the Main causes of blockages that occur in the capillary
the Main causes of blockages that occur in the capillary tubes of the very nature of the manifestations of blockages in CT may have several causes. Here are some of them:
1 Contraction geometry of the internal diameter of the pipe in both longitudinal and transverse sections.
In this case appeared before the fold (Burr) possible accumulation of a small amount of mechanical suspension, it is soaked viscous components of the oil and then sealed. Alternatively, perhaps a simple freezing of the particles (if the location of the clog is near injection in the evaporator). For protruding from the mass of shapeless pieces cling new particles, and the process goes on increasing. This kind of blockage is hard to push in the direction of gas flow, ahead of the clog will be the narrowing of the tube, and this tube will only thicken. Recently, this phenomenon occurs because of Zakus" (narrowing at the cut) the tip of the pipe to the injection into the evaporator when the circumcision CT manufacturer, without further processing of the pipe end.
2 Expansion geometry of the internal diameter of the pipe in the longitudinal and cross section.
In this scenario, you receive a kind of "pocket" where you can settle down when you stop the flow of relatively large particles, and their exposed edges will serve as a comb to trap from among other mechanical impurities. This kind of blockage is hard to push in any direction, it is preferable to impregnate the clog detergent solution and rinse the pipe to completely remove traces of the obstruction.
3 for sticky components, for example, due to the formation of paraffin sediments or other effects of the degradation of the environment.
Emitted waxes or other components, freely circulating in the system due to the migration of oil deposited within the cavity CT due to the abrupt cooling at the entrance to the evaporator (at a distance of 20...30 cm from it). To eliminate such tube is quite a bit to warm up this site when the compressor to the pressure difference when the unit got softened by heating the mass in the direction of the evaporator. The composition of such blockages may be classified by several characteristics.
1 Powder or dark gray color.
According to various estimates, such powder may receive from the destruction of the granules of desiccant or interaction of materials in the refrigerant circuit. Most often removed by the application of impregnation clogging detergent solution followed by alternating smooth application of pressure from both sides of the CT scan.
2 Thick dark plastic (usually brown), similar in viscosity to clay.
This weight creates the greatest problems when Troubleshooting clog CT, as it is easily crushed and compacted in the process of trying to resolve the defect. It seems that it appears due to the corrosion of ferrous metal parts in the system. If it is possible to impregnate the tube from the mass of wash solution to reduce the viscosity of, "push" this clog increased pressure in the opposite direction of normal movement of the refrigerant.
3 Flakes of dark color - small, shapeless or needle-like.
the Clog CT of these flakes easily removed by wet impregnation solution with the subsequent purge of excess pressure in the opposite direction of normal movement of the refrigerant. Such solids are similar to normal technological debris (possibly wear parts), and soft - more similar products paints and varnishes (in one of the sources mentioned application in the factory special paint for drawing drawings channels) or waste destruction plastic parts forming part of the motor-compressor.
4 Dark mass, resembling the consistency of a gel.
Remove blockages from this mass is no problem when soft and prolonged application of pressure either side of the CT. The probable source of the emergence of such a blockage - the destruction of the food environment (precipitation of paraffin oil, chemical reaction refrigerant) or the interaction of their constituent parts of the unit. How to resolve blockages in CT.
Factory technology unblocking few. Here they are: 1 Application for impregnation and rinsing specialized solutions, such as liquid desiccant".
allegedly, the composition of these solutions has no destructive action on the parts of the system refrigerant. We note that the use for such purposes methanol inapplicable due to its high aggression of the material of the evaporator - aluminium.
