Detailed Introduction to Desander and Desilter

 

Desanders and desilters are core equipment in a solids control purification system, directly affecting the efficiency of drilling fluid purification and overall operational performance. They are widely used in various slurry treatment applications such as oil and gas drilling, trenchless construction, and slurry shield tunneling projects.

Desander and Desilter: Core Classification Units in the  Solids Control System

The desander is the second solids control device in the solids control system and is also referred to as the third-stage purification equipment. The desilter is the third solids control device and is also known as the fourth-stage purification equipment.

In the system layout, the desander is installed after the shale shaker, while the desilter is installed after the desander.

In theory, the desander removes solid particles sized 45–74 microns, while the desilter removes particles sized 15–44 microns.

In oil and gas drilling mud systems, the common hydrocyclone size for desanders is 10 inches, while desilters typically use 4-inch hydrocyclones. Some desanders use 12-inch hydrocyclones. In other slurry treatment industries, hydrocyclones of 8, 6, 5, 3, and 2 inches are also used.

When a desander and desilter are combined into one unit, it is called a mud cleaner (three‑in‑one system). The installation order and position remain unchanged.

 Main Types and Key Features of Desanders and Desilters

1. Classification by Underflow Shaker:

With underflow shaker: equipped with a dedicated screening unit to perform secondary screening of solids discharged from hydrocyclones, recovering more drilling fluid and reducing slurry loss. Suitable for operations with high mud recovery requirements.

Without underflow shaker: equipped only with a sand discharge chute. The structure is simpler, the cost is lower, and maintenance is easier. Solids are discharged directly through the chute, suitable for simple and cost sensitive mud treatment operations.

2. Subcategories of Units with Underflow Shaker:

Large underflow shaker: usually adopts linear motion or other motion trajectories, with large screening area and high processing efficiency. Suitable for large‑scale projects with high flow rates and high sand content mud.

Small underflow shaker: compact structure and flexible layout, requiring less installation space. Suitable for sites with limited space and moderate capacity requirements.

3. Main Structure and Wear Parts 

The main components of a hydrocyclone separation unit include hydrocyclones, support frame, manifold, underflow shaker (if equipped), vibration motors (if equipped), screen panels (if equipped), springs (if equipped), sand discharge chute (for units without underflow shaker), and pressure gauges.Recommended spare parts include hydrocyclones, screens, blind plates, pressure gauges, clamps, and springs.

 Aipu Desander and Desilter

1.Flexible configuration: the number and size of hydrocyclones can be configured according to project requirements.

2.Premium materials: hydrocyclones are made of high‑quality polyurethane with excellent wear and corrosion resistance.

3.Optimized structure: well‑designed structure ensures better cyclone separation performance.

4.Customized underflow shaker design: options include sand chute configuration, mini compact shaker, and standard vibrating screen. The standard vibrating screen can be designed as Hunter‑MG series or Hunter‑D series. 

Key Advantages of Aipu Desander and Desilter

1.High‑quality raw materials from well‑known Chinese steel mills such as Baosteel and Ansteel.

2.Polyurethane hydrocyclones with strong durability.

3.Motors from MARTIN or OLI (Italy) for reliable performance.

4.Advanced manufacturing processes ensuring precision and refined appearance.

5.Optimized design based on real field conditions.

6.Flexible configuration of hydrocyclones and underflow shakers.

7.Screens tested according to API RP 13C standards.

8.High‑strength springs providing excellent vibration damping.

9.Fine details reflecting quality, including test running and locking mechanisms.

10.Strict coating standards: surface blasting to SA2.5, followed by epoxy zinc‑rich primer and polyurethane topcoat.

11.Customizable services including color, electrical standards, and certifications.

Industry Applications and Operation Guidelines

Desanders and desilters are widely used in oil and gas drilling mud treatment, trenchless drilling slurry treatment, HDD mud recycling systems, water well and geothermal drilling, core drilling and mining operations, and slurry separation in shield tunneling and pipe jacking projects.

In shield tunneling and pipe jacking applications, special hydrocyclone specifications are often required and should be selected accordingly.

1.Working Principle.Mud is supplied to the hydrocyclones through a centrifugal pump. The drilling fluid enters the cyclone inlet and forms a high‑speed rotating vortex inside the cyclone. Heavier solids move downward and are discharged through the underflow nozzle, while lighter liquid exits from the upper outlet and flows to the next stage of the solids control process. 

2.Operation and Equipment Selection.Processing capacity is the key factor in determining the number of hydrocyclones required. The number of desanders or desilters should match the mud flow rate requirement.

Each desander and desilter should have its own dedicated feed pump and should not share the same pump, otherwise separation efficiency and equipment lifespan may be affected.

Conclusion

As key classification and purification devices in the mud solids control system, desanders and desilters provide precise particle separation and are essential equipment in drilling fluid treatment. With flexible configuration, durable materials, optimized design, and strict quality control, Aipu desanders and desilters provide efficient and reliable solutions for oil and gas drilling, shield tunneling, and trenchless construction projects.

 Emial: Ivy@aipusolidcontrol.com

Website: www.aipusolidcontrol.com