18 . 
         [0021]    A feedstock  22  is circulated within a pressure reactor  12  by, for example, a circulation pump  50 . The feedstock  22  is injected into the plasma of the electric arc  18  formed between the two electrodes  14 / 16 , causing the feedstock  22  to react, depending upon the composition of the feedstock  22  and the composition of the electrodes  14 / 16  used to create the arc. One feedstock  22  is, for example, oil, and more particularly, used vegetable or animal oil such as that from deep-fat fryers, etc. Of course, any oil is anticipated, including unused vegetable oil and oil from animal fat. 
         [0022]    Any feedstock  22  is anticipated either in fluid form or a fluid mixed with solids, preferably fine-grain solids such as carbon dust, etc. 
         [0023]    In one example, the feedstock  22  is vegetable oil and the electrodes  14 / 16  are carbon, the vegetable oil molecules separate within the plasma of the electric arc  18  forming the gas  24 , typically including hydrogen (H 2 ) and carbon monoxide (CO) atoms, which percolate to the surface of the feedstock  22  for collection (e.g. extracted through a collection pipe  26 ) and stored in a collection tank  30 . This gas  24  is similar to synthetic natural gas or syngas, but the gas produced though this process behaves differently and produces a higher temperature burn. In embodiments in which at least one of the electrodes  14 / 16  that form the electric arc  18  is made from carbon, such electrode(s)  14 / 16  serve as a source of charged carbon particles that become suspended within the gas  24  and are collected along with the gas  24 , thereby further improving the burning properties of the resulting gas  24 . 
         [0024]    In examples in which the feedstock  22  is a petroleum-based liquid, the exposure of this feedstock  22  to the plasma of the electric arc  18  results in production of a gas that includes polycyclic aromatic hydrocarbons which, in some embodiments, are quasi-nanoparticles that are not stable and, therefore, some of the polycyclic aromatic hydrocarbons will form/join to become nanoparticles or a liquid. Therefore, some polycyclic aromatic hydrocarbons as well as some carbon particles will be present in the gas  24 . In some embodiments, some of the carbon particles are trapped or enclosed in poly cyclic bonds. Analysis of the gas  24 , as produced in this example, typically shows inclusion of polycyclic aromatic hydrocarbons that range from C6 to C14. The presence of polycyclic aromatic hydrocarbons as well as carbon particles contributes to the unique burn properties of the gas  24  that is produced. The gas  24  that is produced has higher burning temperatures. 
         [0025]    In another example, when the feedstock  22  is petroleum based (e.g. used motor oil) and at least one of the electrodes  14 / 16  is/are carbon, the petroleum molecules separate within the plasma of the electric arc  18  into a gas  24  that includes hydrogen (H 2 ) and aromatic hydrocarbons, which percolate to the surface of the feedstock  22  (e.g. petroleum liquid) for collection (e.g. extracted through a collection pipe  26 ) and stored in a collection tank  30 . In some embodiments, the gas  24  produced though this process includes suspended carbon particles since at least one of the electrodes of the electric arc  18  is made from carbon and serves as the source for the charged carbon particles that travel with the gas  24  (including hydrogen and aromatic hydrocarbon) and are collected along with, for example, the hydrogen and aromatic hydrocarbon molecules, thereby the gas  24  produced as describe burns with a hotter flame temperature. In this example, if the feedstock  22  is oil (e.g. used oil) and the fluid/gas  24  collected includes any or all of the following: hydrogen, ethylene, ethane, methane, acetylene, and other combustible gases to a lesser extent, plus suspended charged carbon particles that travel with the gas  24 . 
         [0026]    In another example, when the feedstock  22  is water based (e.g. sewerage or waste water) the water molecules separate within the plasma of the electric arc  18  into a gas  24  that includes hydrogen (H 2 ), which percolates to the surface of the feedstock  22  for collection (e.g. extracted through a collection pipe  26 ) and stored in a collection tank  30 . In some embodiments, the gas  24  produced though this process includes suspended carbon particles since at least one of the electrodes  14 / 16  is made from carbon and serves as the source for the charged carbon particles that travel with the gas  24  and are collected along with, for example, the hydrogen molecules, thereby changing the burning properties of the gas  24  to produce a hotter flame temperature when burned. 
