Application of Polyester Spiral Mesh in Belt Press Filtration Machines —— High-efficiency solutions for wash sand wastewater treatment

In the modern sand and gravel, as well as manufactured sand industry, “ Wash Sand ” It’s long since ceased to be a simple rinsing process—it has evolved into a comprehensive system engineering endeavor encompassing environmental protection, water recycling, solid-liquid separation, and more. As the nation increasingly tightens its standards for mine ecological restoration, wastewater discharge regulations, and water-saving targets, the way sand-washing wastewater is treated has become the key determinant of whether companies can sustain their operations. Among the many solid-liquid separation technologies available, Belt-type press filter combined with a polyester spiral mesh With its features such as efficient dewatering, continuous operation, and low energy consumption, it is gradually becoming the mainstream solution for treating washed-sand wastewater.

I. The Core Challenge in Wash Sand Wastewater Treatment

The sand-washing process generates large amounts of muddy wastewater, which contains fine sand, dust, clay particles, and some organic impurities.
These muds are characterized by:

• Solid content is low (approximately 3% ～ 10% );
• The particle size distribution is complex;
• Some fine silt remains suspended for a long time and is difficult to settle naturally;
• If not addressed promptly, the circulating water will become cloudy, affecting the quality of sand washing.

Traditional processing methods generally include Settling tank + Thickening Machine + Plate-and-frame filter press Although the dehydration effect is relatively good, the plate-and-frame filter press has obvious drawbacks:

• Long working cycle and unable to operate continuously;
• Highly manual operation and large footprint;
• Filter plates require frequent maintenance and consume relatively high energy.

This has prompted many sand and gravel plants to shift toward more efficient, highly automated continuous dewatering systems. —— Belt Press Filter Machine Belt Filter Press ） 。

II. Working Principle of the Belt Press Filter

The belt press filter is a continuous solid-liquid separation device centered around a filter belt. Its basic structure includes: the sludge feeding system, gravity dewatering zone, wedge-shaped pre-compression zone, pressing and dewatering zone, and the filter belt cleaning system.

The work process is as follows:

1. Coagulation and Conditioning Stage
   Mud-containing wastewater is mixed and reacted with a flocculant, causing fine particles to form flocs and enhancing the dewaterability of the slurry.
2. Gravity Dewatering Stage
   The conditioned slurry is distributed evenly onto the filter belt, where gravity naturally helps expel some of the water, forming a preliminary mud layer.
3. Wedge-shaped Pre-compression Stage
   The upper and lower filter belts gradually tighten, clamping the sludge layer and gently pressing to expel free water.
4. Pressing and Dewatering Stage
   The filter belt passes through a series of rollers that alternately apply pressure, further squeezing out the water from the slurry to form a thicker cake with a higher solids content.
5. Mud Cake Stripping and Cleaning Stage
   The dewatered mud cake is scraped off and falls away, while the filter belt undergoes high-pressure spray cleaning before entering the next cycle.

In this process, The water permeability, strength, and abrasion resistance of the filter belt It directly affects the moisture content of the mud cake, the operational stability of the equipment, and the lifespan of the filter belt. This is precisely why the polyester spiral mesh plays a critical role.

III. Polyester Spiral Mesh: For Belt Press Filters “ Core Filter Belt ”

Polyester Spiral Mesh Polyester Spiral Mesh Belt ) is a continuous mesh fabric made by weaving high-strength polyester monofilaments around spiral loops. Initially used in the dewatering stage of paper-making machines, it has since been widely adopted in industries such as sludge dewatering, coal washing, chemical processing, metallurgy, and sand washing.

1.  Structural Features

• Spiral Ring Design : Uniform aperture, smooth drainage, and resistant to clogging;
• Seamless splicing structure : Connected via a polyester coupling ring for smooth operation;
• Single-strand weaving technique : Smooth surface, wear-resistant, easy to clean;
• Forming Heat Treatment : Ensure dimensional stability and high-pressure resistance.

2.  Performance Advantages

( 1 ） High strength and tensile resistance
The polyester spiral mesh is made from high-toughness industrial yarn, enabling it to withstand prolonged tensile forces and high-pressure compression without deforming or breaking.

( 2 ） Excellent water permeability and sludge discharge capability
The spiral structure ensures smooth water discharge and accelerates the dewatering of the sludge cake, significantly improving the solid content of the filter cake.

( 3 ） Excellent wear resistance and anti-clogging performance
In the sand-washing industry, high-hardness quartz sand particles easily cause wear. The polyester spiral mesh features a smooth surface with a low coefficient of friction, making it resistant to mud adhesion and pore blockage.

