Abstract: In order to achieve an increase in energy efficiency and a faster quenching of the workpieces, a device according to the invention is proposed for the treatment of metallic workpieces with cooling gas, comprising a horizontally arranged cylindrical housing (1) with at least one closable opening for the introduction and extraction of the workpieces to be treated, with a quenching chamber (2) located inside the housing (1) for receiving the workpieces to be treated, with two high-performance fans (5 and 6) arranged laterally and outside the quenching chamber (2) for guiding a cooling gas through the quenching chamber (2) and with two heat exchangers (11 and 12) for cooling the cooling gas, that heat exchanger (11 or 12) is respectively associated with a high-performance fan (5 or 6) and that closable guide devices (17 or 18) are arranged above and below the quenching chamber (2).

Abstract: An industrial furnace (1) into which protective gas is admitted for the heat treatment of batches (5) of metal workpieces is described. The heat treating furnace includes an entrance lock (2) which can be sealed with respect to the surrounding environment by means of a first gas-tight closure device (2.2.1). The heat treating furnace also includes a third gas-tight closure device (3.1) disposed between a heat treatment chamber (3) of the furnace and a quenching facility (4) at the exit of the heat treatment chamber. With the foregoing arrangement a pressure of the protective gas admitted into the heat treatment chamber (3) can be maintained during loading and unloading of a batch of metal workpieces (5). The entrance lock may be configured as a dual-chamber vertical arrangement or as a single chamber horizontal arrangement.

Abstract: A vacuum heat treating furnace for the heat treatment of metal parts includes a pressure vessel and a hot zone enclosure that defines a hot zone therein. A heating element array inside the hot zone enclosure includes a first heating element, a second heating element, and a center heating element. The first and second heating elements are suspended on opposing sides of the hot zone enclosure. The center heating element is suspended vertically from the hot zone enclosure between the first and second heating elements. The center heating element is adapted to be connected to the first and second heating elements to form a continuous circuit therewith. The center heating element may be connected to the first and second heating elements with removable/reusable fasteners to provide for reconfiguration of the hot zone to accommodate different size workloads.

Abstract: A process gas preparation device for an industrial furnace system is disclosed. The gas preparation device includes a preparation reactor having a catalyst. A gas feed line and a gas return line are connected between the industrial furnace and the preparation reactor to form a closed loop. A compressor is situated upstream from the preparation reactor in the feed line. The preparation reactor is also connected with supply lines for hydrocarbon gas and air to be supplied to the preparation reactor. The process gas preparation device also includes a control device with which process gas preparation and return can be regulated and controlled. The gas feed line also has a shut-off valve. The control device can check the functional state of the catalyst by measuring the pressure differential across the catalyst and can initiate a burn-out process therein to clear clogging of the catalyst.

Abstract: A load transport mechanism for moving a heat treating load in a multi-station heat treating system is disclosed. The transport mechanism has a compact construction that allows it to fit in a centrally located stationary transport chamber. The transport chamber is adapted to provide ready access to multiple treating chambers arrayed around the chamber. The transport mechanism includes a load translation mechanism for moving the load linearly and a load rotation mechanism for rotating the load within the transport chamber. A multi-station heat treating system having a centrally located quenching chamber that includes the load transport mechanism is also disclosed.

Abstract: A process for quenching heat treated metal parts using a liquid quenchant and high pressure is disclosed. In general, the process includes the steps of providing a load of heat treated metal parts in a pressure vessel wherein the load is at an elevated temperature after being heat treated. In a subsequent step, a liquid quenchant is injected into the pressure vessel such that a vapor of the liquid quenchant forms rapidly in the pressure vessel and cools the metal parts. The step of injecting the liquid quenchant into the pressure vessel is continued for a time sufficient to establish a desired peak vapor pressure in the pressure vessel. An apparatus for carrying out the disclosed process is also described.

