SZL Series Coal Fired Chain Grate Boiler

Zhongding SZL series coal fired water tube boiler is the horizontal type double drum longitudinal type chain grate water tube steam boiler. Zhongding Boiler inherits the current mature technique of SZL assembly chain grate boiler, gains technological breakthrough on the following areas: furnace with water-cooling chamber, back-arch structure design, boiler design with low thermal inertia, seal structure on membrane wall, and contact side seal of the grate. This is a patent product of Zhengzhou Zhongding Boiler, the patent number is ZL 2009 2 0089355.7.

Rated Capacity:







Coal and biomass fuel

Boilers Structure

SZL Series Coal Fired Chain Grate Boiler

1.The boiler boiler adopts membrane water cooling wall structurer, the boiler is full sealing, reduce heat loss, improve boiler efficiency.

2.Whole membrane water cooling combustion chamber and inverted "α" arch furnace technology achieve high combustion efficiency, high output

3.Extended length of the grate, extended the coal burning time, improved the boiler thermal efficiency

4.Light furnace wall structure reduce heating loss, thermal inertia decrease 70%, furnace heat up fast, boiler start-up and shut down quickly

5.Anti-coking heater design, remove the side sealing steel, avoid the problem of grate stuck and uneven air distribution for combustion.

6.Adopt light rail I-beam for the rail under the grate, abrasion resistance and difficult for deformation, improve the reliability of boiler operation.

Auxiliary equipment

Chain grate

Chain grate

The chain grate is 500~1000mm longer than others, lengthen the fuel combustion time, improve combustion efficiency. The grate has small fuel leakage, and could resist the temperature as high as 1200℃, has long working life.

Control system

Control system

We adopt Siemens PLC(Programmable Logic Control)and Schneider electrical components. can realize automatic interlock control of water level, pressure, temperature and feed water with high accuracy Multiple protection can ensure boiler safe operation.



Zhongding adopts aluminum alloy fin tubes, its heating transfer area is 2-10 times larger than the bare tube, and the heating transfer coefficient is 1-2 times higher than that the bare tube, it has a good heating transfer and mechanical property.



We adopts the stainless vertical pump with low noise, stainless impeller and pump body.

Steam header

Steam header

Standard configuration: one inlet, three outlets, equipped with pressure gauge and thermometer. It can be designed according to customers' requirement.

Water softener

Water softener

It is fully automatic and free debugging. We adopts PE material for salt tank body, it has hard texture and it is easy to move, anti-shock, and no leakage.


Zhongding Boiler pay more attention to the boiler quality from raw material to producing process.

boiler quality
we choose domestic well-known manufacturer who can provide component report of raw material, to ensure the raw material is qualified. After the completion of raw material procurement, there are specialized technicians in our factory to make sampling chemical composition analysis and physical performance analysis, and we can also provide raw materials inspection report.
We adopt numerical control cutting, which has the advantage of high precision, neat cutting surface, nice appearance and high material utilization.
Boiler manufacturing
Boiler production
We adopt submerged arc fully automatic welding. When each welding process is done, the 100% X-ray inspection will be arranged for every welding seam, which can prevent the defective parts from flowing into the next process.


Steam Boiler Model SZL4-1.25 SZL6-1.25 SZL8-1.25 SZL10-1.25 SZL15-1.25 SZL20-1.25 SZL25-1.25
SZL4-1.6 SZL6-1.6 SZL8-1.6 SZL10-1.6 SZL15-1.6 SZL20-1.6 SZL25-1.6
SZL4-2.5 SZL6-2.5 SZL8-2.5 SZL10-2.5 SZL15-2.5 SZL20-2.5 SZL25-2.5
Rated Evaporation Capacity (t/h)      4 6 8 10 15 20 25
Rated Working Pressure (Mpa) 1.25/1.6/2.5 1.25/1.6/2.5 1.25/1.6/2.5 1.25/1.6/2.5 1.25/1.6/2.5 1.25/1.6/2.5 1.25/1.6/2.5
Feed Water Temperature (℃) 20 20 20 60 105 105 105
Steam Temperature(℃) 194/204/226 194/204/226 194/204/226 194/204/226 194/204/226 194/204/226 194/204/226
Body Heating Area (m2) 96.5 141.7 177 228 311 727 920
Grate Area (m2) 5.5 7.66 10.4 11.8 17.7 20.8 25.8
Combustion Method Chain Grate
Note: Parameters is for reference only, if any change should follow actual drawings


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