As the development of science and technology, the rotor material nowadays of screw compressor and centrifugal compressor had very great progress and change, the author has done test of a few research to this, this article discusses just a little slightly.
Material of rotor of 1 centrifugal compressor
Centrifugal compressor rotor is multi-purpose stainless steel is made, but the centrifugal empty press on hydrogenous batteries car however somebody uses aluminium alloy to make rotor, and make rotor as generally however as this adjacent car supercharger with stainless steel.
The demand of bulk of centrifugal pneumatics machine that goes up as a result of hydrogenous batteries car is less, rotate speed demand is higher, people feels the rotor of aluminium alloy of use high strenth that make is more likely.
For centrifugal to this kind compressor, reducing rotor vibration is very important, the biggest rotate speed of this kind of compressor is as high as 144 thousand to turn / minute or 160 thousand turn / minute. With the rotor that aluminium alloy makes, as a result of the centrifugal power that lopsided quality produces, the centrifugal power that with the stainless steel of same size the rotor that make produces can reduce 2 times quite, 1/3 what the centrifugal power that the rotor that makes with aluminium alloy namely produces as a result of place of same lopsided quality has rotor of same size stainless steel to leave mental efforts only, the oscillatory meeting that produces from this is reduced greatly. This is the advantage with god-given rotor of material of other of excel of aluminium alloy rotor.
To machine of small-sized and centrifugal pneumatics, rotor of this kind of aluminium alloy has flexibility good, weight is machined gently, easily and the advantage with low cost.
Material of rotor of compressor of 2 pairs of screw
Material of rotor of compressor of fuel injection double screw
Double screw compressor develops initial stage, the foreigner basically makes rotor of compressor of fuel injection double screw with easy cutting steel. The screw rotor that measures average England when Chinese National People’s Congress is special after milling machine, feel Chinese nodular cast iron is cutting function no matter, still process a volume rotor of steel of excel easy cutting, and cost is inferior, consequently rotor of screw of Chinese fuel injection turns and use nodular cast iron much more generally to make. Because Chinese rare-earth element is rich, rare earth technology of nodular cast iron is mature, rotor of nodular cast iron makes the screw compressor rotor of Chinese characteristic.
Rotor of compressor of fuel injection double screw mixes the job below condition in content of oil gas two-phase. In the job, as a result of effort and hydraulic combined action, oil gas is gone to by even eject compressor each base yuan cubage while, also gush scatters rotor and airframe surface, form covering layer, and the air of high speed flow is mixed lube erodes the tiny particle of rotor surface clean again. Although surface of nodular cast iron is not as close as steeliness rotor surface, but still can be competent the function of rotor.
The degree of reliability that screw compressor rotor works is assured by the precision of bearing, look now, steeliness rotor and rotor of nodular cast iron do not have very big difference almost.
To the rotor of large screw compressor, people or apt use steeliness rotor, feel the dependability of steeliness rotor is better still.
Do stuff of screw compressor rotor
Because people need is more reliable cleaner compression gas, and the way that screw compressor adds fuel injection to compress aeriform nicety to filter still cannot replace dry compressor completely. Later, because dependability is mixed the difference of maintenance period, people never abandons restoring of all kinds dry compressor partly.
Rotor of the rotor of dry screw compressor and fuel injection compressor has again different, because the price of dry screw compressor is high, rotate speed is high, compress medium complex, make dry compressor rotor generally with stainless steel consequently.
To enhance rotor fight grind and fight corrode, face of different dry compressor rotor has different preservative coating or film. With period increase its anti-wear properties and anticorrosive performance. As the ceaseless progress of preservative coating technology, the function of preservative coating also gets farther aggrandizement, different compressor manufacturer used different coating or film.
Coating has chemical coating and agglomeration coat two kinds, and vacuum plating titanium is more advanced film technology.
Although film is very thin, but still need polish. Different manufacturer uses different polishing technology, great majority application assists mechanical polish artificially, machining center polish, function of chemical physics polish is much better, of useful also and electrostatic polish, the spare parts of large quantities of quantities uses technology of advanced heat treatment polish.
