BNP
®
6012 and 7212 SUCTION BLAST CABINETS
Page 5
© 2019 CLEMCO INDUSTRIES CORP.
www.clemcoindustries.com
Manual No. 27723, Rev. B 04/19
standard 5/32" orifice air jet with 5/16" nozzle and average
conditions, with variables such as blast pressure,
media/air mixture, visibility inside the cabinet, humidity,
and reclaimer cleaning rate.
Several variables affecting the reclaimer cleaning rate
include reclaimer size (cfm), contamination of parts
being blasted, media friability, damper setting (static
pressure), and dust-collector filter loading (differential
pressure across the dust filters).
As a rule, larger orifice air jets and nozzles deliver more
media, requiring higher performance from the reclaimer.
When using larger nozzles, the maximum mesh size of
media will be smaller than normally recommended.
Using media finer than those recommended may
decrease visibility and, at some point, carryover to the
dust collector. Media coarser than those recommended
may be too dense for the reclaimer to recover from the
cabinet hopper.
1.9.2 Steel
When the recovery hose diameter is
suitably sized (usually reduced one size from standard
as shown in Figure 3) steel may be used with 1200 cfm
and 1800 cfm reclaimers. When using steel media,
conveying hose should have a smooth durable lining,
and rubber curtains should be used to protect the
cabinet walls from peening and rapid wear. Cabinets
configured for steel media use can be ordered from the
factory with appropriately sized conveying hose and
curtains installed. This special requirement must be
specified at the time of purchase. They may also be field
installed at a later date. NOTE: Steel grit or shot is too
heavy to use with cabinets equipped 900 cfm reclaimers.
1.9.3 Sand and slag:
Sand should NEVER be used
for abrasive blasting because of the respiratory hazards
associated with media containing free silica. Slags are
not recommended because they rapidly break down
and, making them unsuitable for cabinet applications.
1.9.4 Silicon carbide, aluminum oxide, and garnet:
These are the most aggressive of the commonly used
media.
Aggressive media may be used, but the service life
of any components exposed to the media will be reduced.
To avoid unscheduled downtime and maximize cabinet
life, periodically inspect the reclaimer wear plate, blast
hose, and nozzle for wear and replace parts as needed.
When using aggressive media only occasionally, install
an optional aluminum oxide kit, which includes rubber
curtains for the cabinet interior and a boron carbide-lined
nozzle. When using aggressive media on a regular
basis, install the aluminum oxide kit and a fully rubber-
lined reclaimer. Rubber-lined reclaimers are available as
factory-installed items, or field-installed liners can be
installed later if the reclaimer has a removable top and it
is designed to accept liners. Nozzles lined with boron
carbide extend nozzle wear life. Refer to
BNP Gun and
Feed Assembly
in Section 9.3.
1.9.5 Glass bead:
Most beads are treated to ensure
free-flow operation, even in environments of moderately
high humidity. Glass beads subjected to excessive
moisture may be reused only after thoroughly drying and
breaking up of any clumps.
1.9.6 Lightweight and fine-mesh media:
When
using lightweight (such as agricultural) media or fine
mesh (180-mesh and finer) media, the reclaimer inlet
baffle may need to be removed to retain media and avoid
carryover. On reclaimer models with bolt-on removable
tops, baffle removal and replacement is easily
accomplished, as explained in Section 7.10. Reclaimers
with welded-on tops require grinding to remove the
baffle, and
once it is removed it cannot be replaced.
This guideline to media selection is based on standard 5/16
orifice nozzle (5/32
air jet) and average conditions,
(air pressure, media/air mixture, visibility, contamination of parts being cleaned, humidity, media breakdown,
reclaimer cleaning rate, etc.) As a rule, larger nozzles deliver more media, requiring higher performance from the
reclaimer. Larger nozzles decrease the maximum mesh size of media from those recommended. Media that is finer
than those recommended may decrease visibility, and, at some point, carryover to the dust collector. Media coarser
than those recommended may be too dense to recover from the cabinet hopper.
MEDIA TYPE
RECLAIMER SIZE
STEEL GRIT
STEEL SHOT
PLASTIC
GLASS BEAD
ALUM. OXIDE
900 cfm with 6
inlet
Do not use
Do not use
N/A See 1.8.7
No. 6 to No. 12 46 to 180-Mesh
1200 cfm with 6
inlet
40 to 120
S230 to S170
Do not use
No. 4 to No. 8
16 to 60-Mesh
1200 cfm with 7
inlet
Do not use
Do not use
N/A See 1.8.7
No. 4 to No. 12 46 to 180-Mesh
1800 cfm with 7
inlet
25 to 120
S280 to S70
Do not use
No. 4 to No. 8
16 to 60-Mesh
1800 cfm with 8
inlet
Do not use
Do not use
N/A See 1.8.7
No. 4 to No. 12 36 to 180-Mesh
Figure 3
