Abstract:
A heated blanket is presented that includes a heat mesh contained therein for uniform heating of the heated blanket. Also presented is a system for heating an article including the aforementioned heated blanket and an optional thermostat for measuring the temperature of an article to be heated. As the temperature of the article departs from a preset temperature range, the thermostat controls power to the heated blanket thereby either completing or interrupting the electrical supply to the heated blanket depending on whether the article must be cooled or warmed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/549,415 having a filing date of Oct. 20, 2011. 
    
    
     BACKGROUND 
     A heated blanket is presented for use in industrial applications such as the automotive, chemical, or other industrial settings. Oftentimes, bulk fluids or chemicals are stored in 55-gallon drums, 400 gallon totes, or in other conventionally-sized containers whereby the applicability, the consistency, and/or the efficacy of the fluid may be compromised as it cools below temperatures normally recommended for its use. In particular, although not thereby limited, an exemplary use of the present blanket is for the maintenance of a residual temperature of chemicals typically stored perhaps outside, in warehouses, or in other areas where the storage area is not necessarily heated. 
     Accordingly, the blanket is contemplated for use in a wrap-around configuration for example. As such, a 55-gallon drum of chemical such as a polymeric blend, or an oil-based fluid might include a heated blanket secured about its periphery. In this way, the temperature may be maintained at a predetermined temperature or temperature range as per the manufacturer&#39;s recommendations, or at a temperature that does not compromise the safe handling or storage of the bulk fluid or chemical. Other uses for the present blanket are also contemplated and include ground thawing applications, concrete curing applications, material curing applications, work mats, and so forth. 
     Certain challenges exist with the current state-of-the-art heated blankets. For example, ensuring safe heating of the blanket with the heating element is one concern. Secondly, ensuring substantially uniform heating across the surface of the heating blanket is yet another concern. Additionally, ensuring that the heated blanket is properly controlled to ensure heating within the desired range is yet another challenge. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a blanket formed in accordance with the present invention. 
         FIG. 2  is a cross-section of  FIG. 1 . 
         FIG. 3  is a schematic diagram of a blanket interfacing with a storage vessel for a desired chemical, wherein control of the bulk fluid temperature is illustrated. 
     
    
    
     SUMMARY OF THE INVENTION 
     A heated blanket is presented that includes a heat mesh contained therein for uniform heating of the heated blanket. Also presented is a system for heating an article including the aforementioned heated blanket and an optional thermostat for measuring the temperature of an article to be heated. As the temperature of the article departs from a preset temperature range, the thermostat controls power to the heated blanket thereby either completing or interrupting the electrical supply to the heated blanket depending on whether the article must be cooled or warmed. 
     Stated another way, the invention may be described as a heating system containing a blanket for heating an article; a first outer panel of the blanket defining an area having a first region or corner, a second region or corner, a third region or corner, and a fourth region or corner; a heating element of the blanket proximate to or adjacent to the first outer panel and substantially coextensive with the area defined by the first outer panel, said heating element fixed to the first outer panel on at least one of the first, second, third, and fourth corners; a power source in electronic communication with the heating element; a second outer panel of the blanket adjacent to the heating element and substantially coextensive with the area defined by the first outer panel, the second outer panel joined to the first outer panel; and a thermostat in thermal communication with an article to be heated by the blanket, the first thermostat in electronic communication with the power supply. 
     DETAILED DESCRIPTION OF THE INVENTION 
     A heating system  10  contains a heatable blanket  11  as shown in  FIG. 1 . The blanket  11  includes a cover or casing  12  that includes an outer panel  12   a  and an inner panel  12   b , and may if desired be weather resistant (e.g. waterproof), and/or heat and/or fire resistant (e.g. made from a fire retardant material), for example. A cross-section of  FIG. 1  is presented as  FIG. 2 . The cover  12  may be formed from vinyl, silicone cloth, fiberglass cloth, or from trade materials known as Cordura® or Kevlar®, for example. The particular application will determine the cover  12  material, as will be appreciated by one of ordinary skill in the art. As shown in the FIGURES, an exemplary blanket  11  includes a first outer panel or layer  12  containing a material such as vinyl, or any other suitable covering for the blanket  11 . The first outer panel  12  surrounds and preferably seals most of the other constituents of the blanket  11 , and thereby functions as a housing. A second layer  14  may be provided and may be juxtaposed to the first outer layer  12  and formed from a foil material such as an adhesive foil pad. The foil material  14  forms an insulating barrier between the first layer  12  and other layers described below. 
