The steamjet pump is basically comprised of an expanding motive steam nozzle producing high supersonic velocities, a combining chamber for bringing the suction fluid into contiguous or mating contact with the highvelocity motive steam, and a diffuser for. Applying the principle of conversion of momentum to the mixing of the steam jet. Often the nozzles are misapplied and can cause problems shortly after installation. Density is a function of both temperature and pressure. When insufficient steam is available, depressurization occurs in seconds. Nozzle is a duct by flowing through which the velocity of a fluid increases at the expense of pressure drop. The flow of steam through nozzles may be takenas adiabatic expansion.
The following table contains 15 criteria for steam trap selection based on the operation of the plant and the speci. In the impulse steam turbine, the overall transformation of heat into mechanical work is accomplished in two distinct steps. In the model, the classical homogeneous nucleation theory. The steam which contains some water particles in superposition. In order of increasing capacity, three boiler types are the firetube, watertube and waterwall boilers. In the divergent parts, the friction loss may be taken as 0. Explanation of nozzles a white paper from assmann polyethylene tanks come with a variety of nozzles. The following is a general guideline to help select the proper nozzles for the job.
Steam nozzle steam nozzle objective type questions and answers. The frictional resistance between throat and exit is 63 kjkg. The outlet pressure of the nozzle will be equal or higher than the critical pressure. Dual lance 20, or steam lance on the hhb303, and exits the nozzle 21. A passage of uniformly varying crosssection in which the kinetic energy of fluid increases at the expense of its pressure energy is called as nozzle. First increase dryness fraction upto certain limit and then decrees it. Steam nozzle article about steam nozzle by the free. Numerical calculation of the steam condensing flow 521 the. The available energy of steam is first changed into kinetic energy, and this kinetic energy is then transformed into mechanical work. Essentially a pumping device with no moving parts, the steamjet ejector consists of the steam chest, which is the connection through which a highpressure motive supply is introduced into the steam nozzle. The nozzle is so shaped that it will perform this conversion of. Allow to steam jewelry for approximately 2 seconds.
Density can be calculated by measuring one variable. The main use of steam nozzle in steam turbines is to produce a. Pdf due to steam condensation passing through the nozzle, simulation of steam flow in nozzle by an ideal gas model is far from the reality. Theory of operation the enertech nozzlecheck valve is constructed with only a few components.
The nozzlecheck valve has one of the lowest vmin of any check valve design in the industry, thereby eliminating mid. The nozzle is said to begin where the chamber diameter begins to decrease by the way, we assume the nozzle is axisymmetric, i. When the dry steam is further heated at constant pressure, the temperature increases the above saturation temperature. Steam nozzles ppt steam nozzles a nozzle is a duct of. In the current paper numerical treatment of wet steam flow through the nozzle of an ejector is presented. A convergentdivergent nozzle is required to discharge he steam at a rate of 2 kgsec. The adiabatic flow process of gas or steam in a nozzle is not only widely used in steam turbines or other power equipment, but also applied to ejectors, impellertype compressors, burners and other thermal devices in air conditioning, ventilation and gas engineering. The addition of divergent part of the nozzle after the throat does not affect the discharge of steam passing through the nozzle, but it only accelerates the steam leaving the nozzle. How to determine the steam flow in the nozzles of the. Venting of lowpressure steam large industrial plants often vent significant quantities of lowpressure steam to the atmosphere, wasting energy, water, and watertreatment chemicals. Consider a convergentdivergent nozzle in which steam enters at 0. In case of steam, the nozzle in which the kinetic energy of the steam increases at the expense of its pressure energy is called as steam nozzle. Menon, in transmission pipeline calculations and simulations manual, 2015.
Maintenance and overhaul of steam turbines wgp42 05. The principle of a steam nozzle may also be applied to a steam injector. The steam nozzle, the heart of the ejector, converts motive pressure to velocity energy that is used to collect vapors in the suction head. Detail idea about convergent and convergentdivergent nozzle.
The convergent parts of the nozzle are sharp and frictionless. Download the book into available format new update. The nozzle is supplied a steam with a pressure at 7 bar and temp 180 0 c. Region of high turbulence between control stage and second stage. The mass flow rate of water steam must be 0,3 kgs1. Unit 4 flow through nozzles velocity and heat drop, mass discharge through a nozzle, critical pressure ratio and its significance, effect of friction, nozzle efficiency, supersaturated flow, design pressure ratio.
