Competition of market of empty now press is intense, consumer is when product of choose and buy, often enter machine character and valence Glenn buy a level in. Accordingly, all sorts of indicative methods with the common place on article general market make one specification, exhaust a power to protect consumer interest.
4 kinds of 01 basic mark methods
1, will express with motor horsepower. This is practicable still when inchoate pneumatics technology is underdeveloped, but the ceaseless development as the technology, even if is to use identical motor now, because of,also meet pressure discretion, pneumatics mechanism builds manufacturer and type size to differ, and the wind force amount that makes place of actual pneumatics machine is discharged has great difference. Accordingly, on catalog only indicative and motor horsepower, it is the course of action that bears the blame least of all.
2, with piston addendum modification (Piston Displacement) (in the light of piston machine) express. Because this is the design data of pneumatics machine, simply takes air cylinder volume on circumgyrate is counted can, so, this data gets the most easily, also be designation of a lot of in order to of manufactory home place. This theoretical value and give the concern with be done not have particular between tolerance actually, the technical capability that inspects manufacturer home and calm.
3, in order to enter gas bulk (Inlet Volume) express. This kind states the method is entering gas mouth side to be measured with bore diameter normally plan (Orifice Meter) will determine, use the measurement of machine of pneumatics of indicative and centrifugal type only at present. Adoption unit uses ICFM, this although relatively before 2 kinds of pattern are exact, but because of not plan in-house loss, reason still is than giving tolerance actually tall.
4, measure with venting his anger freely (Free Air Delivery) express. This law is to use bore diameter to measure stream plan in exit side determines, as a result of accurate become in order to of world main standard to determine consequently of pneumatics machine give wind force actually, be like ISO, ASME, JIS, nevertheless, in some Japanese manufactory catalog, use F.A.D. Come indicative, add again however note Nominal Capacity, normally apprehensible view is: This F.A.D. Not be true, is value of a kind of design only.
Regrettablly is, having a level is one and the same, be being done is one and the same, accordingly, unless the level of a basis shows in black and white on former plant catalog, otherwise, its reliability must sell at a discount greatly.
What express below 02 different operating mode is actual give wind force
What give wind force actually to point to is to consider all loss, in pneumatics machine overall exit (after aftercooler) a measures wind force, give tolerance with freedom normally (Free Air Delivery) will express. Alleged freedom goes tolerance is the air bulk after showing course compressor is compressed the free air state that enrages a mouth in order to enter (temperature, pressure, humidity) will express.
Accordingly, even if used same test level, the number that the ” of “ free air that because take,also can use differs and makes express differs 20% above. It is a few kinds of commonly used free air below state:
1, regular state (Normal Condition) : Denotive method: Nm3/min (or the state entering energy of life that makes clear test place to use)
Indicating air state: 760mmHg, 0OC, index of 0% RH bulk: 1
2, standard state (Standard Condition) : Represent a means: SCFM (or the state entering energy of life that makes clear test place to use)
Indicating air state: 1bar, 20 0C, index of 0% RH bulk: 1.05 (make an appointment with)
3, actual state (Actual Condition) : Represent a means: ACFM, ICFM (or the state entering energy of life that makes clear test place to use)
Indicating air state: 14.4psi, 35 0C, index of 60% RH bulk: 1.2 (make an appointment with)
Give tolerance likewise, want to use different air situation only, can greaten the number 20% .
What the test below 03 different pressure goes out is actual give wind force
Give wind force actually (FAD) numerical value and the air state that consult are concerned, at the same time also with below what pressure the test is concerned.
For example, the air-blower of 55kW gives wind force actually to be 40m3/min about in what measure when 0.5barg, what the machine of pneumatics of type of small oily screw of 55kW measures when 8barg is actual give wind force to be 9.1 M3/min about, and wind force goes out actually to be 6.8m3/min about in what measure when 13barg.
Comparing consequently differ with power of brand pneumatics machine when giving wind force actually, want to consider the pressure when its check discharge. Here does not have strict theoretical calculation formula to come conversion, but an accepted experience formula can make reference.
To machine of pneumatics of type of fuel injection screw, what if be when pressure is elevatory,still should keep same is actual give wind force, need increases the rotate speed of rotor, should use up 6 ～ more at the same time the motor power of 7% . To having machine of pneumatics of oil screw type completely, need to increase the power of about 10% to use up.
E.g. , assume a 55kW is small A of oily screw machine is measured actually below 7barg give wind force to be 9.54m3/min, b of machine of screw of another 55kW small oil is measured actually below 8bar give wind force to be 9.1 M3/min, is the efficiency that the efficiency that is A after all is returned high is B tall?
The experience above the basis is formulary, a still should maintain 9.54 M3/min to give wind force below 8barg changeless, the power that needs to increase 6% above is used up, namely 55kW×1.06=58.3 KW compares bothly can be respectively:
A: 58.3kW÷9.54m3/min=6.11kW/ (M3/ Min)
B: 55kW÷9.1 M3/min=6.04kW/ (M3/ Min)
(6.11-6.04) ÷6.04×100%=1.16% , the efficiency of machine of pneumatics of B of this that is to say is tall 1.16% .
The motor power of 04 pneumatics machine
The gives wind force and motor place actually to use up power of the efficiency of pneumatics machine and empty press is concerned. Give wind force actually to because check,be met method and state the method is different and is very big difference on numerical value, there is similar case likewise when the motor power that inspects pneumatics machine. In the meantime, the efficiency of pneumatics machine still serves coefficient with motor, motor efficiency relevant.
1, the axial horsepower of specific pressure
People is commonly used than can (Specific Energy) - the power that the unit gives tolerance is used up will measure pneumatics machine efficiency, the motivation here consumes the axial horse power that those who say is specific pressure, when exit of means pneumatics machine presses China to constant pressure to nod, the power that place of pneumatics machine main shaft consumes. Because the pressure point of different manufacturer make choice of is different, indicative axial horsepower value is consequently different also.
2, service coefficient (Service Factor)
What the motor power of pneumatics machine points to is motor nominal horsepower or rated power, but the power that this differs to be used up actually at motor. To the manufacturer of Europe and Chinese China, motor and real power consumes the rated power that should be less than famous brand to go up commonly, and production manufacturer of the United States deserves to use lesser motor in customarily, its service coefficient is bigger like 1.25, and when full load, motor exerts oneself 15% what can exceed nameplate, if the label is the motor of 100HP, its exert oneself actually to exceed 115HP possibly. The real power that this makes “ motor consumes the rated power that is less than motor nameplate to go up certainly this one old regulation was broken ” .
Accordingly, generally speaking, to be the same as the empty press of horsepower, the wind force data of European brand is less than the wind force data of American brand, reason as above. The production manufacturer of some Europe brand has begun the practice of United States of follow the lead of now.
The efficiency of 05 pneumatics machine
As above is narrated, the efficiency that considers pneumatics machine should consider his to check a method, state pressure of condition, test is nodded, real power is used up etc, consider motor efficiency even at the same time, because axial horsepower is motor output part only, the user pays charge of electricity is to press power input calculative, the efficiency that inspects pneumatics machine has to consider motor efficiency.
Say so, if do not understand each manufactory to approach machine and the level that when choosing motor, use in indicative sky, sheet compares its efficiency by the data on its catalog, be without a meaning almost. In fact, even if understood each manufactory all detail, special also compare hard, because differ,the relation between the standard decides very hard.