CLEANING SOLUTION

<Desc/Clms Page number 1>

Cleaning solution the present invention relates to a rinsing composition (cleaning). The invention more particularly relates to a cleaning composition internal heat transfer systems.

The heat transfer systems include including refrigerators, heat pumps and air conditioning systems.

In such devices, a refrigerant of suitable boiling point is evaporated at low pressure, by taking heat in a first medium (or zone) surrounding. The vapor thus formed is then compressed using a compressor and is then passed through a condenser where it is transformed to a liquid state by giving rise to a heat output in a second surrounding area. The thus condensed liquid then flows through an expansion valve at the outlet of which it forms into a two phase mixture of liquid and vapor, which is then introduced into the evaporator where the liquid is again evaporated at low pressure, thus completing the cycle.

The mechanical energy required for compressing the steam and fluid flow is provided by an electric motor or internal combustion engine. As in any mechanical device, it is necessary that the moving parts are appropriately lubricated. The lubricants used are an integral part of the heat transfer system and condition both its performance and life time by maintaining proper lubrication.

In particular, the cooling medium which is in the compressor at each passage in contact with the lubricant on its moving parts, tends to carry a certain amount, which accompanies the refrigerant in its cycle and is therefore in the evaporator. Gold it is typically worn at a low temperature, at which the viscosity of the lubricant is particularly high, such that the occurrence may accumulate in the evaporator and now merely has the ability to go back to the compressor, this return being qualified in the present text "oil return".

Thus, if the oil return is insufficient, the amount of lubricant present on the moving parts of the compressor cannot TREs kept constant in time, which thus has reached the proper function of said compressor and to its lifetime.

II is therefore necessary to use a refrigerant/oil torque which is perfectly compatible, in particular with regard to the oil return line.

The R-22 monochlorodifluoromethane or is a refrigerant type HCFCs (hydrochlorofluorocarbon) commonly used in heat transfer applications including the fixed air conditioning, refrigeration commercial and practical, as well as

<Desc/Clms Page number 2>

for heat pumps. There are currently many heat transfer systems designed for the R-22; lubricants implemented, because suitable R 22 in particular with regard to the oil return, are either mineral oils or alkylbenzene oils.

Although the R-22 has an ozone depleting potential (hereinafter PGA) very low, its use is however also the object restriction, and products HFC (hydrofluorocarbons) have been developed, particularly advantageous for the stratospheric ozone layer, since HFC's have an ODP of zero.

Among these products, the R-407c has particularly been developed to replace the R-22 in air conditioning applications. This product is a mixture combining R 32, R 125, R 134a in the proportions of 23/25/52% by weight. The R-32 is the common name in the loom difluoromethane, R-125 is pentafluoroethane, and the R-134a denotes the 1.1, 1, 2 a-tetrafluoroethane. the R-407c has thermodynamic properties which closely approximate those R-22. Therefore, the R-407c can TREs used in existing systems designed to operate with the R-22, thereby permitting the replacement of a fluid HCFCs and HFCs safer by fluid opposite the stratospheric ozone layer, in the context of a conversion of these older systems.

These new products HFC, and in particular the R-407c, however are not compatible with mineral oils or alkylbenzene used for systems operating with the R-22 with regard to the lubrication of mechanical members, in particular due to insufficient oil return. Thus they require the use of novel oils, polyol ester (POE-) type or polyalkyleneglycol (PAGs).

Replacing the R 22, in the many existing heat transfer systems have been designed to operate with R-22, by a fluid thermodynamic performance with close-and a potential of destroying ozone equal to 0, therefore requires, replacing the refrigerant, changing the lubricating oil, or even changes in certain components of the refrigerating circuit such as seals and connecting pipes. Such a conversion procedure requires several rinses with the new oil to remove all of the old oil. The most common current referral is that oil level old (mineral or alkyl benzene) in oil new (PoE or PAGs) is less than 5 or even 1% by weight after scours.

Known is the R-141b (1, 1 dichloride, 1-fluoroethane) HCFCs as a cleaning solution. Subsequent to its disappearance due to varying regulations a composition

<Desc/Clms Page number 3>

comprising the R-134a and an oil type with the POE was proposed use cleaning.

However this composition is lowly performance.

More rinse-off (or cleaning) have been proposed. Thus, the US Patent 5,750 046 describes a composition containing 75% by weight of butyl oleate, 12.5% by weight of ethoxylated polyoxypropylene having a molecular weight of 2000.10% by weight of an ester of phosphated alcohol and ethoxylated in the form of its potassium salt and 2.5% of a surfactant such as nonylphenol ether and polyethylene glycol. A composition comprising a mixture of tetraflouroethane, 2, and 3 a-[...] of a polyol ester has also been described in US 6,403 540.

