Patent ID: 12215826

DETAILED DESCRIPTION

Cryogenic dewars may be used to transport cryogenic liquids, such as Oxygen, Nitrogen, and Argon, at low temperatures. Cryogenic dewars may include a first, inner tank, mounted inside and supported by a second, outer, tank. The use of nested tanks may insulate the cryogenic liquid to help maintain low temperatures of the liquid during transport. An example illustration100of a cab106pulling a trailer104holding a cryogenic dewar102is shown inFIG.1. Transportation of cryogenic liquids on federal highways is regulated by a variety of statutory provisions, such as the Surface Transportation Assistance Act of 1982 and the Federal Bridge Formula. Such provisions require that vehicles transporting cryogenic liquids on federal highways comply with certain weight and size guidelines. For example, many trailers for transporting cryogenic liquids may be 102 inches wide and at least 48 feet long, although some trailers may be between 28 feet and 48 feet. A maximum weight on trailer axels may be 20,000 pounds, while a maximum weight on tandem axels may be 34,000 pounds. A gross allowable weight for a trailer hauling a cryogenic dewar and the cargo may be 80,000 pounds. Trailers for transportation of cryogenic liquids may be between forty and forty-two feet long, or more, carrying the maximum weight of 80,000 pounds. However, such length may render trailers difficult to maneuver, particularly in urban areas where tight turn radiuses may be desirable. Furthermore, trailers made of heavy materials, such as steel, may have a high weight, even when not transporting cryogenic liquids. However, a dewar102and/or a trailer104made primarily or completely from aluminum may have a substantially lower empty weight. Aluminum trailers and dewars may also be resistant to corrosion. Furthermore, aluminum has a high strength-to-weight ratio and may maintain structural integrity of cryogenic dewars and or trailers while lowering an overall weight of the dewars and/or trailers. A lower trailer and/or dewar weight may allow a maximum amount of cryogenic liquid to be stored and transported on a shorter trailer, allowing for enhanced maneuverability of the trailer and reducing transportation costs. For example, a spacing between axels of the trailer, such as between first and fifth axels of the trailer and cab and/or between second and fifth axels of the trailer and cab, may be reduced while maintaining compliance with federal and state regulations. For example, a trailer length104may be reduced to less than thirty-five feet, such as thirty-four feet or thirty-two feet, hauling loads of 75,500 or 74,500 pounds, respectively.

An example cryogenic dewar200is shown inFIG.2. The cryogenic dewar200may include a plurality of trunnion mounts202A-C and204A-C for mounting an inner tank of the dewar (not shown) to the outer tank208of the dewar200. For example, a first set of trunnion mounts202A-C may be mounted between a rear of the inner tank of the dewar200and a rear of the outer tank208of the dewar200. A first trunnion mount202A may be mounted on a curb side of a rear portion of the dewar200. A second trunnion mount (not shown) may be mounted on a road side of the rear portion of the dewar200, opposite the first trunnion mount202A. A third trunnion mount202B may be mounted on a top of the rear portion of the dewar200. A fourth trunnion mount202C may be mounted on a bottom of the rear portion of the dewar200opposite the third trunnion mount202B. Thus, each trunnion mount of the first, second, third, and fourth trunnion mounts202A-C may be spaced across from one of the four trunnion mounts and approximately equidistant around a circumference of the dewar200from the other two of the four trunnion mounts. A second set of four trunnion mounts204A-C may be mounted between a front of the inner tank of the dewar200and a front of the outer tank208of the dewar200. A fifth trunnion mount204A may be mounted on a curb side of a front portion of the dewar200. A sixth trunnion mount (not shown) may be mounted on a road side of the front portion of the dewar200, opposite the first trunnion mount204A. A seventh trunnion mount204B may be mounted on a top of the front portion of the dewar200. An eighth trunnion mount204C may be mounted on a bottom of the front portion of the dewar200opposite the third trunnion mount204B. Thus, each trunnion mount of the fifth, sixth, seventh, and eighth trunnion mounts204A-C may be spaced across from one of the four trunnion mounts and approximately equidistant around a circumference of the dewar200from the other two of the four trunnion mounts. The eight trunnion mounts202A-C and204A-C may provide enhanced stability to the inner tank of the dewar200and its contents. For example, the trunnion mounts202A-C and204A-C may provide enhanced stability for lightweight dewars constructed primarily or completely of aluminum handling complex forces that may be encountered by the dewar200during transportation of cryogenic liquids. In some embodiments, the only portion of trunnion mounts202A-C and204A-C visible from an exterior of the dewar208may be a plurality of patch plates welded or otherwise fixed in place over the internal trunnions. The location of the first and second sets of four trunnion mounts may vary along the length of the dewar200, but in some embodiments the first four tunnion mounts may be located in a front quadrant of the dewar200and the second four trunnion mounts may be located in a back quadrant of the dewar200.