Abstract: A process and apparatus for quenching a metal workload from an elevated heat treating temperature are disclosed. The process includes the step of flowing a vegetable oil quenchant over the metal workload to provide a cooling rate sufficient to transform the metal substantially completely to a desired second phase comprising martensite, bainite, pearlite, or a combination thereof within a preselected time period. The apparatus includes a quenching chamber that has a base, an upper housing, a door, and an associated actuator for opening and closing the quenching chamber. The apparatus also includes a vessel for holding a volume of a vegetable oil quenchant, means for conducting the vegetable oil quenchant from the vessel to the quenching chamber, and means disposed in the quenching chamber for flowing the vegetable oil quenchant over a metal workload disposed in the quenching chamber.

Abstract: A lifting apparatus for a vertical vacuum furnace is disclosed. The apparatus includes first and second support modules arranged in spaced parallel alignment and first and second reversible lifting mechanisms mounted on respective ones of the first and second support modules. The apparatus also includes first and second motive means coupled to the first and second reversible lifting mechanisms for driving the reversible lifting mechanisms. First and second trolleys are operatively connected to the first and second reversible lifting mechanisms and adapted for engaging with a payload. The apparatus further includes a control system connected to the first and second motive means for controlling the operation of the first and second reversible lifting mechanisms whereby the first and second trolleys can be raised or lowered. A vertical vacuum furnace assembly including the lifting apparatus is also disclosed as well as a support module and a bottom head assembly for the lifting apparatus.

Abstract: In order to increase energy efficiency in an industrial furnace (1) operated by heating gas and protective gas for thermally treating materials, a first burner (3.1) is actuated for heating with priority over a second burner (3.2), the second burner (3.2) is engaged additionally and operated when the output from the first burner (3.1) falls below the level necessary to heat the industrial furnace (1) up to a temperature setpoint, and the second burner (3.2) is switched off when the temperature setpoint has been reached.

Abstract: An apparatus for sealing a fan drive shaft in a vacuum heat treating furnace is disclosed. The sealing apparatus includes a housing having an annular body and a central opening. An inflatable first seal surrounds the central opening of the annular body. A second seal surrounds the central opening and is adjacent to the inflatable first seal. The sealing apparatus also includes a channel formed in the annular body adjacent to the second seal for conducting a purging fluid into the central opening. A means for injecting the purging fluid into the central opening is operably connected to the channel. A vacuum heat treating furnace and a fan drive system incorporating the sealing apparatus are also described.

Abstract: In a device for preparing process gases (3) for heat treatments of metallic materials/workpieces, the respective process gas (3) is to be fed into at least one treatment chamber (1.1) in an industrial furnace (1) having been practically fully prepared, homogenised and heated, and the method is to be carried out both with newly built and particularly with already existing installations of industrial furnaces (1) with the aid of the device, wherein the process gas (3) is prepared with compression at temperatures uncoupled from the temperature in the treatment chamber (1.1), in a process separate from the heat treatment process in the treatment chamber (1.1), and in a temperature range up to about 1250° C., and is rendered usable for economical and low-emission heat treatment (FIG. 3).

Abstract: An industrial furnace (1) into which protective gas is admitted for the heat treatment of batches (5) of metal workpieces is described. The heat treating furnace includes an entrance lock (2) which can be sealed with respect to the surrounding environment by means of a first gas-tight closure device (2.2.1). The heat treating furnace also includes a third gas-tight closure device (3.1) disposed between a heat treatment chamber (3) of the furnace and a quenching facility (4) at the exit of the heat treatment chamber. With the foregoing arrangement a pressure of the protective gas admitted into the heat treatment chamber (3) can be maintained during loading and unloading of a batch of metal workpieces (5). The entrance lock may be configured as a dual-chamber vertical arrangement or as a single chamber horizontal arrangement.

Abstract: Energy-efficient control of a vacuum pump having a pump controller integrated in a control and regulation device used in an industrial furnace complex is disclosed. A method and an industrial furnace complex provide incremental deactivation or activation of the vacuum pump depending on whether a vacuum is needed by using a program having one or more program steps, including a first query about whether a heat treatment process is active in the industrial furnace, a second query about whether the vacuum pump is required in a current phase of the heat treatment process, a third query about whether the vacuum pump will be required in a future phase of the heat treatment process, and/or a fourth query about whether a time until the next operation is greater than a required lead time for the vacuum pump to warm up.

