How to understand vacuum unit and vacuum system

Vacuum unit is composed of vacuum pump, various pipelines, integrated sensors, vacuum meters, measuring devices, electrical control systems and a series of supporting vacuum auxiliary equipment. It is named according to the type of main pump. The vacuum application range is divided into low vacuum unit, medium vacuum pump unit, high vacuum unit and ultra-high vacuum unit.
1) The low vacuum unit generally adopts the direct exhaust type vacuum pump, such as the positive displacement reciprocating pump, water ring pump, oil seal mechanical pump, screw vacuum pump, wet roots pump, jet pump, molecular sieve adsorption pump, etc. the low vacuum unit has high working pressure and large exhaust volume, and is mainly used for vacuum transmission, vacuum impregnation, vacuum filtration, vacuum degassing of vacuum dryer, etc.
2) Medium vacuum unit is mainly composed of Roots vacuum pump + oil seal mechanical pump, roots vacuum + water ring vacuum pump and double roots vacuum pump. With the wide use of screw oil-free vacuum pump, oil-free vacuum units such as roots vacuum pump + screw vacuum pump are gradually increasing, which are suitable for various vacuum systems requiring large pumping speed and obtaining medium vacuum, such as coating machine, vacuum smelting, vacuum heat treatment, medicine and chemical industry, electric welding and other industries.
3) The high vacuum unit works in the molecular flow state, with the working pressure range of 10-2 ~ 10-6pa, small displacement and large pumping speed. The main pump is mainly composed of diffusion pump, molecular pump and titanium sublimation pump. If the low-temperature condensate pump can not work directly in the atmosphere, it needs to be equipped with front pump, pre pumping pump, etc., and maintenance pump and air tank are also equipped to prevent the air pressure fluctuation.
4) The pressure range of ultra-high vacuum unit is 10-6 ~ 10-10pa, the limit vacuum of main pump is 10-7 ~ 10-8pa or above, and the corresponding pumping speed shall be ensured in the pressure range. The material of system composition shall be able to withstand high temperature baking of 200 ~ 450 ℃ and ensure low air leakage rate and air outlet rate.
The vacuum unit system is a real-time monitoring and automatic adjustment of the key parameters of the vacuum unit, such as "vacuum degree (negative pressure or pressurization)", "flow", etc., such as the completion of "vacuum pressure maintaining", "automatic timing shutdown, start", timing and quantitative "vacuum suction filtration", etc., which is called the vacuum system.
As a means to realize intelligent automation, vacuum unit and system have been widely used in many aspects, such as electronics, semiconductor component assembly, automobile assembly, automatic handling machinery, light industry machinery, medical machinery, printing machinery, plastic product machinery, packaging machinery, forging machinery, robot, etc.

CL 1001 vacuum pump
Liquid Ring Vacuum Pump Transferring Air and Gas
industrial Air compressor in pressure sensor
Air compressor for gas transmission

How should vacuum pump leak?

For you to answer the vacuum pump leakage how to do.
1 vacuum pump seal is not tight
Tighten all the connecting bolts, tighten the packing gland, tightly wrap the pipes and connect the meters to other components. Or replace the gasket and packing. For air leakage, oil and lime can also be used as temporary remedial measures.
2 bearing deflection
This phenomenon causes the impeller to be tilted in the pump body. For a single acting pump, its axial clearance is uneven. When the blade is rotating, some part will be rubbed against the side cover, and the side cover and impeller end face will be scratching, so that the axial clearance will increase. The compressed cavity gas is leaked into the suction chamber through the enlarged gap, reducing the vacuum or exhaust pressure. At this time, the bearing should be removed for repair, and then installed correctly.
3 the front and rear side covers are not concentric
It is possible that the front and rear side covers of the vacuum pump have larger axial degrees and the consequence is the same as that of the bearing.
4 vacuum pump heating
When the vacuum pump temperature rises, the saturated vapor pressure will also increase, what's more, it will reduce the vacuum degree, but this has no effect on the exhaust pressure.
If we use vacuum pumps, we can analyze the above situation and see what is wrong with us.

high vacuum pumps manufacturers
oil-free spiral vacuum pump
Air compressor for light industry
Air compressor for rubber and plastic products

