Pneumatic conveying systems compared with traditional delivery methods
| Comparison Project \ Species |
Pneumatic conveying |
Air tank |
Tube chain conveyor |
Belt
Conveyor |
Chain
Conveyor |
Spiral
Conveyor |
Fighter
Hoist |
Vibration
Conveyor |
| Particle diameter was transported materials/mm |
< 50 |
－ |
< 30 |
No special restrictions |
< 50 |
< 30 |
< 100 |
< 30 |
Materials being transported
Maximum temperature/ ℃ |
300 |
80 |
200 |
Ordinary tape 80
Heat Tape 180 |
300 |
300 |
80 |
80 |
| Tilt angle of pipeline/（O） |
Any |
Down4~10 |
|
0~40 |
0~90 |
0~90 |
90 |
0~90 |
| Maximum transmission capacity/t·h-1 |
50-200 |
300 |
50 |
3000 |
300 |
300 |
600 |
10 |
| Maximum transmission distance/m |
1000 |
200 |
100 |
8000 |
200 |
10 |
50 |
10 |
| Power consumption required |
General |
Small |
Larger |
Small |
big |
Medium |
Small |
big |
| Maximum transmission speed/m·s-1 |
0.10~35 |
30~120 |
1~30/min |
15~180m/min |
10~30 |
20~100r/min |
20~40 |
－ |
| Delivery of materials flying |
No |
No |
No |
may be |
No |
No |
No |
may be |
| Foreign matter and fouling |
No |
No |
yes |
may be |
No |
No |
No |
No |
| Residual materials transportation |
Very small amount of |
Very small amount of |
yes |
no |
yes |
less |
yes |
yes |
| Pipeline configuration flexibility |
Free |
Straight line |
More difficult to |
Straight line |
Straight line |
Straight line |
Straight line |
Straight line |
| Diversion may |
Easy |
may be |
Can not |
may be |
hard |
Can not |
Can not/TD>
| hard |
| Section occupy space |
small |
中 |
large |
large |
large |
Medium |
large |
large |
| Major repair parts |
Elbows, valves |
－ |
Pipes, chains, blades |
Care roll, bearing |
Chains, bearings |
Comprehensive |
Chains, bearings |
Comprehensive |
Pneumatic conveying of the advantages and disadvantages
Delivery from pneumatic conveying mechanism and application in practice show that it has a number of advantages: low-carbon, environmental protection, transportation efficiency, the overall structure more flexible equipment, maintenance management
Convenient management, easy to automate and help the environment. Especially when used for transport within the factory floor, you can transport a combination of process and production process, so that
Help simplify the process equipment. To this end, can greatly improve labor productivity, reduce costs and floor space.
To sum up, pneumatic conveying have the following characteristics:
1) The pipeline can be flexibly arranged, so that a reasonable allocation of plant equipment and technology.
2) to achieve bulk material handling, high efficiency, reduce packaging and handling and transportation costs,
3) the system closed, less dust escape, environmental health conditions are good.
4) less moving parts, easy maintenance, easy to automate.
5) to avoid the material damp, stained, or mixed with other debris, can guarantee the quality of delivery of materials.
6) In the course of transmission can achieve a variety of process operations such as mixing, crushing, grading, drying, cooling, measurement, dust and so on.
7) can be sent by the concentration of a number of points or a number of points scattered sent to remote operation.
8) For the chemical properties of unstable material, the use of inert gas can be transported.
To a certain extent, the comparison with other forms of transport, power consumption may be slightly larger or decrease, due to higher transmission speed, the local pipeline wear and may have been transported
Small amount of broken material. Of course, the deficiencies in the low transmission speed, high mixing ratio transfer case can be significantly improved, in addition, the particle size of materials being transported
Inch are also subject to certain restrictions, in general, when the particle size more than 30mm, adhesion, moisture absorption, the powder difficult than its delivery.
Suction feed type and pressure pneumatic conveyor delivery comparison of advantages and disadvantages
| Transportation in the form |
Advantage |
Shortcoming |
Practical applications |
Suction
feed
type |
1.Easy to get material for demanding applications to take material does not produce dust
2.Applicable from the lower, deep or narrow and by a few points to take materials to a focus on feeding the occasion
3.As the gas supply system, the most in the end, not mixed with oil or water and other materials to be transported
4.As the conveying pipe system pressure lower than atmospheric pressure, so even if the resulting wear and tear and the presence of the gap, the material being transported will not leak outside the Plaza
5.As the delivery system pressure lower than atmospheric pressure, moisture evaporates easily, so much water pressure feed type materials are more easily transported
6.Inlet end of the installation of dust filters can be used to clean gas |
1.Work in general small vacuum 0.08Mpa, so throughput and transmission range can not take large values
2.Should be set up in the air before the good performance of the separation and dust removal equipment
3.As the air suction device used to send the air leading to the expansion of large-scale equipment.