Water is lubricant material of rotor of double screw compressor
The rotor material majority of compressor of lubricant double screw is the water that rolls out at present stainless steel, rotor of compressor of lubricant without the water that discovers other material double screw. Of course airframe also is stainless steel material pledges.
Material of rotor of compressor of 3 odd screw
The rotor material of different odd screw compressor is different.
Material of rotor of compressor of fuel injection odd screw
Rotor of compressor of odd screw of Chinese fuel injection uses easy cutting steel and nodular cast iron generally to make, astral annulus piece use carbon fiber aggrandizement get together ether aether ketone is made.
Water is lubricant material of rotor of odd screw compressor
In recent years, water is lubricant odd screw compressor is more extensive use at the industry such as pharmacy, food, beverage, spin. Different manufacturer stems from different consideration, use stainless steel and copper alloy to make rotor, because water is lubricant price of compressor of Chan Luo lever is higher, manufacturer uses the rotor of which kinds of material to be able to obtain good economic benefits. The rotor of different of course material is comfortable the bit that mixes certain recipe annulus piece basically be aggrandizement get together material of ether aether ketone, water is lubricant the star of odd screw compressor annulus sheet makings and compressor of lever of fuel injection Chan Luo are different.
The airframe of compressor of lubricant odd screw mixes water rotor material matchs, rotor material hardness is taller, of airframe material cast fluidity betterer.
Rotor of 4 screw compressor and machine temperature spend an analysis
The temperature that analyses screw compressor rotor and airframe correctly changes, conduce to righter choice rotor stuff.
Rotor job temperature and airframe job temperature
Screw compressor rotor is in regular job loop, rotor surface nods temperature to change ceaselessly between temperature of inlet temperature and exhaust each, go round and round, its are average the intermediate value that temperature accords with inlet temperature and exhaust temperature basically.
Because the machine is phyletic the airframe temperature situation of screw compressor will be different and endless identical, but accord with inspiratory end basically temperature is low (be close to inlet temperature) , exhaust carries temperature tall (adjacent at exhaust temperature) the rule.
In working normally actually, the average temperature temperature of rotor is spent under machine temperature.
Although airframe suffers,connect the tie of conduit, flange, but what answer relatively with this still is rotor heat expands the heat that is less than airframe expands. The feeling of this rule and people has difference. This rule decided screw compressor rotor and airframe match be safety.
Screw compressor rotor and airframe change in the temperature of phase of different type of work
The rotor temperature of screw compressor and airframe temperature are in start, work normally and begin to stop when machine, can produce bigger change.
Screw compressor is in the temperature in starting process
When screw compressor starts, the gas of unit cubage or gas fluid begin to be compressed, temperature rises quickly, gas or gas fluid and compressing temperature drama to rise is change of a kind of molecularity voice, temperature instantaneous lifts or lift immediately, be without defer. And the rotor that serves as be heated and airframe are solid, have different thermal resistance, what temperature has different kind is elevatory. Rotor be heated is sufficient, temperature can lift at airframe first. Airframe decides because of the structure, thermal resistance is great, temperature rises slow at rotor, but the average temperature of rotor still won’t exceed airframe temperature. This kind of condition lasts after zero second or number second, compressor enters regular job state.
Regular job temperature accords with screw compressor temperature of “ rotor job and rule of ” of airframe job temperature
This is a relatively stable temperature condition, in this condition, screw compressor gives trouble not quite easily, unexpected damage brings about the solid grain that unless compressor engulf exceeds,allows or bearing.
Screw compressor is beginning to stop the temperature when machine
Screw compressor is beginning to stop when machine, the air current of high-pressured high temperature that exhaust carries can flow backwards instantly to inspiratory end, rotor is inspiratory the temperature that carries the surface lifts instantly under adjacent at exhaust temperature, airframe temperature changes not quite, hasten is bordering on average temperature, formed inspiratory end the dinky clearance of rotor and airframe instant.
