What is desander and how it works?

The desander is mainly an auxiliary equipment used in our daily pile foundation construction. It can effectively control the sand content and particle accuracy of the mud during the construction process, separate the solid particles in the mud from solid-liquid, and separate The separated waste residue is dehydrated and discharged. It helps to improve the porosity of the pile foundation, reduce the cost of slurry during the construction process, and realize the recycling of construction mud.

The desander mainly consists of 5 parts:

• Electrical system

The electronic control system of the desander refers to the electrical control system of the desander, including power supply, control unit, sensor and actuator.

The main function of the electronic control system of the desander is to control the operation of the desander, including starting, stopping, operating status monitoring, fault diagnosis and other functions of the equipment. The electronic control system can realize automatic control of the sand remover and can adjust and control it according to the liquid flow rate, sand particle size, equipment running time and other parameters to achieve better sand removal effect.

In addition, the electronic control system can also provide safety protection for the desander, such as automatically shutting down or alarming when equipment malfunctions or abnormal conditions occur to avoid equipment damage and personal injury.

• Screens

The vibrating screen of the desander is a high-efficiency screening equipment that uses the vibrating screen to quickly separate and filter materials on the screen surface under the action of vibration.

The vibrating screen is mainly composed of vibration motor, screen box, screen mesh, shock-absorbing spring, etc. When working, the vibration motor drives the screen box to vibrate, causing the materials to continuously roll and jump on the screen surface, thereby achieving the purpose of separation and screening.

• Cyclone

The cyclone of the desander is a widely used solid-liquid separation equipment. Its working principle is that after the sandy sewage is pressurized by the pump, it enters the interior of the cyclone from the tangential direction through the liquid inlet pipe. Due to the change in flow direction, the fluid forms a swirling state. When the fluid enters the acceleration part, the flow speed increases rapidly, the fluid forms a spiral state, and generates centrifugal force. The centrifugal force forms an air column from the center to the periphery. The larger and heavier particles in the liquid are thrown toward the cyclone wall under the action of centrifugal force, and vortex changes and falls under the action of cyclone and gravity, and is discharged from the bottom flow hole. A small part of the finer particles flows out of the underflow hole, and most of them change direction when approaching the underflow hole, and are discharged through the overflow pipe in an upward spiral flow to achieve solid-liquid separation.

The main features of the cyclone include simple structure, small size, light weight, low cost, no moving parts, easy installation and operation, no need for ancillary equipment, and polyurethane rubber used for the cyclone pipe, which increases wear resistance and extends service life .

• Slurry Pump

The desander's slurry pump is a heavy-duty industrial pump specially designed to transport high-concentration granular materials. These materials often have the characteristics of large particle size, high specific gravity and high viscosity, and usually include coal slurry, slag, silt, sand, mud, etc. Slurry pumps are widely used in mining, metallurgy, construction, chemical industry and other industries, in which they play a vital role.

The main working principle of the slurry pump is to use centrifugal force (that is, the rotation of the pump impeller) to increase the energy of the solid-liquid mixed medium and convert electrical energy into kinetic energy and potential energy of the medium. In terms of physical principles, the slurry pump is a type of centrifugal pump, but conceptually, it uses centrifugal force to pressurize the conveyed medium, so it has its own unique characteristics.

• Storage Tank

The slurry storage tank of the desander is a container used to store and preliminarily settle sand particles. During the operation of the desander, after the liquid containing sand particles enters the desander, it first enters the slurry storage tank. In the slurry storage tank, the sand in the liquid will naturally settle due to gravity, forming sediment. There is usually a sand discharge port at the bottom of the slurry storage tank, and the sediment in the slurry storage tank should be cleaned regularly.

The design and structure of the slurry storage tank will vary depending on the specific application scenario and equipment model, but generally it needs to meet the requirements of being able to hold a sufficient amount of liquid and facilitate sand discharge and cleaning.

And the 5 parts can be divided into 13 more detailed parts as below

1. Vibration Motor
2. Fine Filter Screen
3. Storage Tank
4. Slurry Pump
5. Cyclone
6. Cyclone Sand Outlet
7. Coarse screen
8. Cyclone Drain Outlet
9. Holding Tank
10. Automatic Level Control
11. Stock inlet
12. Drain outlet
13. Sand outlet

How does a desander work?

1. When the liquid is introduced, the lower layer of the vibrating screen performs a rough screening of the liquid, the solids are discharged from the machine, and the liquid enters the slurry storage tank.

2. When the liquid after preliminary screening enters the slurry storage tank, the sand in the liquid will naturally settle to the bottom under the action of gravity to form sediment.

3. The slurry pump pumps the liquid in the slurry tank into the cyclone

4. The cyclone separates sand and liquid by causing centrifugal motion of the liquid. The sand enters the upper layer of the vibrating screen and is discharged from the machine, and the liquid enters the liquid level balance tank (part of it is returned to the tank to supplement the insufficient liquid input, and part of it is discharged)

In short, the desander is a key point for solid-liquid separation of mud in pile foundation projects, reducing the sand content of the mud, realizing mud recycling, and improving the pile formation rate.