Chain Grate Boiler, Coal Fired Stoker Boiler - Best Systems

Chain Grate Boiler – All Questions Answered

Introduction

The growing trend of chain grate boiler requires perfect literature of chain grate stokers, their types, and their working principle. Therefore, we have compiled the most asked questions about the chain grate stoker boilers and provided expert answers to all of them.

Apart from that, it is a fact that the chain grate stoker can boost your boiler’s thermal efficiency. For that reason, knowing it and its alternatives may turn out to be beneficial, especially when buying a boiler. So, without any further ado, let’s start from the very start of the chain grate boiler.

What Is A Chain Grate Boiler?

Overview

The chain grate boiler refers to the steam boilers with a chain grate or reciprocating grate feeding system. Basically, the chain grates are the fuel’s support inside the furnace. It feeds solid fuel to the furnace automatically. You won’t need labor to provide fuel continuously. Rather, you fill the boiler hopper and let the chain grate system feed fuel automatically.

In a chain grate coal fired steam boiler, coal resides and burns on the chain grate stoker. It travels inside the furnace like a conveyor belt and sends burned coal to the other side.

The chain grate stoker has holes in order to allow air for combustion. It is fully automatic and works without any operator. The travelling speed of the traveling grate boiler is adjustable. However, for the best performance, you should ask our experts. It also depends on the coal size you are burning on it. So, make sure you consider these factors before adjusting the chain grate stoker speed.

Chain Grate Boilers

Following are the chain grate coal fired steam boiler series. They all have a highly-efficient design with an efficiency of more than 90%.

• DZL series biomass/coal fired chain grate steam boiler
• DZH series biomass/coal fired chain grate boiler
• LHG series biomass/coal fired chain grate boiler
• SZL series biomass/coal fired chain grate boiler

Characteristics Of Chain Grate Boiler

• Even a small chain grate boiler can bear a temperature up to 1100 ^o
• The chain grate stoker boiler has longer operation life.
• It automatically feeds fuel. Thus, reducing the need for labor.
• It offers straightforward and cheap maintenance without even turning off the boiler.

Auxiliaries Of Chain Grate Boiler

• Slag machine
• Chain grate
• Valves
• Pressure gauge
• Steam header
• Chimney vent
• Control panel
• Economizer
• Water tank
• Water softener
• Pumps

Chain Grate Boiler Applications

• Chemical processing industries
• Textile industries
• Food processing mills
• Power production
• And all industries that require 100% dry steam for their products

What Are The Types Of Grate Stoker?

There are multiple types of chain grate stokers. However, two types are most common in the industrial boilers:

1. Travelling grate stoker
2. Spreader stoker

1. Travelling Grate Stoker

The travelling grate stoker, also known as chain grate stoker, is a mechanical moving grate. It consists long chain which can move linearly. When the grate moves, it drags the coal or other solid fuel to the boiler furnace. It has two ends. At one end, you feed the solid fuel, and at the other, the solid fuel drops in the form of ash.

The chain grate stoker boiler system is common in most industrial boilers due to its advantages. Following are some of the main advantages of chain grate stoker

• It increases the thermal efficiency of the boiler’s furnace.
• It requires no fireman or stoker to feed the fuel manually.
• It has a robust design and can tolerate very high temperatures of flue gases.
• It comes with an automatic cleaning feature.
• It has convenient and cheap maintenance.
• High automation level.

2. Spreader Stoker

Spreader stoker has an automatic system of separating solid fuel according to their size. It has two parts; Suspension and grate burning. The small pieces of solid fuel separate and fall into the suspension. On the other hand, the larger size fuel falls into the grate burning.

chain grate stoker diagram

The spreader stoker automatically feeds the fuel from above using a rotating drum. It consists of moving blades. When the solid fuel drops on them, it rotates and sends fuel to the furnace. Many factories prefer a spreader stoker boiler due to its distinct properties. Following are some of its advantages:

• It is compatible with different size solid fuels.
• It can quickly cool the ash because the air comes from under the ash.
• It has cheaper operating costs.
• It is the best option for fluctuating loads.

What Is The Difference Between Travelling Grate Stoker And Spreader Stoker?

The spreader stoker and travelling grate stoker are most commonly used in industrial boilers. But how do they differ? Following are their differences:

How Do Primary Air And Secondary Air Work In A Furnace?

The furnace in boiler requires air for combustion. Therefore, the boiler chain grate stoker has holes to allow air. For complete combustion, we commonly use two types of air; primary air and secondary air.

