Abstract: A system for collecting gas generated in an anaerobic pond which is covered by an insulated cover. The system includes a series of gas collection pipes which are laid on top of and are secured to the panel units of the insulated cover and a solid cover which fits over the top of the collection pipes.

Abstract: A floating inlet assembly for use with a mixing apparatus in a digester. The floating inlet assembly comprising a floating inlet housing which is vertically reciprocable with respect either to a fixed inlet tube or to a guide tube structure.

Abstract: A clarifier is disclosed with a cover or roof configured and disposed to minimize headspace between a top level of liquid in a clarifier vessel and a bottom of the roof. In one aspect the roof or cover includes one or more removable panels which permit access to a clarifier vessel's interior; the panels removably secured to a purlin system which is connected to a truss support secured to the vessel. In one aspect one or more circumferential purge air inlets are provided through which flow purge air. Purge air and gaseous material emitted from a mixture in the clarifier flow to a vent or vents through which they exit the clarifier. In one aspect the air inlet or inlets are disposed to provide uniform flow from the inlets to the vents. In one aspect one or more roof panels is connected with a known force and has a known rupture strength so that before explosive damage to other parts of the clarifier the panel is explosively disconnected and ruptured to relieve pressure in the clarifier.

Abstract: A gas-holding sludge digester is disclosed having a sideskirt which telescopes in a liquid chamber which is separate from a main digester tank and wherein the ballast is structured to increase gas pressure of the gas contained within the cover as the sideskirt telescopes upward.

Abstract: A floating inlet assembly for use with a mixing apparatus in a digester. The floating inlet assembly comprising a floating inlet housing which is vertically reciprocable with respect either to a fixed inlet tube or to a guide tube structure.

Abstract: An anaerobic reaction system for treatment of a continuous flow of wastewater comprises a wastewater inlet, a first anaerobic reactor connected to the inlet, a second anaerobic reactor connected to the inlet and parallel to the first reactor, and a split box between the inlet and the first and second reactor. The split box channels the continuous flow of wastewater to the first reactor and to the second reactor. Effluent empties from the first reactor while wastewater in the second reactor is anaerobically reacted upon and clarified. Alternately, effluent empties from the second reactor while wastewater contained in the first reactor is anaerobically reacted upon and clarified.

Abstract: A method of treating a liquid waste or process stream that includes a sludge component and that enhances sludge treatment or stabilization. The sludge is acidified to a pH of less than 4.0 in an oxygen enriched environment. A nitrous acid level is maintained sufficiently high to kill pathogens, in a closed chamber so that the nitrous acid won't be lost from the chamber through volatilization.

Abstract: A sludge digester having a main tank in conjunction with a gas-holding cover is disclosed. The cover includes a roof and a depending sideskirt which telescopes in relationship to the main tank. Positioned at the bottom edge of the sideskirt are a multitude of ballast members. A chamber, adapted to contain a quantity of liquid, is associated with the main tank. The sideskirt and the ballast members are submerged within the liquid contained within the chamber to form a gas tight seal of the cover with the main tank. The chamber also includes a system for maintaining a predetermined liquid level in the chamber dependent on the position of the ballast members in the chamber.

Abstract: A sludge digester gas-holder is disclosed having a gas-holding cover with ballast members submergible in a liquid medium contained within a chamber circumscribing the upper portion of the tank wall and separate from the main tank cavity.

Abstract: A floating roof liquid storage tank, having a tank shell which is supported on a fixed base, and a floating roof supported by the liquid stored in the tank. Included in the base or roof is a displacement device to substantially displace the stored liquid when the floating roof is in its lowest position. In this way the volume of the heel of liquid unable to be removed from the tank is reduced. The displacement device can take the form of a container which protrudes downwardly from the roof, or a layer of ballast on the base of the tank. The ballast layer can be a liquid heavier than the stored liquid which can be retained in a dam if desired.

Abstract: The invention relates to apparatus for carrying out mixed liquid, gas and solid phase reactions and is intended for use in sewage digestion tanks where the removal of sludge and foam from the tanks is required. A reactor vessel is provided which includes a floating cover vertically movably maintained within the vessel. A device for limiting gas pressure is connected to the vessel below the cover. A buoyancy chamber is provided which is supported by the cover and located therebelow and is intended to be at least partially immersed within the liquid in the vessel. A foam/sludge withdrawal opening is located below the uppermost portion of the buoyancy chamber and connects the interior of the vessel to the exterior. In a preferred embodiment, a ballast member is supported from the cover and extends from the roof to below the buoyancy member.

