Patent Publication Number: US-6986326-B1

Title: Additional security for a steam boiler

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention pertains generally to boilers, and more particularly to steam boilers and safety devices for consumer steam boilers. 
   2. Related Art 
   Portable steamers which may be used for cleaning have become increasingly popular in recent years. Steaming devices used to apply steam to household objects are well known. The uses of the devices vary widely, and may include application of steam to drapes or other fabrics to ease wrinkles, and application of steam to objects to assist in cleaning the objects. 
   Conventionally, portable steamers can be battery-powered or can be electrically powered by a power cord which may be plugged in a conventional electric outlet. Typical steam devices may use the electrical power to power a heating element to heat water in a steam generation unit, or boiler. The heated water generates steam, which may be directed towards its intended destination through a nozzle which controls application of the steam. Nozzles may typically be disconnectable from the steam generation unit to allow different nozzles to be used, based on the object to be steamed. The nozzle may be closely coupled to the steam generation unit, or may be located at a distance from the steam generator and may be coupled by tubing or other steam transfer structures interconnecting the steam generator and discharge nozzles. Most steamers have a hose which may be used to transport the steam from the steam generation unit, or boiler, to the point of use of the steam. 
   Various safety mechanisms exist to guard against dangers of excess pressure buildup in a steam boiler. 
   One conventional safety feature prevents inadvertent release of steam when attaching or removing a hose, concentrator nozzle, or other accessories. 
   SUMMARY OF THE INVENTION 
   In accordance with an exemplary embodiment of the present invention, an improved boiler for use in a steam generating device may include a second pressure relief device calibrated to relieve pressure at a higher second pressure level than a conventional first pressure relief device in a filler cap which is calibrated to relieve pressure at a lower first pressure level. 
   According to an exemplary embodiment of the present invention, a steam generation apparatus may include: a housing; a boiler adapted to generate steam within the housing; a filler cap adapted to be removably coupled to the boiler; a first pressure relief device coupled to the boiler adapted to release steam at a first pressure level; and a second pressure relief device coupled to the boiler adapted to release the steam at a second pressure level, where the second pressure level is higher than the first pressure level, the first pressure relief device is incorporated into and is made to vent into the filler cap, and the second pressure relief device is made to vent internally to the housing. 
   According to one exemplary embodiment of the present invention, the boiler may be constructed of stainless steel; or aluminum. 
   According to one exemplary embodiment of the present invention, the first pressure relief device may include a spring type pressure release valve. 
   According to one exemplary embodiment of the present invention, the second pressure relief device may include a brass octagon valve threaded into a wall of the boiler. 
   According to one exemplary embodiment of the present invention, the boiler may be included as part of a steam cleaner; or an iron steam station. 
   According to another exemplary embodiment of the present invention, the first pressure level may be calibrated to release at approximately 4 Bar to 6 Bar of pressure. 
   According to one exemplary embodiment of the present invention, the second pressure level may be calibrated to release at a higher pressure level than the first pressure level. In one exemplary embodiment, the second pressure level may be approximately 10 Bar to 15 Bar. 
   According to one exemplary embodiment of the present invention, the steam generating apparatus may further include a thermostat. In an exemplary embodiment, the thermostat may include a temperature sensor proximate to the boiler and a control system adapted to shutoff a heating element of the boiler upon sensing a threshold temperature. 
   According to one exemplary embodiment of the present invention, the apparatus may further include a fuse proximate to the boiler adapted to cutoff power to a heating element of the boiler if a temperature in excess of a fuse melting temperature is exceeded. 
   According to another exemplary embodiment of the present invention, the apparatus may further include a water level sensor adapted to cutoff power to a heating element proximate to the boiler if a water level in the boiler falls below a threshold water level. 
   According to one exemplary embodiment of the present invention, the apparatus may further include a hose coupled to the boiler at an outlet; and a nozzle coupled to the hose. According to one exemplary embodiment of the present invention, the nozzle may include a steam pocket nozzle; a steam pocket body; and a steam pocket towel. 
