Ferranti Effect

In a medium or ling transmission line when open-circuited or lightly loaded the receiving end voltage is found more than the sending-end voltage. This phenomenon of rise in voltage at the receiving-end of the open-circuited or lightly or loaded line is called the ferranti effect owing to its first being observed on the depot ford mains laid down by S.Z. de Ferranti in 1890. The effect is due to voltage drop across the line inductance, due to charging current, being in phase with the applied voltage at the sending end of the line. Thus both capacitance and inductance are necessary to causes phenomenon. The capacitance, and therefore, charging current is negligible in short line but significant in medium and long transmission line . On a 3000 km line operating on 50 hz supply, the receiving-end voltage on open circuit is usually  found to be roughly 5% higher than the sending end voltage.

Advantage on HVDC Transmission

i. Cheaper Costa: in DC transmission only 2 conductor is for positive'+' and negative '-' terminal less cross arms then 3 phase 3 wire  AC system.

ii. No skin effect: No frequency in DC system i.e. no skin effect in dc, so there unifirm distribution of current over the section of conductor.

iii. Lower Transmission losses: HVDC transmission system needs only two conductors and , therefore the power loss in a dc line are lesser than the losses in ac line of the same power transfer capacity.

iv. Voltage regulation: There is no inductance , hence the voltage drop due to inductive rectance does not exist in DC transmission line. Thus voltage regulation is better in case of dc transmission.

v. Greater Reliability:  A two-conductor bipolar is more reliable then a 3 wire 3 phase ac line  because the dc line may be operated in a mono-polar mode with ground return when the other line develops a fault.

vi. No stability limit: There is no stability limit in dc system and transmission line may not length.

vi. lesser dielectric loss: The cables has lesser di-electric losses.

WATER TREATMENT PLANT (WTP) IS USED IN INDUSTRY

Generally now a day our government and the world deeply thinking about pollution like Water, Air, soil , Noise etc. Our main aim to reduce pollution anyhow, so our many companies thinking about it and they many machineries for healthy environment.

In industries they not allow to to used underground water for their working purpose. So they they used raw water from river or lake.

Raw Water:

i.                     Suspended material

ii.                   Selica

iii.                  Hardness

iv.                 Desolved Gasses

v.                   Anerobic becteria etc

So we have to remove those from water for softness of water.

Raw Water    --- ------   Aeration    -------- -----    Clerifloculator ------------------Strainner --------------          

                                  +chlorine dogging                       Flocs+ other

                                   + Alarm dogging                         Suspended Particals

Clarified Water----------Gravity Filter/ Sand filter ------------ACF(Ativated Carbon Flter)--------------

     Remove Terbidity

CE(Chemical Exchanger)----------------Anion Excganger---------------Mixed Bed --------DM  Plant

RH + NaCl – Rna + Hcl                     ROH + HCL –RCL+H2O                        

                                /H2SO4

                                /HNo3