An apparatus and method for a low pressure laundry treating appliance having a cabinet defining an interior, and a drum provided within the interior, the drum including at least an inner wall and an outer wall. Pressure differentiations and flash evaporation can enable drying without excess use of conventional heating methods.

An apparatus and method for a low pressure laundry treating appliance having a cabinet defining an interior, and a drum provided within the interior, the drum including at least an inner wall and an outer wall. Pressure differentiations and flash evaporation can enable drying without excess use of conventional heating methods.

Systems and methods for drying or bonding materials are described. A material to be dried or bonded may be passed through a through air dryer (TAD) (or other dryer). Some of the air output by a TAD may be recirculated to be passed back through material. As the air is recirculated, it is heated and mixed to a desired temperature for drying or bonding. A separate hot air injection system may heat ambient air and/or air exhausted by the TAD and inject the heated air into the recirculated air.

Methods of improving the drying rate of a cellulosic web, such as a tissue web, by providing an apparatus having two noncompressive dewatering devices, such as two through-air driers, where the temperature of the drying medium supplied to each device is separately controlled. The temperature of the medium supplied to the first device may exceed 450 F., such as from about 450 to about 600 F. On the other hand the temperature of the medium supplied to the second device may be less than the temperature supplied to the first, such as from about 350 to 450 F. Drying the web in this manner not only improves drying efficiency, but also limits or prevents degradation of the web, such as the combustion of cellulosic fibers making up the web or monosaccharides associated therewith. As such, webs that are substantially free from furan and acetaldehyde may be produced by the present methods.

Methods of improving the drying rate of a cellulosic web, such as a tissue web, by providing an apparatus having two noncompressive dewatering devices, such as two through-air driers, where the temperature of the drying medium supplied to each device is separately controlled. The temperature of the medium supplied to the first device may exceed 450 F., such as from about 450 to about 600 F. On the other hand the temperature of the medium supplied to the second device may be less than the temperature supplied to the first, such as from about 350 to 450 F. Drying the web in this manner not only improves drying efficiency, but also limits or prevents degradation of the web, such as the combustion of cellulosic fibers making up the web or monosaccharides associated therewith. As such, webs that are substantially free from furan and acetaldehyde may be produced by the present methods.

Systems and methods for drying or bonding materials are described. A material to be dried or bonded may be passed through a through air dryer (TAD) or through air bonder (TAB). Some of the air output by the TAD/TAB may be recirculated to be passed back through material. As the air is recirculated, it is heated and mixed to a desired uniform temperature distribution. As heated air of the desired uniform temperature distribution is passed through ducting for transport to the material, the desired uniform temperature distribution deteriorates due to heat loss experienced at the walls of the ducting. Heating tape is implemented with respect to particular locations of ducting and selectively operated to maintain air traveling through the ducting at the desired uniform temperature distribution. Heat generated by the heating tape is used to counteract heat loss experienced by air traveling through the ducting.

Methods of improving the drying rate of a cellulosic web, such as a tissue web, by providing an apparatus having two noncompressive dewatering devices, such as two through-air driers, where the temperature of the drying medium supplied to each device is separately controlled. The temperature of the medium supplied to the first device may exceed 450 F., such as from about 450 to about 600 F. On the other hand the temperature of the medium supplied to the second device may be less than the temperature supplied to the first, such as from about 350 to 450 F. Drying the web in this manner not only improves drying efficiency, but also limits or prevents degradation of the web, such as the combustion of cellulosic fibers making up the web or monosaccharides associated therewith. As such, webs that are substantially free from furan and acetaldehyde may be produced by the present methods.

Methods of improving the drying rate of a cellulosic web, such as a tissue web, by providing an apparatus having two noncompressive dewatering devices, such as two through-air driers, where the temperature of the drying medium supplied to each device is separately controlled. The temperature of the medium supplied to the first device may exceed 450 F., such as from about 450 to about 600 F. On the other hand the temperature of the medium supplied to the second device may be less than the temperature supplied to the first, such as from about 350 to 450 F. Drying the web in this manner not only improves drying efficiency, but also limits or prevents degradation of the web, such as the combustion of cellulosic fibers making up the web or monosaccharides associated therewith. As such, webs that are substantially free from furan and acetaldehyde may be produced by the present methods.

Systems and methods for drying or bonding materials are described. A material to be dried or bonded may be passed through a through air dryer (TAD) (or other dryer). Some of the air output by a TAD may be recirculated to be passed back through material. As the air is recirculated, it is heated and mixed to a desired temperature for drying or bonding. A separate hot air injection system may heat ambient air and/or air exhausted by the TAD and inject the heated air into the recirculated air.

A papermaking process including the steps of forming a wet paper web on a papermaking machine, pulling vacuum through the web to remove water from the web and thereby generate discharge air, and diverting at least a portion of the discharge air through a control loop to a hot air drying system within the papermaking process to aid in drying the web, wherein the vacuum is generated by centrifugal blowers.