A flow nozzle which is held between flanges of pipe carrying the fluid whose flow rate is being measured. Steam expands in a set of nozzle from 10 bar, 300 0c to 1 bar. Steam boilers seem to operate efficiently with good steam quality when subjected to a steady steam demand at a rate matching the output of a boiler. Pressure and temperature of the water steam is 80 bar respectively 500 c at input to the nozzle. In this paper we will describe steam flow in nozzle and the nozzle calculation, especially the relationship between the flow. Both theory and experiment demonstrate that the conditions imposed upon the supersonic flow immediately downstream of the nozzles e. Fuel exits the fuel pump, into a fuel solenoid valve 25 which controls fuel flow to the fuel nozzle 26. A 100% steam quality translates to zero amount of saturated steam liquid and, in this condition, the steam is termed to be dry. Openings are provided at two places 1 and 2 for attaching a differential pressure sensor utube manometer, differential pressure gauge etc. If the steam floe rate is 1 kgs and the initial velocity of steam is negligible, find the minimum area of the nozzle.
When compared to stable flow, the available enthalpy drop for supersaturated flow of steam through a nozzle remains same increases decreases is unpredictable the expansion of steam through a nozzle is so rapid that steam may not get time to condense and may remain in a state of homogeneous vapour. Unit iii unit iii steam nozzles and turbines flow of steam through nozzles, shapes of nozzles, effect of friction, critical pressure ratio,supersaturated flow. Venting of lowpressure steam us department of energy. Steam nozzle 215 steam nozzle analysis 217 supersaturated flow 220 normal shock 224. Steam nozzles a nozzle is a duct of smoothly varying cross sectional area, in which a steadily flowing fluid can be accelerated to a high velocity by a drop in pressure of the fluid along the duct. Steam turbine design options, how to specify or upgrade 31 figure 4. Steam quality ranges from 0 to 100% and is defined as the ratio of the amount of saturated steam vapor to the total steam amount which may consist of both saturated steam vapor and liquid. My theory is that it may be appropriate to feed the nozzle from the front of the pressure vessel, and the resultant gas steam can be addressed in a conventional manner at the nozzle. Loss in the nozzle is 15% in divergent portion only. The expansion process is then stated to be critical thermally equilibrium metastable. Pdf steam ejector is an important component in engineering applications, which require high vacuum, such as steam. Impulse and reaction principles, compounding, velocity diagrams for simple and multistage turbines, speed regulationsgovernors and nozzle governors. Flow nozzles are used in thermal power plants for hightemperature and high pressure steam and water flow services, for example, main steam, hot and cold reheat steam. The maximum gas flow through a nozzle is determined by critical pressure.
Vtunptelnmeict project progress report the project on. Theory of simple carburettor 49 petrol injection 51 5 fuel supply in ci engine. Know everything you want to know about steam nozzlesturbine excluded. Consequently, when a steam system valve opens quickly, a rapid steam load demand occurs, and the boiler will depressurize.
Htff 1522 condensation in a laval nozzle by moses and stein, dykas et al. Calculate base dimensions of the nozzle and state of water steam at the exit. The focus here will be on boilers sized in between these two extremes, which is also where there is the greatest diversity of design. Steam accumulators and steam boiler response to load. The steam possessesa very high velocity at the end of the expansion. Requirements are detailed in the asme documents previously listed.
Pressure graph of 3 o inclination angle convergentdivergent nozzle. To stop steaming, simply pull back on the steam button which will release the continuous steam setting. Steam jet ejector cooling powered by low grade waste or solar heat by. It utilises the kinetic energy of a steam jet for increasing the pressure and velocity of. Using the tweezers, hold jewelry approximately one inch beneath the steam nozzle. Please contact factory or customer service for availability and material breakdowns. Vanita thakkar bit 52 supersaturated flow when steam flows expands through a nozzle, it would be normally expected that the discharge of steam through the nozzle would be slightly less than the theoretical value. Steam then leaves the turbine and is utilized in other parts of the plantthat usetheheatofthesteamforotherprocesses.
But, experiments on flow of wet steam show that discharge is slightly greater than that calculated by the formulae. When whole mass of steam is converted into steam then it is called as dry steam. Nozzle nozzle is duct of smoothly varying crosssectional area in which a steadily flowing fluid can be made to accelerate by a pressure drop along the duct. In noncondensing turbines or backpressure turbines, steam exhausts at a pressure greater than atmospheric. Pdf steam jet refrigeration sjr is one of the most widely applied technologies in the industry. I would like to hear from the more knowledgable about this subject, whether my proposed mod might improve the breed. In the step of admission of steam turbines reation there are several nozzles that distribute the steam to the blades.
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