Abstract:
The purpose of the invention is to divert all of the city or industrial wastewater, and particularly to prevent the pathogenic elements from flowing back to the rivers or waterways. The product of the whole process will be decontaminated, transformed into fertilizer and brought to the farmlands and forests through networks of hoses. The new idea is to treat municipal and industrial organic waste and wastewater by a methanation process in floating bioreactors revolving on themselves by air ejected underneath. Various new valves, pumps, and a new model of steam engine are created for the process. The gas produced furnishes a source of heat and its pressure is used for the functioning of the whole system. All the actions of the system, mixing, heating and pumping, are self-motion, and in the end, the new steam engine activates generators that produce electricity.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    A petition for the grant of a patent on the same invention was filed with the Canadian Intellectual Property Office and a filing certificate has been issued with the application number 2,875,345 and a filing date of Dec. 16, 2014. At the time, the title of the invention was stated as LE PROCEDE DE METHANISATION GILLES NADON. The title will be changed to FLOATING METHANATION SYSTEM (in French SYSTEME DE METHANISATION FLOTTANT). The Canadian Intellectual Property Office has attributed the international classification CO2F 11/04 (2006.01) to the application. 
         [0002]    A certified copy of the filing certificate will be forwarded by mail. 
         [0003]    The applicant is claiming the benefit of this prior-filed pending application. 
       BACKGROUND OF THE INVENTION 
       [0004]    The invention is in the field of the treatment of wastewater by methanation. 
         [0005]    Methanation is a process that transforms putrescible material into a gas by anaerobic digestion. The putrescible material is mixed, in a closed tank, during several weeks. In this milieu, microorganisms are formed that will nourish themselves from the putrescible material. The products of this process are: a biogas that can be refined into methane and a digestate usually dehydrated to be used as a fertilizer. 
         [0006]    For centuries, it is known that gas can be produced from sediments. Equatorial developing countries have constructed bioreactors that consist of an airtight dome with tunnels diametrically opposed to create a chamber where bacteria consume excrements and produce the gas used for cooking and lighting. 
         [0007]    Countries with a colder climate have taken up the idea to generate electricity, sometimes adding cultivated material to the input, each of them reproducing the airtight chamber as stationary structures above the ground were the mixing and heating elements are accessory. The problems related to such structures concern the costs involved in building and operating them, and the energy needed for mixing and heating the contents. 
         [0008]    High costs are also involved when the energy produced has to be used as a force to mix the contents when the conditions that facilitate the movement are absent. When the movement has to be applied to the mixture in a stationary structure, the force never achieves its autonomy of movement because it is too slow. The stagnating elements tend to clog and to annihilate the force. 
         [0009]    Considerable energy is also needed to maintain the very precise temperatures essential to create a favorable environment for the microorganisms to transform the material into biogas. The energy has to drive through clogged elements when the construction is fully exposed to a rigorous climate. 
         [0010]    Concerning the waste disposer, one of the problems that seem to be related to the current state of technology in this domain is the odor emanating. 
         [0011]    A research has been conducted by Eric Fincham &amp; Company. This research has yielded information concerning five existing U.S. patents in related fields of endeavor. These are listed in the attached letter from the agent dated Jul. 28, 2015. None of the existing patents have demonstrated a floating system such as the one that is claimed in this application. 
       SUMMARY OF THE INVENTION 
       [0012]    The technical field to which the invention relates is the treatment of wastewater by methanation. 
         [0013]    It is common to build stationary processors where different means are used for mixing and heating. 
         [0014]    The new idea is floating vessels revolving on themselves by the action of air being ejected from beneath them. Revolving in water keeps the process in perfect temperature and totally blends all the content, and the invention includes an odorless waste disposer unit. 
         [0015]    In the proposed invention, the processors consist of cylindrical vessels floating in water, mixing their content by revolving on themselves by the action of air ejected from underneath that lodges into buckets set as the teeth of a circular saw. 
         [0016]    The invention aims to bring solutions to the problems identified in the background section, i.e. structure problems, as well as mixing and heating problems. 
         [0017]    The new approach aims to be economical with regards to the structure of the containers simply because they float with their contents, in perfect relaxation, and by adding to the vessel flotation rings that annihilate its own weight. 
