Differences and selection between water-tube boilers and hot pot stoves

The structural features of water-tube boilers are as follows: 1. The furnace of a water-tube boiler is located outside the cylinder, and its volume can be adjusted to meet the requirements for combustion and to increase the evaporation capacity. 2. The drum of a water-tube boiler is generally not exposed to direct heat; the tubes used to hold water vapor are placed in the furnace and flue as heat-exchanging surfaces, which significantly improves the heat transfer efficiency and safety performance. 3. The preheating of water in water-tube boilers, as well as the superheating of steam and vapor, take place in the economizer, water wall and convective tube banks, and superheater that are part of the heating surfaces. 4. The water and steam system, combustion system, and auxiliary systems of water-tube boilers are relatively complex, but the structure of individual pressure-bearing components in water-tube boilers is relatively simple. 5. In water-tube boilers, the preheating of water, as well as the superheating of the steam and water, take place inside the tubes; it is difficult to remove scale that forms on these tubes. Therefore, water-tube boilers require high standards regarding water quality, as well as high levels of skill in operation and maintenance. Comparison table of water-tube boilers and fire-tube boilers. Boiler type, Advantages, Disadvantages: Fire-tube boiler: 1. Simple structure, lower construction costs, and easy to operate. 2. Fewer failures, easy to maintain, and lower maintenance costs. 3. It has a large capacity for storing water and steam, offering greater flexibility in response to changes in load. 1. Its thermal efficiency is not as high as that of water-tube boilers, averaging only 70%–75%, with a maximum of 80% at most. 2. It has a large water storage capacity, resulting in a wide area of damage in the event of a rupture. Tube-type boiler: 1. Composed of components with smaller diameters, it can be disassembled and reassembled, making it easy to transport. Its structure is suitable for high pressure and large capacity. 2. The fuel equipment can be selected freely, the combustion chamber can be designed as desired, resulting in more complete combustion. 3. It has a large heat transfer area, resulting in good thermal efficiency and fuel cost savings. 4. In terms of the heating area, the amount of water in the furnace is not large, resulting in rapid steam generation; moreover, in the event of a disaster, the extent of damage is reduced. 5. The part that is exposed to heat is the water pipe, and the part that can expand and contract is carried by this water pipe, resulting in lower thermal stress on the furnace body. 1. It has a complex structure, its manufacturing costs are much higher than those of fire-tube types, and it is difficult to clean. 2. The impact of scale is quite significant, and strict water quality requirements are necessary. 3. Due to the small capacity of the water storage drums and steam drums, foaming between steam and water easily occurs, resulting in steam with high humidity. 4. Water pipes in prolonged contact with high-temperature combustion gases are prone to damage. 5. The steam storage volume is small, so the pressure fluctuates greatly.

For the medium inside the tube, fire tubes are generally used in vertical designs

It depends on how large a furnace you need and where it will be used