High Consistency Reactor

Teksti

South-Eastern Finland University of Applied Sciences (Xamk) is purchasing a pilot scale high-consistency batchwise reactor according to this tender documentation. Reactor will be located to Fiberlaboratory RDI-unit in Savonlinna. Primary use for the reactor is cellulose derivatization. The cellulose material to be mixed is mainly moist, sticky and fibrous, and the reactions will be done in high consistencies. ‘High-consistency’ refers to cellulose pulp, which contains approximately 70 % water. At this consistency, the pulp behaves almost like a solid and is challenging to mix.
Description of the process conditions:
— the cellulose pulp is mixed with additives, the reactor is heated to a desired temperature, derivatizing reagents are added, and the reaction is allowed to proceed,
— the main reaction solvent is tap water,
— heating is achieved by feeding steam into a jacket, which is around the reactor drum.
In this document, the term ‘reactor drum’ refers to the part of the reactor where the mixing and reactions take place. For reactions that require higher pressures than what the solvent’s vapor pressure naturally induces in a given temperature, pressurized air will be used to increase the pressure in the drum. In exothermic reactions, the temperature might need to be lowered by feeding cold water into the jacket,
— afterwards, heating and lowered pressure will be used to dry the material,
— the operational gauge pressure range of the reactor must be at least 0-10 bar and the temperature range must be at least 0-200 C. Higher maximum pressures and/or temperatures are also permitted. Higher reactor drum pressures are encouraged by rating the tendering results based on price and drum pressure as detailed below,
— the minimum inlet and outlet size is DN 200.
The outlet must be situated in the bottom of the reactor, and it must not create dead-space in which the mixing would be suboptimal. An outlet is not required if the reactor can be tilted to allow for draining of product efficiently from the inlet. Please upload a description of the loading and unloading system.
Special needs of the process:
— the reactor must have additional homogenizing elements, e.g. ‘choppers’, in addition to the main mixer elements in order to ensure homogeneous mixing conditions,
— the mixing elements should be able to disperse cellulose fibers but the mixing should not be so strong that it breaks the individual fibers. This is important when the desired product is surface-treated cellulose fibers, as opposed to ‘bulk treated’ cellulose, where the entire cellulose fiber structure is derivatized. Our goal is to be able to do both surface-treatments and bulk treatments.
Additional information:
— equipment will be placed in non-ATEX area. Equipment does not need to be ATEX compatible,
— reactions will be done in mostly aqueous media,
— a used device is also acceptable if it fulfills the set criteria.

Teksti

South-Eastern Finland University of Applied Sciences (Xamk) is purchasing a pilot scale high-consistency batchwise reactor according to this tender documentation. Reactor will be located to Fiberlaboratory RDI-unit in Savonlinna. Primary use for the reactor is cellulose derivatization. The cellulose material to be mixed is mainly moist, sticky and fibrous, and the reactions will be done in high consistencies. ‘High-consistency’ refers to cellulose pulp, which contains approximately 70 % water. At this consistency, the pulp behaves almost like a solid and is challenging to mix.
Description of the process conditions:
— the cellulose pulp is mixed with additives, the reactor is heated to a desired temperature, derivatizing reagents are added, and the reaction is allowed to proceed,
— the main reaction solvent is tap water,
— heating is achieved by feeding steam into a jacket, which is around the reactor drum.
In this document, the term ‘reactor drum’ refers to the part of the reactor where the mixing and reactions take place. For reactions that require higher pressures than what the solvent’s vapor pressure naturally induces in a given temperature, pressurized air will be used to increase the pressure in the drum. In exothermic reactions, the temperature might need to be lowered by feeding cold water into the jacket,
— afterwards, heating and lowered pressure will be used to dry the material,
— the operational gauge pressure range of the reactor must be at least 0-10 bar and the temperature range must be at least 0-180 C. Higher maximum pressures and/or temperatures are also permitted. Higher reactor drum pressures are encouraged by rating the tendering results based on price and drum pressure as detailed below,
— the minimum inlet and outlet size is DN 200.
The outlet must be situated in the bottom of the reactor, and it must not create dead-space in which the mixing would be suboptimal. An outlet is not required if the reactor can be tilted to allow for draining of product efficiently from the inlet. Please upload a description of the loading and unloading system.
Special needs of the process:
— the reactor must have additional homogenizing elements, e.g. ‘choppers’, in addition to the main mixer elements in order to ensure homogeneous mixing conditions,
— the mixing elements should be able to disperse cellulose fibers but the mixing should not be so strong that it breaks the individual fibers. This is important when the desired product is surface-treated cellulose fibers, as opposed to ‘bulk treated’ cellulose, where the entire cellulose fiber structure is derivatized. Our goal is to be able to do both surface-treatments and bulk treatments.
Additional information:
— equipment will be placed in non-ATEX area. Equipment does not need to be ATEX compatible,
— reactions will be done in mostly aqueous media,
— a used device is also acceptable if it fulfills the set criteria.