         [0027]    The resulting gas is stored in, for example, a collection tank  30  and moved/distributed as known in the gaseous/liquid fuel industry. 
         [0028]    In the example shown in  FIG. 1 , a circulation pump  50  flows the feedstock  22  through the plasma of the electric arc  18  formed between the electrodes  14 / 16 . In such, manual adjustment of the arc, power, and refilling of the feedstock are performed. 
         [0029]    In the example shown in  FIG. 2 , the circulation pump  50 , the power supply, and/or the electrodes  14 / 16  are controlled by a control system  40 , typically a computer-based controller. The control system  40  monitors the performance of the electric arc  18 , controlling the current flowing through the electric arc  18  by the power supply  10 , moving the anode  14  and/or cathode  16  closer to each other or farther away from each other to adjust the resulting plasma of the electric arc  18 , cycling the electrodes  14 / 16  as one or both electrodes  14 / 16  erode due to the electric arc  18 , and adjusting speed of the circulation pump  50  and, therefore, flow rate through the plasma of the electric arc  18 . 
         [0030]    As some of the feedstock  22  is transformed into the gas  24 , the feedstock  22  that remains becomes more viscous, especially when impurities are suspended in the feedstock  22 . One example of such is a feedstock  22  of used motor oil. As the viscosity of the feedstock  22  increases due to higher concentrations of, for example, fine metal particles, it takes more work for the circulation pump  50  to maintain the same flow rate through the plasma of the electric arc  18 . In some embodiments, the load of a motor driving the circulation pump  50  is measured, which will correlate the viscosity of the feedstock  22  being pumped. As the load of the motor increases, the control system  40  increases power to the circulation pump  50  to maintain a certain level of flow, for example, a constant flow rate. In other embodiments, a viscosity sensor  42  provides a signal to the control system  40 , informing the control system  40  of the current viscosity of the feedstock  22  and the control system  40  adjusts the pump speed to compensate for the measured viscosity. At some point, the measured viscosity or the load of the motor driving the circulation pump  50  exceeds a pre-determined level, the control system  40  indicates such to an operator for stopping, cleaning, and/or refilling the system. The viscosity sensor  42  is any sensor known anticipated for use in this application. 
         [0031]    In the example shown in  FIG. 3 , a feedstock replenishment pump  62  and a feedstock replenishment tank  60  containing fresh feedstock  23  is included to the example of  FIG. 2 . In this, the circulation pump  50 , the power supply  10 , the feedstock replenishment pump  62 , and/or the electrodes  14 / 16  are controlled by the control system  40 . The control system  40  monitors the performance of the electric arc  18 , controlling the current flowing through the electric arc  18  by the power supply  10 , moving the anode  14  and/or cathode  16  closer to each other or farther away from each other to adjust the resulting plasma of the electric arc  18 , cycling the electrodes  14 / 16  as one or both electrodes erode due to the electric arc  18 , and adjusting the speed of the circulation pump  50  and, therefore, flow rate through the plasma of the electric arc  18 . The control system  40  also controls the feedstock replenishment pump  62 , signaling the feedstock replenishment pump  62  to pump additional feedstock  22  from a feedstock replenishment tank  60  containing additional feedstock  22 . 
         [0032]    As some types of feedstock  22  are transformed into the gas  24 , the feedstock  22  remaining in the pressure reactor  12  becomes more viscous, especially when impurities are suspended in the feedstock. One example of such is used motor oil, as the oil content is converted to gas  24  by the plasma of the electric arc  18 , the remaining feedstock  22  (oil) becomes more concentrated with, for example, suspended fine-grain metal particles. As the viscosity of the feedstock  22  increases, it takes more work for the circulation pump  50  to maintain the same flow rate through the plasma of the electric arc  18 . In some embodiments, the load of a motor driving the circulation pump  50  is measured, which will correlate the viscosity of the feedstock  22  being pumped. In some embodiments, a viscosity sensor  42  provides a signal to the control system  40 , informing the control system  40  of the current viscosity of the feedstock  22 . When the control system  40  finds the viscosity to be too high, the control system  40  either adjusts the speed of the circulation pump  50  to compensate for the high viscosity or initiates operation of the feedstock replenishment pump  62  for a specific period of time to further dilute the feedstock  22  within the pressure reactor  12  with fresh feedstock  23  from the feedstock replenishment tank  60 . In some systems the control system  40  does both, adjusting the pump speed to compensate for the high viscosity and initiating operation of the feedstock replenishment pump  62  to insert a certain amount of fresh feedstock  23 . In some embodiments, the feedstock replenishment pump  62  is operated for a specific period of time or until the measured viscosity lowers to a predetermined level. It is anticipated that various level and pressure sensors are used to make sure that the pressure reactor  12  is not overfilled, etc. 
