2 replies to this topic

[mggyi2006]

Dear professional,

 

what is the criteria for choosing high level and low level point inside storage tank (50 m3).

 

Best Regards

Tun

[sidibouziane]

Hi, 

this is very small size tank. 

 

i do consider 4 levels: normal liquid level, high liquid level, low liquid level and low low liquid level.

 

for the top, once the NLL there should an alarm. between the NLL and HLL  calculate the time needed by your pumping system to to reach the HLL  or height lquid to take an action.

 

similarly for emptying the tank, the LLLL should the minim head for the pump.  an alarm should be signaled once you reach the LLL. between the LLL and LLLL  keep a room to de-activate your sucking pump.

hope this help 

[Raj Mehta]

yes, there are 4 levels HHLL (High High Liqiuid Level), HLL (High Liquid Level), LLL (low liquid level) and LLLL (Low Low liquid level) appearing as written, in the order from top to bottom in the tank.

 

Level Indicator Controller (LIC) should have high & low set points corresponding to HLL (as low set point) and a value between HHLL and HLL as high set point. This will be directly connected to the control valve on the feed side. So if the feed raises the tank level after one point this indicatro will trip the feed control valve and you can till that time discharge and maintain the tank level to desired level. 

 

On the other hand, one level controller will be connected to the discharge pump and will trip the pump as soon as the level reaches between LLL & LLLL.

 

Hope your query is solved.