Skip to main content

TURBINES AND PUMPS

 TURBINES

A turbine is a device that harnesses the kinetic energy of the fluid, such as water, steam, air and combustion of gases. It turns in to the rotational motion of the device itself. This devices are generally used in engine, electrical generations and propulsions of jet systems. Basically there are two types of turbines :- a) Impulse Turbine    b) Reaction Turbine

IMPULSE TURBINE

An Impulse Turbine, as the name indicates, is a turbine which runs by the impulse of  water. In an impulse the water from the dam is made to flow through a pipeline, and then through guide mechanism and finally through the nozzle. In such a process, the entire energy of water is converted into kinetic energy, by passing it through the nozzles; which are kept close through the runners. The water enters the running wheel in the form of a jet, which impinges on the buckets, fixed to the outer periphery of the wheel. 

The jet of water impinges on the buckets with a high velocity, and after flowing over the vanes, leaves with a low velocity; thus imparting energy to the runner. The pressure of water boyh at entering and leaving the vanes, is atmospheric. The common example of impulse turbine is pelton wheel, windmill etc.

REACTION TURBINE

In Reaction Turbine, the water enters the wheel under pressure and flows over the vanes. As the wheels flowing over the vanes, is under pressure, therefore wheel of turbine runs full and maybe be submerged below the tail race and may discharge into the atmosphere. The pressure head of water while flowing over the vanes is converted in to velocity head and is finally reduced to the atmospheric pressure, before leaving the wheel.

The main components of reaction turbine are:- a) Spiral Casing, b) Guide Mechanism, c) Turbine Runner and d) Draft Tube. 

PERFORMANCE OF TURBINE:-

  • Keeping the discharge in constant, the head of water and output may vary. In such cases the speed should be adjusted, so that there is no appreciable change in efficiency.
  • Keeping the head of water and speed constant, the output may vary. In such cases, the discharge of turbine should be adjusted.
  • In turbines working under low heads, the head of water and speed may vary. Although the speed of water is allowed to fluctuate within narrow permissible limits, yet the head may vary upto 50%.
  • Keeping the head of water and discharge constant, the speed may vary by adjusting the load of turbine.

PUMPS

We all know that pump is device that is used to lift water. Basically there are two types of pumps. They are:-  a) Centrifugal Pumps  b) Reciprocating Pump

CENTRIFUGAL PUMP



The pump which raises water from higher level to lower level by action of centrifugal force is called centrifugal pump. It is reverse than that of reaction turbine. In reaction turbine, the water at high pressure, is allowed to enter the casing which gives mechanical energy as its shaft; whereas centrifugal pump, the mechanical energy is fed into the shaft and water enters the impeller which increases the pressure energy of the outgoing fluid. The water enters the vane radially and exerts outside the vane axially.

RECIPROCATING PUMP

A reciprocating pump is called a positive displacement pump, as it discharge a definite quantity of liquid during the displacement of its piston or plunger. A reciprocating pump in its simplest form consist of the following parts as shown in the figure:-

  1. A cylinder C, in which piston P works. The movement of the piston is obtained by connecting rod, which connects the piston and rotating crank.
  2. A suction pipe connecting the source of water and the cylinder.
  3. A delivery pipe, into which the water is discharged from the cylinder.
  4. A suction valve a, which admits the flow of suction pipe into the cylinder.
  5. A delivery valve b, which admits the flow from the cylinder into the delivery pipe. 

PERFORMANCE OF PUMP:-

Sometimes, there is a monor change in the requirement of the head of water or the discharge of the pump from its designed head of water or discharge. In such a case a slight adjustment in the pump is made to suit the new set of conditions. This done either:-
    1. Varying speed of the pump or impeller.
    2. By changing the diameter of the pump impeller.

Comments

Popular posts from this blog

MACHINES USED AT CONSTRUCTION SITES

 The most commonly used machine at any construction site is JCB where it's technical name is Backhoe. It is the most common and widely used machine in any construction project whether its big or small project. It becomes easier and makes the work faster for the companies at any time of interval.    All other machines such as Transit Mixer, Concrete Mixer, Roller etc are also used in any kind of road project or building project. Transit Mixer is used for large large building projects, bridge projects, some kind of road projects etc. whereas concrete mixer is for small building projects. Roller is used for road project and bridge project for its elevation.  For any building project the most commonly used machines are concrete mixer, transit mixer, concrete pump, bar bending machine, needle vibrator, water pump and many more. All these machinery works make the work easier and faster. Otherwise if the work is done with labourers it will take more time and less efficient ...

How to edit grid systems in Etabs

 Okk in the last blog I had discussed about Etabs for beginners. You have got at least some ideas about it. If you have not seen it then click here . But here I am going to discuss how you will edit Grids/Columns in Etabs. As I had said by clicking on "Modify/Show Grid Systems" option a new dialog box appears, their you can edit anything. But you can also do it by different way. On the left side in grid dimensions (plan) you can see that two options are available. One is "Uniform Grid Spacing" and the other is "Custom Grid Spacing". Click on the "Custom Grid Spacing" and you see that Edit Grid Data option is available. Just click on that, and you can edit it as you want by giving the required dimensions in X-axis and Y-axis only. Ok whatever be lets come to the topic. If you have done it like as I have shown earlier then follow those steps. And the one who were new to this blog this is just for that. That's why I underlined with BLUE line an...

Excavation for RE Wall.

 So, hey guys! How are you? You might have read my previous blogs about panel casting  and panel placing . Now it's time to learn about panel erection or what to do after 3-4 months of casting the panels. So the first step is about excavation for RE Wall. Then only you can erect the panels. So let us learn about this excavation part.  You all know excavation work is done by JCB or Falkland. To excavate the soil and then carry it to the other dumped areas. But before excavation you all know, to marked the center line as well as the outer line also so that the area doesn't excavate much as per the requirement. For excavation just you need to take 500mm more, then that of the given drawing.  Doing this excavation is easy. But what to do if it's flooded with rain water/ or water coming from other sources. Definitely your answer will be to do dewatering work with a water pump. That's fine. But do this dewatering work with almost by fixing 3-4 water pumps. So that it soaks...