         [0018]    The invention also aims to perform well with respect to the mixing of the contents or substrate by being more economical pertaining to the energy required. Revolving in water engages all elements in a collective momentum, from a multiplied force, because of the constant free power of each air bubble captured by the exterior buckets and grouped as a lifting force. 
         [0019]    As for the heating problems, the fact that the processor is floating in water and bathing under the ground level, it is not exposed to cold. Furthermore, it is possible to easily establish entirely homogeneous and precise temperatures that are needed for the mesophilic and thermophilic processes. 
         [0020]    The invention also entraps the gas production in all processors to rise it in pressure and use it as power to several assets and new embodiments expressed as follows: 
         [0021]    Pressure in each vessel will be arranged in a decreasing cascade from one to one to push the sludge through all of them. 
         [0022]    Gas pressure will activate pumps that will supply the air to revolve the processors. 
         [0023]    Gas pressure will also activate hydraulic pumps to add to fluid pressure that will power sludge inlet pumps. 
         [0024]    The gas pressure will activate rotary pumps that will carry all the incoming water through some of the process stages, and all the way through a network of hoses through rivers, streams and ditches to bring the matter as fertilizer which most is decontaminated to farmlands and wild land. 
         [0025]    Finally, the gas will boil distilled water to run a steam engine that will drive a generator and transfer the heat in the system and purify most of the wastewater. 
         [0026]    The putrescible material that is to be treated by the methanation process would preferably come from the sewage systems; therefore, the invention proposes an odorless waste disposer unit. This device addresses the problem of odor emanating from the sink by flooding the chopping chamber with water and using a swivel plug that leaves a gap of fresh water from the last use of the tap. 
     
    
     
       BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWINGS 
         [0027]      FIG. 1  illustrates a sectional side elevation view of an immersed processor where the exterior air conduit would make it revolve, and consequently inside gas bubbles would go up while the heavy material would go down. This figure could be used as the front page illustration. 
           [0028]      FIG. 2  represents a general view of the spirit of the system. 
           [0029]      FIG. 3A  is a perspective view of a processor with a cut showing the inside. 
           [0030]      FIG. 3B  is a sectional perspective view of the inside of the exit end of a processor. 
           [0031]      FIG. 3C  is a sectional perspective view of the outside of the exit end of a processor, also showing a sinking reservoir that receives heavy material to be discarded. 
           [0032]      FIG. 4  shows the different pumps and other apparatuses for the functioning of the system. 
           [0033]      FIG. 5  is a sectional elevation view of the primary inlet pump. 
           [0034]      FIG. 6A  shows a partial perspective view of the heat exchanger. 
           [0035]      FIG. 6B  shows a close-up partial view of the coil scrapers inside the heat exchanger tubes. 
           [0036]      FIG. 7A  shows sectional elevation views of the primary inlet pump, and of the first swiveling valve exhaust pump, also illustrating the hydraulic match in-between these two pumps. 
           [0037]      FIG. 7B  is a sectional elevation view of the second and last swiveling valve exhaust pump. 
           [0038]      FIG. 8A  is a cut elevation view of the inside of the swiveling valve, showing the cross-directional tunnels. 
           [0039]      FIG. 8B  is an exploded diagonal view of the swiveling valve, and its casing. 
           [0040]      FIG. 8C  is a cut top view of the swiveling valve, showing the command of rotation and the balls transfer connection. 
           [0041]      FIG. 8D  is an expanded cut view of the balls transfer connection. 
           [0042]      FIG. 9A  is a sectional elevation view of the air pump. 
           [0043]      FIG. 9B  is an expanded view of the valve portion of the air pump. 
           [0044]      FIG. 10  is a sectional elevation view of the hydraulic pump. 
           [0045]      FIG. 11  shows a diagram of the hydraulic addition of each element. 
           [0046]      FIG. 12  shows a diagram of the ideal display of all components of the system, including the hydraulic power line. 
           [0047]      FIG. 13A  shows an elevation cut view of the rotary pump. 
           [0048]      FIG. 13B  shows a perspective view of the rotary pump. 
           [0049]      FIGS. 13C and 13D  show expanded views of the flap water valves in the rotary pump. 
           [0050]      FIG. 14A  shows a detailed expanded cut view of the rotary valve. 