Some dewars may require external offloading systems to offload cryogenic liquids once the dewar has reached its destination. A lightweight dewar, such as a dewar constructed primarily from aluminum may include an internal offloading system, or one located on the same trailer as the lightweight dewar, while transporting a similar volume of cryogenic liquids to an amount contained in a dewar made of steel and remaining within federal weight limits. Including an offloading system in the dewar200or on a trailer transporting the dewar200may enhance the efficiency and speed of offloading cryogenic liquids. A dewar200may include multiple valves206A-C.

An example cross section300of a cryogenic dewar showing positioning of trunnion mounts302A-D is shown inFIG.3. For example, trunnion mounts302A-B,302D may be analogous to trunnion mounts202A-C or204A-C, as shown inFIG.2. As shown inFIG.3, the four trunnion mounts302A-D may be aligned about a circumference of the dewar300. For example, the dewar300may include an outer tank304and an inner tank306housed within the outer tank. The inner tank306may be connected to and supported by the outer tank304by a plurality of trunnion mounts302A-D. The plurality of trunnion mounts302A-D may be coupled to an outer surface of the inner tank306and may extend through a portion or entirety of the outer tank304. For example, the outer tank304may include windows or cutouts for the trunnion mounts302A-D. In some embodiments, patch plates may be welded or otherwise attached to a surface of the outer tank304over openings in the outer tank304for each of the trunnion mounts302A-D. In some embodiments, additional reinforcing metal work and/or welding, such as one or more internal longitudinal support stiffeners, may be attached to an interior surface of the inner tank306at each trunnion mount to further support the connection of the inner tank306to the outer tank304and a structural integrity of the inner tank306itself. As shown inFIG.3, a first trunnion mount302A may be connected between the inner tank306and the outer tank304on a curb side of the dewar300opposite a second trunnion mount302C on a road side of the dewar300. A third trunnion mount302D may be connected between the inner tank306and the outer tank304on a top of the dewar300opposite a fourth trunnion mount302B on a bottom of the dewar300. Cutouts308A-B,310,312may be made for tubing, drain holes, and/or weep holes in the dewar300.

An example trunnion mount302C is shown in greater detail inFIG.4. The trunnion mount302C may attach the inner tank306to the outer tank304. The trunnion mount302C may be welded to a surface of the inner tank306. For example, a reinforcing pad422, such as a circular reinforcing pad, may be welded to an outer surface of the inner tank306, forming a base for all or part of the trunnion mount302C. In some embodiments, the reinforcing pad422may include four quarter-circle pie-shaped plates that are each welded to each other, to form a circle, square, or other shape, and to the surface of the inner tank306. Furthermore, the trunnion mount302C may be welded to an interior of a cutout or window in outer tank304. For example, a circular, or other shaped, cutout may be made in outer tank304and a frame of the trunnion mount, such as a support frame weldment including an outer support frame420, may be welded to the circumference of the cutout in the outer tank304.

The trunnion mount302C may include a tubing segment410, such as an aluminum tubing segment to form the core of the trunnion mount302C. The tubing segment410may be a segment of eight inch outside diameter tubing. The tubing segment410may be welded to a surface of a reinforcing pad422. In some embodiments, a support frame408, which may include one or more support retainers for housing fiberglass supports, may be welded in place about the tubing segment410. The support frame may, for example, include a fiberglass support segment406. The fiberglass support segment406may provide enhanced insulation to cryogenic fluid in the inner tank306, inhibiting flow of heat from the inner tank306to the outer tank304and an external environment via the trunnion mount302C. A support doubler402may be attached to the reinforcing pad422and may provide enhanced support to the trunnion mount302C.

Furthermore, additional support insulation404, such as fiberglass support insulation, may provide enhanced insulation between the inner tank306and the outer tank308. A support frame weldment416may connect the frame to408to an outer support frame420that is welded to a surface of a cutout in the outer tank304. The support frame weldment416may include one or more stainless steel bars. A patch plate418may be welded or otherwise attached to an outer surface of the outer tank304over the cutout for the trunnion mount302C. Additional insulation patches, such as a support insulation patch412may be included between the tubing segment410and the patch plate412of the trunnion mount302C.

In some embodiments, two or more of the trunnion mounts may include internal longitudinal support stiffeners to reinforce the inner tank at the trunnion attachment areas and reduce torsional forces in the inner tank. An example segment500of an inner tank is shown inFIG.5A. For example,FIG.5Amay be a top-down view of a cross section of an inner tank of a cryogenic dewar showing a first trunnion mounting location514A and a second trunnion mounting location514B. A first trunnion mounting location514A may include an internal longitudinal support stiffener506attached to an interior surface of the inner tank502at the mounting location514A. The internal longitudinal support stiffener is shown by lines506and512inFIG.5that together indicate the structure of the stiffener. The stiffener may, for example, include one or more L-shaped aluminum bars and may couple the interior of the inner tank502at the first trunnion mounting location514A to the interior of the inner tank502at the second trunnion mounting location514B. For example, the stiffener506,512may couple an interior of the inner tank502at a trunnion mounted on a curb side of the dewar to an interior of the inner tank502at a trunnion mounted on a road side of the dewar. Thus, the support stiffener506,512may span the width of an interior of the internal tank502and may further support the structure of the inner tank502. The stiffener506,512may be located at the front and rear of the inner tank502in line with the location of the support stiffeners506,512. In some embodiments, support stiffeners may similarly be included between trunnion mounting locations at a bottom and a top of the inner tank502. Such support stiffeners may be included between curb side and road side trunnion mounting locations and/or between top and bottom trunnion mounting locations at both front of the inner tank and a rear of the inner tank. As shown in the enlarged view504ofFIG.5B, an additional lateral reinforcement element508may couple the longitudinal support stiffener506to a further area of the inner tank, such as an area of the inner tank502outside of a trunnion mounting location514A, providing additional support. In some embodiments, a support doubler may be located at an exterior of the inner tank at the trunnion mounting locations514A-B.