Primary Air

The primary air in the boiler chain grate stoker is the air coming from the environment. It decides the amount of fuel burning. If reduced, less fuel will burn. Likewise, if increased, more fuel will burn.

Secondary Air

Sometimes, the fuel does not burn completely due to insufficient incoming primary air or leaks. Therefore, it takes the help of secondary air from forced draft fans. Generally, the chain grate boiler working is normal in its absence. However, providing secondary air can improve combustion efficiency dramatically.

What Is The Maintenance Of Chain Grate Stoker?

Chain grate boiler, either fire tube or water tube boiler, has the highest thermal efficiency compared to other grates. However, they require maintenance in order to maximize their performance. Following are the sections of the chain grate stoker boiler that will require timely maintenance:

Feedwater System

For high performance, you should check the condition of the water supply tank from time to time or at least annually. Moreover, you should check your water treatment plant and the temperature of feedwater to ensure they are according to your settings. Feedwater plays a vital role in impacting your boiler’s thermal efficiency.

Exhaust System

The exhaust gases must completely exit the boiler, or else they may damage your boiler’s grate and chimney pipes. Therefore, timely check of the blower, ID fan, and gate opening intervals are according to the factory settings. Poor de-slagging will cost your boiler’s efficiency and other boiler components.

Combustion In Furnace

It is incredibly crucial to check whether your fuel reserves supply a sufficient amount of fuel to your boiler hopper — insufficiency results in damaging the boiler chain grate stoker and other chain grate boiler parts.

Automation

The chain grate steam boiler has automatic settings and alarm settings. It is crucial to calibrate alarm settings of water level, water temperature, overpressure, interlock, etc. Even after calibration, you must check whether the alarms go off on your specified settings.

What Are Your Chain Grate Boiler Types?

Yongxing has the ability to equip you with various models:

• travelling grate stoker boiler
• reciprocating grate boiler
• chain grate steam boiler
• dumping/step grate furnace boiler
• pulsating grate boiler
• Power
• how to repair the chain grate damage?

They have a similar design from the outside, but the internal furnace design, the fire grate bar choice, and the travelling grate length are fully unique and customized in the best settings.

However, the reciprocating grate and the pulsating grate have a little bit different structure from the others. They usually use a 10-25 degree inclined grate angle to push the fuel back and forth. This design is to make your boiler burns the coal efficiently even in complicated conditions, such as too high humidity and too low heating value.

How Does Your Chain Grate Boiler Working?

As long as the fuel burn in your chain boiler furnace, a big sum of fuel ignite immediately. That is how the coal stoker boiler generates a large amount of heat energy instantly.

These heat energy and convective radiation energy are all absorbed by your boiler drum & downpipes. Finally, softening water inside your boiler changes into saturating steam or hot water to use.

How About Your Chain Grate Boiler’s Furnace?

Yongxing’s chain grate coal boiler furnace design can reduce your flue gas emission concentration immensely. A refractory wall appears at the tail of the chain furnace, that perfectly blocks the particles in your flue gas. Therefore, your bottom chain grate will transport the slag to the ash conveyor efficiently.

What Is Ash Handling?

Ash handling refers to the process of managing the waste resulting from the burning of solid fuels. Different types of ash remain by various solid fuels. Some of the most common are:

• Fly ash
• Bottom ash
• Ash clinkers
• Bed ash

In order to manage these solid fuel wastes, industrial steam boilers employ various techniques. They may adopt pneumatic or mechanical ash conveying systems depending on the type of ash.

Fly ash refers to the fined or powdered ash of the solid fuel. It is usually gathered from the dust collectors or other components in the boiler’s ash handling system.

On the other hand, the large or coarse size ash isn’t directly sent to the ash collectors. Instead, the boiler ash handling system sends it to the crusher (ash clinkers), where they reduce to the fine-size ash. Afterward, after reducing their size, the ash collector gathers them and ready them for removal.

Best Chain Grate Boiler

Undoubtedly, a chain grate boiler has more thermal efficiency than boilers with other grates. However, it is important to consider if it fits your industrial requirements. Besides that, it is more important to know whether the chain grate steam boiler you are buying is worth the cash you are spending on.

So, to get rid of all these puzzles, we introduce you to Yongxing chain grate steam boilers. We have world-class steam boiler systems that come with futuristic chain grate stokers. It has a very low fuel consumption rate and is pre-set to burn each coal piece completely. Plus, we have pre-determined the compatible coal sizes in the chain grate boiler operation manual so that you get complete fuel utilization.

If you have other queries regarding our chain grate steam boilers, we have a 24/7 active customer support team to answer all of them. So, contact us now!