Circular stockyard stacking and reclaiming system for coal-fired
power plant
Introduction
Circular gantry scraper stacker and reclaimer is mainly used in
building materials, coal, metallurgy, electric power, port, and
other industries, and is mostly used to stack limestone or coal and
other bulk materials. The cantilever of the stacker is equipped
with a belt conveyor, which passes through the steel structure grid
roof of the circular stockyard from the belt conveyor on the
trestle, and the input materials complete the ring conical stacking
through the belt conveyor on the cantilever of the stacker; The
reclaimer completes the reclaiming work via three linking
processes: traveling system, luffing system, and scraper system.
The scraper reclaimer scrapes the materials into the conical hopper
under the central column along the slope of the pile and outputs
the materials through the vibrating feeder and underground belt
conveyor.
Feature
| project | stacking and reclaiming equipment |
| painting | HEMPEL |
| color | by user |
| capacity | 1800 t/h |
| character | heavy duty |
| advantage | low maintenance |
| benefit | low cost |
| application | coal handling |
Main components of circular stacker and reclaimer
1. Stacking steel structure, cantilever belt conveyor
The cantilever stacker takes the central column as the center, one
end is the belt conveyor with cantilever steel structure, and the
other end is the counterweight box. The middle stacking slewing
part is connected with the central column by slewing bearing, and
the stacker can rotate by meshing the pinion on the slewing driver
with the gear on the central column. The materials entering the
circular stockyard are unloaded at the head of the cantilever belt
conveyor and directly stacked to the stockyard. The stacker rotates
at a certain angle for slope stacking until it is stacked into an
annular pile.
There are two main structural types of cantilever stacker,
cantilever fixed type and cantilever luffing type.
Comparison of the two types of stackers:
(1)The advantages of the fixed stacker are simple structure and low
cost. The disadvantage is that when the lower part of the stacker
is not stacked or the material pile is low, the difference is huge,
and the dust in the stockyard is more serious (even with a spray
system).
(2)The luffing stacker uses the hydraulic cylinder to raise or
lower the cantilever. Its advantage is cantilever can raise up and
down according to the stacking height to reduce the material drop
and avoid dust flying. As well, it can reduce the height of the
central column and reduce the cost. The disadvantage is that the
structure is more complex.
2. King column and slewing mechanism of circular stacker and
reclaimer
(1) The king column of the stacker reclaimer is located in the
center of the circular stockyard. It is an important component of
the stacker reclaimer. It not only bears the load of the main
components and the input trestle but also is the installation
center of the components. Therefore, its manufacturing and
installation process requirements are very high. It is made of
steel plate rolled into a cylindrical shape and welded and
assembled. The utility model is provided with a stacking steel
structure, a rolling bearing for the stacking rotary part, and a
cable drag connecting various equipment components
(2)The top of the king column is the stacking rotary part, the
upper part of which is connected with the belt conveyor trestle
entering the circular stockyard through the rotary bearing and
serves as a support point for the trestle load, and the lower part
is connected with the middle column through the rotary bearing.
(3) To enable the slewing bearing device to bear large vertical
force, horizontal force, and overturning moment, the slewing
bearing support type is adopted. The rotary bearing is protected by
a dust cover. Its structure can adapt to the harsh working
environment and has the functions of dust prevention, water
immersion prevention, refueling, cleaning, and maintenance.
3. Reclaimer luffing mechanism:
The luffing mechanism is composed of a driving device, drum
assembly, double steel wire rope, and pitching electrical detection
and control system. The luffing operation of the scraper reclaimer
is completed through the pitching mechanism, to achieve the purpose
of layered reclaiming.
The luffing mechanism uses double steel wire rope single winding,
and the balance mechanism is adopted at the intersection of the two
steel wire ropes to ensure that the stress of the left and right
steel wire ropes is balanced and the work is safer.
The driving device of the luffing mechanism is mechanically driven
by frequency conversion and speed regulation to accurately control
the amplitude variation, to control the change of the reclaiming
amount. To ensure the safety and accurate and reliable positioning
of the pitching mechanism, the driving device adopts a double
braking system
4. Hydraulic system
The hydraulic system of stacker reclaimer mainly includes stacker
luffing hydraulic system, scraper chain tensioning hydraulic
system, and belt conveyor manual tensioning hydraulic system
The luffing control hydraulic system is composed of a main pump
motor unit, control valve unit, oil cylinder, oil tank assembly,
hydraulic accessories, and hydraulic pipelines. The pipeline of the
luffing cylinder is equipped with a pipeline rupture safety valve
and a safety valve group.
The tensioning cylinder control hydraulic system is composed of a
pump motor group, control valve group, accumulator, oil cylinder,
oil tank assembly, hydraulic accessories, and hydraulic pipelines.
The tension of the tensioning cylinder can be adjusted by the
corresponding pressure-reducing valve.
5. Lubrication system
The centralized lubrication system of stacker reclaimer is composed
of stacker mechanism, reclaimer mechanism, scraper conveying
sprocket mechanism (built-in chain), and open-gear mechanism.
Lubricating points of the stacking mechanism: upper and lower
slewing large bearings, oil cylinder hinge points, stacking arm
hinge points, and drum bearings. Lubrication method: automatic
double line / progressive hybrid centralized lubrication system,
with PLC control.
Lubrication points of reclaiming mechanism: lower rotary large
bearing, luffing pulley block of reclaiming arm, traveling
mechanism, etc.
Lubrication method: automatic double line / progressive hybrid
centralized lubrication system, with PLC control.
The oil dropping lubrication system of scraper conveying sprocket
consists of the oil tank, liquid level switch, electromagnetic
switch, oil dropping regulating valve, and pipeline accessories,
which mainly realizes the oil lubrication of scraper conveying
chain on both sides.
Lubrication method: automatic oil dripping lubrication, adjustable
oil dripping amount, and PLC control
Rotary open gear lubrication mode: automatic oil dripping
lubrication, and the lubrication amount is controlled by PLC.
6. Water spray dust controlled system
The water spray dust controlled system on the stacker reclaimer is
composed of a booster pump, pipeline, filter, manual valve,
electric valve, check valve, automatic drain valve, pressure gauge,
flowmeter, water level gauge, and spray nozzle group.
The position and function of the nozzle group are as follows:
Around the outside of the lower hopper at the head of the arm
stacking belt conveyor, the nozzle group sprays water to form an
umbrella water curtain to control the dust generated by stacking in
the spray.
2) The material receiving of the cantilever stacking belt conveyor
is enclosed in the guide chute. Spray water on the nozzle group to
control the dust in the closed guide chute.
3) Auxiliary spray system: it is mainly composed of two remote
sprayers, which are installed at the central column of the stacker
reclaimer. The head of the auxiliary stacker arm can effectively
suppress the dust in the stockyard.
