HVAC/R Flush Solvent Composition for Moisture, Acid, and Oil Removal

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Solution Overview

Problem

Current refrigeration system flush solvents, such as trans-dichloroethylene (t-DCE), are inadequate in moisture and acid absorption capacities, flammable, and require additional non-flammable co-solvents or propellants to meet safety standards, limiting the concentration of effective cleaning agents like t-DCE in HVAC/R systems.

Innovation Solution

Incorporating n-propanol into t-DCE-based solvent mixtures with hydrofluoroethers or hydrofluorocarbons, along with increased propellant concentrations, to enhance moisture and acid absorption while maintaining non-flammability, allowing higher concentrations of t-DCE and n-propanol for improved cleaning efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If trans-dichloroethylene (t-DCE) is used as a flushing solvent, then oil solvency is improved, but moisture and acid absorption capacities remain insufficient

Engineering Contradiction:
Improveoil solvencyVSAvoidmoisture and acid absorption capacities
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent combines t-DCE with n-propanol and HFC-365mfc to create a composite solvent system. The n-propanol component specifically addresses moisture and acid absorption, while t-DCE maintains oil solvency, and HFC-365mfc provides flame suppression. This composite approach allows the solvent to simultaneously achieve multiple cleaning functions that t-DCE alone cannot provide.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If t-DCE concentration is increased for better cleaning, then cleaning effectiveness is improved, but flammability increases requiring additional non-flammable co-solvents

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidflammability
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

HFC-365mfc acts as a flame-suppressing intermediary in the solvent system. It has high compatibility with both t-DCE and n-propanol, allowing the formulation to maintain high concentrations of effective cleaning agents while HFC-365mfc suppresses flammability. The HFC-365mfc mediates between the cleaning effectiveness requirement and safety requirement, enabling both to be satisfied simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If non-flammable co-solvents and propellants are added to suppress flammability, then safety is improved, but the concentration of effective cleaning agents like t-DCE is limited

Engineering Contradiction:
ImprovesafetyVSAvoidconcentration of effective cleaning agents
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent optimizes the specific parameters of the solvent system by selecting HFC-365mfc with its particular flame suppression properties and high compatibility. By changing the chemical composition parameters to include this specific HFC isomer, the system achieves superior flame suppression efficiency, allowing higher concentrations of t-DCE and n-propanol to be formulated while maintaining safety standards.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If n-propanol is added to enhance moisture and acid absorption, then moisture and acid removal is improved, but flammability increases

Engineering Contradiction:
Improvemoisture and acid absorption capacitiesVSAvoidflammability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent merges n-propanol with HFC-365mfc in a compatible solvent system. The HFC-365mfc component provides flame suppression that counteracts the increased flammability from n-propanol addition. This merging allows the formulation to achieve enhanced moisture and acid absorption from n-propanol while the HFC-365mfc simultaneously suppresses the flammability risk, enabling both functions to work together.

Inventive Principle:
Principle #5Merging (Combining)

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 formulation significantly increases moisture and acid absorption capacities and allows for higher concentrations of t-DCE and n-propanol, providing superior cleaning performance while remaining non-flammable, thus extending the life of refrigeration systems by effectively removing critical impurities.

Implementation Method 1

The addition of n-propanol to a t-DCE-based solvent mixture significantly increases moisture and acid absorption capacities

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

n-propanol into t-DCE-based solvent mixtures with hydrofluoroethers or hydrofluorocarbons, along with increased propellant concentrations, to enhance moisture and acid absorption

Methodology Applied
Scientific EffectSolvation: Solvation

Implementation Method 3

Hydrofluorocarbons (HFCs) can also be used to inhibit the flammability of t-DCE. One particular HFC for inhibiting flammability is 1,1,1,3,3,-pentafluorobutane (HFC-365mfc)

Methodology Applied
Scientific EffectFlame suppression:

Implementation Method 4

HVAC/R system contaminant removal solvent having N-propanol and flame suppresion additives, and method for flushing HVAC systems using the solvent

Methodology Applied
Scientific EffectAerosol: Aerosol

Data Source

PatentUS9873856B1HVAC/R system contaminant removal solvent having N-propanol and flame suppresion additives, and method for flushing HVAC systems using the solvent
Publication Date: 2018.01.23 MAINSTREAM ENGINEERING CORP

AI summary

An aerosolized HVAC/R system solvent for decontaminating HVAC/R components and line sets The solvent contains 25-90 wt % propellant, and 10-75 wt % solvent mixture which is about 60-95 wt % trans-1,2, dichloroethylene, about 5-20 wt % n-propanol, and an inerting constituent providing a weight percent ratio of the inerting constituent to n-propanol of less than 1.5. The solvent is packaged in a container that is connected to the HVAC/R components or line sets to be decontaminated for supplying the solvent mixture under pressure to the HVAC/R components or line sets.