In ministry of American Chinese and Western, most food manufactory is used compress air and spot to make nitrogen undertake produce and be packinged to a variety of food. It is 4.5 cent when electrovalency / when KWh, the defray that goes up every year in the specific power consumption that reduces air system is manufacturer 430, 344 dollars.
This project basically studies food packs the air in the process to reduce a system, study achievement can make the factory reduces the aeriform flow of 689scfm, managing $54, the cost of 671. What the method that this project uses open mode to blow rehabilitate of leak of gas, nitrogen and use air oscillator will keep a product is mobile.
Because the word counts limitation, the article will reveal us to be in for the reader the result that reduces observation of square place of aeriform system demand to arrive, undertake be elaboratinged in detail to dropping the specific plan of aeriform discharge.
Compress aeriform system to evaluate
This factory has two compressor houses, among them core computer room makes azotic device offer for factory production area and pressure swing adsorption compress air, another computer room is offerred for biscuit unripe inn compress gas.
.jpg)
Of core computer room compress air system to include 3 250-hp to be decided without oil fast rotate screw air compressor, at the same time they do not have oily gearshift drive to rotate through conduit and two 400-hp screw air compressor is linked together, gas of the implementation in will compressing gas to carry chance of two large freeze-dry together by these 5 equipment is dry.
And another computer room by rotate of two 250-hp without oil composition of helix lever compressor, and in compressor inside buy has billabong HOC (hot pressing) desiccator of gas bosomy type, in order to is dry gas.
The compression in two computer rooms air system works every year 8, 600 hours. Laden curve of the system (air demand) relative in all moving orders stability. As a whole, annual systematic gas discharge is in 4, 000scfm arrives 6, between 200scfm, it is on average about 5, 200 to 5, 500scfm.
If the watch is shown 1 times, the average system flow rate of core computer room is 3, 627scfm, average air compressor discharges pressure to be 105psig, the system is average pressure is 9psig. Total power input of core computer room is 748kW, it is 4.85scfm/kW than power. Every unit discharge compresses airy charge of electricity to be annual $79.81/scfm, charge of electricity of airy of every unit pressure is annual $1, 447.38 Psig. The charge of electricity with core annual computer room is $289, 476.
The average system flow rate of bakery computer room is 1, 968scfm, discharge pressure on average to be 90psig, average system pressure is 80psig. Computer room total power input is 364kW, it is 5.4scfm/kW than power. Every unit discharge compresses airy charge of electricity to be annual $71.58/scfm, charge of electricity of airy of every unit pressure is annual $704.34psig. The charge of electricity with core annual room is 140, 868 dollars.
Through the working analysis of compressor, compress equipment to move in two place good. But the situation that no less than often encounters when undertaking air is evaluated compression is same, our group discovers, an air compressor may achieve rated power in power when, offerred empty throughput is gotten lesser than what what need however much. But from the watch 2 we can see, air current (bear) the electric power of effective demand and aircrew is used up match, because this kind of circumstance is done not have,appear in this food factory.
Remove dust the system evaluates: Food factory cannot evasive problem
In any food factories, remove dust systematic assessment appears very important. In this food factory, we checked 12 dust catcher to use compress airy circumstance, discover dust catcher take makings measure appropriate, and have between every dust arrester store enoughly space. Demand control is very effective, the hop-pocket of dust arrester also is in proper when change. In addition, move and did not use timer of these device, but although will low-pressure gas is connected,enter the other conduit around or be the problem also won’t produce in connecting dust catcher.
Remove dust in typical pulse efflux in the system, dust is used hop-pocket or pectination eliminate implement after collecting, can form the dust with size appropriate structure piece, usable compress air pulse to erode its from hop-pocket come down. Should dust piece is moved to divide from inside dust catcher by correct ground when, the system will appoint dust eliminate of the environment successfully, and hop-pocket has normal service life; But if dust piece cannot by effective ground from the eliminate in dust catcher, dust arrester will lose the function that remove dust, and can shorten greatly the service life of hop-pocket.
The compression when equipment when aeriform feed condition is normal, use demand to controller can use up fewer air and achieve better result. But if be in,without appropriate compression air feed condition issues use demand controller, may use up more air, and reduce the service life of hop-pocket and performance. Accordingly, correct operation dust catcher to reducing cost is mixed improve systematic efficiency crucial. In the meantime, the dust collection system that also has a lot of is to pass timer to control those who compress air pulse, operation personnel installs timer through particular case, so that move effectively,divide dust piece and the service life that ensure hop-pocket.