Do not become repaired word to the end taking energy of life of rotor of odd screw compressor, in stop happen likely when machine hold in the arms machine.
Aluminium alloy of 5 high strenth suits to make rotor
To the analysis of screw compressor rotor and airframe temperature, benefit at be opposite material of screw compressor rotor has more comprehensive knowledge. Wait as steel of easy cutting of traditional rotor material, nodular cast iron, stainless steel, copper alloy can replace with partial other material.
The data strength of canister of oil gas of high strenth aluminium alloy can be accomplished not under high grade carbon steel. The treatment surface of the spare parts is bright and clean, whorl aperture brightness is pliable, better than nodular cast iron much.
Above analysis sees high strenth aluminium alloy has the advantage of certain respect not hard, engine of pardonable and high-grade car evolves for completely aluminous engine, also use the possibility of aluminium alloy rotor with respect to compressor of easy understanding screw thereby.
Because rotor suffers force and airframe to differ, each bits of temperature is different, consequently compressor makes the aluminium alloy material of rotor answer to match correctly with the aluminium alloy material of maker put oneself in another’s position, the brand of aluminium alloy (composition) also differ with heat treatment; The aluminium alloy hardness of rotor should taller, integrated intensity is higher also.
6 authors make the test that pass and development
The author goes up in compressor of double screw air, had developed tube of aluminium alloy oil gas. Before 2002, the railroad traffic apply the brake that Germany has a company to produce 2m3/min uses screw pneumatics machine, canister of its oil gas is aluminium alloy material pledges. And the railroad traffic apply the brake that a company of Chinese produces 2.4 ～ 3m3/min uses screw pneumatics machine to lack material of canister of aluminium alloy oil gas and technology, and oil gas canister is steel weldment. Weight of canister of steel weldment oil gas is great, yi Sheng becomes rusty, suit railroad traffic form a complete set not quite, falling without commutable circumstance, be used constrainedly.
The author discovers this phenomenal hind in this company, the proposal leads approval to develop so as to of canister of aluminium alloy oil gas to replace tube of steeliness oil gas. After be being approved via heading research, the author chooses aluminium alloy of a kind of special high strength to regard oil gas as the material of the canister. From the design, to reflect the advantage of canister of aluminium alloy oil gas adequately, author and other engineer are used together finite internal to oil gas canister composition undertook yuan of method written guarantee compose is optimized, reduce stress concentration, after many relapse, after the blueprint that finish is designed, throw sample trial-produce via approval.
On the foundation of sample trial-produce, sample of oily to aluminium alloy inflator undertakes compression experiments, the author is accomplished in 4 times actuating pressure hydraulic experiment falls, oil gas canister is in good condition nondestructive, without leak phenomenon (pressure vessel asks to have 2 times actuating pressure commonly hydraulic experiment) .
At that time, railway ministry electronic motor car introduces expert group group leader to bark Zhang Laoxian gives birth to be an official (old gentleman has participated in China to introduce 4 A Ersi the earliest to connect electronic motor car, come into railroad treasure chicken in treasure wind city paragraph roundtrip, replace stage or 3 two steam locomotive in order to move) see try after pressing a case, relatively feeling is gratified, study via them, think to be able to mount car trial. After the experiment that assemble a car comes to an end, via affirming, approve again in undertaking, try. In in try a foundation to go up, turn into formal form a complete set.
On this foundation, the author developed aircraft of pneumatics of screw of canister of oil gas of aluminium alloy of appropriative of motor-car, light course, subway for this company, this company is using the product of author research and development all the time up to now.
Rotor of 7 screw compressor adjusts an agent
Want to make screw compressor rotor more reliable, new machine succeeds, the author recommends the machinery of company of corridor Kang Ning to adjust an agent quickly. When screw compressor is assembled, the Fu of besmear of easy attrition place in rotor and airframe a few adjust an agent this kind, can be at the beginning of routine test when starting, prevent to be pulled accidentally, very reasonable be to one’s profit. Of author research and development fight grind repair agent to have more in this respect have distinct effect.