Urea Melt Drop Former Mixing Uniformity
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Solution Overview
Problem
Existing methods for producing pastilles from mixtures of substances, particularly urea mixtures, face challenges in ensuring uniform and intimate mixing of components, leading to inconsistent product quality due to separation issues and poor miscibility of substances with different physical properties.
Innovation Solution
A method involving the production of a liquid melt, admixing substances before a drop former with a rotating, perforated drum, and utilizing a two-stage heated grinding and mixing unit, along with ultrasound and a stirring device within the feed channel, ensures uniform mixing by breaking down substances into fine particles and preventing segregation, resulting in pastilles with a uniform composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If substances are simply mixed and dropped without intensive mixing, then the process is simple and fast, but the mixing uniformity is poor leading to inconsistent product quality
Solution Approach 1:
The mixing process is divided into multiple stages: initial mixing in the feed channel, continued mixing during rotation in the outer drum, and final mixing at the nozzle. This segmentation allows thorough mixing without requiring a single complex mixing device, as each stage contributes to the overall mixing uniformity.
Solution Approach 2:
Substances are pre-mixed in the feed channel before entering the outer drum, and liquid additives are pre-admixed with the melt immediately before the drop former. This preliminary action ensures that mixing is well underway before the dropping process begins, improving uniformity without adding complex post-mixing equipment.
2Manufacturing precision
If liquid additives are mixed early in the process, then there is more time for mixing, but the liquids may separate due to different specific weights during transport
Solution Approach 1:
A liquid intermediary substance is introduced that is miscible with both the urea melt and the liquid additive to be added. This intermediary acts as a mediator that prevents phase separation by creating a stable emulsion or solution, allowing the liquids to remain mixed throughout transport to the drop former.
Solution Approach 2:
The mixing action continues uninterrupted from the point of additive introduction through the feed channel and into the rotating outer drum. The continuous motion and agitation prevent liquid separation by maintaining turbulent mixing throughout the transport process, ensuring composition stability.
3Adaptability or versatility
If solid additives are added to the melt, then product composition can be varied, but achieving uniform mixing requires intensive grinding and mixing
Solution Approach 1:
The physical state of solid additives is changed by heating them to melting point or near-melting point temperatures before introduction to the melt. This parameter change (from solid to liquid) dramatically improves miscibility and mixing uniformity, reducing the need for intensive grinding while maintaining product composition flexibility.
Solution Approach 2:
The feed channel serves multiple functions: it acts as a heating zone, a mixing chamber, and a transport conduit. This multi-functionality allows solid additives to be heated and mixed without requiring separate dedicated grinding and mixing equipment, reducing overall device complexity while achieving uniform mixing.
4Manufacturing precision
If the outer drum rotates slowly, then drops have time to form properly, but productivity decreases
Solution Approach 1:
The outer drum rotates at variable speeds during different phases of operation. During the mixing phase, it rotates slowly to ensure uniform mixing. During the dropping phase, it increases rotation speed to enhance centrifugal force for proper drop formation and to increase the rate at which drops are discharged, thereby maintaining both quality and productivity.
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 achieves intimate and uniform mixing of substances, ensuring consistent product quality by maintaining the mixture's uniformity throughout the process, even for poorly miscible liquids and solid particles, and enhances the use of elemental sulfur as a fertilizer by increasing its surface area for biological oxidation.
Implementation Method 1
The admixture immediately before the gob former prevents the liquid melt of the first substance and the added further liquid substance from separating again during transport to the gob former, for example due to different specific weights
Implementation Method 2
ultrasound and a stirring device within the feed channel, ensures uniform mixing by breaking down substances into fine particles
Implementation Method 3
the provision of a two-stage, heated grinding and mixing unit has proven to be extremely advantageous in order to ensure a uniform and intimate mixture of the originally solid further substance and the liquid melt of the first substance
Implementation Method 4
the mixture is mixed inside the drop former until just before exiting through nozzles and openings of the rotating outer drum by means of a stirring device inside the gob former extending agitator and wherein the mixture is stirred inside the feed channel of the gob former
Implementation Method 5
two-stage, heated grinding and mixing unit
Implementation Method 6
a drop former with a rotating, perforated external drum, The urea melt is pressed through the outer drum and falls in drop form onto a cooled steel belt
Implementation Method 7
solidification of the droplets of the mixture on the steel belt to form pastilles
Data Source
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AI summary
1.1. The invention relates to a method for producing tables made of mixtures of a plurality of materials, and method for producing a sulfurous fertilizer. 2.1. The invention relates to a method for producing tablets made of mixtures of a plurality of materials, particularly urea mixtures, having the following steps: - producing a liquid melt of a first material, - adding at least one further material in solid or liquid form to the melt for producing a mixture, - output of drops of the mixture onto a steel belt by means of a drop former having a rotating, perforated outer drum, - solidification of the drops of the mixture on the steel belt into tablets, wherein the at least one additional material is mixed into the liquid melt in liquid form immediately before the drop former or into the liquid melt in solid form upstream of a two-stage heated grinding and mixing unit. 2.2. Use for producing fertilizer, for example.