( 4 ） Highly resistant to chemical corrosion
It can withstand corrosion from common flocculants and acidic/alkaline cleaning solutions, making it suitable for a wide range of operational environments.

( 5 ） Easy to install, simple to maintain
The polyester spiral mesh can be quickly assembled and disassembled, with short on-site splicing time and low downtime maintenance costs.

IV. The Practical Application Value of Polyester Spiral Mesh in the Sand-Washing Industry

The slurry in the sand-washing industry typically contains large amounts of fine sand, dust particles, and clay components, making solid-liquid separation particularly challenging. However, using a belt press filter equipped with a polyester spiral mesh enables continuous, efficient, and energy-saving dewatering operations.

1.  Dehydration efficiency significantly improved

The polyester spiral mesh features a uniform pore size distribution, allowing for smoother water removal during the pressing process. Practical tests have shown that, after adopting the spiral mesh, the moisture content of the dewatered sand sludge can be reduced to 60% By the way, the filter cake can be directly loaded onto trucks for transportation or stacked for storage.

2.  Operating costs are significantly reduced.

Compared to plate-and-frame filter presses, belt press filters equipped with spiral mesh can operate continuously, eliminating the need for frequent filter plate replacements or manual sludge removal—and thereby saving significant labor and downtime.

3.  Enhance the utilization rate of circulating water

The filtered clean water can be directly reused in the sand-washing process, significantly reducing the consumption of fresh water and enabling water-saving, environmentally friendly production.

4.  Reduce chemicals and energy consumption

Due to the stable filter belt structure, the slurry is evenly distributed during the pressing process, leading to improved flocculant utilization and allowing for a reduction of approximately [amount] in chemical dosage. 15%-20% , overall machine energy consumption reduced 10% That's all.

5.  Extend service life

After the polyester spiral mesh undergoes surface abrasion-resistant treatment, its durable lifespan typically reaches up to 6 More than one month, representing an improvement of approximately 40%。

V. Analysis of Typical Application Cases

Produced in a certain year 200 Taking the 10,000-ton mechanized sand project as an example, its sand-washing system processes approximately daily wastewater. 3000 m³ , with a silt content of approximately 8% Originally used precipitation + The plate-and-frame filtration system has a long sludge discharge cycle, leading to severe on-site sludge accumulation.
Switch to Double-Belt Press Filter Machine + Polyester Spiral Mesh Afterward, significant results were achieved:

This case clearly demonstrates that the application of polyester spiral mesh in belt press filter machines not only optimizes equipment performance but also significantly enhances the automation and economic efficiency of sand-washing production lines.

6. Industry Trends: From Filter Tapes to System Solutions

Today, the sand and gravel industry is rapidly moving toward “ Eco-friendly, intelligent, and systematic ” Polyester spiral mesh, as the core filtration medium, is evolving from a mere consumable into an integral part of system engineering.
Future trends are primarily reflected in the following aspects:

1. Customized Filter Belt Design
   For different slurry characteristics (such as high fines content, high sand content, pH Such as slightly alkaline conditions), customizing the filter belt's pore size, thickness, air permeability, and surface treatment.
2. Integrated with the intelligent monitoring system
   Through sensing systems such as tension detection and filter belt wear monitoring, remote control and predictive maintenance are achieved.
3. Applications of Polymer-Modified Materials
   The new high-temperature and corrosion-resistant polyester material will further extend the filter belt's lifespan and enhance filtration stability.
4. Energy-saving and Environmentally Friendly Comprehensive Solutions
   Enterprises from “ Purchase filter belts ” Turning “ Purchase a dehydration system ” Considering energy consumption, chemicals, maintenance, and environmental costs comprehensively.

In this transformation, companies with independent R&D capabilities and system integration expertise, such as Xiamen Xadias ( Xiamen CITIUS Filter Media Technology Co., Ltd. ） , leveraging 30 years of accumulated expertise in filtration fabric technology and equipment R&D, we are now able to provide the sand and gravel industry with solutions ranging from filter belts to complete machines. One-stop solution , helping customers achieve efficient, stable, and eco-friendly mud dewatering and water circulation systems.

VII. Conclusion: Make filtration smarter, and make environmental protection simpler.

The competition in the sand-washing industry is no longer just about output and cost—it’s increasingly a battle between environmental sustainability and operational efficiency.
Polyester Spiral Mesh + Belt Press Filter Machine Combining these features—continuous operation, energy efficiency, and high dewatering rates—the technology has become a crucial support for achieving green production in today's sand-and-gravel industry.

In the future, as filtration material technology, equipment intelligence, and system integration continue to advance, polyester spiral mesh will remain a key player in the solid-liquid separation field, helping more companies achieve their goals. “ Clean water circulation, sludge reduction ” The Sustainable Development Goals.

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