What Is An EB Drilled Screen Basket? Basics for Black Liquor Pulp Mill Treatment

If you operate a pulp mill, you know black liquor treatment is a critical part of the pulping process— and the screen basket is the "heart" of the black liquor pressure screen. Among all pressure screen baskets, the EB Drilled Screen Basket is the most widely used choice for black liquor screening, especially for medium and high-concentration black liquor with high impurities. But what exactly is an EB Drilled Screen Basket? How does it work for black liquor treatment? What makes it different from other screen baskets? This article breaks down all the basics clearly, for your pulp mill’s daily production and equipment selection.

1. What is an EB Drilled Screen Basket? A Clear Definition

An EB Drilled Screen Basket is a custom-engineered metal filter component designed for the black liquor pressure screen in pulp mills. It is the core working part of the pressure screen, responsible for separating solid impurities (such as fiber scraps, pulp residues, and grit) from black liquor, to purify the black liquor and ensure the smooth operation of subsequent evaporation, combustion and recovery processes.

As a professional drilled screen basket for black liquor, its core feature is the precision-drilled hole design on the stainless steel screen plate— different from slotted or wedge wire screen baskets, it uses a full-drilled structure to adapt to the high abrasion, high corrosion and high impurity characteristics of black liquor. It is widely applied in chemical pulping, OCC waste paper pulping and other mainstream pulping processes, and is the standard configuration for most pulp mill black liquor pressure screens.

2. Core Structure of an EB Drilled Screen Basket (Easy to Understand)

The EB Drilled Screen Basket for black liquor treatment is not a single metal plate— it is an integrated assembly with a simple and sturdy structure, all parts are designed for the harsh working environment of black liquor. Its core structure includes 3 key parts, no complex components, easy to install and maintain:

2.1 Main Screen Cylinder (The Core Filter Part)

It is the main body of the screen basket, made of 304/316L stainless steel (customizable according to black liquor corrosion level). The whole cylinder is processed with precision mechanical drilling, the hole diameter is 【0.5-3mm】, the hole tolerance is ±0.05mm, and the opening rate is 【15%-30%】— high drilling precision ensures uniform black liquor filtration and no blockage during operation.

2.2 Top & Bottom Flange (Connection & Fixation Part)

Made of thickened stainless steel, it is used to connect and fix the screen basket to the black liquor pressure screen body. The flange is designed with a precise size to match the standard pressure screen models (such as 【Andritz/Valmet/Voith】 and other mainstream brands), ensuring a tight connection, no leakage of black liquor and stable operation at high pressure.

2.3 Reinforcing Ribs (Structural Support Part)

Evenly welded on the inner wall of the main screen cylinder, it is used to enhance the structural strength of the screen basket. Black liquor screening works under high pressure (≥【1.0MPa】), and the reinforcing ribs prevent the screen cylinder from deforming or cracking under pressure, extending the overall service life of the screen basket.

3. How Does an EB Drilled Screen Basket Work for Black Liquor Treatment?

The working principle of the EB Drilled Screen Basket is simple and efficient, fully matching the working process of the black liquor pressure screen, and the whole filtration process is completed in the closed pressure screen body— no manual operation is needed, and it is suitable for continuous production of pulp mills:

1. Feeding: The unpurified black liquor (medium/high concentration, with solid impurities) is pumped into the pressure screen body at a certain pressure;

2. Filtration: Driven by pressure, the pure black liquor passes through the precision-drilled holes on the EB Drilled Screen Basket’s main cylinder, and flows out of the screen basket to enter the subsequent purification process;

3. Impurity Separation: The solid impurities in black liquor are larger than the drilled hole diameter, so they are blocked inside the screen basket, and are continuously discharged from the pressure screen’s reject port by the rotation of the screen’s rotor;

4. Continuous Operation: The whole process is a closed continuous cycle, the EB Drilled Screen Basket maintains stable filtration efficiency, and ensures the continuous and smooth operation of the pulp mill’s black liquor treatment line.

4. Why Do Pulp Mills Choose EB Drilled Screen Basket for Black Liquor Treatment?

Black liquor is a typical harsh medium— high temperature (up to 100℃), strong corrosion, high abrasion and high impurity content. Common screen baskets (such as slotted screen baskets) are easy to block, wear and corrode when used for black liquor treatment, leading to high replacement frequency and production downtime. The EB Drilled Screen Basket is specially designed for these pain points, and its core value is fully reflected in black liquor treatment:

4.1 High Abrasion & Corrosion Resistance

Made of food-grade 304/316L stainless steel, and the screen surface can be plated with hard chrome (thickness 【0.05-0.1mm】), which effectively resists the abrasion of solid impurities in black liquor and the corrosion of alkaline black liquor, and the service life is 2-3 times longer than ordinary screen baskets.

4.2 Anti-Clogging & High Filtration Efficiency

The precision-drilled hole structure is not easy to be blocked by fiber scraps and pulp residues in black liquor, and the optimized opening rate ensures high black liquor filtration efficiency, which can reduce the energy consumption of the pressure screen and improve the overall production efficiency of the pulp mill.

4.3 Sturdy Structure & Stable Operation

The integrated welding structure with reinforcing ribs has high structural strength, no deformation or cracking under high pressure working conditions, and the operation is stable— no frequent shutdown for equipment maintenance, reducing the production loss of the pulp mill.

4.4 Customizable & Wide Compatibility

The hole diameter, opening rate, screen cylinder size and flange size can be fully customized according to the pulp mill’s black liquor concentration, impurity content and pressure screen model, and it is compatible with all mainstream black liquor pressure screen brands on the market.

5. Key Application Scenarios of EB Drilled Screen Basket

The EB Drilled Screen Basket is specially designed for black liquor treatment, and its application scenarios are highly targeted— it is not suitable for low-concentration pulp screening, and its core application scenarios in pulp mills are:

- Medium and high concentration black liquor treatment (3%-6% concentration)

- OCC waste paper pulping black liquor screening (high impurity content)

- Chemical pulping (kraft pulping/sulfite pulping) black liquor purification

- Black liquor treatment in small and medium-sized pulp mills (standard configuration)

Which EB Drilled Screen Basket is Right for Your Pulp Mill?

After understanding the basics of the EB Drilled Screen Basket, you may be wondering: What type of EB Drilled Screen Basket is suitable for my pulp mill’s black liquor treatment process? The answer depends on many key factors, such as black liquor concentration, impurity content, pressure screen model and production capacity.

Our professional team has rich experience in black liquor treatment screen basket selection, and we can provide you with a free customized selection plan according to your pulp mill’s actual production situation. At the same time, we also provide high-quality EB Drilled Screen Baskets with full customization, precision drilling and long service life— all products are strictly tested before leaving the factory, to ensure the stable operation of your black liquor treatment line.