Polyamine Steam Heating Efficiency in Papermaking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In papermaking facilities, existing methods to improve steam heating efficiency often result in reduced production rates and require significant facility renovations or lead to clogging issues when chemical agents are used to prevent condensed water film formation in steam dryers.
Innovation Solution
The use of a specific polyamine, such as N-octadecenylpropane-1,3-diamine, injected into the steam system suppresses condensed water film formation without reducing drum rotation rates or necessitating facility renovations, thereby enhancing heating efficiency and reducing cleaning frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If long-chain aliphatic amine is added as contact angle-increasing agent to suppress condensed water film formation, then heating efficiency is improved, but clogging occurs in the system and cleaning frequency increases
Solution Approach 1:
The invention changes the chemical structure parameter of the amine from straight-chain (long-chain aliphatic amine) to branched-chain (polyamine with alkyl groups containing branching). This structural parameter change fundamentally alters the molecular packing and adhesion properties, preventing the clogging issue while maintaining the condensed water film suppression effect and heating efficiency improvement.
2Loss of energy
If drum rotation rate is reduced to make condensed water film ununiform, then condensed water film formation is suppressed, but papermaking rate and production amount decrease
Solution Approach 1:
The invention introduces polyamine as a chemical intermediary substance that mediates between the steam and the condensed water film. The polyamine modifies the surface properties of the condensed water film, making it less adherent to the drum surface. This allows the drum to rotate at normal high speeds while still achieving effective condensed water film suppression, thus maintaining both heating efficiency and papermaking rate.
3Loss of energy
If spoiler bars are installed in the drum to suppress condensed water film formation, then heating efficiency is improved, but facility renewal and engineering work are required
Solution Approach 1:
The invention replaces the mechanical system (spoiler bars physically installed in the drum) with a chemical system (polyamine injected into the steam). Instead of using mechanical structures to disrupt the condensed water film, the polyamine chemically modifies the film properties through surface activity. This substitution eliminates the need for mechanical facility renewal and complex engineering installations while achieving the same heating efficiency improvement.
4Loss of energy
If chemical agents are excessively added to suppress condensed water film formation, then heating efficiency is improved, but clogging occurs and cleaning frequency increases
Solution Approach 1:
The invention optimizes the dosage parameter of the chemical agent by changing its molecular structure to polyamine. The branched-chain structure provides superior performance at lower concentrations, reducing the total amount of chemical agent needed. This parameter optimization ensures effective condensed water film suppression while minimizing clogging risks and cleaning frequency, improving ease of operation.
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
This approach effectively improves steam heating efficiency, maintains production rates, and reduces steam consumption, preventing clogging and allowing for stable operation with energy savings.
Implementation Method 1
a specific polyamine provides no clogging problem and can reduce the cleaning frequency more greatly than the long-chain aliphatic amine proposed in Patent Literature 1. It has also been found that by causing the polyamine to be present in a steam system, the heating efficiency of a steam dryer can be improved without involving the reduction of the production efficiency
Implementation Method 2
Condensed water W generated by condensation of water vapor in the drum 11 is fed to a flash tank 14 via a siphon pipe 12 and a pipe 13
Implementation Method 3
In the drum 11, the condensed water W is pressed against the inner peripheral surface of the drum 11 by a centrifugal force accompanying the rotation of the drum 11 to be lifted in the rotation direction of the drum 11
Implementation Method 4
The drying step of the paper in the papermaking facility involves gradually raising the temperature of moisture and pulp contained in the wet paper to evaporate water. A needed quantity of heat is imparted mainly by steam in individual dryers
Data Source
AI summary
A method for improving the heating efficiency of steam wherein a polyamine represented by the following general formula (1) is caused to be present in a steam system to be used for heating. R1-[NH-(CH2)m]n-NH2 ··· (1) wherein R1 represents a saturated or unsaturated hydrocarbon group having 10 to 22 carbon atoms; m is an integer of 1 to 8, and n is an integer of 1 to 7; and when n is 2 or more, a plurality of NH-(CH2)m may be identical or different.