The present invention concerns a composition for the internal cleaning of heat transfer systems. The invention also relates to a cleaning composition for removing or reducing the impurity content (debris solder or spider, solid dirt) within the circuit heat transfer systems. The invention more particularly relates to a cleaning composition for removing or reducing the level of the old oil in the conversion procedure.

The rinsing composition, according to the present invention, comprises one or more propellant (e) (has) flammable HFC-type, one or more compound (e) (d) (e) selected from among propane, butane, isobutane, propylene, trans 1, 2-dichloroethylene, ethyl chloride, or dimethyl ether and carbon dioxide and 5 to 85% by weight, 20 to 40% and preferably by weight of one or more oil lubrication (e), polyol ester (POE-) type or polyalkylene glycol type (PAGs).

The rinsing composition preferably comprises from 12 to 94% by weight of propellant (e) has, of 0.15 to 19% by weight of compound (e) 5 to 85% b and the weight of one or more oil lubrication (e).

The rinsing composition advantageously comprises from 54 to 79% preferred weight of a propellant (e) has, of 0, 6 to 8% by weight of compound (e) 20 to 40% b and the weight of one or more oil lubrication (e).

The polyol ester type oil (OEC) is especially suitable for rinse composition.

The thruster (has) can TREs selected from the R-134a, R-125 and the R-227ea (1.1, 1.2, 3.3, 3-heptafluoropropane are).

As rinse composition, including especially the following compositions: the lubricating oil with the R-134a and isobutane, the R-134a and dioxide

<Desc/Clms Page number 4>

carbon, the R-134a and trans 1, 2-dichloroethylene, R-134a and butane, R-125 and the (OSI) butane or the R-227a and the isobutane (OSI).

Preferred compositions are the following: - 67, 9% by weight of R-134a, 2.1% by weight of butane and 30% by weight of POE, - 68, 3% by weight of R-134a, 1.7% by weight of isobutane and 30% by weight of POE, - 66, 5% by weight of R-125.3, 5% by weight of butane or isobutane and 30% by weight of POE, - 66, 5% by weight of R-227ea, 3.5% by weight of butane and 30% by weight of POE, - 68, 6% by weight of R-227ea, 1.4% by weight of isobutane and 30% by weight of POE.

A means for implementing the invention includes connecting a container containing a cleaning composition to some or all of the refrigeration plant. Thus [...] by the presence of the propellant (has), the composition (a solution) cleaning circulates in the installation by driving soil (impurities) and old oil.

The mixture of propellant (e) (has) and compound (e) (d) is extractable by vacuum drawing of the installation. II can easily reduce the level of residual mineral oil or alkylbenzene POE oil in the new PAGs or suitable HFCs.

Examples: various compositions were prepared and subjected to the following tests.

Oil return: a load of 10 g of mineral oil [...] 3gs is. introduced into a. (1) refrigerated coil placed in a cryostat (2) to 0 C..

This coil is connected upstream, via a conduit provided with a throttle valve (3) and ARTJ a pressure sensor (4) (5) to a bottle containing the test composition, equipped with a dip tube and placed in a bath at 30 C..

The coil is extended downstream by a conduit comprising a control valve (6) and a valve (7) ARTJ that arrives in the bottom part of a bottle (8) recovery placed in a heating bath to 60 C. a piping leading from the top of the recovery bottle is provided with a gas meter (9).

<Desc/Clms Page number 5>

The circuit described in Figure 1 is representative of a refrigeration circuit in the vicinity of the evaporator, and the oil return test involves measuring the fraction of the load oil placed in the coil which is dissipated by the test composition.

Is circulated during 15 min, by initial opening of the valve (7) and then ARTJ the ARTJ (3) valve, a current of the test composition or R-134a, due to a flow rate of about 1 m3/hr measured at room temperature and under 1 atmosphere, through the circuit described above and particularly in the coil containing the charge of oil.

At the end of the test, the amount of oil recovered in the bottle (8) is weighed.

The recovery rate or "oil return" (as a percentage) is equal to the weight of the oil thus recovered divided by the weight of the charge of oil initially positioned in the coil.

Table 1 emi5.1 examples n-|1|2|? ?3 4 1, 2 3, 4 L-[...] examples only.

(pod in %), R 134a 100, 95 90, 95 R 134a 100, 95 90, 95 R 600a 5 carbon dioxide 10 [...] 5 amount of mineral [...]:; [...], ; X-ser Ntn having 15 [...] NISA, [...] based. T-pure r134a.) 100,200 136,204 the results in this table show that the addition of R-600a (butane), of co2 [...] or increases the quantity of mineral oil driven by the R-1 34a pure