A calcined gypsum treatment apparatus has an agitating type of cooler provided with a cooling region for cooling the calcined gypsum, and a moisture supplying device for incorporating moisture into the calcined gypsum. The moisture supplying device includes a humid gas-feeding port which introduces humid gas including moisture or steam, directly into the cooling region. The calcined gypsum is introduced through a calcined gypsum introduction port into the cooling region, and the moisture is incorporated into the calcined gypsum to modify the calcined gypsum. The humid gas-feeding port is positioned in vicinity to the calcined gypsum introduction port so as to allow the spouted or delivered flow of the humid gas to be brought into contact with the calcined gypsum immediately after introduced into the cooling region.

A conveyor grate for conveying bulk material (preferably cement clinker) in a conveying direction, which has at least two conveying means and at least one motor for advancing such conveying means in the conveying direction and for retracting the conveying means, The grate can be installed and operated at reduced costs, if a first of these conveying means is coupled via a first clutch to the motor and a second of these conveying means is coupled via a second clutch to the same motor.

A conveyer system for vertically and helically conveying a workpiece includes a main bracket, on which interconnected heating furnace and cooling furnace are arranged in parallel. The heating furnace includes a 1.sup.st spiral supporting plate, a conveyer belt arranged on the 1.sup.st spiral supporting plate along the spiral direction and one or multiple gas inlet/inlets to fill protective gas into the heating furnace. The cooling furnace includes a 2.sup.nd spiral supporting plate, the conveyer belt extended from the heating furnace arranged on the 2.sup.nd spiral supporting plate along the spiral direction and one or multiple gas inlet/inlets to fill protective gas into the cooling furnace. A drive mechanism for a conveyer belt is installed on the main bracket. The conveyer belt runs through the heating furnace and cooling furnace and forms one loop via the drive mechanism.

According to the present disclosure, a heat treatment apparatus includes a heating treatment unit that heat-treats a strip-shaped sheet while transferring the strip-shaped sheet, and a cooling unit that cools the strip-shaped sheet having been heat-treated in the heating treatment unit while transferring the strip-shaped sheet. The cooling unit includes a cooling roller that allows a refrigerant to flow through the inside thereof, and an outer wall that surrounds the space in which the cooling roller is disposed. The heat treatment apparatus may further include a take-up unit in which the strip-shaped sheet having been cooled in the cooling unit is wound.

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).

A conveyor grate for conveying bulk material (preferably cement clinker) in a conveying direction, which has at least two conveying means and at least one motor for advancing such conveying means in the conveying direction and for retracting the conveying means, The grate can be installed and operated at reduced costs, if a first of these conveying means is coupled via a first clutch to the motor and a second of these conveying means is coupled via a second clutch to the same motor.

The disclosure discloses a method for preparing calcium oxide using multistage suspension preheater kiln. The steps of the method are: (1) the limestone powder is fed to the multistage suspension preheater kiln for preheating to 800 C. to 900 C.; (2) A preheated material is fed to a decomposition furnace, and calcined at 900 C. to 1100 C. for 25 s to 35 s; (3) A calcined material is fed to a rotary kiln, and calcined at 1100 C. to 1300 C. for 25 to 35 minutes, and finally cooled to obtain calcium oxide.

The disclosure discloses a method for preparing calcium oxide using multistage suspension preheater kiln. The steps of the method are: (1) the limestone powder is fed to the multistage suspension preheater kiln for preheating to 800 C. to 900 C.; (2) A preheated material is fed to a decomposition furnace, and calcined at 900 C. to 1100 C. for 25 s to 35 s; (3) A calcined material is fed to a rotary kiln, and calcined at 1100 C. to 1300 C. for 25 to 35 minutes, and finally cooled to obtain calcium oxide.

A vertical batch furnace assembly for processing wafers comprising a cassette handling space, a wafer handling space, and an internal wall separating the cassette handling space and the wafer handling space. The cassette handling space is provided with a cassette storage configured to store a plurality of wafer cassettes. The cassette handling space is also provided with a cassette handler configured to transfer wafer cassettes between the cassette storage and a wafer transfer position. The wafer handling space is provided with a wafer handler configured to transfer wafers between a wafer cassette in the wafer transfer position and a wafer boat. The internal wall is provided with a wafer transfer opening adjacent the wafer transfer position for a wafer cassette from or to which wafers are to be transferred. The cassette storage comprises a cassette storage carousel with a diameter between 1.1 and 1.6 meter.

A vertical batch furnace assembly for processing wafers comprising a cassette handling space, a wafer handling space, and an internal wall separating the cassette handling space and the wafer handling space. The cassette handling space is provided with a cassette storage configured to store a plurality of wafer cassettes. The cassette handling space is also provided with a cassette handler configured to transfer wafer cassettes between the cassette storage and a wafer transfer position. The wafer handling space is provided with a wafer handler configured to transfer wafers between a wafer cassette in the wafer transfer position and a wafer boat. The internal wall is provided with a wafer transfer opening adjacent the wafer transfer position for a wafer cassette from or to which wafers are to be transferred. The cassette storage comprises a cassette storage carousel with a diameter between 1.1 and 1.6 meter.