Vertical Membrane Water Tube Boilers

A vertical membrane water tube boiler, designed for biomass and/or oil firing with a capacity range of 50 kg/hr to 1500 kg/hr and a working pressure of 10 bar (approximately 145 psi or 10.2 kg/cm²), is a specialized industrial steam generator. This small-to-medium capacity range is often utilized by process industries that require reliable steam in a compact footprint.

Key Features & Characteristics

1. Vertical Design

Compact Footprint: The vertical orientation makes the boiler highly space-efficient, which is a significant advantage in factories or facilities with limited floor space.
Natural Circulation: The vertical arrangement often promotes natural water circulation due to density differences (hot water/steam rises, cold water falls), aiding boiler safety and efficiency, though some small units may be assisted by a pump.

2. Water Tube Configuration

High Pressure Capability: In a water tube boiler, water flows inside the tubes while hot flue gases pass outside. This design is inherently better suited for higher pressures (like your specified 10 bar) and quicker steam generation compared to fire tube boilers, which are more common in this small capacity range.
Faster Response: Water tube boilers generally have a smaller water content relative to their steam output, allowing them to respond quickly to changes in steam demand.

3. Membrane Water Walls

Enhanced Heat Transfer: The membrane wall construction involves welding closely spaced water tubes together with a flat steel bar (the membrane) between them. This forms a gas-tight furnace enclosure.
Reduced Refractory: It minimizes or eliminates the need for refractory lining in the furnace, which reduces maintenance costs and time associated with refractory repairs.
Efficiency: The membrane tubes absorb radiant heat directly from the flame, significantly increasing thermal efficiency and protecting the outer casing from high furnace temperatures.

4. Fuel Flexibility (Biomass/Oil Fired)

Biomass Firing: For the biomass option, the boiler likely includes a specialized external furnace or a suitable internal grate system (like a static or moving grate) to handle solid fuels such as wood, briquettes, husks, or other agricultural waste.
- External Furnace: A separate furnace chamber is often used for biomass to ensure complete combustion before the hot gases enter the main boiler tubes.
Oil Firing: For oil (light oil, heavy oil, or gas), the boiler uses a burner assembly attached to the furnace, providing a more compact and automated firing solution.
Multi-fuel Options: The design may be hybrid, allowing the use of both biomass (solid fuel) and oil/gas (liquid/gaseous fuel) with minimal changeover, offering fuel flexibility based on cost and availability.