Simple Vacuum Generator
Minimum operational differential pressure of Check Valve (CV, CVP series) is less than 0.001Mpa(10kPa) and it is possible to use for negative pressure.
But Check Valve tolerate leak so that it should not be used for the application with which complete air tightness is required.
Using Check Valve is not suitable for retaining for long period of time. Short period of time is the premise to install Check Valve. Also be aware of Minimum checking differential pressure.
Fluid medium is limited to air in principle.
But there are some cases which suck oil and other liquid by supply air flow in case of ring blower type vacuum generator (VRL). Exhaust air is mixed with oil and becomes nebulized at exhaust port.
"Tube exhaust type" which does not exhaust air and installing a silencer are recommended.
However, be aware when smooth plumbing without resistance is not carried out such as with too long tube to exhaust, it becomes resistance to exhaust and impair the vacuum degree.
The vacuum characteristic of each type is different.
【H type】
High-vacuum type (Rated supply pressure* : 0.5Mpa)
【L type】
Large-flow type (Rated supply pressure* : 0.5Mpa)
【E type】
High-vacuum at low air pressure supply type (Rated supply pressure* : 0.35Mpa)
For high-vacuum, H type, to provide large-suction flow, L type, and to save supply air, E type is recommended respectively. (Details of final vacuum and suction flow are determined by choice of the nozzle diameter.
*)
What is rated supply pressure?
Rated supply pressure guarantees product performance under the designated conditions and is also the supply pressure, which a vacuum generator supplies, of basis to design and use. The ultimate vacuum reaches to the max. around the rated supply pressure value.
The following graph shows the case of H type. The ultimate vacuum is the highest near 0.5Mpa. (ex. Simple vacuum generator VHH07 (Nozzle dia. 07: ø0.7mm)
When the product performance is reduced, the followings can be the causes.
Please check the product in terms of these points.
1) Check the supply air
Please check if the supply air flow volume and the air pressure are sufficient.
2) Check the nozzle clogging
When foreign substances are clogged in the nozzle, do flushing to clean it.
3)Clogging of the vacuum filter on sucking side or the silencer on the exhaust side.
When a filter is clogged, replace it with new one.
Rated supply pressure of Vacuum Generator is designated according to the vacuum characteristics (H, L and E type) respectively.
This rated supply pressure is required air pressure to start operating Vacuum Generator. When the supply air pressure is under the rated supply pressure, abnormal sound may be caused by some particular supply pressure.
During abnormal sound is being generated, the vacuum characteristics may become unstable and cause troubles such as influencing pressure detection by a sensor. Reset the product to keep the supply pressure satisfying the rated supply pressure in that case. ( Product spec. is the value in operation of Vacuum Generator.)
There are two ways of measuring pressure, absolute pressure and gauge pressure.
Absolute pressure
Absolute pressure is zero-referenced against a perfect vacuum.
It is commonly used to measure flow rate.
When indicated, "abs" is inserted following the unit, for example 10 kPa abs.
Gauge pressure
Gauge pressure is zero-referenced against ambient air pressure.
It indicate how much pressure per １cm2 is against the ambient air pressure. It is commonly used for indication of manometer. When the pressure is over the ambient air pressure, it is called "positive pressure" and when it is under the ambient air pressure, it is called "negative pressure."
Search by keyword
If your problem is not solved, please contact us from the following link.
You will be contacted by a representative at a later date.
If you are in a hurry or would like to contact our sales office directly by phone, please see the list of sales offices.