Engine Compatibility: Tamel skg-100l2 3kW 2880rpm for a 3-Piston Cabin Sandblaster Compressor

Hello.
I am starting to build a compressor for a cabin sandblaster, so I care about the highest possible efficiency of the compressor, I have a Tamel skg-100l2 ik-396 220 / 380v engine, 3kw 2880rpm, I would like to use a 3-piston compressor, but the engine power suggested by the manufacturer is 7 , 5 kw and the air pump speed is about 980 r / min, max suction capacity 1370L / min, piston diameter 90 mm, pulley diameter 34 cm. Will this engine be able to power this compressor?

Since the compressor manufacturer suggests / recommends? 7.5kW, there is no point in using a weaker motor.
This engine will be able to drive this compressor, but not with the efficiency stated by the manufacturer.
With a 3: 1 gear ratio, the revolutions would fit, but not very power. The engine would be overloaded.
At takeoff with the air tank empty, the engine would have a low load. However, as the pressure increases, the load (pressure on the pistons) will increase. Such work would overload the engine, increase temperature and burn (in extreme cases), possibly continuous operation of the engine protections. Increasing the gear ratio means lowering the speed and hence the efficiency. In addition, there is the issue of compressor lubrication. When the compressor speed is reduced, the splash lubrication may be too low and will lead to seizure.

Maybe my colleague has an idea that higher revs will give more air. Nothing could be more wrong. The nominal speed of the air pump must not be exceeded. Such a big difference in engine power is unacceptable, especially with the work you suggest. The engine will have trouble reaching the desired pressures.

Hello friend, this is not what I meant, I know that the performance values given by the manufacturers are in most cases a lot overstated, I even wanted to give a smaller pulley on the engine to reduce the efficiency of the pump, so that it would not work at maximum speed only on 60-70% of the max efficiency, so that it can be increased if necessary by changing the pulley on the motor. I prefer to buy a more powerful compressor and let it work with less power than a weaker and working at the limit of maximum efficiency, because it will fall faster. Let's say that at this engine speed and the diameter of the pump pulley, the recommended diameter of the wheel on the motor is about 11.5 cm and I would like to reduce it to say 8.5 cm, then the pump efficiency will drop to the value I need and the pump will not work at maximum power. But will the engine withstand it, will it not have too much load when starting?

badboy82 wrote:

But will the engine withstand it, will it not have too much load when starting?

arturavs wrote:

At takeoff with the air tank empty, the engine would have a low load. However, as the pressure increases, the load (pressure on the pistons) will increase.

It is supposed to be a sand blaster compressor, and these are very demanding devices in terms of efficiency. By reducing the speed, you will reduce the efficiency of the compressor. Additionally, I suspect that the pulley on the compressor shaft also has a fan cooling the compressor. Basically, in order to establish anything meaningful, you need to know the exact type of compressor and the construction of the sand blaster nozzle (known engine parameters). The scenario I predict is this:

You turn on the power, the motor starts and pumps up to e.g. 8 bar. The pressure switch cuts off the power. You start sandblasting. Pressure drop to e.g. 6 bar. The pressure switch starts the engine. The engine can't break the compressor. Motor protection tripped.

I would use a 7.5 kW 2800 r / min motor (it is more convenient to choose the gear ratio). It is easier to choose a pulley and a belt / and than to replace the motors. Sell what you have a little bit and buy the right one.

Hmm. .. Okey then I will be looking for some 7.5 kw only question about the speed 1400 rpm (wheel diameter on the motor 22cm) or 2800 rpm (diameter 11.5cm)?

badboy82 wrote:

Hmm. .. Okey then I will be looking for some 7.5 kw only question about the speed 1400 rpm (wheel diameter on the motor 22cm) or 2800 rpm (diameter 11.5cm)?

arturavs wrote:

I would use a 7.5 kW 2800 r / min motor (it is more convenient to choose the gear ratio). It is easier to choose a pulley and a belt / and than to replace the motors. Sell what you have a little bit and buy the right one.

Good luck

Engine or 1400 or 2800 no matter, only for such an engine would be useful Y / D switching automatics and a decompressor to start, after the description you can see that it is a 3090 pump and these are said to be able to handle 5.5kW. You live too far so we would do a replacement for engines.

vcc wrote:

automatic Y / D switching

Most recommended.

vcc wrote:

decelerator to start

At this engine power, compared to the manufacturer's recommendation? I see it miserably. In the absence of power and the strain relief will not help.

vcc wrote:

it's about the 3090 pump and these are said to be able to do with 5.5kW.