Abstract: A collecting and treating tank which holds liquid and in which a vertically movable cover floats on the liquid or on a gas layer above the liquid, comprising a tank having a vertical cylindrical circular wall, a bottom at and joined to the wall, and a circular cover which fits loosely inside the circular wall so that it is vertically displaceable with change in liquid and/or gas volume beneath the cover; and a plurality of cover guides, spaced radially around the cover edge, which are adapted to maintain the cover periphery spaced from the tank wall; said cover guides being faced with a solid polymeric layer which is slippery and has a low coefficient of friction so that the cover is readily displaceable vertically solely with change in volume of liquid, gas or both beneath the cover.

Abstract: In an anaerobic sludge digestion tank system having walls communicating with a floor forming a storage container for the sludge and a fixed outer cover overlaying the storage container having a center stack communicating with the storage container, a flexible gas membrane is provided extending between the wall and the center stack over and above the storage container and a pressurizing membrane extends over the top of the gas membrane between the gas membrane and the cover and between the wall and center stack. The two membranes are sealingly attached to the top of the wall at their bottom portion and the center stack at their upper portion and form an inner pressurizing chamber.An air injection system is provided for injection of air under pressure between the gas membrane and the pressure membrane into the inner chamber thus forcing the inner chamber to expand via the downward movement of the gas membrane.

Abstract: A plant for production of fuel gas by anaerobic fermentation of organic materials comprises a pit-like hemispherical fermentation chamber and a flexible and foldable cover which, when inflated, has the form of a complementary hemisphere and is in open communication with the fermentation chamber at the horizontal equatorial plane. Organic materials are introduced into the fermentation chamber to the level of said plane. The cover is weighted to be foldingly contracted when unpressurized and to be inflated to its hemispherical form by generated gas.

Abstract: A digestor includes a tank and an inverted dish-shaped cover, the lower end of which extends into sludge contained within the tank. The cover is ballasted by a number of ballast members which resemble tubs and which are integrally formed of concrete. Each ballast member is mounted with its cavity facing upwardly so that the ballast cavities automatically fill with sludge upon start-up of the digestor. When partially surfaced above the sludge, the predetermined total weight of sludge in the ballast members causes a substantial increase in the pressure exerted by the cover on the contained gas than would be exerted by the cover and unfilled ballast members.

Abstract: An improved anaerobic digester 10 includes a cylindrical concrete sidewall 16 having a plurality of guide channel assemblies 40 bolted thereto at uniformly spaced locations along its circumference. The digester further includes a cover 18 adapted to be buoyed upwardly above the surface of the liquid by the digester gas. The digester cover is guided by roller assemblies 70 that cooperate with the guide channel assemblies 40. When gas is not present within the digester, the cover is supported by the cooperation of a plurality of stop tubes 76 and 78 that project radially outwardly of the cover from a thrust ring 24 incorporated at its periphery and a plurality of stop members 60 and 62 that are affixed to the guide channel assemblies at readily accessible locations close to the top of the tank.

Abstract: Apparatus for generating methane from degradable organic material, the apparatus consisting of a tank containing the material in a liquid slurry and gas collector slidably mounted in its upper portion, the gas collector having rods which extend downwardly through a slotted retainer into the organic material for agitating the organic material within the liquid slurry.

Abstract: An apparatus and method for the recovery of gas evolved from fermentation is disclosed. The apparatus comprises a vessel containing the fermentation material, and a head slidably mounted on the vessel forming a substantially gas tight chamber therewith. Mounted on the head are a series of projections of various shapes which extend into the chamber. As the fermentation proceeds, the generation of gas causes the head to rise. When it has risen a sufficient amount, a gas outlet valve is opened and the gas is introduced into a collector. The reduction in gas pressure causes the head to drop. The movement of the head causes the projections to break through the scum layer at the surface of the fermentation broth, thereby enhancing the reaction. In a preferred form of the device, the projections are so formed as to urge the scum towards the discharge means, thereby breaking and removing the scum without the use of any additional energy. A method for using the apparatus is also disclosed.

Abstract: A modular capping arrangement for an anaerobic slurry digester comprising a basin which may conveniently be dug out of the earth and a plurality of elongate capping members of inverted channel form comprising wall members which, when the channel members are placed in side-by-side arrangement, define therebetween channels which are upwardly open. The capping members are formed with outlets in upper regions thereof for removal of gas produced during slurry digestion and are weighted down on the slurry by ballast means positioned in the upwardly open channel. The capping members are disposed in parallel arrangement and held together at the ballast means and are so formed that the capping arrangement is capable of floating on a body of slurry while being held thereon by the ballast means and being lifted therefrom by gas under pressure thereunder.

Abstract: An organic digester apparatus is provided for the production of liquid fertilizer and methane gas from organic waste materials. The apparatus includes a plurality of digesters each having a gas sealing well between the tank and the roof member of the digester. In addition, each digester includes means for supporting the roof with pressurized gas, for rotating the roof, for washing the digester, and for observing the interior of the digester.