search query: @keyword pyörrepuhdistus / total: 2
results-list
reference: 1 / 2
« previous | next »
Author:Heiskala, Olli
Title:Optimization of cleaning and screening processes of paper machine
Paperikoneen erotusprosessien optimointi
Publication type:Master's thesis
Publication year:2011
Pages:iv + 116 s. + liitt. 6      Language:   eng
Department/School:Puunjalostustekniikan laitos
Main subject:Paperi- ja painatustekniikka   (Puu-21)
Supervisor:Paltakari, Jouni
Instructor:Siiskonen, Olli
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
Instructions
close

Reading digital theses in the closed network of the Aalto University Harald Herlin Learning Centre

In the closed network of Learning Centre you can read digital and digitized theses not available in the open network.

The Learning Centre contact details and opening hours: https://learningcentre.aalto.fi/en/harald-herlin-learning-centre/

You can read theses on the Learning Centre customer computers, which are available on all floors.

Logging on to the customer computers

  • Aalto University staff members log on to the customer computer using the Aalto username and password.
  • Other customers log on using a shared username and password.

Opening a thesis

  • On the desktop of the customer computers, you will find an icon titled:

    Aalto Thesis Database

  • Click on the icon to search for and open the thesis you are looking for from Aaltodoc database. You can find the thesis file by clicking the link on the OEV or OEVS field.

Reading the thesis

  • You can either print the thesis or read it on the customer computer screen.
  • You cannot save the thesis file on a flash drive or email it.
  • You cannot copy text or images from the file.
  • You cannot edit the file.

Printing the thesis

  • You can print the thesis for your personal study or research use.
  • Aalto University students and staff members may print black-and-white prints on the PrintingPoint devices when using the computer with personal Aalto username and password. Color printing is possible using the printer u90203-psc3, which is located near the customer service. Color printing is subject to a charge to Aalto University students and staff members.
  • Other customers can use the printer u90203-psc3. All printing is subject to a charge to non-University members.
Location:P1 Ark Aalto  2173   | Archive
Keywords:screening
pressure screening
centrifugal cleaning
lajittelu
painelajittelu
pyörrepuhdistus
Abstract (eng): In this thesis process parameters of screening and cleaning processes on two paper machines were defined.
Based on literature, the design and operating parameters of pressure screens and centrifugal cleaners were determined.
Objective was to find targets for enhancements of processes.
Experimental studies were conducted based on the findings in literature.
The objective of the machine survey was to define operational parameters of pressure screens and centrifugal cleaners of short circulation as well as pressure screens of broke handling.
Objectives of the mill trials were to increase the reject rate of the first stage centrifugal cleaner of paper machine 6 to the recommendation of a supplier and to simplify the broke handling of paper machine 7 from five stages to three stages to comply with the best practice available.

Machine survey was done on both paper machines.
In machine survey reject rates, pressure differences and flows for pressure screens and centrifugal cleaners were defined.
Reject rates were determined using laboratory consistency measurements.
Pressure differences were defined with a calibrated pressure gauge and flows with locally mounted sensors.
In the mill trial on paper machine 6 the same measurements as in machine survey were used.
In the mill trial on paper machine 7 dirt count was determined using modified ISO 5350-1:2006 standard.

On paper machine 6 a reject rate increase of 20 per cent level was achieved.
The broke handling of paper machine 7 can be operated in three stages, without disturbing the other processes and without degrading the quality of screened stock.
Three stage operation would enable annual savings of a 50 000 Euros in costs of energy and maintenance.
Finally, also the knowledge of the screening and cleaning processes as well as maintenance was increased among the personnel of paper mill.

As a conclusion, it can be said that attention must be paid to the operational parameters of screening and cleaning processes so that paper machine would work without interruptions.
Great savings can be achieved in screening and cleaning by tuning the process and by bypassing extra capacity.
The objectives of the whole thesis were well achieved.
Abstract (fin): Työssä selvitettiin paperikonelinjojen lajitteluprosessien prosessiolosuhteet.
Kirjallisuuden pohjalta selvitettiin painesihtien ja pyörrepuhdistimien suunnittelu- ja ajoparametrit.
Tavoitteena oli löytää parannuskohteita prosesseista.
Kokeellisen osuuden tutkimukset tehtiin kirjallisuudesta löytyneiden havaintojen perusteella.
Konetutkimuksen tavoitteena oli selvittää lyhyenkierron painesihtien ja pyörrepuhdistimien sekä hylynlajittelun painesihtien toimintaolosuhteet.
Koeajojen tavoitteena oli nostaa paperikone 6:n pyörrepuhdistuksen I-portaan rejektisuhde toimittajan suosittelemalle tasolle ja yksinkertaistaa paperikone 7:n hylynlajittelu viisiportaisesta vastaamaan parasta olemassa olevaa käytäntöä.

Konetutkimus suoritettiin kummallekin paperikoneelle.
Tutkimuksessa määritettiin painesihtien ja pyörrepuhdistimien rejektisuhteet, paine-erot sekä virtaamat.
Rejektisuhteet laskettiin laboratoriossa tehtyjen sakeusmääritysten avulla.
Paine-erot määritettiin kalibroidulla käsimittarilla ja virtaamat paikallismittareilla.
Paperikone 6:n koeajossa käytettiin samoja menetelmiä kuin konetutkimuksessa.
Paperikone 7:n koeajon roskalaskenta suoritettiin muokattua ISO 5350-1:2006 standardia käyttäen.

Paperikone 6:n rejektisuhde saatiin nostettua halutulle 20 prosentin tasolle.
Paperikone 7:n hylynlajittelua voidaan ajaa kolmiportaisena, ilman että muu prosessi häiriintyy ja lajittelutuloksen laatu kärsii.
Ajo kolmiportaisena mahdollistaisi 50 000 euron vuotuiset säästöt energiankulutuksen ja kunnossapidon kustannuksissa.
Lopputuloksena myös paperitehtaan henkilökunnan tietämys lajitteluprosesseista ja kunnossapidosta karttui.

Johtopäätöksenä voidaan todeta paperikoneiden lajitteluprosessien toimintaan ja ajoparametreihin tulee kiinnittää huomiota paperikoneen häiriöttömän toiminnan takaamiseksi.
Lajittelussa pystytään tekemään huomattavia säästöjä tehostamalla prosessin toiminta tarkoituksenmukaiseksi ja ohittamalla ylimääräistä kapasiteettia.
Työn tavoitteet saavutettiin hyvin.
ED:2011-06-13
INSSI record number: 42157
+ add basket
« previous | next »
INSSI