When compressor discharge decreases, as rotate the generation of stall and development, the aeriform discharge of compressor and exhaust pressure are periodic low frequency, great amplitude ground is fluctuant, cause the intense vibration of the machine, the asthma that this kind of phenomenon calls compressor brace up.

Asthma brace up the air current when fluctuates and rotate the air current when stall is pulsatile disparate: Breathe heavily brace up when, direction of air current wave motion is axial, and unlike rotates pulsatile edge axial has the air stream when stall; Asthma brace up when the whole gas discharge that passes compressor (or average discharge is worth) fluctuate considerably, and rotate when stall, the average flow that passes compressor is constant, discharge is pulsatile be around average discharge pulsatile; Rate of asthma Zhen Pin and amplitude are to shed the cubage size place of the road to control, and rotate stall and their concern is not big; Rate of asthma Zhen Pin is low and rotate stall frequency is general taller.

Form asthma brace up the serious stall that immanent cause is air current and patulous, exterior condition is compressor and condition of operating conditions of combination tubal a network.

Asthma brace up can divide breathe heavily to lose brace up breathe heavily with deepness brace up, there is boundary between them, appear commonly refluent asthma brace up breathe heavily for deepness for certain brace up. Asthma brace up the phenomenon has following macroscopical features normally:

1) compressor job is extremely flabby calm

When compressor runs normally, the parameter such as exhaust pressure, discharge is pulsatile the value is little, frequency is tall, if pursue 1 (A) . Reduce discharge to arrive be close to asthma brace up when discharge, pulsatile aggravate, occurrence from time to time of from time to time disappears. Without clear rule, continue to reduce discharge to arrive occurrence asthma brace up when, pneumatic parameter can appear to fluctuate periodicly, amplitude is big, frequency is low, at the same time value of average exhaust pressure falls, if pursue 1 (B) . Breathe heavily to deepness brace up for, flow into compressor afterwards from vent-pipe net as a result of gas and via compressing again eduction, make air current temperature may lift quickly.

2) breathe heavily the noise of periodic air current of Zhen Youjiang intense, blare of occurrence air current

The sound of the air current when normal movement is chirp sound, to asthma brace up before change of air current voice is not big. Asthma brace up when appear suddenly to explode periodicly sound, reduce flow again, sound of grand of meeting occurrence rumble. Sometimes as a result of the hum with other spots, or to compressor of double cylinder body, in asthma brace up slight when, listen possibly also not apparently, but it is can apparent below most circumstance listen get.

3) the machine is intense and oscillatory. The amplitude such as airframe, bearing increases quickly

Compressor is not to allow to be in breathe heavily brace up move below the condition, because the harm is very great.

The first, be like,it may damage the compressor component such as annulus of form of sealed, O, damage the axis sheds compressor to use a part of a historical period especially, cause even move, the great collision attaint such as static component. Push bearing to produce wallop to stopping, destroy stability of bearing oily film, attaint bearing. The likelihood destroys oily sealed system, the oily baric difference that makes oily film sealed is maladjusted, create oily film sealed breakdown.

The 2nd, the likelihood destroys the installation quality of the machine, destroy departmental cent to adjust good space to be worth, cause an axis even be out of shape etc, cause aggravate of the vibration in after the machine is in, moving.

The 3rd, the likelihood makes malfunction of a few concerned instrument or make appearance accuracy is reduced.