A pipe-within-a-pipe and method of use are provided. The pipe-within-a-pipe comprises a first tube overlaying a second tube. The first tube and the second tube have different structures in some respect.

A straight fin for a device for recovering the waste heat of raw coke oven gas in the ascension pipe of the coke oven includes the straight fin body and a group of V-shaped notches disposed on the straight fin body. The depth h of the V-shaped notches is less than the width H of the straight fin body. The distances between the adjacent V-shaped notches increase from bottom to top in the longitudinal direction of the straight fin body. The present invention further provides a heat recovering device and a power generation device both including the straight fins. Moreover, the width, the angle, and the distances in the longitudinal direction of the V-shaped notches at the top of the straight fin are determined according to the temperature field distribution during use of the device.

An apparatus for reducing mercury content of cement kiln exhaust gas 11 comprising: a mixing and heating device 19 for mixing cement kiln dusts D2, D4 included in a cement kiln combustion exhaust gas G1 into a cement raw material R2 withdrawn from a cyclone 4C (or 4B) other than the highest stage cyclone 4D and the lowest stage cyclone 4A of a preheater 4 for preheating cement raw material R1 while heating the cement kiln dusts D2, D4 through sensible heat of the cement raw material R2; a mercury recovery device 21 for recovering mercury Hg vaporized from the cement kiln dusts D2, D4 by the mixing and heating; and a feeder for feeding mercury-removed dusts D5, D6 discharged from the mixing and heating device 19 to a cyclone 4B (or 4A) positioning at a lower stage from the cyclone 4C (or 4B) from which the cement raw material R2 is withdrawn.

An apparatus for reducing mercury content of cement kiln exhaust gas 11 comprising: a mixing and heating device 19 for mixing cement kiln dusts D2, D4 included in a cement kiln combustion exhaust gas G1 into a cement raw material R2 withdrawn from a cyclone 4C (or 4B) other than the highest stage cyclone 4D and the lowest stage cyclone 4A of a preheater 4 for preheating cement raw material R1 while heating the cement kiln dusts D2, D4 through sensible heat of the cement raw material R2; a mercury recovery device 21 for recovering mercury Hg vaporized from the cement kiln dusts D2, D4 by the mixing and heating; and a feeder for feeding mercury-removed dusts D5, D6 discharged from the mixing and heating device 19 to a cyclone 4B (or 4A) positioning at a lower stage from the cyclone 4C (or 4B) from which the cement raw material R2 is withdrawn.

A pressurized cavity is provided around at least a portion or all of a regenerator, within which gas such as flue gas is maintained at a pressure in excess of the pressure within the regenerator, to protect against leakage of gas through the walls of the regenerator.

According to an embodiment, a semiconductor manufacturing apparatus includes a holder configured to hold a processing object, a heater provided at the holder and configured to heat the processing object, a first exhaust port provided above the holder and facing the holder, and an exhaust duct. The exhaust duct is provided on an outer side surface of the first exhaust port and includes an extension and contraction function.

A process and a plant for cleaning furnace gas includes utilizing one or more sensors to continuously monitor one or more parameters indicative for an expected temperature peak in the blast furnace gas flow. The gas flow is then passed through a conditioning tower. In case the measured parameter exceeds a predefined limit value, a coolant, such as water, is sprayed into the blast furnace gas flow in the conditioning tower. Subsequently the flow of blast furnace gas passes one or more filter stations.

An apparatus for the gasification and vitrification of waste comprises a plasma arc furnace provided with two movable graphite electrodes. The furnace includes an air-cooled bottom electrode adapted for transferring the current through a slag melt. The furnace is entirely sealed and is also provided with gas tight electrode seals adapted to control reducing conditions inside the furnace. An electrical circuit is further provided, which is adapted for switching from transferred io non-transferred modes of heating, thereby allowing the furnace to be restarted in case of slag freezing.

A thermochemical regenerator system is operated without encountering accumulation of unwanted solids on the interior surfaces of the passages through which flue gas passes.

Method and installation for calcining cement raw meal in a calciner whereby fuel and a calciner oxidant having an oxygen content of at least 30% vol are introduced into the calciner so as to generate either an oxidant-lean zone or a fuel-lean zone in the calciner located between the lowermost fuel inlet level and the lowermost oxidant inlet level of the calciner, between 50% and 100% by weight of the raw meal being supplied to the calciner upstream of and/or within the oxidant-lean, respectively the fuel-lean zone.