           [0051]      FIGS. 14B, 14C, and 14D  show detailed expanded sectional views of the inside of the rotary valve. 
           [0052]      FIG. 15  shows a perspective elevation view of the steam engine. 
           [0053]      FIG. 16A  shows a detailed perspective elevation view of the ascending slopes of the hoses in the network of hoses. 
           [0054]      FIGS. 16B and 16C  show detailed expanded views of the floating valve on top of the elbow and Y connections in the hoses. 
           [0055]      FIG. 17A  is a perspective cut view of the waste disposer unit showing the chopping chamber. 
           [0056]      FIG. 17B  is an exploded view of the waste disposer unit showing the bypass valve. 
           [0057]      FIG. 17C  is a perspective cut view of the waste disposer unit showing the swivel plug and the float. 
           [0058]      FIG. 17D  is a perspective cut view similar to  FIG. 17A  showing the watertight plug. 
           [0059]      FIGS. 17E, 17F, and 17G  show different embodiments of the waste disposer unit for industrial uses. 
           [0060]      FIG. 17H  shows a close-up sectional view of the waste disposer unit showing the grid. 
           [0061]      FIG. 17I  shows a partial expanded view of the motor, the grid, and the back blade of the waste disposer unit for the purpose of pumping. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0062]    Referring to the drawings in greater detail and by reference characters thereto, there is illustrated an anareobic methanation system that works by means of multiple cylindrical vessels (bioreactors or processors) almost totally immersed in water. A sectional side view of one of these bioreactors is shown in  FIG. 1 . 
         [0063]    Each immersed vessel is a pressurized cylindrical bioreactor  10 , comprising flotation rings  11  positioned at each end to stabilize its horizontal level. Air buckets  12  are positioned along the longitudinal middle shell to trap air ejected through a conduit  13  beneath the vessel  10 , and to use this air as a force to revolve the vessel  10 , and mix its content. These can be viewed in  FIG. 2  and  FIG. 3A . Since there are several processors, the first one of a series is designated as processor  10   a , the middle ones that can be more or less numerous are designated as  10   b ,  10   c ,  10   d , etc., and the last processor is designated as processor  10   z.    
         [0064]    Other buckets  14  (see  FIG. 3A ) are positioned inside the revolving vessels  10  facing in the opposite direction from the outside ones  12  to grab and mix the contents by sinking the gas, and floating elements while raising the heavy matter from the bottom to let it sink back, crossing the climbing gas bubbles. 
         [0065]    Each vessel has an inlet and outlet spout  15  in the middle point of its longitudinal ends. The spouts  15  leave the bioreactors free to swivel into inlet and outlet conduits  16  that drive and exhaust the substance from vessel to vessel. The conduits  16 , drawing from a surface point, could be used to maintain the position of the processors  10 . The spouts  15 , and the conduits  16  are best seen in  FIG. 3A . 
         [0066]    Because the purpose of the invention is to divert all of the wastewater, and particularly to prevent the pathogenic elements from flowing back to the rivers or waterways, the gas created from the solid and putrescible matter is trapped in each processor to rise in pressure and activate a chain of mechanical motions. These will be explained in more detail later. 
         [0067]    In  FIG. 3A , it can be seen that the inlet conduit  16  carries a pipe  17  releasing the gas captured inside the top portion of the vessels  10 . This pipe  17 , coming from the top space inside the vessel  10  where the gas accumulates, could cross the inlet conduit  16  at the elbow  18 , follow this conduit  16  to the outside surface of the basin where the gas could be held by a pressure relief valve, and directed to all the apparatuses for the functioning of the system. 
         [0068]    As can be seen in  FIG. 3B , inside the exit end of each vessel, there is a spiral channel  19  used to screw the heavy stuff from the bottom through the outlet spout  15 . The first vessel  10   a , used to decant the unwanted matter such as sand and gravel, has helical flatbars  19   b  along its inside shell to plow it quickly. The exhaust plumbing elbow  18 , could carry a lower extra port  19   c  to let the heavy stuff fill a sinking reservoir  19   d  that a valve will empty from the pressure of the vessel when the said reservoir  19   d  has sunk to a certain level. 
         [0069]    In addition to the floating and rotating processors, several types of pumps and other apparatuses are part of the invention for the functioning of the whole system. 
