China straight-through type wet drum separator

China direct-flow wet drum separator is not just equipment for removing ferromagnetic impurities. This is a technological solution that determines the stability of crushers, the service life of conveyor belts and the purity of the final product in cement plants, coal mines and processing complexes. We have seen one mis-selected separator cause three emergency shutdowns per week at a processing plant near Kemerovo. Cause? Insufficient throughput and lack of adaptation to the humidity of the feedstock. That is why the direct-flow wet drum separator has become the standard where water, clay and fines are not the exception, but the rule.

Why exactly the direct-flow type solves real problems

Unlike countercurrent or circulation models, a direct-flow separator ensures a single passage of pulp through the active zone - from inlet to outlet - without reverse flows or stagnation. This is critical when working with viscous suspensions: for example, when enriching ferruginous quartzites with a solid phase content of up to 65% by weight. Under such conditions, counter-flow systems quickly become clogged, while direct-flow systems maintain a stable flow rate of up to 320 m³/hour with minimal hydraulic resistance.

We tested this at a facility in the Belgorod region: when replacing an outdated separator with a model with a direct-flow circuit and magnetic induction of 0.85 Tesla, we were able to reduce the iron content in the finished concentrate from 0.42% to 0.07%. At the same time, the inlet pressure dropped by 18 kPa - this is a direct energy saving at the pumping station. Direct flow works when other solutions fail: at pulp temperatures of +5...+45 °C, at pH from 3 to 11, even in the presence of abrasive particles up to 25 mm in size.

What “wet” hides - and why it’s not just water

“Wet” in the name is not an indication of operating conditions, but a principle of separation. The pulp is fed directly onto the surface of a rotating drum, covered with wear-resistant rubber with a hardness of 65–70 Shore. Water here performs three functions: it washes away the layer of material from the drum, cools the magnetic system and creates a hydrodynamic cushion that prevents shock loads on ferromagnets.

But water is not a universal solution. We have encountered cases where customers tried to use a wet separator in dry conditions - the result: rapid wear of the drum and loss of magnetic force. And vice versa: when air gets into the pulp (for example, due to leaky suction), air jams occur and efficiency drops by 30–40%. Therefore, the key parameter is not “how much water”, but “how it is distributed.” Modern models have adjustable nozzles with a spray angle of 90° and a pressure of 0.2–0.6 MPa. They ensure uniform moistening of the entire width of the tape without the formation of “dry stripes”.

How to choose - and what mistakes are most common

Three parameters that cannot be ignored when choosing:

• Drum diameter: from 600 to 1200 mm. The more, the higher the performance, but the stricter the requirements for the foundation and drive power. For lines up to 150 t/h, 800 mm is sufficient.
• Drum axis tilt angle: from 5° to 15°. At a low angle, the slurry flow rate decreases and the risk of clogging increases. When large, the time of contact with the magnetic field decreases. The optimum is 8–10°.
• Drum cleaning system: automatic brush with adjustable pressure or hydraulic reset. The brush is reliable for large inclusions; hydraulic discharge - for fine and sticky impurities.

A common mistake is to focus only on the declared performance. In fact, it depends on the density of the pulp, the content of magnetic particles and their shape. For example, plate-like inclusions are captured worse than spherical ones at the same weight. We always require samples of raw materials from clients for testing in the laboratory - otherwise the calculation will turn out to be theoretical.

LONGI Corporation: an experience that cannot be imitated

Shenyang Longji Scientific Electromagnetic Co., Ltd. has been creating direct-flow wet drum separators since 1993. Over 30 years, the company has grown from a small research institute into an enterprise with an area of ​​140,000 m² with its own foundry, testing station and certification department. More than 60% of engineers have higher technical education, and the annual output is 4,000 units of equipment.

In practice, this means: each separator undergoes a three-level test - for magnetic induction (using a Hirst GM05 digital teslameter), for housing tightness (hydraulic tests at 1.5× operating pressure) and for drum balancing (dynamic balancing up to G2.5). This approach allows us to guarantee a resource of 120,000 hours of operation without major repairs - subject to compliance with the maintenance regulations.

China direct-flow wet drum separator from LONJI is not a compromise between price and quality. This is a solution that takes into account the physics of pulp, the mechanics of rotation and the realities of Russian operating conditions: from minus 40 °C in Yakutia to high humidity in Kaliningrad. The selection begins not with a catalog, but with an analysis of your pulp. Connection diagrams, installation recommendations and test reports are available on the websiteljmagnet.ru.