2 replies to this topic

[Deicide Dunkelheit]

Dear all,

 

The main character of the topic is Mycom Mayekawa 4032LSC 1,5 MW Electic Driven Fixed Speed Screw Oil-injected Compressor applied in a relative new helium liquefaction plant.

 

The process allows the dicharge pressure to vary from 0,9 MPa (ga) to 1,6 MPa (ga), which has no contradiction with the manufacturer's data sheets and so on.

 

But the suction pressure ranges is what I'm concerned. The initial plant Psuction low values had been determined as 10 kPa (ga) for L and 5 kPa (ga) for LL. But later the plant operating personnel step be step lowered the values to 1 kPa (ga) for L and 0,3 kPa for LL to maximize the liquid helium production rates. This hasn't led to any deleterious consequences and all the compressor parameters are consistently normal for now.

 

May this kind of operation later result in any serious problems? Has the design Psuction value been chosen in accordance with some practical rules?

 

UPD: just found out that the manual operating limits allow a slight vacuum. But the manual data is not comprehensive to answer my question.

https://www.manualsl...?page=21#manual

[Pilesar]

The problem I would watch for is air ingress if the suction pressure got too low. Helium being non-flammable, this seems a quality and economic issue.

[breizh]

Hi,

Why don't you ring or email the manufacturer with your concern?

You may have issue with the mechanical integrity of the equipment working at low suction pressure.

Seals?

Talk to your mechanical engineer.

Agree about risk of air ingress, ask your lab for analysis (gas GC).

Breizh