If top-reliability and high performance in the paper industry are your main concerns, we have the solutions. Metso provides a full range of top quality, on-off and control valves for applications ranging from wood handling and approach systems to the paper machine and finishing processes. Metso has been a pioneer in the paper business since the very beginning, which is why today most of the world's pulp flows through our valves. We have good references and satisfied customers in every part of the world Our customers know that they can rely on us.
Steam and condensate
The thermo-mechanical pulping (TMP) method is a pulping process in which the wood fibers are separated by means of mechanical forces. As a result of frictional forces, part of the mechanical energy is converted into heat, which aids in softening the lignin binding the wood fibers together. The mechanical energy converted into heat generates large amounts of steam in TMP refining. The finished thermo-mechanical pulp contains the lignin of the wood, so that the pulp yield is double that of the pulp yield obtained in a chemical pulping process.
Metso valves and actuators have performed successfully in TMP systems since their inception. The R-Series control valve, with its rugged seat design, has quickly proved itself to be the answer. The availability of Q-TRIM® (with its noise and vibration reduction benefits) for the R-Series valve has made it the valve of choice for steam control. In the TMP discharge, the specially designed MC-segment valve provides an optimized flow path for medium consistency pulp. The body is equipped with a flushing connection and the flow path in the valve is continuously increased to eliminate restrictions where material may build up.
The technology of processing recycled fibers is more complex than that used for virgin fibers (chemical and mechanical fibers) because of the composition of the raw material. The goals in processing waste paper are to restore the original properties of the paper fiber and to remove impurities. The removal of printing inks is called de-inking. The aim of de-inking is to produce recycled pulp that is as white and pure as possible. Prior to de-inking, the printing ink must be released from the fiber. The ink is then removed by flotation and washing. The removal and separation of printing inks requires the application of both chemical and mechanical methods.
Metso is a leader in providing the right valve solutions for de-inking plants (DIP) and old corrugated container plants (OCC). We are your single source supplier, from simple shut-off to control solutions featuring segment
and ball valves
. Because the whole de-inking plant includes several important process stages, flawless valve operation is essential. The R-series segment valve
offers the best control features for consistency control, while Metso’s triple
eccentric butterfly valves are used in on/off applications, where excellent tightness is needed. Butterfly valves are also a cost-effective solution for control purposes in low consistency applications.
Secondary fiber preparation pulping and cleaning
Secondary fiber preparation - deinking and thickening
Stock preparation or "stock prep" is the process located between the pulp mill and the paper mill. It includes mechanical treatment of the stock before the machine chest, proportioning, and blending of the main stock components. Stock preparation begins with re-pulping or dilution of the pulp from integrated mill operations at the pulp storage towers and ends at the machine chest.
Metso offers a variety of solutions for stock preparation. Stock preparation is a long and demanding process for valves. Important properties for valves in this process are positional accuracy and low hysteresis. No backlash or stiction can be tolerated from valves in stock proportioning. The R-series segment valve
is widely used in stock preparation because of its superior control properties. For more demanding applications, such as filler proportioning, we can offer ceramic ball valves
, which have the best resistance to erosion.
Short circulation is the part of the paper making process where water filtering through the wire is utilized for diluting the stock supplied to the head box. In the mill, the short circulation is located between stock proportioning and the head box of the paper machine. Short circulation has a very important role in paper quality. Most of the paper properties are formed in the short circulation area, after which those properties cannot be altered. Flawless operation is therefore vital.
Metso is a pioneer in the pulp and paper business. We have a complete solution for every short circulation construction available. Our state-of-the-art basis weight control valve, nelesACE
, is the most accurate control valve available on the market today. It has a very high resolution and fast response, which will help you to make fast and accurate grade changes. In addition, the other Metso valves used in the short circulation area are tailor-made to ensure the best possible function and quality.
nelesACE™ basis weight control valve
Broke is paper that is discarded at the manufacturing or finishing processes inside the paper mill. The purpose of the broke system is to create broke that is suitable for re-use in paper production. The goal is to prevent the re-used broke from causing runnability problems on the paper machine or paper quality problems as well as to minimize the amount of fiber and filler discharged as reject from the broke system. As a rule, broke handling costs should be minimized by the efficient re-use of the broke.
Thanks to our long history and in-depth application knowledge of the pulp and paper business, we are better able to help you to select the correct valve types and sizes in broke handling systems. If too small a valve is selected, the pipeline can easily become clogged after the pulpers, where consistency is not always constant. On the other hand, using too large a valve will not be good from the control point of view. In most parts of the broke-handling system positional accuracy is a critical feature. That is why most of the valves are R-series segment valves
, but butterfly valves
are sometimes used in some parts of the process.
Steam and condensate
The steam and condensate system is a part of the paper machine. Its purpose in the paper machine is to provide the steam for the drying. Final drying is carried out in the drying section. This is achieved by means of several steam-heated dryers (cylinders). These are driven in groups of a few together. The paper sheet runs over a large number of dryers and moisture is evaporated as the sheet is pressed between a fabric and the hot drying cylinder. The temperature of each of the dryer surfaces must be precisely controlled. The temperature is lower in the first groups of dryers and then raised slowly in the later groups at the end of the drying process
The biggest single expenditure in a paper mill is on energy consumption. That is why faultless valve operation has an important role in the steam and condensate system. Metso offers a wide choice of on-off
and control valves
for the steam and condensate system. Good tightness is a preferred feature for all steam valves. If accurate control is your concern, the R-series segment
valve is the obvious choice. It will help you to adjust temperatures in the steam and condensate system fast and accurately, for example in a grade change situation. Furthermore, our cost-effective triple eccentric butterfly valves offer excellent tightness and good control properties for steam and condensate systems.
Steam and condensate system