     A third layer  16  may be juxtaposed to the second layer  14  and is radially inward therefrom, whereby the second layer  14  is sandwiched between the first layer  12  and the third layer  16 . In an alternative embodiment, the third layer  16  may be “proximate” to the first outer layer  12 , in the event the second layer  14  is not utilized. When used in this context, the term “proximate” is meant to denote and convey that the third layer  16  is either immediately adjacent (juxtaposed) to outer layer  12 , or, that it is near but perhaps not immediately adjacent to layer  12 . For example, layer  14  may be sandwiched between layers  12  and  16  and layer  16  may still be described as being “proximate” to layer  12 . The third layer  16  is a conductive and/or radiating heating material that emanates heat as electricity is passed therethrough. An exemplary material useful as the third layer/heating element  16  may be a mesh or weave formed from a lattice of carbon conductor covered with a polymeric but heat conducting material. Unlike many heating elements, during operation, the mesh  16  thereby provides uniform heating across the area of the mesh. The third layer  16  may be purchased for example as a product known as “heat net” from Space Int., Ltd. of Kanseok Dong, South Korea. The heating element  16  may also be purchased for example, from Centech Co., Ltd of Hwaseong-si in South Korea. U.S. Pat. No. 7,781,706 is instructive, and is hereby incorporated by reference as if fully stated. An electrical power source  18  is configured with the third layer/heating mesh  16  in a known manner to provide power throughout carbon conductors of the heat mesh. As shown in  FIG. 1 , the electrical source is an AC source of 120 VAC, but other sources such as an AC source of 240 VAC, or a battery source having 12/24 VDC may also be employed, as will be appreciated by one of ordinary skill in the art. The mesh or third layer  16  may be generally formed from a carbon yarn or carbon thread conductor that is encased with a polymer such as silicone. Or, the mesh layer  16  may alternatively be formed as some other carbon composite conductor encased within a polymer such as silicone. It will be appreciated that the silicone/polymer will have a predetermined thermo-conductivity that may be iteratively determined based on the power applied and based on the type of polymer encasement, and also based on the thickness of the polymeric substrate. 
     Ultimately, the mesh  16  is fixed across a substantial area of the blanket  11  to co-extend across the area  12   c  defined by either the front panel  12   a  or the inner panel  12   b , but internally of the blanket  11 . A fixing means or fastener  20  fixes the mesh  16  to span across the area of the blanket  11  by providing a plurality of attachment zones at various locations of the heat mesh  16 . Migration or general movement of the mesh  16  during use of the blanket  11  is thereby prevented or substantially prevented to ensure a c9ontinual uniform heating across the area of the blanket. The fixing means  20  may be a plurality of fasteners  20  such as heat-resistant fasteners that extend through panel  12   a  through the mesh  16  and ultimately through panel  12   b  wherein the mesh is then secured in place in a known way, such as by shank rivets, lock and key fasteners, button fasteners, bayonet fasteners, and other known suitable fasteners. Alternatively, another fixing means  20  may simply be a plurality of stitches, where each attachment zone is defined by a stitching that extends through the interstitial area of the mesh  16  and then attaches/sews the mesh  16  to panel  12   a  and/or  12   b . The plurality of attachment zones that define the fixing means  20  may preferably be configured to support the mesh at least at a top left area or corner  12   c  and top right area or corner  12   d , and at least at a bottom left area or corner  12   e  and a bottom right area or corner  12   f . Accordingly, when the term “corner” is used herein, it refers to a general area proximate to the actual corner of the blanket. Yet another alternative to the fixing means  20  may simply be an adhesive backing applied to the mesh  16  that then fixes the mesh on the foil layer  14 , again across the surface area  12   c  defined by  12   a  or  12   b . It will be appreciated that any fixing means  20  may be employed that retains the mesh in a position that is substantially co-extensive with the area of the blanket  11  as defined by panel  12   a  or panel  12   b.    
