Optimization strategy for water flow regulation of spiral sand washing
machine: improving cleaning and separation performance
Water flow is the core driving force for the spiral sand washing machine to
achieve quartz sand impurity removal and sand water separation. Its flow rate,
velocity, stability, and distribution uniformity directly determine the
equipment cleanliness, fine sand recovery rate, and operating efficiency. In
actual production, problems such as excessive residue of mud powder, severe loss
of fine sand, and incomplete separation of sand and water often occur due to
improper water flow control. Based on the operational characteristics of
large-scale quartz sand production lines (daily processing capacity ≥ 3000t), a
water flow control optimization plan is developed from four dimensions:
parameter matching, system upgrade, structural optimization, and operation and
maintenance management, to comprehensively improve equipment performance.
1、 Accurately match water flow parameters, adapt to material characteristics
and processing capacity
The water flow parameters need to be dynamically matched with the feed mud
content, particle size composition, and equipment rated processing capacity to
avoid performance imbalance caused by "one size fits all" regulation.
Firstly, clarify the core parameter benchmark: for the demand of quartz sand
washing, the inlet flow rate should be calculated based on "0.35-0.45m ³ of
water per ton of sand". For equipment with a rated processing capacity of
250t/h, the benchmark inlet flow rate should be controlled at 87.5-112.5m ³/h;
The water flow velocity needs to be adjusted in conjunction with the spiral
speed, and the effective water flow velocity in the groove should be maintained
at 0.6-0.8m/s, which can not only take away the peeled mud powder, but also
avoid the loss of fine sand (≤ 40 mesh) with the water.
Dynamic adjustment logic: When the mud content in the feed exceeds 8%,
increase it by 10% -15% based on the benchmark flow rate, and adjust the screw
speed to 25-28r/min to enhance the friction strength of sand water mixing; When
the mud content is ≤ 5%, the flow rate is reduced by 5% -8%, the speed is
reduced to 22-24r/min, and the loss of fine sand is reduced; When processing
coarse sand (20-40 mesh), set the upper limit of flow rate to improve the
carrying capacity of mud powder; When processing fine sand (40-70 mesh), set the
flow rate to the lower limit and use a slow flow device to protect the fine
sand.
2、 Upgrade the water flow control system to enhance stability and
accuracy
Traditional manual control is prone to problems such as flow fluctuations and
water level imbalances, which require upgrading automation equipment to achieve
precise and controllable water flow.
Installation of high-precision monitoring and control equipment: Install an
electromagnetic flowmeter (measurement accuracy ± 0.5%) at the inlet end to
provide real-time feedback on the inlet flow rate. Paired with a variable
frequency constant pressure water supply pump, the pump frequency is
automatically adjusted when the flow deviation exceeds 5% to ensure stable flow;
A liquid level sensor is installed in the middle of the tank to monitor the
water level height in real time. It is linked with the electric regulating valve
of the overflow outlet to stabilize the water level at 30-50mm from the top of
the tank, avoiding sand splashing caused by high water level or mud powder
deposition caused by low water level.
Build a segmented water flow control logic: divide the sand washing tank into
a feed mixing section, an intermediate cleaning section, and a discharge
separation section. The feed section adopts a "strong water flow+high mixing"
mode, with an inlet flow rate of 40% to enhance mud powder stripping; The middle
section adopts a "stable water flow+uniform mixing" mode, with a flow rate of
35%, continuously carrying away the mud powder; The discharge section adopts a
"slow water flow+weak mixing" mode, with a flow rate of 25%, to assist in the
sedimentation and separation of sand and water. Each section achieves precise
flow distribution through diversion valves.
3、 Optimize auxiliary structural design to improve water flow distribution
and utilization efficiency
By modifying the inlet, distribution, and drainage structures, the problems
of uneven water flow distribution and low utilization efficiency can be solved,
and the sand washing and separation effects can be strengthened.
Optimize the water inlet and distribution structure: Replace the single water
inlet with multiple sets of spray type water inlets distributed along the width
of the groove, and install adjustable nozzles for each set of water inlets to
ensure uniform distribution of water flow along the width of the groove and
avoid local water flow being too strong or too weak; Install a guide plate on
the inside of the water inlet to guide the water flow in a spiral direction,
forming a spiral water flow, enhancing the mixing and friction effect of sand
and water, and improving the efficiency of mud powder stripping.
Improve drainage and slow flow structure: Expand the diameter of the drainage
pipeline (≥ 350mm), install pipeline dredging devices, regularly clean the
sediment powder in the pipeline, and avoid abnormal water level caused by
blocked drainage; Install a slow flow plate in front of the dewatering screen at
the discharge end to slow down the water flow rate and prolong the settling time
of sand and water. At the same time, set up an inclined guide groove at the
bottom of the tank to guide the sediment to move towards the discharge outlet
and reduce secondary sedimentation of mud powder.
4、 Strengthen daily operation and maintenance management to ensure continuous
and effective water flow regulation
Inadequate daily operation and maintenance can easily lead to the failure of
control equipment and drift of water flow parameters. It is necessary to
establish a sound operation and maintenance mechanism.
Regularly calibrate monitoring equipment: calibrate electromagnetic flow
meters with standard flow meters every week, and calibrate liquid level sensors
every month to ensure accurate monitoring data; Check the operation status of
the variable frequency pump and electric valve, replace aging seals and worn
parts in a timely manner, and avoid equipment failure causing flow and water
level loss of control.
Maintain water quality and pipelines: regularly clean the inlet filtration
device to avoid impurities blocking the inlet; Maintain the tail water reflux
system to ensure the normal operation of the sedimentation tank and filter
screen, control the cement powder content in the reflux tail below 0.5%, and
avoid secondary pollution affecting the sand washing effect; Clean the sediment
powder in the tank every week, check the installation status of the guide plate
and slow flow plate, and ensure stable water flow guidance.
Through the optimization measures of water flow regulation mentioned above,
the cleanliness of the spiral sand washing machine can be increased to over 99%,
the recovery rate of fine sand can be increased by 5% -8%, the moisture content
of finished sand can be stabilized below 6%, while reducing equipment energy
consumption and operation costs, and meeting the continuous and stable operation
requirements of large-scale quartz sand production lines. If there are special
material characteristics or equipment model differences in production,
parameters and structural design can be adjusted based on actual conditions.