I will give advice. But will it maintain the pressure with such a reception as a sandblaster? I doubt it.

vcc wrote:

Engine or 1400 or 2800 no matter

So in these compressors it does not matter whether they turn 1420 or 2990, that's how I understood it.

Krzysztof Reszka wrote:

So in these compressors it does not matter whether they turn 1420 or 2990, that's how I understood it.

Probably the point was that the engine does not matter what speed it has, only to use the appropriate gear to match the optimal speed of the compressor.

vcc wrote:

only for such a motor would be useful automatic switching Y / D

What a problem, you need three contactors and one time trial.

Hello. The sandblaster is assumed to be with a pressure tank, capacity of about 5 liters, so it will not have as much air demand as a traditional siphon, from what I knew, such a sandblaster must have an air demand of 500-600l / min so maybe a little exaggeratedly I want to make such a large compressor, it will also be used for painting elements,

vcc wrote:

after the description you can see that it is the 3090 pump and these are said to be able to handle 5.5kW

This is exactly what I meant with the 3090 pump, but after analyzing a few things, I think the 2090 pump should be enough for me, i.e. a 2-piston pump with a capacity of 710-915 l / min, recommended 3-4kW motor, so with this option I would not have to change the engine? Does any of your colleagues know about the durability of these pumps? But how with the efficiency of my 3kW powered by 230 / 380V, does a typical 3kW 380V 3-phase have much higher efficiency and lower power consumption, is there not such a big difference at this power?
Added after 5 [minutes]:

Rezystor240 wrote:

vcc wrote:

only for such a motor would be useful automatic switching Y / D

What a problem, you need three contactors and one time trial.

A colleague could expand the topic, because I do not understand what this Y / D switching automatics is about?
best regards

badboy82 wrote:

A friend could elaborate on the topic,

Here you are.

The time trial controls the contactors and they switch the motor to a star for light start and a delta to the run state.

In this topic you have a diagram:
https://www.elektroda.pl/rtvforum/topic1965202.html

wojtek1234321 wrote:

Probably the point was that the engine does not matter what speed it has, only to use the appropriate gear to match the optimal speed of the compressor.

Well, what about the size of the wheel and the angle of the belt?

Rezystor240 wrote:

badboy82 wrote:

A friend could elaborate on the topic,

Here you are.

The time trial controls the contactors and they switch the motor to a star for light start and a delta to the run state.

In this topic you have a diagram:
https://www.elektroda.pl/rtvforum/topic1965202.html

Hmmm ... okey, but with my 3kW 230/380 V motor, is it not possible to use it, I would have to have a typical 3-phase 380 / 400V, am I wrong?

badboy82 wrote:

Rezystor240 wrote:

badboy82 wrote:

A friend could elaborate on the topic,

Here you are.

The time trial controls the contactors and they switch the motor to a star for light start and a delta to the run state.

In this topic you have a diagram:
https://www.elektroda.pl/rtvforum/topic1965202.html

Hmmm ... okey, but with my 3kW 230/380 V motor, is it not possible to use it, I would have to have a typical 3-phase 380 / 400V, am I wrong?

If you have a motor powered from the former 380V, now 400V it is a phase-to-phase voltage, i.e. you have a three-phase motor.

Krzysztof Reszka wrote:

What about the size of the wheel and the angle of the belt?

Well, then you would have to "combine" with the diameter of both wheels to properly match the "good values".

badboy82 wrote:

Hmmm ... okey, but with my 3kW 230/380 V motor, it can't be used,

Rezystor240 wrote:

If you have a motor powered from the former 380V, now 400V it is a phase-to-phase voltage, i.e. you have a three-phase motor.

We know that, the author asked you something else.

Rezystor240 wrote:

The time trial controls the contactors and they switch the motor to a star for light start and a delta to the run state.

Automation is not a problem, I have submitted to Wan AW and if someone has an idea, it is not a problem, as for the 2090 pump, the suction performance is given, in reality they achieve something around 550L, as for 1400 or 2800 revolutions, it is obvious that it was about the engines.
If a friend wants to play sandblasting, there is never enough air, it is better to add and buy a larger pump.