     As shown in  FIGS. 1 and 3 , a first thermostat  24  preferably electronically communicates with the electrical supply and the interior of the blanket  11 , thereby controlling the temperature of the blanket  11  responsive to other control parameters described below or as otherwise known. One control parameter may be the surface of a container  21  to be warmed and temperature-controlled for example. Accordingly, the thermostat  24  is configured in a known manner to measure the temperature of the surface of the container or some other appropriate control surface and to switch on the electrical power supplied to the heat mesh grid  16  once the temperature is reduced below a preset temperature range. 
     A second optional thermostat  25  including a temperature sensor (not shown) may be included wherein the second thermostat may be submerged within a fluid  23  contained within the container  21 . Stated another way, the second thermostat may thermally communicate with an article  27  such as container  21  and/or fluid  23  to be heated. Other “articles” that may be heated include concrete, floors, or work mats for example. As the fluid temperature fluctuates, either colder or hotter, the thermostat  25  by and through its sensing means may then, based on a preset temperature range for example, electronically communicate with the power supply in a known way, to complete or interrupt the power supply to the blanket  11 , thereby providing a secondary heat control of a blanket heating system  10  in accordance with the present invention. 
     Stated another way, the blanket  11  is adapted to thermally respond to a thermostat  25  in thermal communication with an article  27  to be heated. It will be appreciated that the temperature of the blanket controlled by the first thermostat  24  may be markedly different than the temperature of the bulk fluid or substrate that may optionally be controlled by the second thermostat  25 . For example, it may be necessary to heat the blanket to a relatively greater temperature to provide the necessary heat transfer to the fluid  23 , thereby controlling the fluid at a relatively lower temperature. Probe immersion thermostats providing sensor temperature control may be provided by companies such as DeVale Industries of Buford, Ga., United States of America. Certain probe immersion thermostats provided by DeVale for example, are thermally sensitive bi-metallic switch assemblies that provide reliable control of fluids and air. 
     An in-line ground fault circuit interrupter (GFCI)  26  may be employed as a safety precaution and to ensure that the risk of electrical shock is mitigated or eliminated. As shown in  FIG. 1 , the GFCI may be simply hard-wired or connected to the power supply  18  and to the blanket  11 , thereby interrupting electrical power in the event of a hazardous condition such as a wetting of the blanket  11  for example. 
     A fourth layer  28  may be provided and contains an EVA foam insulation layer  28  that provides a cushion about the vessel to be wrapped, and also provides an insulation to save power needed to heat the bulk fluid contained within an associated vessel  21 , shown in  FIG. 3 . Again, other substrates or materials to be heated may include concrete, batteries, and other areas exposed to relatively cold conditions. 
     Finally, the inner panel  12   b  covers the foam layer  28  and is attached to the outer panel  12   a  by stitching or heat sealing inner panel  12   b  to the outer panel  12   a , thereby providing a sealed blanket  11 . Other sealing means may be employed if desired. Ultimately, a blanket  11  is provided that exhibits uniform heating across its area in a manner heretofore not realized. 
     The outer panel  12   a  may contain straps or other restraining means (not shown) that may be used to strap the blanket  11  about the vessel (not shown). It will be appreciated that as known in the art, the blanket may be sized and shaped to accommodate a myriad of shapes of vessels. Alternatively, the outer panel  12   a  may contain grommets or other fasteners that may be used to secure or tie down the blanket  11  on substrates such as concrete, for example. 
     In sum, the present invention may be basically stated as being, a heatable blanket containing a first cover panel  12   a ; a second layer/foil layer  14  adjacent/juxtaposed to the first cover panel  12   a ; a heating/conducting element  16  adjacent/juxtaposed to the second layer  14  and fixed across and substantially co-extensive with the area defined by the first cover panel  12   a ; a power source  18  electronically communicating with the heating element  16 ; and a second cover panel  12   b  attached to the first cover panel  12   a . The constituents or components of the present invention are off-the-shelf items and may be supplied by known manufacturers. Various references that teach related items may be described in U.S. Pat. Nos. 5,931,343, 3,668,367, 7,880,121, and 7,851,729, wherein the teachings of each reference are herein incorporated by reference as if fully stated. 
     It will be appreciated that the various embodiments and features described herein are merely illustrative and exemplary, and are not meant to limit the invention. As such, the invention should be given full breadth consistent with the range of equivalents that may be found relative to each constituent, consistent with the appended claims.