Discontinuous Crystallization Unit for Ball-Shaped Crystal Production

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Solution Overview

Problem

Existing methods for producing small to medium-sized ball-shaped crystals, such as ammonium perchlorate, often result in rough-grained products with poor filtration capabilities and unwanted small particles due to high-speed agitator use, or require continuous processes that are complex and costly.

Innovation Solution

A discontinuous crystallization unit with a metallic cylindrical vessel and high-speed agitator, combined with a circulation system and heat exchanger, that mechanically 'beats' crystals and controls temperature fluctuations to produce round, medium-sized crystals with a narrow particle size distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a high-speed agitator is used to mechanically beat crystals during crystallization, then crystal rounding is improved, but fine particles are generated and filtration capability deteriorates

Engineering Contradiction:
Improvecrystal roundnessVSAvoidfine particle generation
Core Design Contradiction:
ShapeVSObject-generated harmful factors

Solution Approach 1:

The patent applies periodic action by alternating between high-speed agitation (for crystal rounding) and low-speed agitation (for particle separation). The agitator speed is periodically changed: high speed during crystal growth phase to round crystals, then reduced to low speed to allow fine particles to settle and be removed from the crystallization system, preventing their accumulation in the final product

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements discarding and recovering by separating and removing fine particles generated during high-speed agitation. The circulation system with solid-liquid separator continuously removes fine particles from the mother liquor, discarding them from the crystallization process while retaining and growing larger ball-shaped crystals, thus recovering the valuable product while eliminating harmful fine particles

Inventive Principle:
Principle #34Discarding and recovering

2Shape

If temperature fluctuation around saturation temperature is used to dissolve small crystals and rectangular surfaces, then ball-shaped crystal formation is improved, but process complexity increases

Engineering Contradiction:
Improveball-shaped crystal formationVSAvoidprocess complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into a single integrated crystallization system. The agitation device serves both crystal rounding and particle separation functions through variable speed control. The circulation system combines crystal suspension, temperature control, and solid-liquid separation in one continuous loop, eliminating the need for separate dissolution and crystallization vessels described in prior art

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies parameter changes by dynamically adjusting agitation speed as a control parameter. The agitator speed is changed from high to low based on the crystallization stage, enabling the same system to perform different functions (crystal rounding vs. particle separation) without changing physical equipment configuration, thus reducing overall process complexity

Inventive Principle:
Principle #35Parameter changes

3Productivity

If continuous crystallization process is used to produce ball-shaped crystals, then production efficiency is improved, but cost and operational complexity increase

Engineering Contradiction:
Improveproduction efficiencyVSAvoidoperational complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements periodic action in the crystallization process by cycling through stages of high-speed agitation for crystal rounding and low-speed agitation for particle removal. This periodic operation within a continuous circulation system maintains high productivity while simplifying the overall process compared to truly continuous industrial crystallizers, making the system more suitable for small to medium-scale production

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The circulation system performs self-service by automatically separating and removing fine particles through the solid-liquid separator while continuously circulating mother liquor back to the crystallization vessel. This self-regulating circulation eliminates the need for complex external control systems and manual operations, maintaining productivity while reducing operational complexity

Inventive Principle:
Principle #25Self-service

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

The unit efficiently produces high-quality, round ammonium perchlorate crystals with controlled size and shape, preventing fine particles and ensuring high purity and reproducibility, while being cost-effective and suitable for small-scale production.

Implementation Method 1

temperature periodically fluctuates around the saturated solution temperature

Methodology Applied
Scientific EffectTemperature fluctuation around saturation:

Implementation Method 2

through at least 1 heat exchanger (3) for the inlet of a heated solution and/or heated suspension of the solution and crystals

Methodology Applied
Scientific EffectHeat exchanger: Heat Exchanger

Implementation Method 3

high-speed agitator (8) ... enabling speed control and thus the rate of the impact of the mechanical action of the agitator on roundness of crystals

Methodology Applied
Scientific EffectMechanical impact: Impact Force

Implementation Method 4

circulation pump (2) and through at least 1 heat exchanger (3)

Methodology Applied
Scientific EffectCirculation flow: Pump

Implementation Method 5

double jacket (4) for cooling of the solution and/or suspension of the solution and crystals

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3122433B1A discontinuous crystallization unit for the production of ball-shaped crystals
Publication Date: 2019.01.09 ERUCA TECH SRO
  • EP3122433B1 patent drawingFigure 1
  • EP3122433B1 patent drawingFigure 2
  • EP3122433B1 patent drawingFigure 3

AI summary

The invention introduces a discontinuous crystallization unit for the production of ball- shaped crystals comprising a crystallizer (1) that consists of a metallic cylindrical vessel with its inner surface of a hard material, with an oval or circular cross-section with a conical or vaulted bottom (12), fitted along its length with a duplicator (4) for cooling of the solution and/or suspension of the solution and crystals and a high-speed agitator (8) of a hard material with a drive (9) enabling speed control and thus the rate of the impact of the mechanical action of the agitator on roundness of crystals inside the vessel together with the inner surface of the vessel containing at least 2 baffles (5) of a hard material while the vessel is fitted with at least 1 orifice (10) at the top that at least 1 independent branch of the circulation circuit (11) is connected to from the outside for the inlet of a heated solution and/or heated suspension of the solution and crystals by means of at least 1 circulation pump (2) and through at least 1 heat exchanger (3) and together with the duplicator (4) ensuring controlled periodic changes of temperatures of the crystal suspension around the cooling curve while an interconnection (13) pipeline is connected to the bottom (12) of the crystallizer (1) vessel that is connected to at least one branch of the circulation circuit (11).