 अँर्वी दिः चार्दिय क्णर्टेशंदाएilled at i kulkharni assistant professor, department of mechanical engineering, शैलाप करी लिए पास कोच इजाट आब वल्चाःः इस्टी टिट तोाखटेकन्नारऽी शुला पूर today i am going to deliver a video session of types of steam condensers. आद the end of this video session you will be able to classify the steam condenser and explain the working of Z types of steam condensers. The contents of this video session are types of steam condensers, comparison between jet and surface condensers, parallel flow low level jet condenser, counter flow low level jet condenser and high level jet condenser. Now let us see what are the different types of steam condensers. Broadly the steam condensers are classified into two categories. First is jet condensers which are also called as mixing type of condenser, further which are classified into parallel flow type low level jet condenser, counter flow type low level jet condenser and counter flow type high level jet condenser. Then under jet condenser we have one more type that is called as ejector type of jet condenser. In second category we have a surface condenser or which are called as non mixing type of condenser. Under this surface condenser we have sub types like down flow type surface condenser, central flow type surface condenser, inverted type of surface condenser, regenerative type of surface condenser. Now let us try to understand what is the exact difference between the jet condenser and surface condenser and last type of surface condenser is evaporation type. Now let us see what is the difference between jet and surface condenser. As we can see in this figure the jet condensers are also called as direct contact type or mixed type of surface condenser. In this we have a closed condensing chamber or condenser shell in which the exhaust steam from steam engine or steam turbine will be entering into this particular condensing chamber. And cooling water is also supplied in the same chamber and these exhaust steam and cooling water they are mixed with each other. Thus in case of jet condenser the exhaust steam and cooling water they get mixed with each other and the condenser which is formed is the mixture of cooling water plus condenser to steam. Whereas in case of surface condenser which are called as indirect contact type or non mixed type the exhaust steam is emitted just like a state condenser from into the condensing chamber from exhaust of the steam turbine or steam engine. However the cooling water is passed through the cooling coil or cooling water tubes in case of surface condenser. Thus hot exhaust steam does not come directly in contact with the cooling water because the cooling water is separated and it is flowing through the surface of the coils inside the pipe. Therefore these are called as surface type of condenser. So in case of surface condenser the condenser which we get is only the condenser exhaust steam not the cooling water. Cooling water circuit is different in case of surface condenser. Now let us see the comparison between the jet and surface condenser. As we have seen just now in case of jet condenser the cooling water and steam are mixed with each other whereas in case of surface condenser because cooling water and steam they do not come in direct contact they are not mixed with each other. In case of jet condenser because the construction is simple their manufacturing cost is low whereas in case of surface condenser as we require the water tubes and headers etc the manufacturing cost of surface condenser is higher compared to jet condenser. The jet condenser are relatively compact and they require a smaller floor space whereas the surface condenser require large floor space. As in case of jet condenser the steam and water are mixed with each other the condenser cannot be reused as a feed water to the boiler unless this is free from impurity. So if cooling water is free from impurity then only we can use. However if the cooling water is not free from impurity we cannot use condenser again as a feed water to the boiler. Whereas in case of surface condenser as we have just seen the condenser is nothing but the condenser exhaust steam. So this condenser can be reused as a feed water to the boiler as it is not mixed with the cooling water. Further we can see that in case of jet condenser the less power is required for water pump. Because there is a direct mixing of exhaust steam and cooling water the heat transfer rate will be higher so the cooling water required is also less and power required is also less. Whereas in case of surface condenser the large quantity of cooling water is required to condense the steam. Per kg of steam we require more than 100 kg of cooling water and therefore the power required for cooling water pump is also more with the help of surface condenser. With the jet condenser the condensing plant is simple whereas with the surface condenser because we require some more elements in the condensing plant. The plant becomes complicated in case of surface condenser. However in case of jet condenser the vacuum produce is not high therefore these are not much suitable for high capacity plants. These are normally used for low capacity plants whereas in case of surface condenser because the vacuum efficiency due to high vacuum produce these surface condensers are more suitable for modern steam power plant. In case of jet condenser because it is simpler we require less maintenance and lower upkeep whereas in case of surface condenser we require a more maintenance cost as well as higher upkeep. Now let us see the construction and working of parallel flow low level jet condenser. The low level jet condenser is a condenser in which the height of this condensing chamber is quite low and the overall unit is so small that we can place this particular condensing chamber below the steam turbine. Now as you can see in the figure here we are having the condensing chamber and into which from the top side the exhaust steam from the turbine will be entering. Now here why we call this as a parallel flow jet condenser because the exhaust steam is moving from top to bottom as well as the cooling water which is taken in from the cooling pond into the condenser and which is sprayed through the orifices. It also flows from top to bottom as the direction of flow of exhaust steam and cooling water is same therefore it is called as parallel flow low level jet condenser. Now as we can see here the vacuum produce inside this condenser is enough to take the liquid from cooling pond inside this particular condensing chamber. Therefore we do not require a separate injection pump or cooling water circulating pump. So this exhaust steam when it enters into this particular condensing chamber the cooling water is sprayed and it gets mixed. For breaking of this water spray into fine droplets the baffle plate is provided in between which will cause help in better mixing of steam and water droplets. Now this after condensing the mixture of the condense steam and cooling water is stored at the bottom of this condensing chamber and this condensate is removed with the help of condensate extraction pump and it is supplied to the hot well. For removal of air from this condensing chamber the air pump is connected at the bottom. Now this is the working of parallel flow low level jet condenser. Similarly we have a counter flow low level jet condenser. Now the only difference between the parallel flow and counter flow is that in case of counter flow low level jet condenser the exhaust steam is admitted from the bottom side of the condensing chamber not from the top as it was there for parallel flow. So exhaust steam will be moving from bottom to top whereas the cooling water is moving from top to bottom. So exhaust steam and water they are moving opposite to each other and therefore it is called as counter flow low level jet condenser. Similarly the air pump is connected suction of air pump is connected at the top side in case of this counter flow condenser instead of at the bottom side. Now the exhaust steam when it enters into the condensing chamber the cooling water is taken with due to the pressure difference present inside the condenser and atmospheric pressure. This water will be sprayed with the help of this particular water nozzle and it will be striking on the baffle plates or water trays which are provided and that will get mixed and condensate is collected. And similar to parallel flow the condensate is removed with the help of condensate extraction pump and it is supplied to the hot well from where it is supplied to the boiler. Now let us see the construction and working of high level or barometric jet condenser. Now the question should arise in our mind that why it is called as high level or barometric jet condenser. Let us recall the meaning of barometric pressure. Now here for removal of condensate in case of high level jet condenser the we are using this tail pipe from the discharge point the height of tail point tail pipe is greater than barometric pressure that is 10.33 meter practically it will be more than 12 meter. So in case of high level jet condenser the condensing chamber or condenser shell is at much higher level compared to this particular discharge point and therefore it is called as high level or barometric jet condenser. Now the working of this condenser is almost similar to low level jet condenser with the only difference that in this case in case of barometric or high level jet condenser because the height at which the condensing chamber place is too high the vacuum produce inside the condenser is not sufficient to draw the water cooling water from the cooling point. So we require the injection pump for supplying the cooling water from the pond into this particular high level jet condenser. This water is sprayed and it is striking on the baffle plates which are provided in zigzag manner and the exhaust steam will flow from the bottom to top. The exhaust steam and cooling water they are mixed up and this condenser form is coming out from the tail pipe due to the gravity that is the height provided which is more than barometric head. Similarly for removal of air the suction of air pump is connected at the top and the air is removed from the top. These are the references. Thank you.