         [0070]    There is a primary inlet pump  20 , heat exchangers  30 , a first swiveling valve exhaust pump  40 , a second and last swiveling valve exhaust pump  50 , air pumps  60 , hydraulic pumps  70 , rotary pumps  80 , and rotary steam engines  90 . For illustration purposes, these have all been grouped together in  FIG. 4 . 
         [0071]    Inlet of substance to the first processor is supplied by the primary inlet pump  20  controlled from a shut-off valve  201  that opens or closes the hydraulic line  25  (see  FIG. 5 ) depending on the level of immersion of the processor. Flow from vessel to vessel goes through a shut-off valve  202  (shown in  FIG. 3A ) on the inlet conduit  16  of all the processors following a cascade of decreasing pressure from one to the other. A diagram showing the ideal display of all components of the system including the hydraulic power line  25  is shown in  FIG. 12 . 
         [0072]    The primary inlet pump  20  (best viewed in  FIG. 5 ) would preferably be positioned at the sludge level, so as not to require any suction force. It is made of diaphragms  21 , shaped as typical vehicle tires except the reinforcement display and the elastomer component. It is acting from two hydraulic cylinders  22  and  23 , attached to a middle hollow shaft  24 . One cylinder  23  is following the hydraulic action of its parallel first swiveling valve exhaust pump  40 , and the main cylinder  22  is driven by the hydraulic power line  25 , ideally through a mechanical pilot valve  26 . 
         [0073]    The sludge flows through check valves  27 , penetrates, and escapes the pump diaphragms from a bottom path  28  relative to each diaphragm so that no low cavity spots will be left to retain heavy substance. 
         [0074]    The crossed hydraulic connection  29 , in-between the primary inlet pump  20  and the first swiveling valve exhaust pump  40  (best seen in  FIG. 7A ) serves to squeeze the pressure force created by the heat exchanger  30  as a vise action. 
         [0075]    The heat exchangers  30  (seen in  FIGS. 6A and 6B ) are standard equipment, but these hold coil scrapers  31  inside their tubes. These scrapers  31  (seen in  FIG. 6B ) will turn occasionally to remove any sticking matter from the inside walls of the tubes. The scrapers  31  could turn by a hydraulic motor driven by the hydraulic power line. Each of them could be activated independently by dog shifters, engaging in sprockets. 
         [0076]    The first swiveling valve exhaust pump  40  (see  FIG. 7A ) is a diaphragm pump identical to the primary inlet pump  20  except that it acts from a swiveling valve  41  (seen in  FIGS. 7A and 7B , and in more detail in  FIG. 8A to 8D ) that shifts the sludge direction from one diaphragm  21  to the other to retain the pressure until the stroke lets it free. 
         [0077]    As best seen in  FIG. 8B , the form of the swiveling valve  41 , sitting in its casing  42 , is conic to use the perfect fit as a sealing force to retain the entering pressure, and seal in-between the pieces. The swiveling valve  41  has two cross-directional tunnels  43 , reaching each diaphragm  21 , when it turns from side to side. 
         [0078]    The swiveling valve  41  is driven to reverse its alignment at the end of each stroke of the pump action. To break the taper squeezing force of the swiveling valve  41  in its casing  42  while turning, the device of rotation  44  transfers its motion to balls  45 , lugged in-between conic holes  46  of which the facing angle is perpendicular to the swiveling valve  41  taper edge. Activating the shifting motion pushes back the conic swiveling valve  41 , so that the pressure keeps the gap closed while turning with no friction. The swiveling valve  41  makes a back and forth half-rotation to prevent the winding of unwanted material. During the turning movement, the cross-directional tunnels  43  start from their full openings to a diaphragm  21 , go through a surface of total obstruction to arrive finally to the other full openings to a second diaphragm  21 , giving access to the reverse direction without losing anything. 
         [0079]    The second and last swiveling valve exhaust pump  50  (shown in  FIG. 7B ) is identical to the first swiveling valve exhaust pump  40  except that the fluid produced from its cylinder strokes transfers indirectly to the mechanical pilot valve  26  of the primary inlet pump  20  by increasing its pressure by several hydraulic pumps  70  along the hydraulic power line  25  by check valve systems (see  FIG. 11  and  FIG. 12 ). 
