Obstruction of capillary tube: how to solve it? - Refrigeration Club - En-us (2024)

FAQs

How to remove the blockage on the capillary tube? ›

If you are using open capillaries for your research, you may be able to push any blockage out with a syringe fitted with tubing the snugly fits the OD of your capillary. It is difficult to push liquids through a capillary even when there is no blockage.

Remedy: To resolve this issue, use a heavy-duty pipe cleaner or screwdriver and place it vertically on the tube cap. Gently tap on handle or top. This will help unclog debris. If the blockage didn't unclog, change the filter mesh of the cap tube.

You could try running a vacuum pump for 30 min. If that doesn't get then flush with nitrogen. Or replace the capillary if accessible.

Restrictions in the capillary tube are usually caused by lack of proper maintenance. When systems overheat the oil within refrigerant piping becomes overheated & damaged. The burnt oil causes the blockage of pipe which causes system to fail.

If the tube does become blocked, then the evaporator becomes starved. The suction pressure drops, less refrigerating effect takes place, and the compressor is forced to work harder, resulting in increased head pressures with accompanying increases in temperature.

The results demonstrate a significant decrease in system performance and energy consumption, along with an increase in compartment air temperature when the capillary tube is clogged. As a result, the system fails to achieve its intended functionality.

When the capillary tube is completely blocked because of humidity, the system will stop functioning. An easy way to identify this defect is to check for ice on the evaporator's inlet. Heat this location and see if the fluid starts circulating again.

Flush the Drain Hole: Pour a mixture of warm water and mild detergent into the drain hole to flush out any remaining debris. Use a turkey baster or a syringe to facilitate the process. Continue flushing until the water flows freely through the drain hole.

You can do this with either a specific hole clearing tool you get with the fridge, or with a straw, cotton bud or pipe cleaner.

I blow it out with nitrogen till I can feel flow, and have even changed the filter drier. Now i must state that there is no strainer in the tubing leading up to the cap tube after the liquid line drier.

How to clean a capillary? ›

Using a spray bottle filled with 70% isopropanol or ethanol solution, gently spray the capillary array window. Use a small nylon paintbrush to gently brush the capillaries in one direction while they are still wet. Alternatively, a lint-free cloth can be used to blot the array window dry.

Unlike most analysis modes where the sample is isolated from the innards of the instrument, with capillary viscometers, the sample compartment is the instrument. Cleaning, therefore, becomes critical for achieving reproducible and accurate results.

If you are testing a room air conditioner, you know that the range of evaporator temperatures will be between 34° and 42°. If the balance tester should read 25°, it means that there is a restriction in the cap tube or strainer. If the tester balances at 60° you know that the compressor in inefficient.

Factors Affecting Capillarity

The diameter of the capillary is also inversely proportional to the capillary action. More is the diameter of the tube, less is the capillarity. Capillary action is directly proportional to the surface tension of the liquid. Capillarity also depends on the angle of contact.

The refrigerant is a non-equilibrium two-phase flow composed of subcooled liquid and subcooled vapor. Capillary tube inlet can be fill with liquid by increasing compressor speed and reducing capillary tube diameter.

These tiny capillaries routinely get “stuck,” clogged by cells, fat and debris in the blood.

These treatments include using liquids or air (enemas) or small mesh tubes (stents) to open up the blockage. Surgery is almost always needed when the intestine is completely blocked or when the blood supply is cut off. You may need a colostomy or an ileostomy after surgery.