Exhaust heads, also commonly referred to as exhaust silencers, are a
special type of centrifugal separator designed to be installed at the
end of a vent pipe. The most common application for exhaust heads
are for venting steam from a boiler blowdown tank, although there are some industrial processes that exhaust
air containing entrained droplets which are also applicable to this type
of centrifugal separator.
The four most common reasons for using
an exhaust head for steam venting are:
- Aesthetics, reducing
the opacity of discharged steam
- Environmental, reduce carry-over of
water vapor and any contaminants it might contain to the surrounding
area (such as oil and water treatment chemicals)
- Economics, reclaim and recycle boiler treatment water/chemicals
- Reduction of condensation on
Exhaust heads for non-steam applications might include venting of
reactors and mixing vessels to reduce carryout of product and additives.
primary difference between an exhaust head and centrifugal separator is
that exhaust heads are NOT a pressure vessel. Since an exhaust
head is attached to the end of a pipe with one side always open to
atmospheric pressure, its' "design pressure" is "atmospheric".
This is frequently misunderstood because although it is still a fully welded
product with a connection corresponding to the pressure class of the pipe
it is installed, the exhaust head itself (when properly sized) will not
experience more than atmospheric pressure.
It is commonplace for
exhaust heads to be referred to as "silencers" and although there is a
muffling effect with regards to the exhaust sound, this noise reduction
is a byproduct of the indirect exit path and not a design factor;
exhaust heads are not designed to reduce the vent sound, rather they are
designed to reduce droplet carry-out by removing 99% of entrained
droplets larger than 10 microns.
We offer exhaust heads made of cast
iron, carbon steel and stainless steel (304 or 316). Refer to the
sizing chart below which is an indication of the internal element size
required. The element size and inlet connection size is usually
the same, although we can reduce the connection size to match your
existing vent pipe size as needed.
|2 - 2½"