Dear Mr Prabhudesai,

derived from your information:

A screw compressor with internal compression of 525 kW can deliver 120 m3/min at 2.5 bar.

For flyash (approx. 50 microns) an end velocity of 16 m/sec should be sufficient

The pipe line diameter is then 0.393 m (16 inch)

Using my program for flyash (may be not your type of flyash) I get the following result:

Forum mspd d 04-16-2008

Pressure discharge Fly-ash

Convey length = 1000 m

Nu of bends= 10

Pump vol = 2 + 2 m^3/s

q-convey = 2.21 m^3/s

Dia begin = 393 mm Dia end = 393 mm

Kettle volume = 40.0 m^3

Fly-as vol.= 35.0 m^3

C-Vessel = 1000 tons/hr

Kettle Fly-as content = 34.0 tons

Pipevolume = 121.3 m^3

-----------Pipeline---------Syst. /Nr of .

Press.--- Cap---- mu------Cap. /kettles ----- v-begin-----v-end ---kWh/ton ---- res.time

2.500----189------23-------152 / 4.4----------- 5.8--------- 19.1 ----- 2.45--------132.18

2.250----182------22.------149 / 4.3------------6.3----------19.3----- 2.34 ------- 123.72

2.000----173------20.------145 / 4.2 ---------- 6.9 ----------19.5 ---- 2.24 ------- 115.15

1.750----163------19.------140 / 4.1-----------7.5 ----------19.7 ------2.14------- 106.59

1.500----152------17.------133 / 3.9-----------8.4 ----------19.9-------2.04--------97.99

1.250----139------16.------125 / 3.6----------- 9.4 --------- 20.2-------1.95 ------ 89.28

1.000----124------14.------113 / 3.3---------10.8------------20.5------1.89 ------ 80.57

0.750----103------11. -------97 / 2.8---------12.6------------20.8------1.88-------71.72

Empty pipeline pressure ...= 1506.5 mmWC

Maximum system capacity : 152 t/hr 2.5 bar(o)

In case you require only 60 tons/hr, this installation is oversized.

(Other combinations of air volume, pressure and pipesize may give a better solution)

For the shorter distance (100m) it might be worth considering a smaller compressor and a smaller pipe.

A big advantage will be the smaller filter area in the receiver.

The above is only to be considered as a rough indication, based on very limited information.

The real installation should be properly designed and built by a competent manufacturer.

Success ■

Dear Mr.Prabhudesai,

Optimum motor size for 60 tons/hr over 1 km:

In the previous calculation a 525 kW compressor could deliver 152 tons/hr

For 60 tons/hr a motor of 60/152 * 525 = approx. 220 kW is necessary (with a different pipe size and filters)

A recalculation should be done by the vendor.

At a shorter distance, the used energy for the same capacity is less, but maintaining the airflow will be resulting in an oversized installation (also the filters).

The shorter distance should be designed separately.

Reducing the pipe size with the same compressor will reduce the capacity, increase the energy consumption per conveyed ton and increases the wear of the pipeline and valves.

(If fed correctly it will function)

By iterative designing, a correct combination of pipe size, air volume, pressure, capacity, power requirement can be designed for a certain distance.

Experts needed!

take care ■