Dear Matt,

For a turbo compressor try thr internet, f.i. using “turbo compressor manufacturer”

A lot of companies that make turbochargers for diesel engines, can supply also units built as a turbine compressor.

BUT, why use a complicated turbine compressor, that has to be kept at full pressure

for proper operation.

(drive is overloaded at a pressure ratio=1 , unless a diffuser vane control is applied)

A small oil free screw compressor. less volnurable, will do the same job as well.

success

teus ■

Are you sure you are not looking at a regenerative blower? they look exactly like turbines/ turbochargers.

This is probably where you made the mistake of identifying them or it.

A regenerative blower will run through a Rockford clutch drive or a PTO gear box through a pulley very easily and cost effectively at a very hgh RPM which is exactly what they need. a screw compressor is fine but for two BAR and only two BAR its not a lot of PSI for a screw compressor.

Do not forget that you are moving cement in dilute phase only so its really a waste of power and useable energy- as Tues said the compressor is either under full load or not.

If you have a plug up the pressure will build to the relief point and

the system will clog them where will you be if the pipe does not blow before the relief valve kicks it out? etc.

Why dont you start out by telling us the discharge pipe diameter and the discharge length first? then determine what size and type of air mover you want. ■

Bingo.

I examined the installation of a Holset turbcharger unloader when they came on the market in about 1967.

After comparing the engine specific heat release at the rpm required to produce the no load airflow I reported that the radiator capacity was on the limit. Risk of boiling the job dry while the driver is away round the back attending to the rsend of the tanker.

Gardner diesels banned their use, any turbocharger in fact. That latter is one of the reasons why they (Gardner) are no longer seen around. Cummins would not cover with warranty but Rolls Royce didn't mind. Mind you R R diesels were the roughest in creation & perhaps they knew the device would shake loose soon after starting up. Perkins were in the Gardner camp.

You don't see them around because they must be more trouble than they're worth. Air must be piped under the cab floor, around the Suzies. With machinery recommended by the other respondents the engine runs at mechanical loads which can be recognised & accommodated by the ECU. Hopefully things have progressed since 1967 but I cannot reconcile the idea of piping hot air under a cab floor. Turbocharged air is for getting the beast up the hill. Holset are still in business making proper straighforward turbochargers. ■

dear Leon, John, Matt

The original question is about a compressor for unloading bulk trailers.

I assumed, without any further thinking, that the involved pressures were up to 2.0 barg

As turbo chargers on diesel engines can deliver up to 2.5 – 3.5 barg, I also assumed that a turbo compressor can do thejob.

(although I was wondering, why a turbo compressor was selected)

Maybe I should not assume so much?

An oil free screw compressor with internal compression is normally used for pressures up to 3.5 barg in these applications.

Below 1 barg, a normal blower with isochoric compression can be used.

As regenerative blowers (multiple stages) can deliver pressures up to 11 psi (approx. 0.75 barg), a blower would be a good alternative.

In the past, I conducted trials and performance measurements on 2 grainuloaders in the port of Rotterdam, equipped with turbo compressors of 750 kW and 300 kw in vacuum mode.

The results were, that the installations were expensive in investment and energy demand per conveyed ton, due to the full power requirement at partial conveying load.

When we stopped the turbo blower after work, it sounded as we were just landed with a jumbo jet

Indeed, we need the full information on the installation before we can really advise to the point,

All for now

teus ■