The invention relates to a process and a machine for making a tissue paper web (W) in which the tissue paper web W is passed through an extended nip N formed between an extended nip unit (2) and a Yankee drying cylinder (1) and in which the tissue paper web W is carried on a felt (3) through the extended nip N in such a way that, in the extended nip N, the tissue paper web W contacts the outer surface (4) of the Yankee drying cylinder (1). The web W and the felt (3) are led over a suction roll (5) prior to the extended nip N in such a way that the felt (3) contacts the suction roll (5) and the tissue paper web W is separated from the suction roll (5) by the felt (3). The suction roll (5) has a suction zone (6) over which the felt (3) and the tissue paper web W pass together, and a first hood (7) is arranged opposite the suction roll (5) and partially surrounds the suction roll (5). The first hood (7) has an extension around the suction roll such the first hood (7) covers the entire suction zone (6), and moist hot air is fed from the first hood (7) and sucked through the tissue paper web and the felt (3) by the suction roll (5). The tissue paper web W is directly exposed to the first hood (7) such that the moist hot air reaches the tissue paper web W without passing through a fabric before reaching the tissue paper web W. The Yankee drying cylinder (1) is covered by a second hood (8) which is a Yankee hood which has an air heating and distribution system (9) and hot exhaust air from the second hood (8) is fed through a conduit (10) to the first hood (7) and used to supply the first hood (7) with moist hot air. The moist hot air has a temperature in the range of 130 C.-300 C. and a moisture content of 300 g/kg dry air-1000 g/kg dry air at a rate of 90-130 m.sup.3/minute per square meter suction zone area. The moist air is then sucked through the tissue paper web W by the suction roll (5) such that moisture condensates on the tissue paper web W and thereby raises the temperature of the tissue paper web W before the tissue paper web W passes through the extended nip N.

The invention relates to a process and a machine for making a tissue paper web (W) in which the tissue paper web W is passed through an extended nip N formed between an extended nip unit (2) and a Yankee drying cylinder (1) and in which the tissue paper web W is carried on a felt (3) through the extended nip N in such a way that, in the extended nip N, the tissue paper web W contacts the outer surface (4) of the Yankee drying cylinder (1). The web W and the felt (3) are led over a suction roll (5) prior to the extended nip N in such a way that the felt (3) contacts the suction roll (5) and the tissue paper web W is separated from the suction roll (5) by the felt (3). The suction roll (5) has a suction zone (6) over which the felt (3) and the tissue paper web W pass together, and a first hood (7) is arranged opposite the suction roll (5) and partially surrounds the suction roll (5). The first hood (7) has an extension around the suction roll such the first hood (7) covers the entire suction zone (6), and moist hot air is fed from the first hood (7) and sucked through the tissue paper web and the felt (3) by the suction roll (5). The tissue paper web W is directly exposed to the first hood (7) such that the moist hot air reaches the tissue paper web W without passing through a fabric before reaching the tissue paper web W. The Yankee drying cylinder (1) is covered by a second hood (8) which is a Yankee hood which has an air heating and distribution system (9) and hot exhaust air from the second hood (8) is fed through a conduit (10) to the first hood (7) and used to supply the first hood (7) with moist hot air. The moist hot air has a temperature in the range of 130 C.-300 C. and a moisture content of 300 g/kg dry air-1000 g/kg dry air at a rate of 90-130 m.sup.3/minute per square meter suction zone area. The moist air is then sucked through the tissue paper web W by the suction roll (5) such that moisture condensates on the tissue paper web W and thereby raises the temperature of the tissue paper web W before the tissue paper web W passes through the extended nip N.

The invention relates to a process and a machine for making a tissue paper web (W) in which the tissue paper web W is passed through an extended nip N formed between an extended nip unit (2) and a Yankee drying cylinder (1) and in which the tissue paper web W is carried on a felt (3) through the extended nip N in such a way that, in the extended nip N, the tissue paper web W contacts the outer surface (4) of the Yankee drying cylinder (1). The web W and the felt (3) are led over a suction roll (5) prior to the extended nip N in such a way that the felt (3) contacts the suction roll (5) and the tissue paper web W is separated from the suction roll (5) by the felt (3). The suction roll (5) has a suction zone (6) over which the felt (3) and the tissue paper web W pass together, and a first hood (7) is arranged opposite the suction roll (5) and partially surrounds the suction roll (5). The first hood (7) has an extension around the suction roll such the first hood (7) covers the entire suction zone (6), and moist hot air is fed from the first hood (7) and sucked through the tissue paper web and the felt (3) by the suction roll (5). The tissue paper web W is directly exposed to the first hood (7) such that the moist hot air reaches the tissue paper web W without passing through a fabric before reaching the tissue paper web W. The Yankee drying cylinder (1) is covered by a second hood (8) which is a Yankee hood which has an air heating and distribution system (9) and hot exhaust air from the second hood (8) is fed through a conduit (10) to the first hood (7) and used to supply the first hood (7) with moist hot air. The moist hot air has a temperature in the range of 130 C.-300 C. and a moisture content of 300 g/kg dry air-1000 g/kg dry air at a rate of 90-130 m.sup.3/minute per square meter suction zone area. The moist air is then sucked through the tissue paper web W by the suction roll (5) such that moisture condensates on the tissue paper web W and thereby raises the temperature of the tissue paper web W before the tissue paper web W passes through the extended nip N.

