Prem Engineering

Jumbo Press

 

Jumbo Press with Extended Pressing Zone

The Jumbo press, typically used as the last press before the web enters the PM drying part, is constructed as a double-roll press with a hydraulic loading of the upper press roll. This design enhances the dewatering process, ensuring increased dryness of the paper web before it enters the drying section.

Design Features

Load Bearing Structure:

  • Designed to withstand high static and dynamic stresses.
  • Adapted for easy felt exchange and press roll removal.

Press Rolls:

  • Modern construction design.
  • Embedded in double-row spherical-roller bearings in bearing housings.
  • Bearings allow for grease or central oil lubrication depending on speed and load.
  • Inner cooling system for roll cover temperature stabilization.
  • Roll cover made of highly elastic rubber with high mechanical and heat resistance.
  • The cover is crowned in accordance with the roll flattening and operating linear load calculation.
  • Blind bored holes in the roll cover for water drainage during pressing.

Felt Guiding and Conditioning:

  • Each roll is suited with press felts designed individually according to speed, linear load, and the product assortment.
  • Includes regulation, felt stretching, and conditioning system.

Drive System:

  • Double-motor drive: each press roll has its own drive unit.

Control and Manipulation:

  • Electric part of the drive, control, and manipulation system (including control panel).
  • Hydraulic loading system for the upper press roll.
  • Paper threading system.

Main Parts

  1. Bearing Structure (1):

    • Made of common steel.
    • Designed for high stress and easy maintenance.
  2. Press Rolls and Embedding (2):

    • Modern design with spherical-roller bearings.
    • Embedded in cast iron housings.
  3. Press Rolls Cooling Device (3):

    • Inner cooling system for temperature stabilization.
  4. Hydraulic Drive (4):

    • Hydraulic system for loading the upper press roll.
  5. Machine Control (5):

    • Includes control panel and electric control system.
  6. Top Felt Guiding (6):

    • System for guiding the top felt.
  7. Bottom Felt Guiding (7):

    • System for guiding the bottom felt.
  8. Machine Guards and Foot Bridges (8):

    • Safety and maintenance access features.

Material

  • Bearing Structure and Guide Rolls: Made of common steel.
  • Press Rolls Embedding: Made of cast iron.

Accessories

  • Roll removal equipment.
  • Jumbo press drive (mechanical and electric part, control included).

Scope of Delivery

  • Complete machine in accordance with the main parts description.
  • Optional accessories based on customer requirements.

Technical Parameters

ParameterValue
Maximal Pressure350 kN/m
Maximal Paper Width7,500 mm
Maximal Speed1,000 m/min
Max. Press Roll Diameter1,500 mm
NIP Width60 – 75 mm

Advantages

  1. Extended Pressing Zone: Provides more effective dewatering.
  2. Increased Dryness: Ensures higher dryness levels after the press part, improving overall paper quality and reducing drying energy requirements.

The Jumbo press’s robust design and advanced features make it a crucial component in modern paper machines, ensuring efficient dewatering and enhancing the overall production process.