We are operating gas gas ejector . And this ejector frequently fail to mentain the pressure in the vessel which cause gas going to flare .all valves are healthy and pressure and the flow of motive gas is normal. What could be the cause ?
At my workplace, a steam jet ejector is successfully transferring an aqueous solution to a destination tank which is 100m away from the source, but the same ejector is not able to transfer organic liquid solution to the same destination. Any idea what might be the reason?
Hi, what will be happen if you inrease the motive pressure above the design pressure. Goes the suction pressure down or up? (Supposed that the condenser is big enough and that the discharge pressure stays constant)Thanks
Depending on how much you go up. Initially with increased motive pressure your suction does go up, but ejector overall looses on efficiency. If you continue increasing the pressure, eventually you will get to the choked flow condition and if you continue to increase even more, you will start loosing your suction. If your ejector was working fine and all of a sudden you need to increase your steam pressure to keep the suction at the design point, you have some issues that need to be addressed as soon as possible. Cheers.
@@mladeen1 hi Mladeen1, is it possible for us to know does our ejector has a shockwave or not in the middle of the choking position?, I am an intern student in mechanical engineering in a power plant, their system has the very low suction capability, they must turn on the hogger all day long parallel with three-stage ejector to vacuum the chamber if they turn off the hogger, the three-stage ejector couldn't maintain the vacuum I assume that there is excessive back pressure, but don't really know because they said they have clean the 3-stage ejector every thing is normal, motive flow 300 Celsius at 0.83bar, but can only vacuum 13fKpa thanks
@@ianm1898 Hi Ian. Shockwave and choked flow are not directly related. Typically, you develop supersonic fluid velocity in the throat of ejector if your discharge pressure is 2 x higher than the suction pressure (this example has 30mmHg suction and 300 mmHg discharge), that is when the sonic shockwave is created (technically there is always a shockwave as you are compressing the fluids, but not in this scenario we are talking about sonic one). Choked Flow is a situation where , no matter how much you increase motive steam pressure, you are not getting improvement on the suction pressure and/or flow. Running hogger at all times is definitely a sign that the system needs to be maintained. Hogger is highly inefficient ejector (uses much more steam than the entire system combined) and should be used only for start-up... The actual numbers you gave really do not matter much, as each ejector system should be designed specifically for the application (at least better ejector companies do so). There are certain steps that you can do to check where the issue may be. Unfortunately, it is not something that can be explained here. I can definitely discuss it with you in more details , but not here, of course. I am also available to offer my consulting services, if your plant decides it is worth it.
Nice video. How the formation of the shock wave ensures the smooth operation of an ejector? I am assuming through the formation of shock wave, the local pressure increases instantaneously, and that pressure rise facilitates achieving high discharge pressure at the diffuser. Is my understanding correct?
The answer is not that simple. You have to inform temperature, operating pressure, water vapor load, etc, etc..... and at the end, the motive steam pressure is the one you have in your facility. The ejector will be designed to that pressure.
hi @Paulo Teixeira Jr and @@ericjohnson6289 is it possible for us to know does our ejector has a shockwave or not in the middle of the choking position?, I am an intern student in mechanical engineering in a power plant, their system has the very low suction capability, they must turn on the hogger all day long parallel with three-stage ejector to vacuum the chamber if they turn off the hogger, the three-stage ejector couldn't maintain the vacuum I assume that there is excessive back pressure, but don't really know because they said they have clean the 3-stage ejector every thing is normal, motive flow 300 Celsius at 0.83bar, but can only vacuum 13fKpa thanks
@@ianm1898 If the hogging ejector is needed, then either the air leakage into the system is too high or the three stage main air removal system has an issue, which could be motive steam related, cooling water issues, mechanical damage, condensate drainage issues, etc. Reach out to Graham at service@graham-mfg.com and we can start assisting you with an official service inquiry.
We are operating gas gas ejector . And this ejector frequently fail to mentain the pressure in the vessel which cause gas going to flare .all valves are healthy and pressure and the flow of motive gas is normal. What could be the cause ?