         [0080]    The swiveling valve  41  of the said second and last swiveling valve exhaust pump  50  will shift mechanically from the end of each stroke but the stroke action will be controlled according to the end of gas production from a shut-off valve  200  on its hydraulic power line connection  25 . This can be viewed in  FIG. 12 . 
         [0081]    A flow meter is adjusted to let a measured quantity of gas escape the last processor. When the gas pressure reduces under a rated range, the last swiveling valve exhaust pump  50  will be free to operate under the processing pressure, consequently letting the last processor  10   z  receive new material. 
         [0082]    Air pumps  60 , illustrated in  FIGS. 9A and 9B , supply the air to revolve the processors. They work off the pressurized gas through proportional diaphragm sizes  61   a  and  61   b  to transfer high pumping volume into big diaphragms  62 , increasing the volume of air, and reducing the pressure to a level sufficient to plunge as deep as underneath the processors  10 . A way of acting a pump is expressed in a drawing ( FIG. 9B ) illustrating a sliding valve  63 , retained momentarily in one of two groove positions  64  on the main hollow shaft  65  of the air pump. Valve  63  directs the gas to inflate a first diaphragm  61   a  whose action will activate a middle wider air diaphragm  62 , and collapse the opposite gas diaphragm  61   b , then releasing its gas content. 
         [0083]    At the end of the stroke, the running course will have compressed a bumper spring  66  before breaking the stubbing position, and shift the valve back to the next groove  64  that reverses the direction. 
         [0084]    Hydraulic pumps  70  (see  FIG. 10 ) would run typically as the air pumps except the pumping force of the cylinder  71  is a stage action adding to the arriving force from the hydraulic power line  25  from check valves. In the invention, all hydraulic actions could be stages adding to each other. Alternatively, one single proportional pump could be used for the same purpose. 
         [0085]    Another way of driving the air and hydraulic pumps could be by accessory valves available on the market. 
         [0086]    The product of the whole process will be fertilizing matter and purified water destined to be brought to the farmlands and forests through networks of hoses that will be described later. 
         [0087]    For the purpose of creating a steady ram to push the fertilizing substance through the long hoses course (kilometer wise) in the rivers, streams, ditches, and underground conduits, rotary pumps  80  have been imagined. 
         [0088]    These rotary pumps  80  (best seen in  FIG. 13A to 13D ) have a bent shaft  81  turning in the middle of a steady bottom diaphragm spider  82   a , rocking an identical top diaphragm spider  82   b , making each diaphragm  84   a  and  84   b  pump consecutively. Inlet and outlet of water could be controlled by flap water valves shown in  FIGS. 13C and 13D . 
         [0089]    The motion power of the rotary pump comes from the pressurized gas driving through ports  86   a  on one side of the rotary valve body  87  (shown in  FIGS. 14B, and 14D ) that follows the rotation of the bent shaft  81 , and blows inner and smaller diaphragms  84   a  that force the bent shaft to turn. Ports  86   b  on the other side of the rotary valve body  87  are for releasing the pressure. Broken arrows in  FIGS. 14B and 14D  show the flow direction of the gas, water or steam. 
         [0090]    In the same spirit as the swiveling valve  41 , where a taper contact face ensures the perfect sealing, its contact load comes from the gas pressure  88   a  against a flange  88   b  surrounding its body  87 . 
         [0091]    Like for the swiveling valve  41 , balls  89   a , lodged in taper holes  89   b , apply a pulling force, acting against the friction of the taper contact. 
         [0092]    Steam engines  90  could function on the same principle as the rotary pumps  80 . They can run only by using two rotary valves  85  connected one on each diaphragm spider  82   a  and  82   b  as illustrated in  FIG. 15 . One will drive water to be pumped from the middle and smaller diaphragms  84   b , and that water running out steadily with pressure will be boiled, and the steam will be directed from the other rotary valve to activate the outer and bigger diaphragms  84   a . The rotating energy can be used to power generators that produce electricity. 
         [0093]    Describing the whole process: 
         [0094]    The sludge is pumped into a heat exchanger  30 , from a primary inlet pump  20 . This sludge is heated and its pressure is trapped in-between a primary inlet pump  20 , and a swiveling valve  41  acting into a first swiveling valve exhaust pump  40  for the purpose of killing all the germs and exploding the particles when releasing the pressure. A ratio in-between the size of diaphragms  21  of the two pumps allows the pressure to create a self-motion. 