   According to yet another exemplary embodiment of the present invention, a boiler for a steam generation apparatus may be set forth. In an exemplary embodiment, the boiler may be adapted to generate steam. The boiler may further include a first pressure relief device coupled to the boiler adapted to release steam at a first pressure level; and a second pressure relief device coupled to the boiler adapted to release the steam at a second pressure level, where the second pressure level is higher than the first pressure level, and the second pressure relief device is adapted to release pressure in the event of malfunction of the first pressure relief device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of exemplary embodiments of the invention, as illustrated in the accompanying drawings. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digits in the corresponding reference number. A preferred exemplary embodiment is discussed below in the detailed description of the following drawings: 
       FIG. 1  depicts a boiler including dual high and low pressure relief valves in accordance with an exemplary embodiment of the present invention; 
       FIG. 2  depicts a blown up detail of the first and second pressure relief valves in accordance with an exemplary embodiment of the present invention; 
       FIG. 3A  depicts an exemplary boiler and a housing of an exemplary steam generation device having first and second pressure relief valves in accordance with an exemplary embodiment of the present invention; 
       FIG. 3B  depicts an exemplary hose group and handle having a trigger of a steam generation device in accordance with an exemplary embodiment of the present invention; 
       FIG. 3C  depicts exemplary accessories including pipes, a steam pocket floor brush, a squeegee, a shoulder strap, a funnel, and packing materials in accordance with an exemplary embodiment of the present invention; and 
       FIG. 4  depicts a parts list table providing an exemplary list of components of the steam generation device of  FIGS. 3A–C  according to an exemplary embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION 
   Various exemplary embodiments of the invention are discussed in detail below including a preferred embodiment. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art can recognize that other components and configurations may be used without parting from the spirit and scope of the invention. 
     FIG. 1  depicts diagram  100  illustrating an exemplary embodiment of a boiler  102  having a first pressure relief device  104 , and a second pressure relief device  106 , according to an exemplary embodiment of the present invention. According to an exemplary embodiment, the first pressure relief device  104  may be placed in a filler cap as shown. In an exemplary embodiment, the first pressure relief device may be any of various conventional spring relief valve pressure release mechanisms which are well known. Further details of an exemplary pressure relief valve may be found in U.S. Pat. No. 4,168,723, the contents of which are incorporated herein by reference in their entirety. According to an exemplary embodiment, the first pressure relief device  104  may vent steam into the filler cap if pressure exceeds a first pressure level. According to an exemplary embodiment, the second pressure relief device  106  may be adapted to sense pressure reaching a second pressure level. According to an exemplary embodiment, the second pressure level may be a higher pressure level than the first pressure level and may act as a safety appartus to provide a backup to the first pressure release device  104  in the event of pressure release malfunction. 
   In an exemplary embodiment of the present invention, a safety device is set forth for the boiler  102 . In one exemplary embodiment, the safety device may be used with a boiler  102  that is used in a steam application. In an exemplary embodiment of the present invention, the boiler  102  may be constructed out of material including, but not limited to, e.g., aluminum or stainless steel. 
   Conventionally, most steam boilers  102  used in steam cleaners and in iron steam stations, include only a single first pressure relief device  104  in a filler cap. This single pressure relief device may include a mechanical relief valve device with a spring, or other bias loaded release, biased to remain closed until a threshold pressure level is reached, causing venting of the gas or steam through a fluid port. 
   Conventionally, in steamers, a heating element heats water in the boiler  102 . Conventional steamers also include a thermostat. The thermostat may include a temperature sensor and a control circuit. The thermostat may conventionally sense the temperature inside the boiler and when the temperature reaches a particular level, the heating element may be disconnected from the electrical power by the the control circuit. Temperature has a direct relationship with pressure, so as temperature rises, pressure rises. Thus the thermostat may act to prevent excess pressure buildup in the boiler  102 . 
   The first pressure relief device  104  may come into play in the event of a malfunction such as, e.g., but not limited to, a thermostat malfunction. For example, if the thermostat malfunctions, in some cases, the fluid in the boiler may continue to heat and pressure might build inside the boiler  102 . The first pressure relief device  104  may be set to release pressure at a calibrated pressure. If the first pressure relief device  104  reaches its calibrated pressure, steam may be released via the exemplary pressure relief valve in the filler cap, avoiding any harm to the boiler. An exemplary first pressure relief security cap may be calibrated to release steam at, e.g., but not limited to, approximately 4 Bar and 6 Bar. In another exemplary embodiment, the first pressure relief security device may have a calibrated pressure level of approximately 7 Bar. 
   Conventionally, if because of some malfunction, temperature continues to rise in the boiler, at some point a fuse may melt causing the heating element to become deenergized and stopping further heating. In an exemplary embodiment, a 172 degrees C. thermal fuse may be used. When a fuse melts down, the steam generating unit typically may become inoperative and the unit may need to be sent back to an authorized servicer to be serviced. 
   In the event of certain malfunctions (e.g., failure of the thermostat to cut off, failure of the fuse to cutoff power, or failure of the first pressure relief device  104  in the filler cap to release accumulated pressure), in some cases it might be possible that pressure could continue to build within the boiler. In such a case, conventionally, even with the many conventional safety mechanisms, a potentially dangerous situation might arise where pressure might continue to accumulate in the boiler. As a means of backup of the various other safety features of a steam generating device, an exemplary embodiment of the present invention provides a further security safeguard, by providing a secondary pressure relief device  106 , as shown in  FIG. 1  and  FIG. 2 . 
