Category: Coal Firing

Troubleshooting Coal Stokers

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All mechanical devices occasionally malfunction or operate below a commonly accepted level of efficiency. Coal stokers are no exception to this rule. Table 3-1 lists the conditions that indicate faulty operation: Table 3-1 Troubleshooting Coal Stokers Symptom and Possible Cause Possible Remedy Abnormal noises. (a) Loose pulleys or belt. (a) Tighten or replace. (b) Dry …

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How to Adjust Coal Feed

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How to Adjust Coal Feed

Figure 3-11 illustrates the steps involved in a typical coal feed adjustment. Their order (in sequence) is as follows: 1. Select the proper amount of coal feed for the furnace (refer to the coal feed chart provided by the stoker manufacturer). 2. When the proper coal feed is selected, the opposite side of the pointer …

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How to Remove Clinkers

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You will find it easier to remove the clinker if you let the fire cool off for 5 to 10 minutes before removing it. Turn the stoker off and open the fire door to cool the fire. Fill the hopper while the clinker is cooling. The clinker normally forms around the retort. Use an iron …

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Starting Coal Firing

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Generally, the procedure involved in starting a fire in a stokerequipped heating installation includes the following steps: 1. Set the room thermostat above the room temperature. 2. Set the coal feed and air setting to the proper rate. 3. Throw the line switch to the on position so that the stoker starts. 4. Open the …

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Coal Selection

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A bituminous coal, low in ash (6 percent or less), with an ash fusion temperature of 2200°F to 2600°F and 1 1?4-inch to 3?8-inch maximum is ideal for stoker operation. Oil treatment of the coal is recommended in order to eliminate dust and add lifetime to the stoker. Generally speaking, in most sections of the …

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Domestic Coal Stoker Automatic Controls

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Domestic Coal Stoker Automatic Controls

Figure 3-8 illustrates typical controls for a stoker in a forced warmair heating system. There are approximately three basic automatic controls necessary for satisfactory operation of the stoker. These three controls are as follows: 1. Thermostat. 2. Limit control. 3. Hold-fire control. The purpose of the thermostat is to start the fire when the room …

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Domestic Coal Stoker Construction

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Domestic Coal Stoker Construction

Although there are variations in the type and design of domestic stokers, the general features are much the same. An elementary stoker is shown in Figures 3-5 and 3-6, which gives the essentials and the names of parts. These parts may be listed as follows: 1. Retort. 2. Fan. 3. Motor. 4. Transmission. 5. Air …

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Stoker Firing

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Stoker Firing

A stoker is a mechanical device designed and constructed to automatically feed fuel to a furnace. Stokers are used in commercial, industrial, and domestic heating systems. Their use results in more efficient combustion owing to constant instead of intermittent firing. According to the ASHRAE Guide (1960), coal stokers can be divided on the basis of …

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Firing Semibituminous Coal

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Semibituminous coal burns with far less smoke than the bituminous type. It ignites with more difficulty than bituminous coal but produces far less smoke. The central cone method is recommended for firing semibituminous coal. In this method, the coal is heaped onto the center of the bed, forming a cone, the top of which should …

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Firing Bituminous Coal

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Bituminous coal is a broad category encompassing many different burning characteristics and properties. Generally speaking, bituminous coals ignite and burn easily with a relatively long flame. They are also characterized by excess smoke and soot when improperly fired. The side bank method is commonly recommended for firing bituminous coal. It consists of moving the live …

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