6
mixers. The hoses accommodate variability in positioning
while providing suitable service life. It is not advisable to
use hoses of smaller diameter than the boot discharge ori-
fice, whether the discharge matches the slickline diameter
or the boot diameter.
Boot Lining
The boot interior should be hardened to nominal Brinell
500 or more, such as chromium-carbide overlay, induction
hardened, or ceramic, from the upper pipe and chamber
segments to around the discharge orifice. The essential
means by which the boot works is providing the principal
impact zone to be the same rock which is being transferred:
rock-on-rock. This can be achieved by pouring and curing
concrete – to the discharge lip – prior to placing the boot
on the slickline. Alternatively, the impact mass begins with
the first transfer load and is developed with subsequent
operation. With operational development of the mass, full
cementitious strength may never be reached due to impact
before curing. The rock-on-rock wear remains effective as
a component minimizing rock on steel or rock on ceramic
impact and abrasion. That follows successful rock box or
dead bed practice in many material handling settings.
Boot Cleanout
Line and boot cleanout is important, especially with
cementitious transfer. Appropriate and unobtrusive injec-
tion port cleanouts can use integrally reinforced fittings
(i.e., weldolets) set in the inlet throat of the boot. Oriented
downward, these can direct air or water onto and across the
impact area and volume, removing detrital material follow-
ing load transfer(s). The primary cleanout volume should
be no less than a load-equivalent volume of water to flush
the line from the collar downward, as discussed in Transfer
Completion/Washdown. Wash out loads charged with a
nominal 230 kg (500 lb) of clean aggregate can be particu-
larly effective in controlling scale, and the aggregate can be
reused underground as road base or blasthole stemming.
Two design philosophies relate to line and device clea-
nout: fixed base and moveable base. Fixed base units are
appropriate for devices which are supported on platforms
or pedestals. Either fixed or moveable bases are suitable
for suspended devices. With fixed bases, all cleanout is
done through the discharge orifice and/or injection ports,
above the impact bed. With moveable bases, the baseplate
is removed or swung aside during or for cleanout, allow-
ing cleanout devices from the discharge station to be fully
aligned with the transfer pipe. This entails removing the
thrust mass (concrete, aggregate, etc.) and replacing it
when the line or boot cleanout is complete and operation
resumes.
Cleanout devices inserted from below include high
pressure sewer cleanout hoses or pipe air lances, with or
without cutter heads.
Support/Suspension
Boots are most efficiently handled and installed with lifting
eyes. With installations relying on basal support, the lift-
ing eyes can be designed for handling lifts, not operational
loading. If the lifting eyes are intended to support the unit
during operation, they must be designed accordingly. Such
components are illustrated in the boot shown in Figure 1.
It is not recommended to transmit the impact load
across a conventional pipe coupling alone. A possible alter-
native in operational support is to transmit the impact load
across the transfer pipe coupling using eyepads which entail
individual or group bolt holes, as necessary. This is advis-
able only if the transfer pipe can be designed and installed
to reliably support the cumulative train of loadings involved
with the transfer process. The primary supports, whether
from back, rib, sill, or the pipe itself, must be well-designed
and installed.
In designing the supports, conventional impact
load analyses (e.g., 5) can be supplemented with tech-
niques such as Computational Flow Dynamics (CFD) or
Discrete Element Modeling (DEM). Attachment and fit-
ting capacities should follow appropriate standards (e.g.,
8), and when used, rock bolts and cables should follow
manufacturer guidelines. Given the inherent difficulty in
modeling these loads, as noted in Underground Station—
Transfer Impact, instrumentation of the final installation is
recommended to confirm the design criteria were appropri-
ate and system objectives can be met.
Finally, in the case of fixed base boots (Boot Cleanout),
the platform or pedestal must support the unit and also
accommodate clearance for device installation and removal.
Though lifting eyes for handling remain prudent, the final
positioning can be done with shim plates or grout pads,
possibly using jack bolts.
FABRICATION/CONSTRUCTION
Principal distinctions between installations include whether
the system is in a shaft or borehole. In shafts, the inlet,
the transfer line itself, and outlet works must not obstruct
the collar, other shaft compartments, and shaft stations,
respectively. The line itself and its support must conform to
codes, standards and practice for shaft accessories. In bore-
holes, the common approaches are either collar suspended
-allowing for relatively direct line replacement upon wear
mixers. The hoses accommodate variability in positioning
while providing suitable service life. It is not advisable to
use hoses of smaller diameter than the boot discharge ori-
fice, whether the discharge matches the slickline diameter
or the boot diameter.