2 Blowdown system compressed dry nitrogen.
Nitrogen can be fed from the container through the gear in either direction, it is important to remember that the capillary tube is capable of withstanding large pressure values than the channels of the aluminum evaporator. Moreover, the pressure on the pipe wall will be proportionally higher with an increase in the internal diameter of the pipe. In this case, play an important role and the materials used. When applying excessive pressure in CT you need to ensure that the system always had opened the nozzle. This is necessary in order to provide relief of excess pressure in case of breakthrough of gas through the clog CT in the cavity of the evaporator. When applying pressure in the direction against the normal movement of the refrigerant (i.e. through a return pipe of the evaporator) it is important to remember that the first pressure acts on the inner cavity of the aluminum evaporator, and then is applied to CT.
3 Impact on the clog of oil under high pressure using special hydraulic presses.
Outwardly similar press resemble conventional jacks for cars. But unlike the latter, they feature a comfortable grip for CT and pressure gauge high pressure(up to 400.600 kgf/cm2). When using this method, it is important not to make one characteristic of repairmen error - when jacking clogging CT in the system for refrigerant R-134a cannot be applied mineral oil. And in General, to clean the CT is desirable to use the same oil, which is tucked into the compressor. Note that inside the press has a special safety valve, release the pressure when a certain (critical) value.
4 Replacing CT with a new one.
this method is mostly available only to service partners manufacturers. In the routings provided by the manufacturers specified even the CT parameters depending on the model of refrigerator. If removable evaporators this operation is quite technologically advanced, modern semi-demountable structures it is very time consuming, as in some designs, you must first remove the insulation, and after work to reset the remote to the floor. In this case, not knowing the exact parameters used CT, you can get unpredictable results.
the Basic requirements for materials used for unblocking CT. Consider the basic requirements and possible applications of the materials used for unblocking CT.
1 Drained neutral gases.
Their application is more optimal, but there are limitations. For example, the use of such gases ineffective in the elimination of the "dry" or nedlasting composition of blockages great length - too long resistance tube obstruction when moving through the tubes. In addition to the nitrogen in various sources described attempts unblocking propane (good solvent paraffin). Used for these purposes propanebutane a mixture of domestic heating cylinders technical purity has large tolerances in the presence of moisture and impurities, so this decision is fraught with negative consequences. Moreover, this gas mixture is flammable, and if you delete it from the system it is necessary to take certain measures to ensure fire safety of this operation.
2 Application of refrigeration oils when bursting pressure.
due to the high pressure oil can get into the cavity of the evaporator. Use mineral oil cannot, if the system is designed for refrigerant R-134a is not known how to behave in a mixture of native compressor oil and oils, used in the process. Therefore, on this aspect, you need to pay special attention. 3 Liquid legisprudence solutions (solvents).
these substances can easily penetrate into the thickness of fouling, reduce the viscosity of the "tube" that can be easily removed from the system by evacuation with purge. These include acetone, and possibly solvents type 646 and the like. However, acetone class HCDA (chemically pure for analysis) in the open sale available. Household acetone to remove blockages to use problematic, since its composition may be water. I would like to warn you about possible negative consequences when applied to the considered objectives of dichloroethane. This substance is a good solvent for plastics, therefore there is a great risk of damage to the plastic parts of the bandage of the compressor. In turn, the degradation products may subsequently become the basis for the emergence of new blockages. In addition, the use of dichloroethane may adversely affect the electrical insulation resistance of the compressor motor. Perhaps a good alternative can serve as freon 113, 114, which are used in industry as a degreasing liquid. Given that consumption is small, the high price does not greatly affect the price of repair. 4 Liquid petroleum products - kerosene, diesel oil (used in presses as the working body), petrol lighter.
the First two substances are quite effective in presses. But they are poorly absorbed even worse are removed from the evaporator blowing. Class purity of these substances can be technical. They tend to thicken/congeal at low temperatures. Be aware that these substances can give unexpected results (not always with positive output) in a mixture with petroleum oils.
Technological methods to eliminate blockages CT.
When conducting operations to eliminate blockages CT it is important to understand the essence of the process, otherwise, for example, attempts needless to expedite the process can result in compaction of the mass of the "tube" that will complicate the removal of the defect.