The force of the vortex pump

A pump that delivers liquid by the action of a rotating impeller on the liquid, delivering kinetic energy to the liquid with an impulse in the direction of movement. The impeller is a first-order thick disk with many small radial blades on both sides of its outer edge. On the pump shell corresponding to the blade, there is an annular flow path with first class section. The entire flow path is divided into two sides by a baffle tongue, which are connected with the suction and exhaust pipelines of the pump respectively. When the liquid in the pump rotates with the impeller, a certain centrifugal force is generated, which is thrown outward into the annular runner in the pump shell, and forced to flow back under the limitation of the runner shape, and re-enter the other blade channel behind from the blade root. Therefore, the trace line of liquid movement between the blade and the annular runner is a kind of forward spiral line for the stationary pump shell. And for the rotating impeller is a kind of receding spiral.
The vortex pump is named for the vortex motion of the liquid. The liquid can enter between the blades many times in a row to obtain energy until it is finally discharged through the outlet. The vortex pump works somewhat like a multistage centrifugal pump, but the vortex pump does not have an energy conversion device like a centrifugal pump volute or guide vane. The vortex pump mainly transfers energy to the liquid by doing continuous work for many times, so it can produce high pressure. In the process of energy transfer, due to many times of liquid impact, the energy loss is large, the efficiency of the pump is low, generally 20 ~ 50%.
Vortex pump is only applicable to the requirements of small flow (1 ~ 40 meters 3 / hour), high head (up to 250 meters), such as fire pump, aircraft refueling vehicle gasoline pump, small boiler feed water pump. Vortex pumps can transport highly volatile and gaseous liquids, but should not be used to transport viscous liquids with viscosity greater than 7 pa · s and impure liquids containing solid particles. The vortex pump is characterized by small flow rate, high head and self-priming function, which can be used to transport solids with viscosity less than 5 ° E and liquids similar to water. Such as gasoline, kerosene, alcohol, etc., can be used for small steam boiler water, chemical, pharmaceutical, high-rise water supply and other purposes. Over - flow parts and stainless steel and other materials can be used to transport acid, alkali corrosive liquid. The temperature of conveying medium is -20~+80 degrees. From the structure can be divided into; Single, double and multistage; Direct form and so on.

Liquid ring vacuum pump vendor
Industrial vacuum pumps for static drying
Air compressor in glass industry
Air compressor in construction industry

Why the sealing effect of dry vacuum pump decreases

When we use dry vacuum pump, sometimes the sealing effect will decline. How can we deal with this situation? To solve the problem, we first need to understand the reasons for this situation. Let's take a look at this article.
1. The bio slime of the dry vacuum pump fills the gap of the tension spring day by day, which affects the compensation effect of the tension spring in the sealing, also intensifies the wear of the dynamic and static ring conflict pairs, and affects the sealing effect of the auxiliary sealing ring. The presentation of this situation requires us to carry out the vacuum pump cleaning regularly.
2. It is inevitable that the working liquid (containing calcium ion) of dry vacuum pump and the calcium carbonate generated by the reaction of carbon dioxide in the compressed medium will damage the mechanical seal, but we can carry out regular protection to minimize this problem.
3. The corrosion of the metal parts of the whole mechanical seal body caused by the induction effect of the oxygen bacteria, biological slime, calcium ion and the related chemicals in the working fluid seriously affects the sealing effect and application time of the mechanical seal.
4. Although most of the dust in the upstream adsorbent is removed through selection and other steps during loading, with the increase of operation time and the flushing of medium air flow, new dust will be generated more or less, and the dust in the dry vacuum pump may enter the sealing position of the mechanical seal at any time, causing damage to it, so we need to carry out regular maintenance and cleaning.
5. The slow corrosion of the added relevant chemicals to the seal ring of the dry vacuum pump will cause seal failure. In fact, prior to the selection of chemicals for use, the experienced manufacturers will select chemicals with less or no corrosiveness.

Cheap liquid ring vacuum pump
Air Cool Rotational Dry Screw Vacuum Pump
Air compressor in ceramic industry
Air compressor in textile industry