         [0095]    The sludge is then released at a lower pressure into the first processor  10   a  to flow from one processor to the other, as many as needed until a second and last swiveling valve exhaust pump  50  releases it from the last processor  10   z  because the production of gas is over. 
         [0096]    The transfer to the first processor  10   a , used for the decantation of sand, gravel, and unwanted particles is regulated by a shut-off valve  201 , mounted on the hydraulic circuit  25  of the dual pumps. This shut-off valve controls the sludge entering according to the flotation level of the processor  10   a . And so on and so forth in-between all subsequent processors  10   b ,  10   c ,  10   d , etc. until the last processor  10   z . Shut-off valves  202  (seen in  FIG. 3A ), proportional and attached to the sludge inlet conduits  16  of all the processors  10  except the first one  10   a , operate according to the flotation level of each processor. 
         [0097]    The total gas produced is proportional in volume to all the wastewater to be processed. This pressurized gas is used for four purposes. 
         [0098]    First, it will activate air pumps  60 , ideally from the production of gas of each processor to furnish the air for rotation. Secondly, it will activate hydraulic pumps  70 , adding to the hydraulic power line  25  subsequent fluid pressure from one to one. Thirdly, it will push the sludge from processor to processor in a cascade of decreasing inside pressure from one to the other. Fourthly, it will drive rotary pumps  80  that will push all the water through the system and the hose network  100 . This network will be described later. 
         [0099]    Since that gas is still all available, it will be used to produce heat in a gas burner to boil distilled water to drive new steam engines  90  that power generators. Then, that steam will cool down in heat exchangers  30  that act as the process heat supply. 
         [0100]    Because there is an abundance of gas, the heat exchangers  30  will also boil as much of the wastewater as possible and mix it with the purified sludge being released from the processors. 
         [0101]    This highly fertilizing purified material, coming out of processor  10   z , is mixed with the purified water, pushed with a constant pressure through networks of hoses  100 , following the bottom of rivers, streams, and ditches to bring the fertilizer to the farmlands. The remaining water is destined to the forests and wild land through a parallel network of hoses  100 . 
         [0102]    To create ascending slopes whenever they are needed, the hoses  100  are installed on top of a pile  101 . Floating valves  102 , set at the top of elbow and Y connections  103 , release the gas bubbles that might still be creating although the production cycle of gas is theoretically over. These elements are shown in  FIGS. 16A, 16B, and 16C . 
         [0103]    Since the ideal way to bring the putrescible material to the processors is by way of the sewage systems, the principle of an odorless waste disposer unit  300  is part of the invention. The waste disposer unit is illustrated in  FIG. 17A to 17I . 
         [0104]    In order to achieve the odorless grinding of waste material, the principle consists of the retention of water flooding the chopping chamber  301 , establishing a ring of clean water around a swivel plug  302  from the ultimate flow of the tap (seen in  FIG. 17A ). The siphon that maintains the water level is equipped with a bypass valve  303  (seen in  FIG. 17B ) that allows complete drainage when maintenance is required. The plug  302  can be tilted and removed (seen in  FIG. 17C ) to facilitate the passing through of the objects. A watertight plug  304  ( FIG. 17D ) can be added over when one wishes to fill the sink. 
         [0105]    A float  305  (shown in  FIG. 17C ) can be used to activate the mechanism when water accumulates in the sink. 
         [0106]    This waste disposer unit can be fabricated in different sizes and adapted to commercial and industrial uses. A few possible embodiments are illustrated in  FIGS. 17E, 17F, and 17G . 
         [0107]    The waste disposer unit segments the objects by slicing them, or by tearing them up several times while they swirl in the water. This process of cutting and tearing continues until the material is reduced to fragments small enough to go through a conical grid  306  (shown in  FIG. 17H  and  FIG. 17I ). 
         [0108]    Behind the conical grid, there may be one or several back blades  307  (seen in  FIG. 17I ); their cutting edges segment the particles coming through the openings of the grid  306 . The tail edges of the blades rise apart as a propeller pitch to create a vortex to pump the material. 
         [0109]    It will be understood that the above described embodiments are for purposes of illustration only, and that changes or modifications may be made thereto without departing from the spirit and scope of the invention.