Abstract: A tank cover, especially a cover on a sewage treatment tank, is provided with an access opening with a liftable hatch cover. Along with the hatch cover is a safety barrier or grate, either connected directly to the hatch cover or to structure surrounding the hatch opening. When the hatch is opened the barrier is deployed to prevent a worker from accidentally falling through the opening. In one form the barrier is pivotally attached to the bottom side of the hatch cover, and can be swung out as the hatch is opened to form an “A” shaped or roof shaped barrier, with the hatch cover and the barrier both inclined and essentially forming a roof over the opening. Braces or struts hold these components in the erected position and provide barriers from the sides. For entry of a person through the opening, the barrier or grate can be retained against the bottom of the hatch cover as the cover is swung fully open, through 180°.

Abstract: A hinged hatch in a gas containment cover particularly for a sewage treatment tank has a slide bolt contained within a shaped channel of an extrusion of the hatch, positioned to engage the bolt at a mid-level position of the adjacent fixed beam or other member of the tank cover. The position of the bolt enables the hinged hatch to fully seal against a rubber-covered lip of the adjacent structural member, so that the bolt latch does not compromise integrity of the gas seal. As the bolt is slid into locking position it forces the hatch cover down more tightly against the gas seal.

Abstract: A modular biofiltration support system for a bed of organic filter medium, formed of a multiplicity of rectangular bed platform modules or floor tiles, provides for bridging across an air/gas supply trench which can be up to 36 inches or even 48 inches wide. The bridging sections, formed of a mix of recycled plastic materials in a high-pressure molding operation, interconnect with edges of the floor tile assemblies on each side of the trench, and also engage with one another at sides. Each module is a high strength beam.

Abstract: An aluminum floor for fencing has an improved friction surface with traction-enhancing grooves and is configured to reduce noise. Aluminum extrusions forming the floor define a flat surface but with series of parallel grooves separated by non-grooved spaces. In a preferred embodiment the grooves are essentially square cut. The grooves and spaces between the series of grooves are configured so as to allow sliding on the floor with the essentially flat soles of a user's fencing shoes when desired, but so as to grip the soles with significant friction when the shoe is heavily weighted causing the sole to deform down into the grooves. The fencing floor is intended to lie over an existing floor, as a series of easily connected floor sections. Rubbery sheet material is secured to the bottom of the fencing floor, preferably in transverse strips, directly beneath each joint and preferably at additional locations.

Abstract: A modular support system for organic filter material, compost material or other material is formed of a multiplicity of polygonal bed platform modules with planar top surfaces, the modules arranged side by side contiguously to form a bed platform which is elevated above a base surface. Perforations are included in at least some of the bed platform modules to allow passage of air, gas or liquid through the elevated support bed platform. The bottom sides of the modules have sockets to receive legs, and special legs are provided at corners where a plurality of adjacent modules meet, to engage with sockets in the undersurface in all of the adjacent nodules. At corners the modules are preferably bolted down to the corner pedestals or legs. The modular support system can support very heavy loads, such as earth-moving equipment used to move and spread filter bed or compost material.

Abstract: A modular support system for a bed of organic filter medium has provision for adjusting the distribution of gases in the plenum defined below the filter bed platform. Once the filter bed platform has been fully erected, with a gas inlet below the platform, slide gates are positioned in special modules which define a gas distribution channel, preferably extending in a series to form a line in the assembled support platform. The slide gates, one at each side of the special flow distribution modules, are adjusted as to the depth of penetration down into the plenum, so as to close the sides of the flow distribution channel to varying degrees along the length of the channel, effective to balance the flow of gases up through the perforations in the platform modules. The proper gate setting can be determined empirically after erection of the filter bed platform, by flowing gas through the platform and checking the distribution of gas exiting the holes in the modules.

Abstract: A substantially gas tight cover for an open-top structure such as a tank requires very few fasteners and allows for thermal expansion and contraction movement while still maintaining the nearly complete gas seal. Unique metal extrusions are assembled on-site in a modular system that is easily put together. An important component of the system is a gutter extrusion which includes an elongated gutter and flanges with sealing gaskets for engaging the top surface of the concrete tank rim as well as engaging the inner wall of the tank below the top. At intervals along the gutter strip are hold-down clips that interlock with the gutter extrusion and are secured in the concrete of the tank, spaced back from the tank edge. Fasteners in the inside face of the tank preferably are avoided. Main spanning beams for the tank cover are connected to the gutter extrusions in a way so as to allow for thermal expansion and contraction, without losing the gas seal.

Abstract: A modular biofiltration support system is quickly erectable in virtually any size and shape using plastic modules that are interconnected at the site. Included in the system are bed platform modules which assemble together to form a bed platform to support the weight of the biofilter medium within the area defined by the frame, and a multiplicity of bed support legs which are assembled into the bed platform modules to hold the bed platform at a raised position above the ground, defining a plenum for entering gases, between the ground and the bed platform. In one embodiment, at least some of the legs include air directing vanes which can be oriented in positions to cause generally even distribution of the gases within the plenum. The bed platform modules have openings to direct the gases to flow upwardly through the biofilter medium.

