Gas delivery equipment

Gas handling equipment for gas compression and transportation equipment in general. In the wide range of applications in various industrial sectors. There are the following

three purposes: (1) transporting the gas from the point A to the point B, the gas does not change the initial and final pressure (blower); (2) to improve the gas pressure (with

Compressor); (3) is used to reduce the gas (or vapor) pressure (vacuum pump). Generally based on the pressure generated into four categories: (1) a blower gauge pressure not

greater than 0.015 MPa (0.15 atm or 1500 mm water column); (2) blower, pressure gauge .015 ~ 0.2 trillion

Pa (0.15 to 2 atm); (3) the compressor, the pressure is the gauge pressure 0.2 MPa (2 atmospheres) or more; (4) a vacuum pump, the pressure below atmospheric pressure.gravity conveyor
Centrifugal blower
Structural characteristics of centrifugal blower: centrifugal blower and centrifugal resemble the shape, internal structure, there are many similarities. For example, a

centrifugal blower volute passage is also circular; but the shell diameter and thickness of the relatively large; impeller blades larger number; high speed

; Are equipped with peripheral impeller Introduction. Single-stage exit at 30kPa gauge more or less; multi-level up to 0. 3MPa. Selection centrifugal blower centrifugal fan with

the same method.
Centrifugal compressor
Structure
Rotor: spindle, multi-stage impeller, shaft and balanced components
Stator: cylinders and partitions
Works
At all levels of the gas in the axial center of the impeller, the impeller is rotated by acting, by the centrifugal force, leaves the impeller at high speed, into the diffuser.

Gas inside the diffuser spin down, pressurization. The diffuser deceleration, pressurized gas into the corners, so that the flow reversed 180 degrees backward

Into the reflux, reflux condenser and then through the impeller into the next one. Obviously, corners and reflux is a communication before and after an impeller impeller

channel. So, the gas is increased in a number of times the impeller, can be very high pressure to leave.
Gas transportation equipment - Industrial Applications
① gas transportation: In order to overcome the resistance of the pipeline, the need to improve the gas pressure purely for the purpose of conveying the gas pressure, pressure

is generally not high. However, a large amount of gas delivery is often transported, often require considerable power.
② generate high pressure gas: the chemical industry requires a number of chemical reactions under high pressure, such as ammonia synthesis, the bulk polymerization of ethylene; automated sorting machine

process also requires a number of separation under high pressure, such as gas liquefaction and separation. These high-pressure gas for the process of the delivery of the

relevant

Outlet pressure equipment presents considerable demands.
③ production of vacuum: a considerable number of unit operations is carried out below atmospheric pressure in the case, then you need to pump the gas out of the device to

generate a vacuum.
Gas transportation equipment - general characteristics
① Power consumption: for a certain mass flow rate, density of the gas, the volume flow rate greatly. Therefore, the flow rate of the gas feed pipe is much greater than the

liquid, the former Economic flow (15 ~ 25m / s) around the latter (1 ~ 3m / s) of 10 times. Thus, in order to convey with their economic flow

Sample mass flow rate through the same pipe length resistance loss of the gas after the liquid is about 10 times. Thus the power consumption of gas delivery equipment are often

large.
② volume of gas delivery devices are generally massive, high mechanical pressure on exports even more.
③ As the compressibility of the gas, the internal gas pressure in the conveying machine while changing the volume and temperature will also change. These changes the structure

of the gas delivery device, the shape has a great influence. Therefore, the gas delivery device needs to be classified according to the outlet pressure

.
Gas transportation equipment - equipment classification
Gas delivery device can also be divided according to the principle of centrifugal, rotary, reciprocating and jet so on. Press the outlet pressure (final pressure) and

compression ratio divided into the following categories:
① fan: final pressure (gauge pressure, the same below) is not greater than 15kPa (about 1500mmH2O), compression ratio of 1 to 1.15
② Blower: final pressure 15 ~ 300kPa, the compression ratio is less than 4.
③ Compressor: final pressure in more than 300kPa, the compression ratio is greater than 4.
④ pump: negative pressure within the apparatus, the final pressure is atmospheric pressure, the compression ratio determined by the degree of vacuum.
Gas transportation equipment - represents the device
Centrifugal fan
Works
(1) In order to meet the requirements of large conveying air, ventilator impeller diameter is generally relatively large.
(2) the number of impeller blades more.
(3) leaves have a straight, curved front, rear bend. The main requirement is that the ventilation fan capacity, not in pursuit of high efficiency, with the former becoming

blades help to improve the pressure head, reducing the impeller diameter.
(4) the gradual expansion chassis and export channel of circular cross-section which is often not rectangular.
Performance Parameters
(1) Air flow: state dollars at the entrance of the exhaust volume per unit time. m3 / s, m3 / h
(2) Total pressure: when the fan unit volume of gas through the energy gained, J/m3, Pa
Equipment Selection
(1) according to the gas type and pressure range, determine the type of fan
(2) determine the required air flow and full pressure. Air volume production tasks according to set; whole pressure by Bernoulli's equation to find, but according to standard

conditions corrected that, according to the state at the entrance of the air flow meter and the corrected total pressure in the product family table to find a suitable model.
Review
(1) When the compressibility of the gas can be neglected, the gas conveying path calculation similar to the calculation of the liquid transfer line, the difference is that the

fan characteristic curve itself and the pipe and the air density. So when the transport is not room temperature, atmospheric air, pipeline characteristic curve should be pre-

Conversion.
(2) with the same pipeline transporting gas, the gas temperature decreases, the density increases, the mass flow rate may be increased significantly.