   As shown in more detail in  FIG. 2 , according to an exemplary embodiment of the present invention, a second steam relief device  106  may be added to the boiler  102 . As shown, in an exemplary embodiment, the second pressure relief valve  106  may include a fluid port  202 . As shown, in an exemplary embodiment, the second pressure relief device  106  may be an octagonal pressure relief device  106  which may be placed in the wall of boiler  102 , as shown. In an exemplary embodiment, the secondary relief device  106  may be calibrated to release pressure at a higher pressure level than the first pressure level. As shown, in an exemplary embodiment, the second pressure relief device  106  may be a pressure release valve and may be placed on top of the boiler  102 . According to an exemplary embodiment, the second pressure relief device  106  may be calibrated to release steam at a pressure higher than the pressure rating of the first pressure relief device  105 . In an exemplary embodiment, the higher, second pressure level, at which the second pressure relief valve  106  may be calibrated to release pressure, may be, e.g., but not limited to, a pressure range of approximately, 10 Bar to 15 Bar. The second pressure relief device  106 , in the exemplary embodiment, may provide another level of safety security to the boiler  102 , in the event of pressure exceeding the first pressure level of the first pressure relief device  104 . 
   The second pressure release device  106  may make the boiler  102  much more secure than conventional boilers used in conventional steamers.  FIGS. 1 and 2  depict a steam boiler  102  with a conventional first pressure relief device  104  in a filler cap.  FIG. 1  further depicts a second pressure relief device  106 , having a fluid port  202 , which in an exemplary embodiment may be made to vent steam into an outer housing of the steam generation device, upon pressure reaching a higher second pressure level, according to the present invention.  FIG. 2  further illustrates at  204  an outlet which would normally be coupled to a hose and/or nozzle for steam use. 
     FIG. 3A  depicts an exemplary boiler  300  and a housing  301  of an exemplary steam generation device having first and second pressure relief valves in accordance with an exemplary embodiment of the present invention. Various exemplary components are illustrated and defined in the parts list table of  FIG. 4 . Boiler  300 , in an exemplary embodiment, may include a boiler top  36 , a boiler bottom  36 , heating elements  37 ,  38 , insulation  45 , various o-rings, washers, and nuts. According to an exemplary embodiment, boiler  102  may include a first pressure relief device  104 , in a filler cap  33 , including, a 7 Bar security valve pressure relief device  104 , and a second pressure relief device  106 , including a higher pressure rating of e.g., 15 Bar. According to an exemplary embodiment, housing  301  may include right body portion  1 , left body portion  2 , windup covers  3  for receiving a power cord, and/or a hose, and various washers, screws, bearings and stoppers. As shown, a thermal fuse  163  may included, as well as a lamp  162  for indicating whether the heating element is heating. 
     FIG. 3B  depicts an exemplary hose group  302  and handle  84 ,  98  having a trigger  81  of a steam generation device in accordance with an exemplary embodiment of the present invention. Various exemplary components are illustrated and defined in the parts list table of  FIG. 4 .  FIG. 3B , in an exemplary embodiment, includes a hose  74 , a handle including a left handle cover  98 , a right handle cover  84 , a trigger  81 , various valve covers, springs, pistons, o-rings, tubes, clamps, cables, lock washers, screws, clamps, flanges, couplings. 
     FIG. 3C  depicts exemplary accessories including pipes  303 , a steam pocket floor brush  304 , a squeegee  306 , a shoulder strap  315 , a funnel  316 , and packing materials  311 ,  312 ,  317  in accordance with an exemplary embodiment of the present invention. Various exemplary components are illustrated and defined in the parts list table of  FIG. 4 . In an exemplary embodiment, the steam generation device may include a floor brush  304  including a steam pocket towel  318  covering a steam pocket body  372  coupled to a steam pocket nozzle  371 , with steam pocket lock pin  373 , o-rings  374 , and floor brush adapter  370 . Advantageously, the floor brush is reversible, providing for double the surface area of a conventional floor brush.  FIG. 3C  further includes an exemplary pipe group  303  illustrating exemplary pipes  149 , with inner pipe  145 ,  147 , o-rings, button and spring.  FIG. 3C  further illustrates an exemplary squeegee  306  as may be used for cleaning, e.g., windows, floors, etc. Various accessories of the steam generation device are further illustrated including, e.g., a shoulder strap  315 , a funnel  316 , terminal socket group  313 , and power cord  305 . Further, exemplary packing materials may include sponge packing  312 , box  311 , and bag  317 . 
     FIG. 4  depicts a parts list table providing an exemplary detailed list of exemplary, but not limiting, components of the exemplary steam generation device of  FIGS. 3A–C  according to an exemplary embodiment of the present invention. 
   While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. While this invention has been particularly described and illustrated with reference to a preferred embodiment, it will be understood to those having ordinary skill in the art that changes in the above description or illustrations may be made with respect to formal detail without departing from the spirit and scope of the invention.