Adjustable Press Nip Cylinder for Pulp Dewatering Rolls
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Solution Overview
Problem
Conventional roll presses for dewatering pulp lack the ability to adjust the press nip size during operation, limiting their flexibility in processing different pulp qualities and material sizes, and managing production variations, which can result in inconsistent dryness and quality of the processed pulp.
Innovation Solution
A device with a first press roll and a second press roll, where the first press roll is movable between two radial end positions, and an adjusting cylinder is used to adjust the press nip by changing the radial distance between the rolls, allowing for adjustable press nip sizes without dismantling the apparatus, utilizing a hydraulic or pneumatic system to facilitate this adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the press roll is made laterally movable to adjust press nip size, then adaptability to different pulp qualities is improved, but device complexity increases due to additional movement mechanisms
Solution Approach 1:
The patent employs a hydraulic cylinder connected to the bearing housing to provide lateral movement of the press roll. The hydraulic system converts fluid pressure into mechanical force, enabling smooth and controlled adjustment of the press nip size between different pulp processing requirements without complex mechanical linkages
Solution Approach 2:
The bearing housing is designed to be movable rather than fixed, allowing the press roll to dynamically adjust its position laterally. This dynamic capability enables the system to adapt press nip size in real-time based on processing requirements while maintaining structural integrity through the movable bearing housing design
2Productivity
If the press roll is made adjustable during operation, then productivity is improved by processing different pulp types, but reliability decreases due to potential position instability
Solution Approach 1:
The hydraulic system incorporates feedback mechanisms through pressure sensors and position monitoring that continuously monitor the press roll position and hydraulic pressure. This feedback ensures the press roll maintains its intended position during operation, preventing fluctuations in press nip size that would affect pulp processing consistency
Solution Approach 2:
The hydraulic cylinder automatically maintains the press roll in the correct radial position through self-regulating pressure control. The system monitors and adjusts hydraulic pressure to counteract any forces that might displace the press roll, ensuring stable positioning without requiring constant external intervention
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient processing of various pulp qualities and sizes, managing production variations by allowing for real-time adjustment of the press nip, ensuring consistent dryness and quality of the dewatered pulp, and upgrading existing roll presses to accommodate different press nip settings.
Implementation Method 1
utilizing a hydraulic or pneumatic system to facilitate this adjustment
Implementation Method 2
utilizing a hydraulic or pneumatic system to facilitate this adjustment
Data Source
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AI summary
A device for adjusting a press nip (126) defined by a first press roll (102) and a second press roll (104), each press roll being rotatable about an axis of rotation (103, 105) and included in an apparatus for dewatering pulp, and the apparatus has a first pair of bearing housings (220) provided with bearings (218) by means of which the first press roll is journalled, each bearing housing of the first pair and the first press roll being movable in relation to the second press roll in a direction substantially transverse to the axial direction of the press nip, the device comprising pressure means (222) for forcing the bearing housings of the first pair in a direction towards the press nip, the first press roll being movable between a first radial end position and a second radial end position. The device is arranged to adjust the press nip during operation of the apparatus and comprises at least one adjusting cylinder (223; 402) for adjusting the first press roll to each of the radial end positions during operation of the apparatus, the adjusting cylinder being arranged to force at least one of the bearing housings of the first pair in a direction away from the press nip to move the first press roll to one of the radial end positions, and the adjusting cylinder has a length of stroke (S) that defines the difference between two different press nips (I, II) for the apparatus, wherein the length of stroke (S) of the adjusting cylinder (223; 402) is adjustable to adjust the difference between the two different press nips (I, II). An apparatus for dewatering pulp comprises such a device for adjusting the press nip.