.jpg)
Remove dust the design set the system to remove dust effectively the pressure of the mouth that take energy of life of needs manifold and pulse a powerful person.
Pulse a powerful person will give ration with booking speed compress gas to send to hop-pocket, in order to erode with clear the dust on hop-pocket piece. Given empty tolerance size depends on pulse nozzle falls in booked circumstance, by the compression of constant voltage infuse airy pressure.
To every time pulse, dust catcher must lie correctly (or adjacent at it) , stable but on reduplicative pressure level, what use timer to control pulse especially is moment. Operation personnel can pass a test, find the sequential ” with the correct “ below needs inlet pressure. But once pressure is changed, systematic function may become poor.
Dust piece keeps clear of from hop-pocket hard is the problem that often appears, main reason may be pulse implement in impropriety when give out pulse to hop-pocket, also may be the time between pulse grows too two, bring about dust piece to accumulate bigger more, as a result keeps clear of effectively hard. This not only can shorten the service life of hop-pocket, still can make systematic performance drops greatly. Appear a few of this kind of circumstance main reasons have:
1. The timer setting that operates a condition is incorrect. The effective demand that decides optimal timer is installed may change as what produce a product and change, change along with season even and change. Because of this timer from install meticulously with respect to need at the beginning, and time monitoring.
2. Enough storage space or ample air supply are lacked in place of air admission hole, make the empty tolerance that the system must reduce aeriform pressure to satisfy pulse place to need.
3. The air inlet duct of dust catcher is transient small, also can produce as similar as air in short supply result.
4. Too small or the control valve of impropriety, cannot handle the aeriform flow that dust arrester place needs.
All these circumstances can bring about aeriform discharge be restricted. Appear the reason of these circumstances is, be before installation or change in certain operation before, did not handle affirmatory and proper gas flow to remove dust. The size of air inlet duct, size of control valve and enter tolerance more or less to need gather into one of frame of reference ” of specific aeriform “ actual flow, and cannot use ” of average discharge of so called “ .
” of “ average discharge is to reduce airy flow (with cubic metre foot / minute for unit) , need with process place or the empty tolerance that is input system has nothing to do. And ” of “ actual flow is the empty throughput that shows systematic place needs (with cubic metre foot / minute for the unit) . If be inside short time, although systematic place needs empty tolerance is smaller, have ” of very big “ actual flow possibly still. This is the characteristic that dust catcher has.
Programme controll implement the effect with the very distinct generation of ” of “ actual flow that can need to systematic place. E.g. , a dust catcher of 6 pulse a powerful person can use 3.5 cubic metre foot compress air, every pulse exceeds half second.
If these two kinds different “ discharge ” is used at control,give tracheal road flow, criterion the influence that they wait for a respect to adjuster dimension will appear similar difference. Enter manifold to be able to cause additional pressure loss with high velocity of flow, affect pulse cleanness then implement function. If be necessary, similar result also can be used on the size that changes air receiver, with reducing the system is mixed press to what enrage pipeline fall.
The commendation that quality pressure expresses
The dust catcher that we suggest to give tracheal way in every normally installs pressure of a quality to express near the entrance. Observe pulse pounds the pressure on the watch, if press,fall exorbitant, be necessary to find out its reason. The cycle time between time of pressure of feed of the aeriform flow that knows dust catcher norms, every pulse, pulse, pulse. Calculate next systematic air flow, examination conduit diameter and storage space are suitable, whether to add storage space in order to decide. Should control diaphragmatic or when pipeline link occurrence problem, can have many compression gas is divulged (10 to 15 cubic metre foot / minute more even) . And such divulging often discover hard, very difficult also rehabilitate.
Choose proper measure and memory unit for dust catcher, the operation that there can be demand of larger volume gas inside will brief period changes the operation with average very small discharge. If do not need short high demand pulse (be less than 1 minute) , should install control valve after receiver.
Adding storage space appropriately is not only consider from energy level, consider from airy quality level more. Correctly control dust catcher can let what nozzle is in press fall right all round systematic influence is reduced, also can improve the function of dust catcher and the service life that prolong hop-pocket at the same time. Dust catcher is a main leak source, detect very hard. Pulse control is diaphragmatic also constant leak, and warning apparatus of electronic air current can discover this problem erupts simultaneously at long bowls, intuitionisticly a signal.
