Theory Of Operation; Fluid (Liquid) Flow Control Path - Brooks Instrument DLI Manual De Instalación Y Funcionamiento

Section 1 Introduction
®
Brooks DLI Vaporizer System

1-7 Theory of Operation

• 2 - 5 micron mean droplet diameter
• Removable cleanable and replaceable
• Capable of supersonic operation
• Low inventory volume liquid feed
• Customer replaceable gas Inlet orifice
Figure 1-3 Fine Droplet Atomizer Detail

1-7-1 Fluid (Liquid) Flow Control Path

1-6
Liquid and gas enter the atomizer where the liquid is atomized, (broken)
into micron size droplets, which enter into the vaporizer to be "gently" and
completely turned into high-quality vapor when coming into contact with
heated carrier gas. Very little liquid ever touches a hot metal surface as
the hot carrier gas does most of the work of vaporization. Using this
principle the liquid is not over-heated and disassociation or decomposition
is eliminated and/or greatly reduced. The gas pressure into the MFC must
be 2.2 X the vaporizer outlet pressure + 10 psig.
Liquid is delivered under a defined pressure range to either a user-
supplied liquid flow controller or a Brooks Instrument Quantim Coriolis
mass flow controller. The Quantim controller will provide flow control at a
selectable rate based on the process conditions provided ensuring the
specified rate of vaporization. The liquid delivery system must provide
smooth and pulse free liquid delivery at a relatively constant pressure. If a
pump is used, it must have either an internal relief by-pass or be used with
a back pressure regulator to allow a constant delivery pressure to the
liquid flow controller. If a pressured system of gas over liquid is used it is
recommend that the push gas be helium. We recommend helium because
of the Henry's Law Constant. Gas over liquid delivery systems work well;
however the push gas will dissolve into the process fluids and when
released during metering can cause control problems when gas bubbles
contaminate the controller's valve. Using helium will decrease these
bubbles. Brooks can also recommend a degasser if this type of system is
to be used and dissolved gas becomes an issue.
Installation and Operation Manual
X-VAP-DLI-Standard-eng
Part Number: 541B203AAG
May, 2016