SZL Membrane Water Wall Coal-fired Steam Chain Grate Boiler

Product Description:

Rated capacity: 15~30t/h

Rated work pressure：1.25~2.45Mpa

Adaptive fuel：Ⅱ.Ⅲ Bituminous coal

Application industry : industrial and mining enterprises, schools, hospitals, etc.

Main Technical Parameters of Assembled Membrace Wall Type Boiler

1.    Structure introduction :

The boiler is a double-drum longitudinal natural circulation assembled water-tube boiler. The combustion equipment adopts light chain grate and equipped with stepless speed transmission device. The front, rear and two sides of the water-cooled wall are arranged in the furnace, and the water-cooled wall on both sides adopts the membrane wall structure. The front and rear water-cooled wall hanging special-shaped refractory bricks form a high and short front arch and a low and long rear arch above the grate, covering about 75 % of the length of the grate. The convection tube bundle is composed of boiler steel tubes, and the flue gas is folded into three return strokes with a partition wall. A cast iron economizer and a horizontal steel tube air preheater are arranged at the tail.

The blower blows cold air into the air preheater from the left side of the boiler, and enters the hot air ducts on both sides of the boiler after heat exchange. It rises to the furnace through nine independent grate air chambers. Each air inlet pipe is provided with an adjustment door, which makes the air distribution adjustment on the grate simple. The coal hopper is arranged in front of the combustion equipment, and the coal gate adopts a water-cooled cast steel serrated shape, which effectively increases the surface area of the coal seam and is conducive to the full combustion of coal.

The fuel enters the furnace through the coal hopper device and burns. The high-temperature flue gas absorbed by the water-cooled wall of the furnace enters the cooling chamber and convection tube bundle. After heat exchange, the furnace body is discharged into the cast iron economizer and tubular air preheater, and then through the dust collector. Finally, the induced draft fan is drawn from the chimney to the atmosphere.

2.Product features :

The membrane water-cooled wall boiler is one of the characteristic products of our factory. Because this type of boiler adopts a variety of new technologies and new structures, it has the characteristics that other boiler manufacturers do not have :

a.The burner, upper & lower drums and convective tube banks are assembled in workshop to reduce to workload at site, shorten the assembly period,ensure the assembly quality and cut the investment for client.

b.The boiler has double drums, total water tube and natural circulation, with large water capacit, large radiation heating surface,,large output capacity and safe & reliable operation.

c.Our boiler is featured in the left & right sides of furnace, where are all membrane walls. This feature helps enlarge the radiation heating surface effectively and enable the boiler with excellent workload capacity. Detailed explanation is follwed:

Ⅰ、Membrane walls have great rigidity and are well sealed, so there will be no transformation of two sides during operation and no need of refractory material, which can be replaced with light insulation material. The light of boiler brickwork and workload & cost of brickwork is less than others.                                                                                                                                                                          

Ⅱ、Due to the well sealed membrane wall, less heat loss and flue gas loss, and higher boiler efficiency.

Ⅲ、The boiler temperature can rise up and cool down more quickly, shortening the start up and shut up time.

d.For ash cleaning of convective tube bank, we provide bypass ash dropped unit and internal ash dropped unit for your choice. Both of them can help keep the cleanness of tube bank and maintain the effective heat exchange between water in the tube and gas.                                                     e.The front and rear membrane wall can extend to the end of fore -and-aft arches, helping them attached to the membrane walls and not breaking downing during cooling.

f.The left & right membrane walls extend until the side sealing, to reduce the coking on the furnace, which affects the burning.。

g.The rear membrane wall is sparse with two rows with fire wall in middle. The fire wall can protect the walls and form a reburning chamber. The carbon in the fly ash can be burned totally in the chamber so that the boiler efficiency is higher and the exhausted gas is cleaner.

h. In the aspect of combustion equipment, the enhanced active grate is adopted to ensure the safe and reliable operation of the grate.. To reduce the coal leak, we apply big grate for passive ones, and seven independent wind chambers under grate, which provide uniformly and adjusted wind from two sides. We can control the wind to meet different working condition's need.

i.The coal gate is water-cooled sawtooth type, which can loosen the coal to improve the burning surface. After years' practice, it's proven that this type coal gate can help the coal burned totally and there will be less coal in slag, and less incomplete combustion loss.

j.Finned tube of economizer can reduce the ash deposition in economizer. There is manhole for check and maintain above economizer. 

Since the shop-assembled boiler of our factory has been put into the market, it has been welcomed by customers with its unique design, good operating performance and low supporting investment.

This series of products was awarded the National New Product Award by the Ministry of Economy and Trade in 1997, and the Golden Bull Award for Excellent New Products of Jiangsu Province in 1998.