After systematic replacement is stable, examine the moving case of every dust catcher, ensure timely ground is right of hop-pocket undertake changing, control working requirement, ensure fine of all without exception between photograph adjacent equipment is affected even.
Solve open mode to play morale problem, achieve the optimal result that blow air
To the factory the compression of two area air system undertook audit and complete assessment, discovery can reduce air flow through a few kinds of methods. Among them one is open mode aspirated optimize.
Onflow compresses air direct from inside conduit ejective, the compression with wasteful and many meeting air, violate professional safety and healthy standard (OSHA) in the regulation of concerned noise, and demand of pressure of far still short of. The spray head that uses air efflux and revulsive air flow replaces open mode to blow air, can reduce noise level, decrease compress airy to use, still can improve the efficiency that blows an exercise and quality normally.
The factory installed the amplifier in proper Wen Qiu and controller. And begin shift of more ground use machinery clear dust piece, use in order to decrease compress air. These optimize measure to make air current demand reduces 305scfm, annual power consumption decreases 539, 644kWh, be equivalent to saving $24 every year, 284.
The product that there are a lot of jet efflux devices and revulsive air stream on market is usable. But the experiment of a nozzle may differ somewhat with another nozzle of same manufacturer, the difference is not big nevertheless. It is the point that need remembers below:
5. In the process that blow air, need pressure thrust (Psig) will become loose should blow the dirt that remove.
6. Once air leaves “ to blow ” plant, thrust is met rapid and abreaction.
7. Blowing in eliminating a process, total wind force (Cfm) , compress air and bring wind to divide work to blowing crucial.
8. costly compression air serves as last method; machine, hydraulic pressure to wait is more energy-saving method forever, often safer also.
9. The air that all blowing go out should adjust to lowest significant pressure. Higher pressure is accompanying larger flow, and this often is done not have necessary, because higher pressure can make manufacturing cost higher. The pressure air that air-blower offers is met more economy.
10. Whenever, should use —— of nozzle of amplifier of the air in Wen Qiu as far as possible to choose offerred air thrust and bulk appropriately, this can decrease normally of at least 50% blow clean to enrage, the air that issues the province is used other on more valuable exercise.
11. Do not need in production when, all processes that blow clean air can stop automatically.
12. The air that produces when air-blower can be used or be in economically apparent and feasible when, should its cost of net energy source and replace the sources of energy to undertake comparative.
Better nitrogen is controlled, better air vibration method
The 2nd method that reduces throughput is emphasized in the factory to use nitrogen (on N2) . After studying the group observed in an area 20 assemble bag of exercise, discovery removes a kind of product outside, system of other major bagging uses nitrogen. Nitrogen is the automata that is 580-scfm by the capacity makes preparation of azotic plant site, serve as with liquid N2 reserve. The dosage of nitrogen is 320 ～ 350 Scfm, purity is in 99.7% ～ 99.8% between. Of nitrogen generate than be 5:1 about, every cross 60 ～ 65 seconds, can have 1750 cubic metre foot air is used to produce 350 cubic metre foot nitrogen. Normally, when product line stops, the supply of nitrogen still is undertaking. In making an on-the-spot investigation on the spot, about 7 sack filling machine were stayed to be on the product line that does not run, the remain in every sack filling machine has 3 to arrive 20 cubic metre foot nitrogen.
The factory was used shut control automatically to solve this problem. When needing nitrogen, it can stop the supply of nitrogen automatically. It still installed control a powerful person to adjust the use quantity of nitrogen. This optimizes measure to make air current demand reduces 300scfm, annual power consumption decreases 530, 800kWh, be equivalent to saving $23 every year, 886.
Finally, the factory implemented a kind of better method, use air oscillator will maintain product or the shift that pack or depart. If the air of an air oscillator that the factory uses makes dosage is every 10 Cfm to control, so similar dynamoelectric oscillator should produce the word of same product, need 2.5-hp or higher power, and the power input that this may need 0.25-hp to control. Demand of this air current when optimizing measure reduces 84scfm, annual power consumption decreases 144, 480kWh, be equivalent to saving $6 every year, 501.
Conclusion
Deal with concrete matters relating to work of the food industry that pack showed his main goal, implement the method with tall cost effectiveness namely, be opposite in order to reduce core production division and bakery reduce airy demand, saved cost in this one process. We will continue to consider to implement new method, in order to decrease to reducing airy demand, improve supply run, in order to achieve more saving.