The invention relates to a process and a machine for making a tissue paper web (W) in which the tissue paper web W is passed through an extended nip N formed between an extended nip unit (2) and a Yankee drying cylinder (1) and in which the tissue paper web W is carried on a felt (3) through the extended nip N in such a way that, in the extended nip N, the tissue paper web W contacts the outer surface (4) of the Yankee drying cylinder (1). The web W and the felt (3) are led over a suction roll (5) prior to the extended nip N in such a way that the felt (3) contacts the suction roll (5) and the tissue paper web W is separated from the suction roll (5) by the felt (3). The suction roll (5) has a suction zone (6) over which the felt (3) and the tissue paper web W pass together, and a first hood (7) is arranged opposite the suction roll (5) and partially surrounds the suction roll (5). The first hood (7) has an extension around the suction roll such the first hood (7) covers the entire suction zone (6), and moist hot air is fed from the first hood (7) and sucked through the tissue paper web and the felt (3) by the suction roll (5). The tissue paper web W is directly exposed to the first hood (7) such that the moist hot air reaches the tissue paper web W without passing through a fabric before reaching the tissue paper web W. The Yankee drying cylinder (1) is covered by a second hood (8) which is a Yankee hood which has an air heating and distribution system (9) and hot exhaust air from the second hood (8) is fed through a conduit (10) to the first hood (7) and used to supply the first hood (7) with moist hot air. The moist hot air has a temperature in the range of 130 C.-300 C. and a moisture content of 300 g/kg dry air-1000 g/kg dry air at a rate of 90-130 m.sup.3/minute per square meter suction zone area. The moist air is then sucked through the tissue paper web W by the suction roll (5) such that moisture condensates on the tissue paper web W and thereby raises the temperature of the tissue paper web W before the tissue paper web W passes through the extended nip N.

Embodiments of the invention involve a machine (1) for producing a fibrous web, such as for tissue, for example paper tissue, the machine comprising a forming section (2) and a drying section (4, 5), wherein the machine is adapted to form a stream of combined air by combining exhaust streams from the forming section (2) and the drying section (4, 5), and to guide the stream of combined air to a combined air heat exchanger (7) adapted to transfer heat from the combined air to a fluid combined air to a fluid.

Embodiments of the invention involve a machine (1) for producing a fibrous web, such as for tissue, for example paper tissue, the machine comprising a forming section (2) and a drying section (4, 5), wherein the machine is adapted to form a stream of combined air by combining exhaust streams from the forming section (2) and the drying section (4, 5), and to guide the stream of combined air to a combined air heat exchanger (7) adapted to transfer heat from the combined air to a fluid combined air to a fluid.

Herein described is a plant (10) for manufacturing web-like paper material which comprises a system for controlling process fluids. The plant (10) comprises a first wet half-hood (14), a second dry half-hood (16) and four unidirectional flow regulating devices (28, 30; 34, 40) which, suitably positioned on the return circuits (22; 24) of the mist from both half-hoods (14; 16), allow the parallel operation of such half-hoods (14; 16). A fifth bidirectional flow regulating device (40) allows to selectively operate the half-hoods (14; 16) both in reverse cascade mode, that is releasing the mist coming from the first wet half-hood (14) on the return circuit (24) of the second dry half-hood (16), and then release all the mist coming from both the half-hoods (14; 16), and in direct cascade mode, that is releasing the mist coming from the second dry half-hood (16) into the return circuit (22) of the first wet half-hood (14), to release all the mist coming from both half-hoods (14; 16) into the atmosphere once again.

A control method for a sheet manufacturing apparatus includes a stop signal input step of inputting, to the sheet manufacturing apparatus manufacturing a sheet, a stop signal stopping manufacturing of the sheet and a drying step of drying a predetermined area of the sheet manufacturing apparatus by controlling a blower of the sheet manufacturing apparatus after the stop signal input step.

A control method for a sheet manufacturing apparatus includes a stop signal input step of inputting, to the sheet manufacturing apparatus manufacturing a sheet, a stop signal stopping manufacturing of the sheet and a drying step of drying a predetermined area of the sheet manufacturing apparatus by controlling a blower of the sheet manufacturing apparatus after the stop signal input step.

The present disclosure relates to a steam supply system for supplying steam to a steam process, for example a paper drying system. The steam process has a high pressure condensate return and a low pressure condensate return. The steam supply system has a high pressure flash tank arranged to receive the high pressure condensate return and to generate a flash steam output for the steam process. The steam supply system also includes a low pressure flash tank arranged to receive the low pressure condensate return and generate a flash steam output. The steam supply system also includes a compressor arranged to compress the flash steam output of the low pressure flash tank and to provide the compressed flash steam to the high pressure flash tank.