Boot Lining
The boot interior should be hardened to nominal Brinell
500 or more, such as chromium-carbide overlay, induction
hardened, or ceramic, from the upper pipe and chamber
segments to around the discharge orifice. The essential
means by which the boot works is providing the principal
impact zone to be the same rock which is being transferred:
rock-on-rock. This can be achieved by pouring and curing
concrete – to the discharge lip – prior to placing the boot
on the slickline. Alternatively, the impact mass begins with
the first transfer load and is developed with subsequent
operation. With operational development of the mass, full
cementitious strength may never be reached due to impact
before curing. The rock-on-rock wear remains effective as
a component minimizing rock on steel or rock on ceramic
impact and abrasion. That follows successful rock box or
dead bed practice in many material handling settings.
Boot Cleanout
Line and boot cleanout is important, especially with
cementitious transfer. Appropriate and unobtrusive injec-
tion port cleanouts can use integrally reinforced fittings
(i.e., weldolets) set in the inlet throat of the boot. Oriented
downward, these can direct air or water onto and across the
impact area and volume, removing detrital material follow-
ing load transfer(s). The primary cleanout volume should
be no less than a load-equivalent volume of water to flush
the line from the collar downward, as discussed in Transfer
Completion/Washdown. Wash out loads charged with a
nominal 230 kg (500 lb) of clean aggregate can be particu-
larly effective in controlling scale, and the aggregate can be
reused underground as road base or blasthole stemming.
Two design philosophies relate to line and device clea-
nout: fixed base and moveable base. Fixed base units are
appropriate for devices which are supported on platforms
or pedestals. Either fixed or moveable bases are suitable
for suspended devices. With fixed bases, all cleanout is
done through the discharge orifice and/or injection ports,
above the impact bed. With moveable bases, the baseplate
is removed or swung aside during or for cleanout, allow-
ing cleanout devices from the discharge station to be fully
aligned with the transfer pipe. This entails removing the
thrust mass (concrete, aggregate, etc.) and replacing it
when the line or boot cleanout is complete and operation
resumes.
Cleanout devices inserted from below include high
pressure sewer cleanout hoses or pipe air lances, with or
without cutter heads.
Support/Suspension
Boots are most efficiently handled and installed with lifting
eyes. With installations relying on basal support, the lift-
ing eyes can be designed for handling lifts, not operational
loading. If the lifting eyes are intended to support the unit
during operation, they must be designed accordingly. Such
components are illustrated in the boot shown in Figure 1.
It is not recommended to transmit the impact load
across a conventional pipe coupling alone. A possible alter-
native in operational support is to transmit the impact load
across the transfer pipe coupling using eyepads which entail
individual or group bolt holes, as necessary. This is advis-
able only if the transfer pipe can be designed and installed
to reliably support the cumulative train of loadings involved
with the transfer process. The primary supports, whether
from back, rib, sill, or the pipe itself, must be well-designed
and installed.
In designing the supports, conventional impact
load analyses (e.g., 5) can be supplemented with tech-
niques such as Computational Flow Dynamics (CFD) or
Discrete Element Modeling (DEM). Attachment and fit-
ting capacities should follow appropriate standards (e.g.,
8), and when used, rock bolts and cables should follow
manufacturer guidelines. Given the inherent difficulty in
modeling these loads, as noted in Underground Station—
Transfer Impact, instrumentation of the final installation is
recommended to confirm the design criteria were appropri-
ate and system objectives can be met.
Finally, in the case of fixed base boots (Boot Cleanout),
the platform or pedestal must support the unit and also
accommodate clearance for device installation and removal.
Though lifting eyes for handling remain prudent, the final
positioning can be done with shim plates or grout pads,
possibly using jack bolts.
FABRICATION/CONSTRUCTION
Principal distinctions between installations include whether
the system is in a shaft or borehole. In shafts, the inlet,
the transfer line itself, and outlet works must not obstruct
the collar, other shaft compartments, and shaft stations,
respectively. The line itself and its support must conform to
codes, standards and practice for shaft accessories. In bore-
holes, the common approaches are either collar suspended
-allowing for relatively direct line replacement upon wear