At my workplace, a steam jet ejector is successfully transferring an aqueous solution to a destination tank which is 100m away from the source, but the same ejector is not able to transfer organic liquid solution to the same destination. Any idea what might be the reason?
How the suction temperature affects ejector performance
Hi, what will be happen if you inrease the motive pressure above the design pressure. Goes the suction pressure down or up? (Supposed that the condenser is big enough and that the discharge pressure stays constant)Thanks
Depending on how much you go up. Initially with increased motive pressure your suction does go up, but ejector overall looses on efficiency. If you continue increasing the pressure, eventually you will get to the choked flow condition and if you continue to increase even more, you will start loosing your suction. If your ejector was working fine and all of a sudden you need to increase your steam pressure to keep the suction at the design point, you have some issues that need to be addressed as soon as possible. Cheers.
@@mladeen1 hi Mladeen1, is it possible for us to know does our ejector has a shockwave or not in the middle of the choking position?, I am an intern student in mechanical engineering in a power plant, their system has the very low suction capability, they must turn on the hogger all day long parallel with three-stage ejector to vacuum the chamber
if they turn off the hogger, the three-stage ejector couldn't maintain the vacuum
I assume that there is excessive back pressure, but don't really know because they said they have clean the 3-stage ejector
every thing is normal, motive flow 300 Celsius at 0.83bar, but can only vacuum 13fKpa
thanks
@@ianm1898 Hi Ian. Shockwave and choked flow are not directly related. Typically, you develop supersonic fluid velocity in the throat of ejector if your discharge pressure is 2 x higher than the suction pressure (this example has 30mmHg suction and 300 mmHg discharge), that is when the sonic shockwave is created (technically there is always a shockwave as you are compressing the fluids, but not in this scenario we are talking about sonic one). Choked Flow is a situation where , no matter how much you increase motive steam pressure, you are not getting improvement on the suction pressure and/or flow.
Running hogger at all times is definitely a sign that the system needs to be maintained. Hogger is highly inefficient ejector (uses much more steam than the entire system combined) and should be used only for start-up... The actual numbers you gave really do not matter much, as each ejector system should be designed specifically for the application (at least better ejector companies do so).
There are certain steps that you can do to check where the issue may be. Unfortunately, it is not something that can be explained here. I can definitely discuss it with you in more details , but not here, of course. I am also available to offer my consulting services, if your plant decides it is worth it.
Nice video. How the formation of the shock wave ensures the smooth operation of an ejector? I am assuming through the formation of shock wave, the local pressure increases instantaneously, and that pressure rise facilitates achieving high discharge pressure at the diffuser. Is my understanding correct?
DO YOU HAVE DISTRIBUTORS IN MEXICO=
Thanks a lot this was very helpful.
Are you on FB?
Thanks
Please what motive fluid pressure to the steam ejector does an 8tons/hr vacuum spray noodle dryer require to work efficiently?
The answer is not that simple. You have to inform temperature, operating pressure, water vapor load, etc, etc..... and at the end, the motive steam pressure is the one you have in your facility. The ejector will be designed to that pressure.
Ejectors can be designed for whatever motive pressure is available. The nozzle geometry is adjusted accordingly to fit the motive conditions.
hi @Paulo Teixeira Jr and @@ericjohnson6289 is it possible for us to know does our ejector has a shockwave or not in the middle of the choking position?, I am an intern student in mechanical engineering in a power plant, their system has the very low suction capability, they must turn on the hogger all day long parallel with three-stage ejector to vacuum the chamber
if they turn off the hogger, the three-stage ejector couldn't maintain the vacuum
I assume that there is excessive back pressure, but don't really know because they said they have clean the 3-stage ejector
every thing is normal, motive flow 300 Celsius at 0.83bar, but can only vacuum 13fKpa
thanks
@@ianm1898 If the hogging ejector is needed, then either the air leakage into the system is too high or the three stage main air removal system has an issue, which could be motive steam related, cooling water issues, mechanical damage, condensate drainage issues, etc. Reach out to Graham at service@graham-mfg.com and we can start assisting you with an official service inquiry.
Qual a causa de um congelamento da carcaça de um Booster?