Pressure screen STU

Pressure screen STU is designed for screening sections of stock preparation lines. Its main features are high capacity, very good screening efficiency, minimum loss of fibres in rejects and low demands on installation, attendance and servicing. Convenient combinations of rotors, sorting screens and drives enable to customise this machine to requirements even of the most demanding customers.

In waste paper processing lines pressure screen works as a primary stage of coarse screening using sorting screen with bored holes or in the end stage of final fine screening (using slotted sorting screen), where removes even very fine granules, plastic foils and stickies from the stock. It can be also used for distribution of the stock flow according to the fibre length - fractionation. With multi-vaned and hydraulically balanced rotor it is installed in front of the headbox to protect paper machine. In this case it is used as a knotter homogenizing the stock and separating the unpulped knots. Pressure screen STU can be successfully used in pulp mills for final fine screening of bleached or unbleached pulp. It separates small knots, bark pieces and nonfibrous components. In ground wood producing lines it can be used for final fine screening of chips.

Design

On the basis of longtime experiences and an accurate develop-ment pressure screen reaches long service life and simplicity of routine maintenance. Machine is characterized by its compact closed design with vertically installed cylindrical sorting screen, inside being wiped by a rotor. Its input branch and branches for discharge of light and heavy impurities are arranged tangentially. The output part for accepted stock is arranged radially. STU can be equipped also with special cover supporting effective deaeration of the stock and separation of the finest impurities (design L).

Material

All parts coming in contact with the stock are made of stainless steel AISI 321 or AISI 316 Ti, other machine parts are made of common structural steel AISI 1020.

Machine design and work safety are in compliance with EU standards.

Main parts

• pressure screen body (1)
• input part (2) with separator of heavy impurities (2a)
• output part (3)
• cover (4)
• sorting screen (5)
• shaft bedding (6)
• rotor on shaft (7)
• frame with V-belt drive (8)
• electric motor (9)

STU-input	duplex: STU-200-accept	duplex: STU-200-accept	STU-080-accept
fluting: STU-200-accept	fluting: STU-200-accept	STU-200-accept	STU-200-accept
STU-accept, slots 0,25 mm	STU-accept, slots 0,20 mm	STU-reject

Advantages

• rugged structure
• high resistance against fouling of sorting screens
• high hydraulic capacity and screening efficiency
• reliability in service easy sorting screen and rotor replacement
• long service life
• disassembly of bearing housing without removal of belt pulley
• simple and easy operationand maintenance

Accessories

• separator of heavy impurities STU-OTN, including two gate valves DN100 with hand lever
  
• cover intended for discharge of light impurities and 2 pcs of pneumatic gate valves (for STU-081 L-EHD)

Technical parameters