Abstract: A process and apparatus for quenching a metal workload from an elevated heat treating temperature are disclosed. The process includes the step of flowing a vegetable oil quenchant over the metal workload to provide a cooling rate sufficient to transform the metal substantially completely to a desired second phase comprising martensite, bainite, pearlite, or a combination thereof within a preselected time period. The apparatus includes a quenching chamber that has a base, an upper housing, a door, and an associated actuator for opening and closing the quenching chamber. The apparatus also includes a vessel for holding a volume of a vegetable oil quenchant, means for conducting the vegetable oil quenchant from the vessel to the quenching chamber, and means disposed in the quenching chamber for flowing the vegetable oil quenchant over a metal workload disposed in the quenching chamber.

Abstract: A furnace loading system for use with a heat treating furnace is disclosed. The furnace loading system includes a platform and a support structure mounted on the platform. First and second transport rails are mounted on the support structure. The furnace loading system also includes a transfer cart that is adapted for supporting a work load and for moving along the transport rails. A lift mechanism is operatively mounted on the transfer cart for vertically displacing a work load supported on the transfer cart. The furnace loading system also includes a drive mechanism mounted on the support structure and operatively connected to the transfer cart for displacing the cart along the rails. A traction device is operatively connected to the platform for moving the furnace loading system relative to a heat treating furnace.

Abstract: A lifting apparatus for a vertical vacuum furnace is disclosed. The apparatus includes first and second support modules arranged in spaced parallel alignment and first and second reversible lifting mechanisms mounted on respective ones of the first and second support modules. The apparatus also includes first and second motive means coupled to the first and second reversible lifting mechanisms for driving the reversible lifting mechanisms. First and second trolleys are operatively connected to the first and second reversible lifting mechanisms and adapted for engaging with a payload. The apparatus further includes a control system connected to the first and second motive means for controlling the operation of the first and second reversible lifting mechanisms whereby the first and second trolleys can be raised or lowered. A vertical vacuum furnace assembly including the lifting apparatus is also disclosed as well as a support module and a bottom head assembly for the lifting apparatus.

Abstract: A quenching apparatus is disclosed which has a generally cylindrical base and upper housing. A removable cover is affixed to the top of the upper housing. The quenching apparatus includes means for supporting the removable cover above the upper housing such that a passageway is defined between the upper housing and the removable cover. A generally cylindrical door is dimensioned and positioned within the quenching apparatus to be coaxial within the upper housing and the base. An actuator is coupled to the cylindrical door for moving the door between an open position and a closed position. In this manner, the door is adapted for closing the opening between the base and the upper housing and thereby provides a closed quenching chamber. Redundant retractable seals are provided in the base and the upper housing to seal the door to the upper housing and the base when the door is closed.

Abstract: A load transport mechanism for moving a heat treating load in a multi-station heat treating system is disclosed. The transport mechanism has a compact construction that allows it to fit in a centrally located stationary transport chamber. The transport chamber is adapted to provide ready access to multiple treating chambers arrayed around the chamber. The transport mechanism includes a load translation mechanism for moving the load linearly and a load rotation mechanism for rotating the load within the transport chamber. A multi-station heat treating system having a centrally located quenching chamber that includes the load transport mechanism is also disclosed.

Abstract: A heating element arrangement for a vacuum heat treating furnace is disclosed wherein the heating elements that make up the heating element arrays have different electrical resistances or watt densities at different locations in the heating element arrays. This arrangement allows for placement of heating elements having electrical resistance selected to provide more or less heat as needed in the furnace hot zone to provide better temperature uniformity in the workload. The electrical resistances and watt densities of the heating element arrays are varied by using a first heating element having a geometry in one segment of a heating element array and a second heating element having a different geometry from that of the first heating element in another section of the heating element array.

Abstract: A heating element arrangement for a vacuum heat treating furnace is disclosed. The heating element arrangement includes a central heating element array as well as first and second outboard heating element arrays spaced apart from and coaxially aligned with the central heating element array. The heating element arrangement also includes first and second end heating elements disposed at respective first and second end positions relative to the central heating element array and the first and second outboard heating element arrays. Power transformers are operatively connected to the central heating element array, to the first outboard heating element array and first end heating element array, and to the second outboard heating element array and second end heating element array for providing electric current to the respective heating element arrays.