4.Discharge under the separator device easily leak and cause the system not working properly, should be considered a good hermetic rotary air lock valve discharge |
1.From the silo, the ground, take the material in the centrifuge
2.Transport the food industry
3.Chemical industry in the delivery
4.Pharmaceutical delivery
5.Transport of toxic materials
6.Hopper export automatic transmission
7.Take conveying bulk warehouse
8.Conveying to take more
9.Open bags of feed station conveying
10.A variety of upstream discharge port transport equipment |
Low pressure
send
pressure
type |
1.For from a distributed to a few of delivery
2.Because the system is positive, so the components of the system even if there is a gap junction, not the atmosphere or water intrusion
3.As the pressure within the system is, the material easily unloaded from the discharge port
4.Gas temperature during transportation of materials can be dried |
1.Suction feed type the feed more difficult to deal with should be transported and the transport properties of materials selection and design parameters appropriate for the feeding device
2.If a gas source blower, the pressure can not reach very high, so throughput and transmission range can not take large values |
1.Chemical industry
2.Petrochemical industry (especially with nitrogen. Dioxide gas distribution)
3.Chemical or food industry in conveying granular or flake |
High pressure
pressure
send
type |
1.The use of high pressure exhaust gas source equipment, transport conditions, it can still be achieved even if the transmission change
2.In the smaller pipes can be adjustable in the mixing ratio transmission, transport efficiency
3.Because a small amount of air required for delivery, it does not end separator, dust collector structure size can be reduced
4.The existence of places can also be transported back pressure
5.For the residues inside the tubes may be cleaned
6.Side can not be expected to correspond to multiple points
7.Equipment as a whole, mobile more convenient. |
1.Positions are closed pressure vessel type to send, if as a continuous conveyor system should be set in the middle of the Ministry before sending tank storage hopper
2.Powder in the tank sent directly by the pressure transmission, however, the coarse material like the material should be sent to set the upper rotary feed valve can
3.Air quality requirements, can not contain water. |
1.Long-distance, high-capacity transport (aluminum fluoride, fluorescent powder, sodium aluminum fluoride, sand)
2.On pressure vessels for conveying (pellets, powder) |
Bolt
flow
type
pressure
send |
1.Due to the low transmission speed, high concentrations of mixing ratio transmission, less broken material
2.Conveying pipe wear with small
3.Conveying air volume is small, so isolated, small dust removal device
4.As the delivery of high concentrations of mixed, so the smaller diameter transmission
5.Lower energy consumption
6.Side can not be expected to correspond to multiple points
7.Equipment as a whole, mobile more convenient. |
1.Promote the use of the static pressure of air transport, the higher the pressure required
2.In order to save transport air volume, air should be a reasonable selection. However, when transmission conditions are no regulated margin changes
3.Pellets of diameter greater than 5mm, the delivery pressure leakage from the particles in the gap, thus affecting the transmission into a bolt of.
4.Air quality requirements, can not contain water. |
1.Long-distance, high-capacity transmission (PVC, bauxite, clay, calcium carbonate)
2.On pressure vessels for conveying (powder) |
Boiling
Teng
on
line
type |
1.Concentration of general transportation.
2.More flexible piping.
3.Delivery pressure is low. |
1.Speed is relatively higher.
2.Conveying air flow slightly.
3.Easy to wear elbow area. |
1.In short distance transport.
2.Power plants. |
Classification of pneumatic conveying state
According to the state in terms of pneumatic conveying, in the gas-solid flow, the movement of materials with the delivery status changes in wind speed changes. When the material is high wind speed, the material in suspension, was like to be evenly distributed air transportation; with lower transmission speed, the material began to reunion; after part of the material gathered in the pipeline, transportation was a group dynamic pulse; continue to reduce the transmission speed, materials plug-section to form an unstable material bolt, bolt material was then air pressure-driven; further reduce the transmission speed, the unstable material bolt will bolt into a stable material, the air pressure-driven transport.
That the material in the vertical tube was evenly distributed in the material boundaries and horizontal tube conveying the boundaries of flight, is dilute and dense phase boundaries. Therefore, the economic speed line can be seen as the dilute phase and dense phase of the line.
So, summed up the entire pneumatic conveying systems can be divided into the following four categories:
1 dilute phase pneumatic conveying air speed is higher, the material suspended in the vertical tube was evenly distributed, the level of the input compound was flying in the state, large porosity. The delivery of materials depends mainly on the high rate of flow of energy held.
(2) dense-phase pneumatic conveying of materials in the pipeline is no longer uniformly distributed, while the state was intensive, but has not been material to plug the pipeline. Which still rely on air power held by the transmission. State design of these mobile devices to send a high pressure, high vacuum suction delivery and fluidized transport.
3 bolt flow pneumatic conveying such transport is a better pneumatic conveying in the middle distance transportation method. It is man-made materials tied to the air-knife pre-cut to a shorter bolt material, air knife to cut material from the middle bolt, bolt material with hydrostatic drive continuous progress, thus shortening the length of bolt material, reducing the delivery pressure, reducing power consumption, and increased transmission distance, in addition, there will be intensive-like material filled tube continuously formed material column for short distance transportation.
4 pneumatic conveying waste on the ground set of N internal waste inlets automatic garbage collection, the pipes under the ground station through the remote fans have powerful suction and transport garbage to the end of the automatic separation of materials, compaction , filter emissions automatic garbage collection.
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