Leading European mills cut chemical costs and boost PM efficiency through accurate charge control
Lack of effective wet-end control can quickly escalate into all kinds of production headaches. By maintaining wet-end stability, charge control systems deliver fast payback through substantial savings on chemical dosing and production downtime.
Leading European tissue manufacturers are choosing BTG’s Mütek™ PCT-20 Charge Analyzer to optimize tissue machine performance and boost profitability. This state-of-the-art analyzer delivers fast, accurate online charge measurement based on the industry benchmark Mütek concept, through direct sampling at the most critical locations throughout the tissue process.
Profitability in DIP-containing grade production
Facilities producing white tissue products – towels, napkins, hygienic papers – using up to 50% mixed waste paper rapidly gain profitability through applied wet end control strategies.
Online cationic demand measurement allows engineers to precisely adjust chemical additive levels, eliminating costly and unnecessary dosing, as well as helping them improve their understanding of the complex interrelation between the pulp suspension, tissue machine performance and final product quality.
A universal goal: increased production volumes
In today’s highly competitive markets, many production managers say their number one priority is to increase machine speed and develop strategies to better handle the dosing of wet strength resin.
For tissue mills that regularly use various raw material qualities and produce different wet strength resin-containing grades, process variability is the principal enemy of increased production volumes. When grades are changed – for example, from towel to hygienic paper – breaks are often frequent and fines management can get out of control. For many, high wet strength consumption with high variability of final sheet strength are daily problems.
Boost machine speed by up to 15% through online charge control
When a Mütek™ PCD-04 Particle Charge Detector is used to establish a database of cationic demand variability, it becomes clear that most mills could greatly stabilize their process through closer monitoring of cationic demand.
Figure 1:
Process flow sheet with PCT-20 installation
BTG’s solution: improve stability through accurate charge control
To remedy process instability, BTG recommends installation of a PCT-20 Charge Analyzer with two distinct sampling points – at the white water and disc filter or press. PCT-20 installation is simple and straightforward, and because the unit can handle all low-consistency process waters directly without any sample preparation, no pumps are required to feed the sample to the equipment.
The 4-20 mA signals are fed to the DCS, allowing operators to quickly view measurement data and take appropriate action whenever the charge level exceeds grade-specific targets.
Figure 2:
Charge monitoring in the start-up phase
Before the implementation of a control approach, variability in RCF grades is usually high. A one-month monitoring phase generally gives operators a good in-depth understanding of the interaction between chemical dosing and PM runnability, detecting over-dosages, explaining flocculant inefficiencies, and allowing the production team to improve fines management.
Trials with chemical additives can be monitored, and the effects of chemical dosage layout changes can be easily and accurately traced. This allows for highly effective optimization of the chemical layout of the approach flow.
Figure 3:
Charge monitoring helps optimize chemical dosage
Figure 3 clearly illustrates how accurate charge control delivers improved runnability. When cationic demand increases towards -1,0 ml at low-wet-strength-containing grades, the application of a cationic fixing agent quickly improves overall runnability. Operators can rapidly bring the machine back to its ‘sweet spot’ at -0,5 ml and production can be stabilized, leading to increased output.
Figure 4:
The PCT-20 Charge Analyzer’s modular design makes life easy for operators
The PCT-20’s modular design facilitates access and ease-of-use, simplifying bi-weekly maintenance. Well-designed sampling, rinsing and cleaning cycles minimize maintenance tasks and ensure consistent, reliable results, while multi-line measurement allows for sampling at the most important process locations.
The results: higher volumes, lower costs
After just six months’ production using BTG’s PCT-20 Charge Analyzer, leading mills report:
- increased machine speed by as much as 15%
- increased blade life in hours
- stabilized drainage through improved fines management
- optimized chemical efficiency
These significant productivity improvements are the result of a more efficient chemical process and a more stable overall wet end. Strategic cationic additives and raw materials all carry charge, and managing that charge is crucial to wet-end control and overall process stability. In today’s highly competitive environment, failing to take measures to effectively control this key parameter is tantamount to throwing money out the window.