In some embodiments, pie-shaped reinforcing pads may be used to strengthen a connection of a trunnion mount to an exterior surface of an inner tank of a cryogenic dewar. For example, as shown in trunnion mounting location600ofFIG.6A, four quarter-circle pie-shaped reinforcing pads602A-D may be used to reinforce a connection of a trunnion mount to an outer surface of an inner tank as well as to strengthen an integrity of a structure of the inner tank and a connection of a trunnion mount to the inner tank. Each pie-shaped piece602A-D may be welded to an outer surface of the inner tank. Furthermore, each pie-shaped piece may be welded to one or more of the other pie-shaped pieces. The welding area provided in the use of multiple pie-shaped pieces may further strengthen a connection of the trunnion mount between the inner tank and the outer tank, as the welding area between the pie shaped pieces may provide additional welding area over use of a single circular reinforcing pad. Additional welding area may strengthen a connection of a trunnion mount to an inner tank of the cryogenic dewar. The pie-shaped pieces602A-D may be shaped to fit an outer surface of the inner tank610, as shown inFIG.6B. The pie-shaped reinforcing pad pieces602A-D may be installed at trunnion mount locations at the front and rear of the inner tank, at the top and bottom of the inner tank, and/or on the road and curb side of the inner tank. In some embodiments, the pie-shaped reinforcing pad pieces602A-D may be made of aluminum. The trunnion mounts, along with the internal longitudinal support stiffeners and pie-shaped reinforcing pad pieces may enhance the ability of the cryogenic dewar to be more resilient in the face of complex radial and axial forces generated by movement of the inner tank within the outer tank during transportation of the cryogenic liquids. The trunnion, comprising for example an eight-inch outer diameter tube, may be centered over the pie shaped pieces of the reinforcing pad.

A method700for assembling a dewar having multiple trunnion mounts between an inner tank and an outer tank is shown inFIG.7. The method700may begin, at step702, with positioning and welding a support frame for a trunnion, such as after welding the reinforcing pads to the surface of the inner tank. For example, a support frame weldment for a trunnion may be placed within an opening cut in an outer tank for the trunnion mount and may be welded in place. For example, the support frame may be welded to an edge of the opening in the outer tank and/or to a surface of the inner tank or a reinforcing pad that has been welded to an outer surface of the inner tank.

At step704, a window may be cut in insulation for the trunnion. For example, insulation may be placed over part or all of the opening in the outer tank and a window may be cut in the insulation for one or more components of the trunnion mount.

At step706, fiberglass supports may be used to position the trunnion mount within the opening in the outer tank. For example, fiberglass supports of the support frame may be used to position one or more components of the trunnion, such as a segment of aluminum tubing. The fiberglass support may, for example, be centered in the frame using one or more stainless steel bars of the support frame. The trunnion mount may then be tack welded, at step708, to the support frame, and part or all of the fiberglass support may be removed. The fiberglass support may be removed during operation of the trunnion mount, such that space406is empty. In some embodiments, stainless steel strips may also be installed between fiberglass supports and retainers during welding. Retainers may also be welded in place as part of a support frame. The dimensions of the trunnion mount, such as support interface dimensions, may be confirmed after welding.

At step710, a doubler support may be positioned at the base of the trunnion mount, either at the surface of the inner tank or at the plurality of pie-shaped reinforcing pads welded to the external surface of the inner tank. At step710, the doubler support, and, in some embodiments, other components of the trunnion such as the segment of aluminum tubing, may be welded to each other and/or to the inner tank.

At step712, insulation may be installed within the trunnion and/or at an outer surface of the trunnion mount. A patch plate may be welded to an outer surface of the outer tank over the trunnion mount opening to cover the trunnion mount opening. For example, the patch plate may be centered over the trunnion mount cutout in the outer tank. The insulation and fiberglass supports may provide insulation to the cryogenic fluids in the inner tank, inhibiting warming of the inner tank by transfer of heat from the cryogenic fluid to the external environment through the trunnion mounts.

The schematic flow chart diagram ofFIG.7is generally set forth as a logical flow chart diagram. Likewise, other operations for the circuitry are described without flow charts herein as sequences of ordered steps. The depicted order, labeled steps, and described operations are indicative of aspects of methods of the invention. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagram, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

Although the present disclosure and certain representative advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the present disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.