         [0033]    It is also anticipated that, at some point in the operation, the measured viscosity exceeds a pre-determined level and the control system  40  indicates such to an operator for stopping, flushing, cleaning, and/or refilling the system. 
         [0034]    In this same example, as some types of feedstock  22  are transformed into the gas  24 , the conductivity of these feedstocks  22  changes due to certain dissolved or suspended materials concentrating in the feedstock  22  remaining within the pressure reactor  12 . One example of such is water containing salts. It is known that pure water does not conduct electricity (e.g. distilled water), but as salts are added to this pure water, water with suspended salts now conducts electricity. If the concentration of salts in the feedstock  22  within the pressure reactor  12  increases to a certain level, operation of the electric arc  18  will be affected. Likewise, in examples where the feedstock  22  is used motor oil, as the concentration of fine-grain particles of metal in the used motor oil increases, so does the conductivity of the feedstock  22 . 
         [0035]    As the conductivity of the feedstock  22  within the pressure reactor  12  increases, operation of the electric arc  18  is affected. In some embodiments, the load (current flow) of the electric arc  18  on the power supply  10  is measured, which will correlate the conductivity of the feedstock  22  being pumped through the plasma of the electric arc  18  as well as the distance between the electrodes  14 / 16 . In some embodiments, a conductivity sensor  44  provides a signal to the control system  40 , informing the control system  40  of the present conductivity of the feedstock  22 . When the control system  40  finds the conductivity to be too high, the control system  40  either changes position of the electrodes  14 / 16  and/or initiates operation of the feedstock replenishment pump  62  for a specific period of time to further dilute the feedstock  22  within pressure the reactor  12  with fresh feedstock  23 . In some embodiments, the feedstock replenishment pump  62  is operated for a specific period of time or until the measured conductivity lowers to a predetermined level. It is anticipated that various level and pressure sensors are used to make sure that the pressure reactor  12  is not overfilled, etc. 
         [0036]    Referring now to  FIG. 4 , a similar system to that described in  FIG. 3  but instead of a feedstock replenishment pump  62  and a source of fresh feedstock  23 , a secondary material tank  70  and secondary material pump  72  is included. In this, the circulation pump  50 , the power supply  10 , the secondary material pump  72 , and/or the electrodes  14 / 16  are controlled by the control system  40 . Again, the control system  40  monitors the performance of the electric arc  18 , controlling the current flowing through the arc by the power supply  10 , moving the anode  14  and/or cathode  16  closer to each other or farther away from each other to adjust the resulting plasma of the electric arc  18 , cycling the electrodes  14 / 16  as one or both electrodes erode due to the electric arc  18 , and adjusting the speed of the circulation pump  50  and, therefore, flow rate through the plasma of the electric arc  18 . The control system  40  also controls the secondary material pump  72 , signaling the secondary material pump  72  to pump a quantity of a secondary material  25  from a secondary material tank  70  that contains this secondary material  25 . Any secondary material  25  is anticipated. Examples of secondary materials  25  include, but are not limited to, distilled water, tap water, petroleum-based solvents, alcohol, turpentine, etc. 
