![]() ![]() Viscosity, as discussed above is the resistance that a fluid offers to flow. However, as the viscosities of gasses are extremely low, it is imperceptible in everyday life. All fluids including gasses have viscosity. This difference is a function of their respective viscosities. ![]() Water on the other hand has a low viscosity and therefore offers much less resistance to flow.Ī simple example of this would be if you pour down a stream of water and honey side by side on an inclined plane, it’s would be evident that the water would flow down much faster down the incline plane then the honey. Examples of this would be syrup, tar, honey, etc all of which have higher viscosity. In any fluid when the viscosity is large the flow of the fluid will be slower because of the larger amount of resistance put forth by the fluid to the flow. Simply put, viscosity refers to the “fluid’s resistance to flow.” Viscosity also describes the internal friction of a moving liquid. Referencesĭiesel Engines 3rd Edition, by A.Viscosity is an empirical quantity that describes the resistance a fluid offers to induced flow under the action of an external force. Differential pressure transmitters are also fitted to directly control the heater temperature and set the right viscosity limit. Thermometer is fitted on the regulator to measure the fuel temperature and maintain the final temperature accordingly. The capillary tube is so designed that the form of flow between the inlet and outlet of the tube generates a pressure difference, which is equal to the viscosity of oil flowing through it.īourdon tubes are used to monitor the viscosity at different points within the capillary tube. A regulated flow of fuel is sent by the pump to a capillary tube. The pump takes suction from the heater discharge and is generally fitted close to it. Viscosity regulator is an “L” shaped instrument which consists of a small gear pump that rotates at a constant slow speed of 40 rpm. The regulator is connected with the heater so that it can measure the viscosity of the oil and regulate the temperature at the same time. It is generally fitted at the outlet of the fuel oil heater. Viscosity Regulator or Viscotherm, is a device used to measure viscosity of the fuel oil before sending it to the engine. Viscosity regulators are used to regulate and maintain the fuel oil viscosity. Generally, fuel oil viscosity is regulated between 10-15 centistrokes at 50 degree Celsius. This practise of deriving fuels from different sources is the main reason for the high viscosity of fuel oil.It is for this reason that the viscosity of oil is checked and maintained within close limits, before sending it to the engine’s cylinder. Even if they are stored in different tanks, they finally get mix with each other when brought to the service tank. It is a usual practise on ship, to store fuels of different grades and properties into the same tank. This can be done by using either, automatically regulated heaters in order to maintain a constant temperature or by using a manual control which can be adjusted according to the requirement. Viscosity of high fuel oils can be reduced by raising its temperature with the help of a fuel oil heater. Thus, it is absolutely important to set the viscosity value in the right range. An efficient atomisation is the basic need for the healthy mixing of fuel and heated air, without which, no ignition or combustion can be derived. A high viscosity fuel oil leads to improper atomisation which in turn leads to incomplete combustion.High viscosity fuel prevents correct atomisation,which takes place in the fuel injectors. Viscosity is one of the most important factors which directly affects combustion quality.Ĭontrolling the viscosity of fuel oil is an important aspect of an efficient combustion. Fuel is the lifeblood on marine engines and hence proper characteristics of fuel need to be maintained on ships. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |