What are the papermaking machinery and equipment?
Material preparation equipment
It is the equipment for pretreatment and processing of papermaking raw materials according to the requirements of cooking or pulping process before cooking or pulping, which is divided into non-wood fiber preparation equipment and wood fiber preparation equipment. The former includes lawn mowers, reed machines and sugarcane cans, while the latter includes peelers and chippers.
Chipping machine is a machine that cuts the logs needed to produce wood pulp into chips with certain specifications, which can be divided into disc type and drum type. The digester is a device that dissolves lignin in papermaking raw materials into cooking liquid to separate papermaking raw materials into fibers, which can be divided into intermittent and continuous types. Wood mill is a kind of equipment for producing ground wood pulp, which can be divided into two types according to the production mode: intermittent and continuous, and hydraulic pressurization and mechanical pressurization according to the pressurization mode of logs.
Pulping equipment
It is the equipment used in the process of separating plant raw materials into fibers. Pulping methods can be divided into chemical method, mechanical method and chemical mechanical method, and the corresponding pulping equipment includes digester, wood mill, thermal mill, pulp washer, pulp bleaching machine, beater and waste liquid recovery equipment.
Wood chips are preheated by steam and then ground under high pressure. This kind of pulp is called hot broken wood pulp. The machine for making thermoground wood pulp is a thermomill, which consumes a lot of electric energy, so making full use of the heat energy in the pulping process is the key problem of the thermomill. The pulp washer is a kind of mechanical equipment that separates the cooked pulp from the black liquor. According to the extraction rate of black liquor, it can be divided into high concentration extraction and low concentration extraction.
The purpose of pulp bleaching is to remove lignin and pigment remaining in pulp after cooking, improve the whiteness of pulp and make pulp white. Bleaching machine is a widely used bleaching equipment, which is composed of spiral propeller of bleaching pool, drum washing and other components. Slurry and bleach are placed in the tank and washing water is continuously added. They circulate in the tank with the help of the screw propeller to complete the process of mixing and chemical reaction. Water with bleaching products and residual bleaching solution is discharged through the inner cavity of the washing drum, thus obtaining white pulp.
paper machine
It is a complete set of equipment for forming paper pulp into paper web, including headbox, wire section, press section, drying section, calender, paper winder, transmission section and other main machines and auxiliary systems such as steam, water, vacuum, lubrication and heat recovery. The wire part of wet paper web is the core of paper machine, so according to the structure of wire part, paper machine can be divided into fourdrinier machine, wire-sandwiched paper machine and rotary paper machine.
Headbox is a kind of equipment, also known as headbox, which sends the slurry with proper concentration to the net evenly and stably through the slurry distributor, rectifier, weir pool, weir plate nozzle and other parts. After the slurry is sprayed on the copper wire from the headbox, a wet paper sheet is formed on the wire and dehydrated; Then press, that is, squeeze the moisture of the wet paper out of the wire by mechanical method to improve the dryness of the paper, improve the surface performance of the paper, eliminate the net marks and increase the smoothness, tightness and strength; And then enters the drying section to further dehydrate the pressed wet paper, so that the paper shrinks, the fibers are tightly combined, and the strength is increased.
After the paper coming out of the dryer is calendered by the calender, the smoothness, gloss and tightness of the paper can be improved, so that the full thickness of the paper is consistent and the air permeability is reduced. Finally, the paper web is rolled into a paper roll by a paper roll machine to complete the main process of papermaking. In order to meet the different needs in the future, there are super calender, rewinder and paper cutter behind the paper rolling machine in the paper workshop.
Lubrication mode of papermaking equipment
Pulping and papermaking machinery includes pulping and papermaking machinery, as well as paper decoration and processing equipment. Specific lubrication methods are as follows:
1, lubrication of pulping machinery
Pulping machinery includes two types of equipment: material preparation and pulping. The lubrication characteristics of pulping machinery are wet and high temperature working environment and impact load. It is generally required to have good heat resistance, oxidation resistance, emulsification resistance and rust resistance, and the viscosity is 46- 100. It is also necessary to use No.2 or No.3 compound calcium-based, sodium-based or lithium-based grease with good heat resistance and mechanical stability, and even molybdenum disulfide or graphite grease can be used. Bearings and gears of pulping and cooking equipment work at high temperature and are often lubricated with industrial gear oil or grease. The lubricating parts of pulping machinery include bearings, worm gears, reducers, closed and open gears, and L-HL hydraulic oil and L-CkC industrial gear oil have also been involved. Calcium-based grease, composite calcium-based grease, universal lithium-based grease, graphite calcium-based grease and semi-fluid lithium-based grease.
2. Lubrication of paper machine
In principle, the lubrication points of paper machines are all closed. Each bearing in the wet end of the paper machine has a sealed bearing shell to prevent cross-contamination caused by water intrusion and grease overflow. Because of the high temperature in the drying section of the paper machine, the central lubricating station is used to transport the lubricating oil under pressure to the bearings everywhere for lubrication and heat dissipation. It is concluded that the lubrication components of paper machine include transmission reducer, worm gear reducer, general sliding bearing, rolling bearing, exhaust fan, wet rolling bearing, steel wire rope and oil for central lubrication station (cadre lubrication). Oils and fats used to be involved include hydraulic oil, total loss system oil, calcium-based grease, sodium-based grease, graphite calcium-based grease and so on.
3. Lubrication of paper machine and its auxiliary equipment
(1) divisional transmission reducer, central lubricating station oil (dry lubrication), vibration box, worm gear reducer and universal sliding bearing:
They are all lubricated by hydraulic oil or total loss system oil. When using L-HL46 or L-AN46, the viscosity of the oil is 4 1.4 ~ 50.6mm2/s at 40℃, and the flash point (opening) >: 180℃, freezing point.
(2) Wet rolling bearing:
Calcium base grease, dropping point >; At 80℃, the penetration (25℃,110 mm) is 265 ~ 295.
(3) Exhaust fans and rolling bearings in hot and humid places: sodium-based grease, dropping point >; 40℃, penetration (25℃,110 mm) 220 ~ 250.
(4) Wire rope:
Graphite calcium-based grease; ZG-S； Dropping point >: 80℃