         [0037]    As some types of feedstock  22  are transformed into the gas  24 , the remaining feedstock  22  becomes more viscous, especially when impurities are suspended in the feedstock  22 . One example of such is used motor oil, as the oil content is converted to gas  24  by the plasma of the electric arc  18 , the remaining feedstock  22  (oil) becomes more concentrated, for example, with suspended fine-grain metal particles. As the viscosity of the feedstock  22  increases, it takes more work for the circulation pump  50  to maintain the same flow rate through the plasma of the electric arc  18 . In some embodiments, the load of the motor that drives the circulation pump  50  is measured, which correlates the viscosity of the feedstock  22  being pumped. In some embodiments, a viscosity sensor  42  provides a signal to the control system  40 , informing the control system  40  of the current viscosity of the feedstock  22 . When the control system  40  finds the viscosity to be too high, the control system  40  either adjusts the speed of the circulation pump  50  to compensate for the high viscosity or initiates operation of the secondary material pump  72  for a specific period of time to further dilute the feedstock  22  within the pressure reactor  12  with the secondary material  25  from the secondary material tank  70 . In some systems the control system  40  does both, adjusting the pump speed to compensate for the high viscosity, and initiating operation of the secondary material pump  72  to insert a certain amount of the secondary material  25 . In some embodiments, the secondary material pump  72  is operated for a specific period of time or until the measured viscosity lowers to a predetermined level. It is anticipated that various level and pressure sensors are used to make sure that the pressure reactor  12  is not overfilled, etc. In the example with used motor oil as the feedstock  22 , a secondary material  25  such as a solvent will dilute the used motor oil, either reducing the viscosity of the used motor oil, reducing the conductance of the used motor oil, or both. 
         [0038]    It is also anticipated that, at some point in the operation, the measured viscosity exceeds a pre-determined level and the control system  40  indicates such to an operator for stopping, flushing, cleaning, and/or refilling the system. 
         [0039]    As some types of feedstock  22  are transformed into the gas  24 , the conductivity of these feedstocks changes due to certain dissolved or suspended materials concentrating in the remaining feedstock  22 . One example of such is water containing salts. It is known that pure water does not conduct electricity (e.g. distilled water), but as salts are added to this pure water, water with suspended salts now conducts electricity. If the concentration of salts in the feedstock  22  within the pressure reactor  12  increases to a certain level, operation of the electric arc  18  will be affected. 
         [0040]    Over time, the conductivity of the feedstock  22  within the pressure reactor  12  increases and operation of the electric arc  18  is affected. In some embodiments, the load of the electric arc  18  on the power supply  10  is measured, which will correlate the conductivity of the feedstock  22  being pumped through the plasma of the electric arc  18  as well as the distance between the electrodes  14 / 16 . In some embodiments, a conductivity sensor  44  provides a signal to the control system  40 , informing the control system  40  of the present conductivity of the feedstock  22 . When the control system  40  finds the conductivity to be too high, the control system  40  either changes position of the electrodes  14 / 16  and/or initiates operation of the secondary material pump  72  for a specific period of time to further dilute the feedstock  22  within the pressure reactor  12  with the secondary material  25 . In some embodiments, the secondary material pump  72  is operated for a specific period of time or until the measured conductivity lowers to a predetermined level. In the example of a feedstock  22  of salts dissolved in water, as the water molecules are converted into the gas  24 , the salt content of the remaining feedstock  22  increases, as does the viscosity and/or conductivity of the remaining feedstock  22 . In this example, when the control system  40  determines that the viscosity and/or conductivity exceeds a predetermined threshold, the secondary material pump  72  is activated for a period of time or until the viscosity and/or conductivity decrease to a lower predetermined threshold. In this example, the secondary material  25  is preferably distilled water, tap water, or pure water, having lower amounts of salts (e.g. tap water). 
         [0041]    It is anticipated that various level and pressure sensors are used to make sure that the pressure reactor  12  is not overfilled, etc. It is also anticipated that, in some embodiments, any combination of pumps  62 / 72  are present with any combination of additional fresh feedstock  23  and one or more secondary material(s)  25 . For example, in one embodiment, a feedstock replenishment pump  62  adds more fresh feedstock  23  (e.g. raw sewerage) and a secondary material pump  72  adds more secondary material  25  (e.g. fresh water). In another example, one secondary material pump  72  adds more of a first secondary material  25  (e.g. fresh water) and another secondary material pump  72  adds more of a different secondary material  25  (e.g. distilled water). Any number and combination of pumps  62 / 72 , feedstock replenishment tank  60 , and secondary material tanks  70  are anticipated. It is also anticipated that, for certain sources of fresh feedstock  23  and secondary material  25 , the fresh feedstock  23  and/or secondary material  25  are not stored in tanks  60 / 70  and, instead, are fed directly from sources of such materials, for example, directly from sewerage lines, water lines, dredge systems, ocean water pumps, etc. 
         [0042]    Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. 
         [0043]    It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.