Technical_reference.pdf - 第95页
Technical Service Manual 95 Revision Dat e: August 2004 INTEGR ATED EX HAUST ST ACK FILT ER The Integrated Ex haust Stack Filter is : ! Standard, (installed on all ovens ) ) An option, (NOT installed on all ovens ) PURPO…
Technical Service Manual 94 Revision Date: August 2004
CONTROLLED EXHAUST SYSTEM (AIR ONLY OR OVENS EQUIPPED WITH AIR SWITCHING)
CONTROLLED EXHAUST SYSTEM (CES) (Air Mode)
This exhaust subsystem extracts heated gas directly from the oven chamber between the last heating zone and the first
cooling zone, minimizing the amount of heat and flux entering the cooling section of the oven. The result is product
cooling improvement and maintenance reduction in the Air Mode. It generates a controllable, positive exhaust flow and
does not depend on the facility exhaust for its operation.
A small amount of compressed air flows through a Venturi (mounted inside the Controlled Exhaust Tube) and creates a
negative pressure at the CES slot in the oven chamber. This draws gas out of the Oven Chamber. The oven chamber
exhaust flow rate is controlled by the amount of air supplied to the oven.
The cooling effect of the incoming compressed air causes an accumulation of flux condensate in the exhaust nozzle.
The nozzle requires periodic cleaning
.
INDIVIDUAL CELL INLETS
The “makeup” gas to replace the exhaust flow is supplied by the gas intakes of the individual Zones (cells). Additional
“makeup” enters the oven chambers at the “onload” and “offload” openings.
CES system is not used with N2 to minimize nitrogen consumption.
Technical Service Manual 95 Revision Date: August 2004
INTEGRATED EXHAUST STACK FILTER
The Integrated Exhaust Stack Filter is:
! Standard, (installed on all ovens) ) An option, (NOT installed on all ovens)
PURPOSE:
To capture and dispose of the byproducts of SMT reflow by condensing and filtering the oven exhaust.
APPLICATION
The Integrated Exhaust Stack Filter option is a simple filtering method for capturing and disposing of many of the by-
products of the Surface Mount Reflow Process. The Integrated Exhaust Stack filter consists of two filters in metal
enclosure. The enclosure has an inlet and a connection point for a factory exhaust duct. There is an access door for
changing the disposable filters.
The introduction ambient room air powered by the facility exhaust accomplishes condensation. The hot gas exhaust
stream from the FFC system is routed to the intake tube of the filter enclosure where it is mixed with several streams of
ambient air. The cooling effect of the room air streams causes flux and other outgassed contaminants to condense in
the exhaust stream as it enters the box, but prior to passing through the filter. Contaminants are trapped in the filter, and
the cleaned gas continues out the exhaust duct.
BENEFITS
• Flux and other out-gassed contaminants are captured in an easily changed, disposable filter.
• Provides increased protection of the facility exhaust system from contaminants.
• Totally within the overall footprint of the Reflow Oven.
• Inexpensive locally available filter
MAINTENANCE:
Filter change interval is approximately every 2 weeks, but is throughput and paste dependent.
Filter change requires 1 minute or less
Filter Enclosure cleaning interval is approximately every two months, but is throughput and paste dependent.
Note: The contaminants caught by the filters are hazardous waste. Proper disposal techniques should be
followed. The filter contaminants are paste and product dependent. Refer to the paste specification for more
information.
Wear latex gloves, eye protection and breathing protection when changing filter.
Filters:
1 – 1x10x20 Polyester Smith 5003, part number #1248601
1 – 1x10x20 SEP Pleated Smith Special, part number #1248701
Technical Service Manual 96 Revision Date: August 2004
FLUX EVACUATION SYSTEM
The Flux Evacuation System is:
! Standard, (installed on all ovens) ) An option, (NOT installed on all ovens)
NOTE: The Flux Evacuation System is STANDARD on all N
2
Ovens
PURPOSE
The Vitronics-Soltec Flux Evacuation System is designed to reduce the flow of flux fumes into the cool zones of the
tunnel, resulting in longer maintenance intervals.
APPLICATION
The Flux Evacuation System is the standard gas management system on Vitronics-Soltec ovens equipped with the
Nitrogen option. This configuration is best suited for applications running nearly exclusively nitrogen recipes. The oven is
setup to minimize tunnel maintenance, optimize nitrogen performance, minimize O2 levels, and minimize N2
consumption.
BENEFITS
The XPM
2
series Flux Evacuation System is designed to inhibit the flow of hot flux fumes into the cool zones of the tunnel
(where they can cause maintenance problems), while still optimizing nitrogen performance. This control of gas flow
insures a cleaner cooling zone with maintenance intervals significantly increased. Although widely varying process
parameters will cause individual maintenance intervals to differ, an average expectation should be up to 8 times less
frequent.
The Flux Evacuation System has secondary benefits. In all applications, there should be a noticeable reduction in cooling
zone temperatures. Actual reductions will, of course, be dependent on individual process parameters. The Flux
Evacuation System will not adversely effect nitrogen consumption or 02-PPM levels, as specified by Vitronics Soltec for
XPM
2
series ovens.
It is important to be aware that fan speed settings lower than 2500 RPM will disable the Flux Evacuation System
and will increase flux contamination in the oven
MAINTENANCE
The Flux Evacuation System is virtually maintenance free if operating properly. To ensure this, it is recommended that the
inlet tube from the Flux Flow Control manifold into zone 2 be checked periodically (every three months) for flux residue. If
a flux accumulation is noticed, the flux evacuation manifold may need to be cleaned.