How to calculate the vacuum degree of vacuum pump

The commonly used vacuum units are PA, kPa, MPa, atmospheric pressure, kg (kgf / cm2), mmHg, mbar, bar, psi, etc.
Before selecting the type, we must make clear several basic concepts about vacuum pump.
Vacuum degree: the thinness degree of gas in vacuum state, usually expressed as vacuum degree. The value read from the vacuum gauge is called vacuum degree. The value of vacuum degree indicates that the actual value of the system pressure is lower than the atmospheric pressure. The value expressed from the table is also called the table pressure, which is also called the limit relative pressure in the industry, that is: vacuum degree = atmospheric pressure - pressure (the atmospheric pressure is generally 101325pa, the limit pressure of water ring vacuum pump is 3300pa; the limit pressure of rotary vane vacuum pump is about 10Pa)
Limit relative pressure: the relative pressure is how much lower the measured internal pressure is than "atmospheric pressure". It shows that the actual value of system pressure is lower than that of atmospheric pressure. Because the air inside the container is pumped, the pressure inside is always lower than the pressure outside the container. Therefore, when expressed in terms of relative pressure or gauge pressure, the value must be preceded by a minus sign, indicating that the internal pressure of the container is lower than the external pressure.
Limit pressure: the pressure is how much higher the measured internal pressure is than the theoretical vacuum (the theoretical vacuum pressure value is 0Pa). The object of comparison is the vacuum pressure value of theoretical state. Due to the limitation of technology, we can not pump the internal pressure to the value of 0 PA, so the vacuum value of vacuum pump is higher than the theoretical vacuum value. So when you use vacuum, there is no minus sign in front of the value.
Pumping capacity: pumping capacity is a measure of the pumping speed of a vacuum pump. General units are L / s and m3 / h. It is a parameter to make up the air leakage rate. It's not hard to understand why it's easy for a vacuum pump with a large volume of air to pump the vacuum degree we need, but a vacuum pump with a small volume of air can't even pump the vacuum degree we want? Because it's impossible for a pipeline or a container to keep air tight all the time, and a large volume of air can make up for the factors that lead to the decrease of the vacuum degree caused by the air leak, so, a large volume of air It is easy to get the ideal vacuum value. It is suggested that, in the case of calculating the theoretical pumping capacity, we try to choose a vacuum pump with a higher pumping capacity. The specific calculation formula of air extraction will be introduced below.
How to calculate the vacuum degree of vacuum pump:
After knowing the basic parameters of vacuum degree, pressure and relative pressure, we can enter the formal selection of vacuum pump.
1. Vacuum degree required by the process
The working pressure of vacuum pump should meet the requirements of process working pressure, and the vacuum degree should be higher than that of vacuum equipment by half to one order of magnitude. (for example, the vacuum degree of 100 Pa (pressure) is required for the vacuum process, and the vacuum degree of the selected vacuum pump shall be at least 50 pa-10 PA). Generally, if the pressure is required to be higher than 3300pa, the water ring vacuum pump is preferred as the vacuum device. If the pressure is required to be lower than 3300pa, the water ring vacuum pump cannot be selected, and the rotary vane vacuum pump or higher vacuum level vacuum pump is selected as the vacuum obtaining device.
2. Air extraction required by the process (extraction rate:
Vacuum pump requires air extraction rate (that is, the ability of vacuum pump to discharge gas, liquid and solid under its working pressure), general unit:
m3/h，L/S,m3/min。 The specific calculation method can refer to the following formula for self calculation and selection. Of course, the selection of vacuum pump is a comprehensive
The integration process involves relevant experience and other factors.
S=(V/t)×ln(P1/P2)
Where: S is the pumping rate of vacuum pump (L/s)
V is the volume of vacuum chamber (L)
T time required to reach the required vacuum (s)
P1 is the initial pressure (PA)
P2 is the required pressure (PA)
3. Determine the composition of the object to be extracted
*. whether the object to be pumped is gas, liquid or particle. If the gas to be pumped contains water vapor or a small amount of particles and dust and other impurities, the rotary vane vacuum pump should be carefully selected. If the vacuum degree is required to be high, a filter device should be added to filter before using the rotary vane vacuum pump as a vacuum obtaining equipment.
Second, it is necessary to know whether the object is corroded (acid or alkaline, what is the pH value?), if it contains acid-base corrosion or organic corrosion and other factors
The gas should be filtered or neutralized to select the rotary vane vacuum pump.
Third, is the object to be pumped contaminated with rubber or oil? For different media to be pumped, corresponding vacuum equipment should be selected. If there is a large amount of steam, particles and corrosive gas in the gas, it should be considered to install corresponding auxiliary equipment on the air inlet pipeline of the pump, such as condenser, filter, etc. (specific technical engineers).
Fourth, whether the noise, vibration and beauty of the vacuum pump affect the factory.
Fifth, as the saying goes, cheap is not good. When purchasing vacuum pump and vacuum equipment, priority should also be given to the quality of equipment, transportation, maintenance and repair costs, etc.

Stainless steel efficiency dry screw vacuum pump
Oil Less design Dry Screw Vacuum Pump
Air compressors for aerospace industry
How much is price of air compressors?