Datasheet

 Vacuum Ejector Selection and Handling Precautions
• If the vacuum ejector makes an intermittent noise (abnormal noise) from exhaust at a certain supply pressure, the vacuum
pressure will not be stable. It will not be any problem if the vacuum ejector is used under this condition. However, if the noise
is disturbing or might affect the operation of the vacuum pressure switch, lower or raise supply pressure a little at a time, and
use in an air pressure range that does not produce the intermittent noise.
 Supply Pressure of Vacuum Ejector
• Use the vacuum ejector at the standard supply pressure.
The maximum vacuum pressure and suction flow rate can be obtained when the vacuum ejector is used at the standard
supply pressure, and as a result, adsorption response time also improves. From the viewpoint of energy-saving, it is the most
effective to use the ejector at the standard supply pressure. Since using it at the excessive supply pressure causes a decline
in the ejector performance, do not use it at a supply pressure exceeding the standard supply.
There are 2 types of ejector flow-rate characteristics: the high vacuum
type (S type) and the high flow type (L type).
During the selection, pay particular attention to the vacuum pressure
when adsorbing workpieces that leak.
If a considerable amount of leakage
occurs between the workpiece and
the pad, resulting in incomplete
adsorption, or to shorten the
adsorption and transfer time, select
an ejector nozzle with a larger
diameter from the ZH, ZM, ZR, or ZL
series.
If there are a large number of
ejectors that are linked on a
manifold and operate
simultaneously, use the
built-in silencer type or the
port exhaust type.
If there are a large number of
ejectors that are linked on a
manifold, which exhaust
collectively, install a silencer at
both ends. If the exhaust must be
discharged outdoors through
piping, make sure that the
diameter of the piping is large
enough that its back pressure will
not affect the operation of the
ejectors.
The vacuum pressure varies in accordance with the leakage volumes
indicated in the above diagrams.
If the leakage volume is 30 L/min (ANR), the vacuum pressure of the S
type is –20 kPa q w e, and for the L type it is –33 kPa q' w'
e'. If the leakage volume is 5 L/min (ANR), the vacuum pressure of
the S type is –80 kPa r t y, and for the L type it is –47 kPa r'
t' y'. Thus, if the leakage volume is 30 L/min (ANR) the L type
can attain a higher vacuum pressure, and if the leakage volume is 5
L/min (ANR), the S type can attain a higher vacuum pressure.
Thus, during the selection process, make sure to take the flow-rate
characteristics of the high vacuum type (S type) and the high flow type
(L type) into consideration in order to select the type that is optimal for
your application.
High Vacuum Type
Flow-rate Characteristics/
ZH13S
High Flow Type
Flow-rate Characteristics/
ZH13L
Ejector Selection Ejector Nozzle Diameter Selection
Manifold Use
Individual exhaust Centralized exhaust
Vacuum pressure (kPa)
Vacuum pressure (kPa)
Suction flow rate (L/min (ANR)) Suction flow rate (L/min (ANR))
Leakage
Vacuum
pressure
Model Selection
Front matter 21