5 types of sand washer working principles and features

Sand washer is a kind of washing equipment for sand and gravel (artificial sand, natural sand), which can make the sand cleaner with higher quality. It is widely used in the construction of sand and gravel quarries, mines, building materials, transportation, chemical industry, water conservancy and hydropower, concrete mixing station and other industries. At present, there are various models of sand washers, the common ones like spiral sand washer, wheel sand washer, rotary drum sand washer, vibrating sand washer, dredging bucket sand washer, etc.

Their working principles and features as follows

1. Spiral Sand Washer

Spiral sand washer is to use the buoyancy effect of water for classifying, with the principle of different specific gravity of solid particles, thus their settling speed in liquid is also different.

The machine rotor adopts the central structure, and the spiral blades are installed on the central shaft, which is connected to the central shaft by the speed reducer for work. The spiral sand washer needs to be installed at an inclination, the lower part of the water tank is surrounded by three sides of the weir plate to form a sedimentation pool, the head of the spiral is immersed in the sedimentation pool, the spiral is driven by the electric motor through the reducer to rotate continuously.

Clean water is fed by the porous plate at the bottom of the sedimentation pool. This spiral sand washer has three functions: cleaning, de-watering and grading.
spiral sand washer

2. Wheel sand washer

The motor drives the impeller slowly through the v-belt, reducer and gears, and the sand enters through the feeding trough, tumbles under the impeller and grinds each other to remove the impurities covering the surface of sand and gravel, and at the same time destroys the water vapor layer covering the sand for dewatering.

At the same time, water is added to form a strong water flow to take away impurities with small specific gravity in time and discharge from the overflow outlet washing trough. The clean sand is taken away by the wheel, and finally the sand is poured into the discharge tank from the rotating impeller, completing the cleaning action of sand and gravel.

Due to the transmission part of the wheel sand washer is isolated from water and sand, so its failure rate is much lower than other common sand washers, it is a good choice for sand washing plant.
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Symons cone crusher or impact crusher? How to choose secondary crushing equipment?

Crushing equipment has a crucial role in the configuration of stone crusher plant. The reasonable equipment configuration is related to the investment, production, product quality of the whole production line.

For secondary crushing equipment, Symons cone crusher and impact crusher are both commonly used equipment, so what is the difference and how to choose between the two equipment? This article analyzes the difference between Symons cone crusher and impact crusher from 8 aspects.

1. Different structures

Both the cone crusher and impact crusher are for secondary crushing, it is easy to distinguish from the crushing principle and appearance.

Symons cone crusher

2. Different working principle

The impact crusher adopts the principle of impact crushing, where the material is crushed by repeated impacts between the hammer bars and the impact plates.

The cone crusher adopts a combination of crushing, shearing and grinding, and the mantle constantly moves toward the bowl liner, squeezing the material in the crushing chamber to crush them.
Symons cone crusher
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Cone crusher wear parts life cycle

For the Symons cone crusher, every user knows the importance of the wear parts of mantle and bowl liner, they are the key components of the Symons cone crusher. The material is directly crushed in the crushing cavity composed of the two, so the wear and tear of the mantle and bowl liner is serious. In theory, their service life is generally in 5-6 months, but according to some feedback of users, the Symons cone crusher wear parts life cycle can hardly reach this level, some may need replacement as short as two weeks. Take the following cases for example

Case 1. Multi-cylinder hydraulic cone crusher in Sichuan province
Rock type: River pebbles
Feed size: ≤130mm
Discharge size: ≤50mm
Crushing Ratio: 3
Capacity: 100m³/h
Mantle and blow liner life cycle: 1.5 months, 10 working hours per day, 25 days per month

Case 2. Symons cone crusher in Zhejiang province
Rock type: River pebbles
Feed size: ≤150mm
Discharge size: ≤30mm
Crushing Ratio: 5
Capacity: 60m³/h
Mantle and blow liner life cycle: 3 months, 12 working hours per day, 25 days per month

3. Spring cone crusher in Shanxi province
Rock type: River pebbles
Feed size: ≤120mm
Discharge size: ≤30mm
Crushing Ratio: 4
Capacity: 80m³/h
Mantle and blow liner life cycle: three weeks, 18 working hours per day, 26 days per month

Above three examples are all based on raw materials of river pebbles, despite the difference in production, the cone crusher wear parts service life cycle differs by several times, why have so big differences? What factors are related to the life cycle of the mantle and bowl liner wear parts?
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Ball mill vs Rod mill, how to choose?

Ball mill and rod mill are the widely used equipment in mineral process plant. They have similarities in appearance and working principle, but also have much differences in the structure, performance and usage. In this article we analyze their similarities and differences from 7 aspects, it will help to choose ball mill and rod mill.

From the analysis of working principle, either ball mill or rod mill, when the cylinder rotates, the grinding medium (ball or rod) inside the drum will be lifted to a certain height under the action of friction and centrifugal force, and then thrown down according to a certain linear speed, so that materials will be crushed by the impact, grinding and extrusion.
ball mill working principle

The working principle is similar, but there are differences as follows

1. Appearance & structure

The cylinder shape ratio is different. For the rod mill, the ratio of cylinder length to diameter is generally 1.5-2.0, also the inner surface is vertical flat liners on both sides covers. For the ball mill, the ratio of cylinder length to diameter is smaller, and in most cases the ratio is only slightly more than 1.

In addition, the rotation speed of rod mill is lower than the rotation speed of ball mill with the same model, so that the steel rods inside work in a cascading state.
deya ball mill

rod mill

2. Grinding medium

Rod mill commonly uses steel rods with diameter of 50-100mm as grinding medium, while ball mill uses steel balls as grinding medium, and the difference of grinding medium is the main difference between them.

The steel balls of ball mill are in point contact with each other, while the steel rods of rod mill are in line contact with each other, so the working characteristics of the two have obvious differences.
grinding balls

steel rods

3. Discharge methods

Among the ball mills, the commonly used ones are grate type ball mill and overflow type ball mills, they are named from the different structure of the discharge section. While rod mills do not use grate plate to discharge minerals, there are overflow and open type for discharging. Also for the rod mill, the diameter of the hollow shaft at the discharge end is generally larger than that of the same size of ball mill.
ball mill discharge

ball mill inside
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