Discharge System for Direct Reduction Furnace

Product Specifications

Technical details and manufacturing context for Discharge System

Definition

The discharge system is a critical component of a direct reduction shaft furnace, responsible for the controlled extraction of direct reduced iron (DRI) or hot briquetted iron (HBI) from the furnace hearth. It operates at the bottom of the furnace, managing the flow of solid metallized product while maintaining the integrity of the reducing gas seal and the furnace pressure. Its design ensures continuous or batch-wise removal of material without disrupting the reduction process occurring above. The system typically consists of a rotating grate or a series of discharge screws/valves at the furnace bottom. As reduction completes, the solid iron product descends by gravity. The discharge mechanism (e.g., rotating arms, screws) actively extracts the material, often into a sealed chamber or conveyor. This action is carefully synchronized with the furnace's overall material flow to maintain a consistent bed height and process stability. Cooling may be integrated to protect mechanical parts from high temperatures. The system is engineered for high-temperature, abrasive service, with components made from heat-resistant alloy steel, refractory linings, and abrasion-resistant castings. Key parameters include discharge capacity (50–200 t/h), operating pressure (1.0–1.6 MPa), operating temperature (400–600 °C), sealing class (ISO 5208 Rate A), drive power (5.5–15 kW), supply voltage (380–690 V AC, IEC 60038), control voltage (24 V DC ±10%, IEC 61131-2), ingress protection (IP54–IP65, IEC 60529), material grade (ASTM A387 Gr.22), and weight (1500–4500 kg). These values are reference ranges for directory purposes and must be verified with the legal manufacturer for specific models. The system is selected based on furnace size, production rate, and process conditions. Interfaces include the furnace bottom structure, reducing gas system, and downstream material handling. Verification questions should address actual performance data, material certifications, and compliance with applicable standards. Maintenance signals include abnormal wear, seal leakage, and drive motor overload. Failure boundaries include loss of gas seal, mechanical jamming, and overheating of components.

Working Principle

The discharge system operates at the bottom of a direct reduction shaft furnace. Reduced iron (DRI/HBI) descends by gravity after reduction. The discharge mechanism, such as rotating arms or screws, actively extracts the material into a sealed chamber or conveyor. This action is synchronized with the furnace's material flow to maintain a consistent bed height and process stability. Cooling may be integrated to protect mechanical parts from high temperatures. The system ensures controlled removal without disrupting the reduction process.

Common Materials

Heat-resistant alloy steel, Refractory linings, Abrasion-resistant castings

Technical Parameters

Parameter	Typical range	Notes & selection driver
Discharge Capacity	50–200 t/h	Matches furnace production rate
Operating Pressure	1.0–1.6 MPa
Operating Temperature	400–600 °C	Material creep limits at upper end
Drive Power	5.5–15 kW	Depends on system size
Supply Voltage	380–690 V AC	Three-phaseIEC 60038
Control Voltage	24 ±10% V DC	For PLC and sensorsIEC 61131-2
Ingress Protection	IP54–IP65	Dust and water spray protectionIEC 60529
Material Grade	ASTM A387 Gr.22	For high-temperature serviceASTM A387
Weight	1500–4500 kg	Increases with capacity

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Rotating Grate/Discharge Table
The primary mechanism that rotates to sweep and guide the reduced iron product out of the furnace hearth.

Material: Heat-resistant alloy steel
Discharge Screw/Extractor Part
An auger or screw conveyor that actively pulls material from the discharge area into a sealed offtake.

Material: Abrasion-resistant steel
Sealing System
Maintains a gas-tight seal around the discharge mechanism to prevent air ingress and reducing gas escape, crucial for safety and process efficiency.

Material: Refractory materials, specialized seals
Drive Unit
Provides the rotational force to the grate or screw, often with variable speed control for rate adjustment.

Material: Steel housing, electrical components
Cooling System Optional
Keeps the grate and screw below their temperature limit where the DRI comes out hot.

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Direct Reduction Shaft Furnace

View system integration details

Manufacturers of Discharge System

2 companies list this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

Guangxi Runxiang Machinery Equipment Manufacturing Co., Ltd.

Guangxi, CN

Also makes: Continuous Casting Machine, Induction Melting Furnace, Dust Collector and 9 more

Listed on the company's own website · profile compiled by CNFX from public sources

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Jiangsu BOOTEC Engineering Co., Ltd.

Jiangsu, CN

Also makes: Bucket Elevator, Screw Conveyor

Listed on the company's own website · profile compiled by CNFX from public sources

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Frequently Asked Questions

What is the function of a discharge system in a direct reduction furnace?

It controls the extraction of DRI/HBI from the furnace bottom while maintaining gas seal and pressure.

What are typical operating temperatures?

The reference range is 400–600 °C, but actual values depend on the specific furnace design and must be confirmed.

Which standards apply to sealing and pressure?

ISO 5208 is referenced for sealing class and pressure testing. Verify compliance with the manufacturer.

How is the discharge capacity determined?

It matches the furnace production rate, typically 50–200 t/h, but must be verified for the specific model.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification

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pressure:	Atmospheric to 2 bar (gauge), with surge capability to 3 bar
flow rate:	5-100 tons/hour of DRI/HBI, depending on furnace capacity
temperature:	Ambient to 600°C (continuous), up to 800°C (intermittent)
slurry concentration:	Not applicable - system handles dry/semi-dry reduced iron, not slurry

Discharge System

Product Specifications

Applied To / Applications

Industrial Ecosystem & Supply Chain Structure

Application Fit & Sizing Matrix

Reliability & Engineering Risk Analysis

Compliance & Manufacturing Standards