A STATIONARY BOILER can be defined as one having a permanent foundation and not easily moved or relocated. A popular type of stationary fire-tube boiler is the HORIZONTAL RETURN TUBULAR (HRT) boiler shown in figure 1-4. The initial cost of the HRT boiler is relatively low and installing it is not too difficult. The boiler […]
Read More…Bent tube boilers usually have three drums. The drums are usually of the same diameter and positioned at different levels with each other. The uppermost or highest positioned drum is referred to as the STEAM DRUM, while the middle drum is referred to as the WATER DRUM, and the lowest, the MUD DRUM. Tube banks […]
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In some fire-tube boilers, the tubes run vertically, as opposed to the horizontal arrangement in the Scotch boiler. The VERTICAL-TUBE boiler sits in an upright position, as shown in figure 1-3. Therefore, the products of combustion (gases) make a single pass, traveling straight up through the tubes and out the stack. The vertical fire-tube boiler […]
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Figure 1-1 is a portable Scotch marine tire-tube boiler. The portable unit can be moved easily and requires only a minimal amount of foundation work. As a complete self-contained unit. its design includes automatic controls. a steel boiler. and burner equipment. These features are a big advantage because no disassembly is required when you must […]
Read More…The STRAIGHT-TUBE class of water-tube boilers includes three types: 1. Sectional-header cross drum 2. Box-header cross drum 3. Box-header longitudinal drum In the SECTIONAL-HEADER CROSS DRUM boiler with vertical headers, the headers are steel boxes into which the tubes are rolled. Feedwater enters and passes down through the downcomers (pipes) into the rear sectional headers […]
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1. Undo the screw retaining the spark electrode to the burner tray (Fig. 40). 2. Undo the screw retaining the burner to the burner tray (Fig. 41). 3. Slide the burner to the left to disengage from the injector. Rotate the electrode slightly and lift the burner out of the tray. 4. Using a soft […]
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Most run capacitors and some starting capacitors are of the oil-filled type. This is especially true for high current motors such as those used to operate compressors. Many manufacturers of oil-filled capacitors will identify one terminal with an arrow, a painted dot, or by stamping a dash in the capacitor can, Figure 11–27. This identified […]
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The permanent-split capacitor motor has greatly increased in popularity for use in the air conditioning field over the past years. This type of split-phase motor does not disconnect the start windings from the circuit when it is running. This eliminates the need for a centrifugal switch or starting relay to disconnect the start windings from […]
Read More…It should be noted that the motor does not use less energy when connected to 240 volts than it does when connected to 120 volts. Power is measured in watts, and the watts will be the same regardless of the connection. When the motor is connected to operate on 240 volts, it will have half […]
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Single-phase motors can also be constructed to operate on two separate voltages. These motors are designed to be connected to 120 or 240 volts. A common connection for this type of motor contains two run windings and one start winding, Figure 11–17. The run windings are labeled T1–T2, and T3–T4. The start winding is labeled […]
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