Fertilizer Granule Recirculation Reactor Clogging Prevention

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Solution Overview

Problem

Current methods for producing fertilizer granules from phosphate-containing raw materials are either cost-intensive or result in inert raw material particles that clog devices, and do not effectively break down phosphate compounds for improved fertilizer quality.

Innovation Solution

A method involving recirculation of the suspension in a reactor unit to extend residence time and adjust reaction conditions, combined with grinding and mixing processes to break down phosphate-containing raw materials, ensuring better conversion and reducing clogging risks, using mineral acids and adjusting pH for optimal mixing and granulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the phosphate-containing raw material is mixed with mineral acid to form a suspension for granulation, then fertilizer granules can be produced, but the raw material particles are inert and tend to clog at narrow points in the device

Engineering Contradiction:
Improvefertilizer granule productionVSAvoidclogging at narrow points
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by recirculating the suspension back to the reactor unit before granulation. This allows the phosphate-containing raw material to undergo further breakdown and reaction with the acid in advance, converting inert particles into more reactive, finer particles that are less likely to clog narrow points in downstream equipment.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the suspension residence time in the reactor is extended to improve phosphate breakdown, then the reaction volume and throughput are reduced, but better conversion is achieved

Engineering Contradiction:
Improvephosphate conversion qualityVSAvoidreaction volume and throughput
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent implements continuity of useful action through recirculation. Instead of extending the residence time of a single-pass suspension (which would reduce throughput), the system continuously recycles the suspension back to the reactor, maintaining continuous reaction and conversion while keeping the overall process flowing at high throughput. The useful action of phosphate breakdown continues repeatedly as material cycles through the reactor multiple times.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The recirculation system acts as a feedback mechanism where the suspension is monitored and returned to the reactor for further processing. This feedback loop ensures that phosphate conversion is optimized by allowing additional reaction time for incompletely converted material, thereby improving manufacturing precision without sacrificing overall productivity since the system operates continuously.

Inventive Principle:
Principle #23Feedback

3Quantity of substance

If extraction methods using carbon dioxide are used to obtain valuable substances from sewage sludge, then valuable substances can be recovered, but the process is very cost-intensive

Engineering Contradiction:
Improvevaluable substance recoveryVSAvoidprocess cost
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent replaces expensive extraction methods (using carbon dioxide and complex separation equipment) with a simpler, more economical approach. Instead of using costly supercritical fluid extraction technology, the invention uses direct acid treatment and recirculation in a straightforward reactor-granulator system, achieving valuable phosphate recovery through inexpensive chemical reactions and mechanical processes.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 method enhances the quality of fertilizer granules by increasing phosphate availability, reducing clogging issues, and improving process efficiency, resulting in higher P2O5 solubility and longer-term fertilizer effectiveness.

Implementation Method 1

the suspension produced in the reactor unit is recirculated in the reactor unit before granulation

Methodology Applied
Scientific EffectRecirculation:

Implementation Method 2

a suspension is produced from a phosphate-containing raw material and an acid in a reactor unit

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 3

the phosphate-containing raw material is ground in the reactor unit. The grinding process that takes place before the granulation increases the process stability, in that the grinding process comminutes the phosphate-containing raw materials that have large raw material particles

Methodology Applied
Scientific EffectMechanical comminution: Abrasion

Implementation Method 4

the sparingly soluble phosphates of the phosphate-containing raw material are at least partially dissolved by the acid in the suspension produced in the reactor unit and converted into a phosphate phase which is soluble in neutral ammonium citrate

Methodology Applied
Scientific EffectAcid dissolution: Solvation

Data Source

PatentEP3772503A1Method for manufacturing fertilizer granules
Publication Date: 2021.02.10 GLATT INGENIEURTECHNIK GMBH
  • EP3772503A1 patent drawingFigure 1~2
  • EP3772503A1 patent drawingFigure 3~4
  • EP3772503A1 patent drawingFigure 5~6

AI summary

The invention relates to a process for producing fertilizer granules, wherein a suspension of a phosphate-containing raw material and an acid is first generated in a reactor unit (6) and is then fed to a granulator for granulation, and wherein the suspension generated in the reactor unit (6) is recirculated in the reactor unit (6) before granulation.