A steam boiler heats water until it becomes steam. It is used when the process requires steam pressure or steam heat, such as garment pressing, textile processing, drying, sterilization, or industrial heating. A hot water boiler only heats water and does not produce steam. It is more suitable for hot water supply, space heating, swimming pools, hotels, hospitals, and spas.

An atmospheric pressure hot water boiler is an industrial boiler used to supply hot water, not high-pressure steam. It operates under atmospheric or near-atmospheric pressure and is suitable for applications that require hot water but do not need steam pressure.

In industrial and commercial applications, atmospheric pressure hot water boilers are commonly used in hotels, hospitals, swimming pools, spas, dormitories, cleaning systems, and general facility hot water supply. Its purpose is to provide hot water, not process steam.

Advantages

• Simpler operating conditions compared with high-pressure steam systems
• Suitable for general hot water supply and circulation heating
• Used in hotels, hospitals, pools, spas, and facility hot water systems
• Practical for sites that do not require steam processes

Considerations

• Not suitable for processes requiring steam pressure
• Pressurized hot water systems may be needed for higher temperature, pressure, or long-distance circulation
• Local safety regulations and installation conditions should still be reviewed

The main difference between an atmospheric pressure hot water boiler and a pressurized hot water boiler is whether the system operates under pressure.

An atmospheric pressure hot water boiler is mainly used for general hot water supply, such as hotels, hospitals, swimming pools, spas, cleaning, and facility hot water. It operates at lower pressure and is suitable for applications that do not require high-pressure circulation or high-temperature hot water.

A pressurized hot water boiler operates under pressure and is usually used for higher water temperature, larger heating coverage, long-distance circulation, or central heating systems. Because pressure is involved, boiler selection, piping design, safety valves, pressure control, and regulatory requirements are stricter.

A fire-tube boiler sends hot combustion gas through tubes surrounded by water. The heat from the gas transfers through the tube wall into the water, producing steam. Fire-tube boilers are commonly used in industrial steam applications because their structure is relatively straightforward and suitable for many medium-capacity steam demands.

A water-tube boiler sends water through tubes that are heated from the outside by hot combustion gas. This structure is often used when faster steam generation, higher pressure, or larger capacity is required. Compared with fire-tube boilers, water-tube boilers may require more complex installation and maintenance.

A chain-grate boiler is an industrial boiler design commonly used for solid fuels. It has a slow-moving grate at the bottom of the combustion area. Fuel is carried gradually into the furnace and burns as it moves forward.

A simple way to understand it is to think of a heat-resistant fuel conveyor. Fuel enters from one side, moves forward while burning, and ash is discharged from the other side.

This type of boiler is commonly used for:

• Coal-fired boilers
• Biomass boilers
• Boilers using rice husks, wood chips, corn cobs, biomass pellets, or other solid fuels

Advantages

• Suitable for continuous solid fuel combustion
• Supports long-hour steam supply
• Works well for coal and biomass fuel applications
• More suitable for factory operation than manual batch feeding

Considerations

• Requires fuel storage and feeding space
• Fuel size, moisture, and quality affect combustion performance
• Ash removal and emission management are required
• Not suitable for gas or liquid fuel systems

A single drum boiler uses one main drum for water and steam separation. The drum is an important component where water is stored, steam is generated, and steam is separated from water.

In industrial boiler products, single drum structures are commonly seen in DZL-type chain-grate boilers. These boilers are generally suitable for medium steam demand, such as applications up to around 6 tons, depending on model design and site conditions.

Advantages

• Relatively simpler structure
• Suitable for small to medium steam demand
• Commonly used in biomass or coal chain-grate boilers
• Installation and system configuration are usually simpler than larger-capacity boilers

Considerations

• May not be suitable for higher steam capacity demand
• Double drum boilers may be considered for larger steam requirements
• Actual capacity depends on fuel, pressure, operating hours, and site demand

A double drum boiler has two drums inside the boiler system. This design supports larger water circulation, larger heating surface area, and higher steam capacity. Compared with a single drum structure, a double drum boiler is generally more suitable for large-capacity and long-hour steam operation.

In industrial boiler products, SZL-type boilers are usually double drum chain-grate boilers and are commonly used for steam demand above 6 tons. They are suitable for facilities with higher steam output requirements and stable fuel supply.

Advantages

• Supports higher steam capacity
• Larger heating surface area
• Suitable for continuous, high-load operation
• Commonly used in larger biomass or coal-fired boilers

Considerations

• Equipment and system configuration are usually more complex than single drum boilers
• Installation space, fuel supply, and emission management should be planned in advance
• Better suited for larger demand, not always necessary for smaller factories