Blower failures

Air flare blower failure test. (Courtesy of John Zink Co. LLC.)... 

Consider the refrigeration system used in one of the Israel supermarkets. The system consists of 4 compressors, situated in the machine room and 2 main axial condenser blowers. It is possible to add one reserve blower. The reserve blower begins to work only when one of the main blowers has failed. Compressor failure rate is one per year and axial condenser blower failure rate is 10 per year. The mean repair time for the compressor is one month and for blower is 24 hours. The state-space diagram for the system without reserved blower is presented in Figure 2. 

Blowers, or positive-displacement fans, have the same common failure modes as rotary pumps and compressors. Table 13.4 lists the failure modes that most often affect blowers and fluidizers. In particular, blower failures occur due to process instability, caused by start/stop operation and demand variations, and mechanical failures due to close tolerances. 

Type B1 cabinets must be hard-ducted, preferably to their own dedicated exhaust system, or to a properly designed laboratory building exhaust. Blowers on laboratory exhaust systems should be located at the terminal end of the duct work. A failure in the building exhaust system may not be apparent to the user, as the supply blowers in the cabinet will continue to operate. A pressure-dependent monitor should be installed to sound an alarm and shut off the BSC supply fan, should failure in exhaust airflow occur. Since this feature is not supplied by all cabinet manufacturers, it is prudent to install a sensor in the exhaust system as necessary. To maintain critical operations, laboratories using Type B1 BSCs should connect the exhaust blow er to the emergency power supply. 

Figure 44.31 Vertical broadband mode shape for Spencer blower indicates potential failure...

If we add the narrowband information acquired from the Hoffman blower, we find that the vertical data is primarily at the true running speed of the common shaft. This confirms that a deflection of the shaft exists. No other machine component or failure mode is contributing to the problem. The horizontal measurements indicate that the bladepass, bearing defect and misalignment narrowbands are the major contributors. 

As we discussed, fans and blowers are prone to aerodynamic instability. The indication of abnormal vanepass suggests that this may be contributing to the problem. The additional data provided by the narrowband readings help to eliminate many of the possible failure modes that could be affect the blower. However, we still cannot confirm the specific problem. 

Without doubt, the most essential characteristics of the scientist-glass blower include persistence, patience and ingenuity. The beginner should never be discouraged by failures, and in moments of anguish and distress he should remember that we are all born knowing nothing, and that what one fool can do, another can do too. 

When handling highly hazardous or flammable materials, it is obvious that the reliability of critical rotating equipment such as blowers, compressors, and pumps is of high importance. Rotating equipment with the highest consequence if a failure would occur (Class 1... 

An opening in the top of the reactor allows samples to be obtained from the interior, the corresponding analyses to be carried out and the behavior of the biomass to be followed. The level inside the reactor is controlled by means of a differential controller, while the appropriate oxygen concentration is maintained by means of a blower that blows air into the reactor, although there is also a connection with a pure oxygen supply in case of failure in the blower. The air enters by means of two pipes one, a venmri and the other linked to four diffusers. Both can be regulated by manual valves. 

Compressor drives. Compressors and blowers in fluid cracking units may be either steam or electrically driven (209). Steam turbines were preferred over electric-motor drives in the design of early units, partly because of fear of a power failure. However, under some circumstances, the economics favor the use of electric motors. Several units have been built with electrically driven main air blowers, and at least one refiner has selected electric motors for the air blower, gas compressor,... 

Mechanical failure of equipment such as bearings, blowers, mechanical conveyers, mills, mixers, and unprotected light bulbs. 

Bearings Undersized replica parts substituted for original equipment size on 200 hp blower Excessive vibration caused premature failure of blower with shutdown to replace bearings Specify replica parts accurately and know if the are applicable... 

One of the advantages of this automatic system is that the state-of-health data recorded for the numerous subsystems, including blowers, component states, temperatures, and other critical information, allow remote failure detection, diagnosis, and possibly prevention. As an example, variation in detector temperature may show the onset of failure of a mechanical cooler. Remote diagnostics are used to schedule repair trips and minimize down time. 

Once the reactor has been placed in operation there will always be active particles within the air passages. To prevent these active particles from entering the Reactor Building, a basic requirement of the reactor air system is that there always be a flow of air in the proper direction. Upon failure of the main exhaust blowers and the auxiliary fans, this flow will he induced by whatever stack draft is available. 

After the reactor has been in operation long enough so that the reactor, reactor air system, and stack are hot, there is a stack draft of about 0.5 in. of water available. This is based on air temperatures of 200°F in the stack and 90°F. atmospheric. I.t is estimated that this, draft.would pr.oduce a flow of 2000 to 3000. cfm through the reactor in..the event of failure of all blowers... 

The main exhaust blowers are started manually within the Blower and Fan House. Tp promote safe operation of the reactor,air system,both of the auxiliary fans start automatically on failure on the main blowers, and one may then be shut down manually. However, in the event of failure of the one left... 

The cooling system someti mes produces refrigeration effect while someti mes not. 1. compressor works normally 1. ice block in the cooling system 2. failure of thermal resistor or temperature sensing bulb 3. poor contact of A/C switch 4. condensing blower damaged... 

Heating not supplied or not sufficiently supplied 1. blower of air conditioner failure 2. relay of the blower damaged 3. heating water pipe blocked 4. cooling water pipe blocked 5. cold/hot damper executor damaged 6. insufficient cooling liquid... 

FAT Acid pump failure Release of unabsoibed SO3 to the atmosphere Air blower and sulfur feed pump should trip automatically (air blower first, followed by sulfur pump)... 

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