Abstract: A cover for an elongated and relatively narrow tank or channel is formed from a series of panels arranged in parallel, edge-to-edge fashion, each panel spanning across the channel and resting on rims of the channel. Each panel is formed of a large plurality of side-by-side, preferably edge-connected deck slats having lengths extending in the longitudinal direction of the channel. At junctions between adjacent panels, structural transverse members have deck slat receiving channels for engaging with and supporting ends of the deck slats. In preferred embodiments the transverse structural members are generally L-shaped, with the L-shaped structural member of one channel nesting into the L-shaped structural channel of an adjacent panel, providing for removal of alternate panels by lifting. Deck slats include special handle slats for inclusion near the two transverse ends of the removable panels to enable lifting of the panels for access to the tank or channel.

Abstract: A cover for an elongated and relatively narrow tank or channel is formed from a series of panels arranged in parallel, edge-to-edge fashion, each panel spanning across the channel and resting on rims of the channel. Each panel is formed of a large plurality of side-by-side, preferably edge-connected deck slats having lengths extending in the longitudinal direction of the channel. At junctions between adjacent panels, structural transverse members have deck slat receiving channels for engaging with and supporting ends of the deck slats. In preferred embodiments the transverse structural members are generally L-shaped, with the L-shaped structural member of one channel nesting into the L-shaped structural channel of an adjacent panel, providing for removal of alternate panels by lifting. Deck slats include special handle slats for inclusion near the two transverse ends of the removable panels to enable lifting of the panels for access to the tank or channel.

Abstract: A deck structure is assembled of a plurality of modular panels including one or more hinged, openable access panels. The panels, comprised of extruded deck planks and framing channels are interconnected at edges. At each access panel a gear hinge connects the panel with the adjacent fixed panel, through the width of the panels. Hinge gears are integrally formed on edges of a hinged plank and a fixed plank of the adjacent hinged and fixed panels, with a keeper member holding the gears enmeshed during opening and closing of the panel. In a preferred embodiment a gas tight seal is formed when the access panel is closed. The gear hinge comprising the hinged and fixed planks is the same width as other planks in the deck structure thereby allowing interchangeability and modularity in building the deck structure and allowing the hinge to be placed anywhere in the deck structure. An articulated, sliding cover using similar gear hinge components is also disclosed.

Abstract: A cover for tank is formed from a plurality of panels attached together by cross members. The panels are sealed to the cross members, and the panels and the cross members are sealed to the tank. The panels are constructed from a multiplicity of edge-to-edge planks. The planks may be connected together without welds, and the panels may be connected to the cross members without welds. The cover may be in the shape of an arch, or the shape of a dome. In another embodiment a dome-shaped cover may be formed from a plurality of panels each having the shape of a section of a circle. Each panel is connected between an adjacent pair of a plurality of radial members arranged in a radial pattern.

Abstract: A floating dock preferably comprised of at least two elongated panels and derives its transverse load supporting strength from flotation tubs at the lower side of the dock. The deck portion of the dock is assembled from aluminum extrusions, preferably without welds. The dock assembly involves a minimum of parts and minimal assembly time. In typical sizes, e.g., about 6 feet in width and 20 to 40 feet in length, the dock units can be prefabricated at a plant and shipped by truck to the point of use.

Abstract: A modular containment system, primarily for secondary containment of potentially hazardous materials, includes a series of interconnectable berm members which can be interlocked together to form virtually any desired containment perimeter. A sheet of flexible plastic material is laid over the containment area, and extends over the shoulders of the perimeter structure as a liner for the containment area. The liner is secured to the top of the perimeter structure, such as by a snap-in tube arrangement. For high stability of the perimeter structure, the modular berm members are hollow, formed of plastic material, to be filled with water or sand, as well as having a low, wide profile.

Abstract: A cover for tank is formed from a plurality of panels attached together by cross members. The cover includes means for sealing the panels to the cross members, and means for sealing the panels and the cross members to the tank. The panels are constructed from a multiplicity of edge-to-edge planks. The planks may be connected together without welds, and the panels may be connected to the cross members without welds. The cover may be in the shape of an arch, or the shape of a dome. In another embodiment a dome-shaped cover may be formed from a plurality of panels each having the shape of a section of a circle. Each panel is connected between an adjacent pair of a plurality of radial members arranged in a radial pattern.

Abstract: A substantially gas tight tank cover is designed such that the structural beams of the cover serve also as an air distribution system for bubbling air through a liquid in the tank. Vertically oriented gas bubbler and orifice devices include hardware enabling easy access to the orifice and bubbler from the top of the tank cover. The design is such that all necessary maintenance including major repairs can be performed from the cover without draining the basin or removing the cover. The system is particularly adaptable to sewage treatment plants, but is advantageous for other applications as well, wherein gases are to be bubbled through liquids at multiple locations.

Abstract: A substantially gas-tight tank cover is designed such that the structural beams of the cover serve also as a gas withdrawal system for removing odorous or deleterious gases from above the surface of a liquid in the tank, such as in the case of a sewage treatment plant. The structural beams are tubular in cross-sectional shape, and have openings at selected locations in communication with the interior of the tank above the liquid. The system efficiently uses the structure of the tank cover as part of the odorous gas withdrawal system.

Abstract: A modular containment system, primarily for secondary containment of potentially hazardous materials, includes a series of interconnectable berm members which can be interlocked together to form virtually any desired containment perimeter. A sheet of flexible plastic material is laid over the containment area, and extends over the shoulders of the perimeter structure as a liner for the containment area. The liner is secured to the top of the perimeter structure, such as by a snap-in tube arrangement. For high stability of the perimeter structure, the modular berm members are hollow, formed of plastic material, to be filled with water or sand, as well as having a low, wide profile.