Dear aliawad1974,

A FK screw pump is nothing else than a feeder from material (in your case cement) from a low pressure region (in your case, atmospheric) to a higher pressure region (in your case the discharge pressure)

The function is to seal the high-pressure zone from the low-pressure zone.

This sealing function is achieved by the formation of a material plug that is forced into the conveying pipeline.

The only parameter that the screw pump and the pneumatic conveying installation share is the conveying pressure.

For proper operation of the screw pump, this pressure is limited to a certain value. (normally approx 1.8 bar)

Therefore, the first question is; at what pressure are you operating the system?

Assuming that the screw pump is manufactured under the license of FL Schmidth, I also assume that the screw pitch ratio is chosen for the application and that the screw pump data on the nameplate are available.

If you can share those data, that would be helpful.

Designing the pneumatic conveying installation for cement is no problem.

However, the desired conveying pressure determines the used pipe size and airflow.

Therefore, I need to know the maximum conveying pressure that can be handled by the screw pump.

Please let us know.

best regards

Teus ■

1) You bought a bit of kit from China and it doesn't work. Go back to the Chinese manufacturer and ask for a solution to the problem.

2) If it was made under licence from F L Smidth and the manufacturer can't/won't help, then go to F L Smidth directly and ask them for a solution saying the licence holder in China can't/won't help. A reputable equipment manufacturer will want to maintain the reputation of his equipment. ■

Dear aliawad1974,

Your original question was about a FK screw pump.

I replied to that question.

The compressor you have is not a screw compressor.

The “air unit” you have is a rotary blower.

Make: Aerzen

Type: GM90S

Airflow 1.451 m3/sec at 1 bar

This blower can supply enough air for a 14” pipeline for cement conveying.

Your installation:

horizontal length = 200 m

vertical length = 70 m

number of bends = 8

Capacity = approx. 132 tons/hr at 1 bar

have a nice day

Teus ■

Dear aliawad1974,

I calculated 2 installations.

1)

pipeline 14”

Compressor Aerzen VM85 1.81 m3/sec at 8275 rpm

Capacity approx. 265 tons/hr at 3 bar

In this case, the installation is operating at the maximum possible load and a slight increase in feeding, results in a possible choking of the pipeline.

A screwfeeder is not applicable because of the high pressure.

2)

pipeline 16” stepped up to 18”

Compressor Aerzen VM140 at 5500 rpm

Capacity approx 350 tons/hr at 2.5 bar

Capacity approx 275 tons/hr at 1.5 bar

In this case, the installation is not operating at the maximum possible load and a slight increase in feeding does not result in a possible choking of the pipeline.

A screwfeeder is now applicable because of the lower pressure.

When I calculated the installations, I noticed that the vertical pipeline of 70 m is a significant cause of the pressure drop.

Therefore, higher than normal velocities were necessary, in order to shorten the time that the particles have to be kept in suspension.

The above data have to be considered as indicative as they are based on a quick design method.

My advice is, not to design and build this installation yourself, but to outsource this project to a well-known and reputable company with proven experience and trustworthy guarantees.

Success and take care

Teus ■

Dear aliawad1974,

Aditionally I calculated

pipeline 14”/16"

Compressor Aerzen VM85 1.81 m3/sec at 8275 rpm

Capacity approx. 250 tons/hr at 2.5 bar

A screwfeeder is not applicable because of the high pressure.

Success and take care

Teus ■

Dear aliawad1974,

The given capacities and pressures are for the installation we were discussing.

horizontal length = 200 m

vertical length = 70 m

number of bends = 8

For an installation of any conveying length (including your installation), a design can be made for any capacity and pressure above the empty pipeline pressure.

Have a nice day

Teus ■

Dear aliawad1974,

This reply referenced to your original question about the FK-pump.

A screwfeeder,which is capaple of sealing a high pressure zone from a low pressure zone by means of a formed, moving material plug.

see:

http://www.flsmidth.com/Pneumatic+Tr...nnovations.htm

Have a nice day

Teus

By the way, this was my 1000th post in this forum ■

Dear aliawad1974,

A screw feeder is a tubular screw conveyor of a short length and a special screw geometry.

The intake of the screw feeder is at atmospheric pressure and the screw flight pitch is 100%.

The last small number of flights in the tube have a pitch, lower than 100% (f.i. 80%), thereby compressing the conveyed material to a strong, though moving, plug.

The outlet of the screw feeder discharges into a pressurized pneumatic conveying pipeline.

The pressure in the pipeline minus the atmospheric pressure at the inlet forms the pressure drop over the plug.

The strength of the compressed plug is sufficient to withstand that pressure difference without leaking air back into the atmospheric zone.

That is meant by the sealing function of the plug.

Sealing the discharge pressure from the screw intake pressure.

Have a nice day

Teus ■

Originally Posted by aliawad1974

Dear Teus

Really i`am honored with you`re esteem answers . Bow for Teus

Think what you might have had to pay to get the guidance from Teus that he's given you for free. A complimentary crate of beer may be order ■

Good Day

An alternative to consider is to replace the screw pump with a pressure tank which can operate at much higher pressures than a screw pump so the exisitng line size may be completely adequate for the rate you want but there would still be a chage to the air supply required.

Regards ■