An in situ system for thermally cleansing hazardous and toxic waste disposal sites is disclosed. The system includes a perimeter wall extending into the site which is sealed to a roof structure surrounding the site to encapsulate the site. A plurality of tubes are sunk into the encapsulated site in a geometric pattern and are directly heated to indirectly heat the site. In time, the temperature of the entire site is raised to a level where the waste is volatilized and the volatiles are collected in the roof and subsequently incinerated.

In situ thermal waste disposal system

An oxygen generating device (11, 211) to which a gas mixture containing oxygen is fed, and which is operable to separate the gas mixture into oxygen rich and oxygen depleted gas components, the device (11, 211) including a negative temperature coefficient material (36a 36b 36c; 236) which is active at an elevated temperature above a minimum operating temperature, to separate the gas mixture into oxygen rich and oxygen depleted gas components, there being an electronic control unit coupled to the device to pass an electrical current through the device (11, 211) to produce a heating effect within the device to heat the gas mixture at least towards the minimum operating temperature wherein the device includes a plurality of active sections (A, B, C) through each of which the gas mixture passes in turn, and the electrical current supply is connected to each of the sections (A, B, C) so that the sections electrically are connected in series.

Oxygen generating device

A pass-through convection oven having a series of gas jet distributors and an exhaust system adjacent later distributors in the series to gather gas for the initial distributors in the series. A distributor in the series is formed of a pair of plenums in series in the gas flow path with a cumulative area of the passageway between them exceeding the cumulative area of the orifice from which the gas jets are formed in that distributor.

Continuous oven with a plurality of heating zones

A cooling system for a processing furnace provides improved cooling efficiency in a more compact arrangement than known furnace cooling systems. In the system a blower is situated within the cooling gas plenum but has its intake exterior thereto. The plenum wall and the furnace outer wall define a recirculation channel which is relatively large and free of obstructions. Heat exchanger coils are disposed within the recirculation channel adjacent the blower intake thereby providing a less restricted flow path for the cooling gas.

Gas cooling system for processing furnace

An improved industrial furnace employing a new and unique heat transfer arrangement is disclosed. The furnace is a closed end cylindrical chamber with a circular, concentrically positioned plate dividing one side of the furnace into a fan chamber containing a fan and the other side of the furnace into a heat treat chamber containing the work. The plate has a central under-pressure opening and its outer circular edge is spaced from the cylindrical wall to define an annular space which is non-orificing. Fan rotation in the fan chamber produces an annulus of wind mass swirling at high circumferential speed which axially travels through the non-orificing space towards the closed end of the heat treat chamber at slow speed. Heating elements extend through the non-orificing space into the heat transfer chamber and are constantly impinged by the swirling annulus wind mass to effect good heat transfer therewith. The under-pressure opening causes the heated wind to contact the work before it is drawn into the under-pressure opening for recirculation. An incineration track is provided in the furnace insulation for incinerating the furnace flue products while also heating the wind mass.

Industrial furnace with improved heat transfer

An improved heat transfer arrangement for use in a unique multi-function, industrial heat treat furnace which employs a sealed, closed end, heat exchanger shell member containing the work The heat transfer arrangement includes a totally contained, internal recirculation system which develops an especially configured annular jet stream that produces highly efficient, convective heat transfer with the shell member After heat transfer between the entrained gases in the jet stream with the shell member has occurred, the jet flow is reversed at one end of the shell and impinged against the workpiece, the spent stream being reformed into the annular jet at the opposite end of the shell member

Convective heat transfer within an industrial heat treating furnace

Method and apparatus is disclosed for heat treating coiled, metal strip in bell shaped annealing furnaces employing an annealing stand upon which coils of strip are vertically stacked. An inner cover removably sealed to the stand surrounds the coil and an outer cover surrounds the inner cover. A vacuum is drawn within the inner cover while the work is being preheated to volatize oil on the coil into hydrocarbon vapors and permit the hydrocarbons to be drawn off prior to annealing so that carbon soot formation does not occur. A unique concentric, two seal arrangement is disclosed which provides for drawing a vacuum between the seals to positively seal the inner cover to the base while providing a fail safe mechanism for monitoring the process thus permitting a potentially explosive reducing atmosphere, such as pure hydrogen, to be used in the annealing furnace in a safe manner.

Method and apparatus for batch coil annealing metal strip

An industrial electrical, vacuum furnace for ion processing of work is provided with an improved feed-through interlock and insulator arrangement. A sealed interlock chamber on the furnace door is in fluid communication with the furnace's heat treat chamber. A bellows outside of the interlock chamber is in fluid communication therewith. When a vacuum is drawn in the heat treat chamber, the bellows distends into a collapsed position to provide a firmly clamped electrical connection with the feed-through which extends through the door into the interlock chamber. The feed-through is thus pinned by the bellows at one end and a V-shaped pulley guide arrangement within the furnace controls thermal distortion of the feed-through. The insulator arrangement includes a plurality of interlocking, ceramic caps or spacers which are stacked one on top of the other to define tortuous paths or gaps therebetween which prevent electrically conductive material deposited thereon during the ionizing process from establishing an electrically conductive path along which or as a result thereof an ion glow discharge or arcing or short circuiting could occur.

Interlock feed-through and insulator arrangement for plasma arc industrial heat treat furnaces

A seal arrangement is disclosed for use in a furnace which utilizes a thin, cylindrical imperforate shell member which is heated from an external source to heat work placed within the shell. An insulated arrangement within and outside of the shell extends a spaced distance from the shell's opening to sandwich the shell's wall therebetween. The arrangement prevents heat flux by radiation and convection from heating the sandwiched wall thus permitting graded cooling of the sandwiched shell wall by conduction to a temperature whereat a conventional elastomer seal can be employed to seal the shell member.

Seal arrangement for high temperature furnace applications

Modifications are provided to a standard, batch type industrial heat treat furnace of a hot wall design which permit the furnace to be operated efficiently at high temperatures. The furnace is of a cylindrical design having a forward heat treat chamber and a rearward plenum chamber with a flat bulkhead plate in-between the chambers. The bulkhead has exit and inlet openings permitting wind mass to flow to the heat treat chamber and back to the plenum chamber. The bulkhead has a plurality of radially extending slits formed therein which permit the bulkhead to remain flat despite temperature and pressure gradients resulting in expansion/contraction of the bulkhead. Additionally, the furnace includes a closed end muffle within the heat treat chamber into which work to be heat treated is placed. A water cooled spring biasing support is provided for the closed end of the muffle to resist downward deformation of the muffle at high temperatures. The furnace additionally includes a heat shield circumscribing the furnace casing to provide a cooling air space for preheating burner combustion air while minimizing heat losses and the cost of furnace insulation.

Klaus H. Hemsath

Papers

Convective heat transfer within an industrial heat treating furnace

Method and apparatus for batch coil annealing metal strip

Interlock feed-through and insulator arrangement for plasma arc industrial heat treat furnaces

Seal arrangement for high temperature furnace applications

High temperature industrial heat treat furnace