Decomposition Furnace Fin for Trichlorosilane Recovery

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Solution Overview

Problem

Conventional methods for manufacturing trichlorosilane from polymers generated in the polycrystalline silicon process are costly due to hydrolytic waste disposal and reduce silicon powder fluidity and conversion efficiency when recycled in fluidized reactors.

Innovation Solution

A method and apparatus that decompose polymers with hydrogen chloride at high temperature in a decomposition furnace, using a center tube with a fin to stir and heat the reactants efficiently, preventing clogging and allowing for effective recycling of trichlorosilane, reducing waste disposal costs and increasing raw material consumption efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If polymers are returned to a fluidized reactor for decomposition, then trichlorosilane can be manufactured, but the fluidity of silicon powder is reduced and conversion rate is lowered

Engineering Contradiction:

Improvetrichlorosilane recoveryVSAvoidconversion rate of silicon powder

Core Design Contradiction:

Loss of substanceVSProductivity

Solution Approach 1:

The invention divides the decomposition process into two separate stages: first decomposing polymers in a fixed bed reactor to generate trichlorosilane, then separately processing silicon powder in a fluidized reactor for chlorination. This segmentation prevents mixing of silicon powder with decomposed polymer residues, maintaining silicon powder fluidity and conversion rate while still achieving trichlorosilane recovery from the polymer decomposition step.

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If polymers undergo hydrolytic process for waste disposal, then environmental safety is ensured, but manufacturing costs increase

Engineering Contradiction:

Improvewaste disposal safetyVSAvoidmanufacturing cost

Core Design Contradiction:

Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The invention converts the harmful polymer waste product into a valuable resource by decomposing it to generate trichlorosilane, which can be reused in the polycrystalline silicon manufacturing process. This transforms the waste disposal problem into a resource recovery opportunity, eliminating the need for costly hydrolytic treatment while reducing raw material consumption and manufacturing costs.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If polymers are decomposed at high temperature, then conversion to trichlorosilane is efficient, but energy consumption increases

Engineering Contradiction:

Improvedecomposition efficiencyVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The invention performs preliminary heating of the polymer feedstock before introducing it to the high-temperature decomposition zone. This gradual heating approach prevents thermal shock, ensures complete decomposition, and optimizes energy utilization by heating the material progressively rather than subjecting it to maximum temperature immediately, thereby reducing overall energy consumption while maintaining high decomposition efficiency.

Inventive Principle:

Principle #10Preliminary action

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

Significantly reduces waste disposal costs by recycling trichlorosilane, increases raw material efficiency, and maintains furnace operation by preventing clogging with efficient heat distribution and silicon oxide management.

Implementation Method 1

decompose polymers with hydrogen chloride at high temperature in a decomposition furnace

Methodology Applied

Scientific EffectThermal decomposition: Pyrolysis

Implementation Method 2

The fin leads the polymer and the hydrogen chloride to the lower-end opening portion of the center tube so as to stir the polymer and the hydrogen chloride

Methodology Applied

Scientific EffectConduction (thermal): Conduction (thermal)

Implementation Method 3

decompose polymers with hydrogen chloride at high temperature

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS8980191B2Method and apparatus for manufacturing trichlorosilane

Publication Date: 2015.03.17 HIGH-PURITY SILICON CORP

AI summary

An apparatus 1 for manufacturing trichlorosilane includes a decomposition furnace 2 into which polymers and hydrogen chloride are introduced, the decomposition furnace 2 includes: a heating device 11 which heats an interior of the decomposition furnace 2; a reaction chamber 4 which is formed in the decomposition furnace; a center tube 3 which is inserted in the reaction chamber 4 along a longitudinal direction of the reaction chamber and has a lower-end opening portion 3a; raw-material-supply pipes 5 and 6 which supplies the polymer and the hydrogen chloride to the reaction chamber 4 at an exterior of the center tube 3; and a gas-discharge pipe 7 which leads out reacted gas from the center tube 3, the apparatus 1 further includes a fin 14 that leads the polymer and the hydrogen chloride to the lower-end opening portion 3a of the center tube 3 so as to stir the polymer and the hydrogen chloride.