Compressor failures

Check valves are required in the piping system at any point where backflow of gas after a shutdown has the ability to restart the compressor, running it backwards or, for that matter, even in the normal direction. Reverse rotation is totally bad, as many components of the various compressor types are not designed for reverse rotation, and there is some possibility, generally remote, that the compressor could reach a destructive over speed. Forward rotation is bad primarily because the intent was to stop the compressor, and it is now operating out of control. This is a problem, particularly if the shutdown was caused by a compressor failure indication, and the need to stop was to prevent further damage. In this mode, it is unlikely that the compressor can attain an overspeed condition. An application with a high potential for backflow is the parallel operation of two or more compressors. 

Streams which must be diverted because of emergency shutdown of downstream equipment (e.g., compressor failure). Diversion routes should be provided where such a contingency would otherwise require the immediate shutdown of the affected process unit, resulting in appreciable economic and operational debits. 

If either casing distortion or rotor expansion occur, the clearance between the rotating parts will decrease and metal-to-metal contact will occur. Since the rotors typically rotate at speeds between 3600 and 10,000 rpm, metal-to-metal contact normally results in instantaneous, catastrophic compressor failure. 

No/None Flow Compressor failure Possible dangerous NH3 cone. low flow pressure alarm (PA1) interlocked to shut-down NH3 flow... 

Intention - transfer secondary air to absorber No Flow Compressor failure... 

Investigation of a Pesticide Explosion, Awilda Puentes A Compressor Failure That MOC May Not Have Caught Alfred W. Bickum... 

Compressor Failures In the process industry there are three types of compressors that have very different maintenance problems ... 

Upon start-ups following emergency shut-ins, due to system component failure and recovery, such as compressor failure, without the opportunity to take inhibition steps. 

In Figure 1 the labelled state of the graph show of the compressor stations of a gas main system corresponding to the different conditions of the compressor stations. Conditions differ from each other by character and quantity of failed units. The number of a condition specifies the compressor failure K = 3i+j, i = 0, 1, 2 j =0, 1, 2. Here i designates the quantity of failed consecutively included compressor stations, and j - quantity of failed basic compressor stations. For example state 0 means that all compressors are efficient, but states 1 and 3 mean conditions when failed is one the basic or one the consecutively included compressor, accordingly. States 2, 5, 6 and 7 represent failures of the compressor station when damaged are two basic compressors two basic and one consecutively included compressor two consecutively included compressors two consecutively included compressors and one basic compressor. Arrows show opportunities of transition from one to other possible state [4],... 

No/None Flow Compressor failure Possible dangerous NH3 cone. ... 

Poisons in feed] depends on reaction/contamination in feed/upstream process or equipment upsets/dianges in feed. Poisons for platforming include high sulfur in feed and high feed end point with upstream equipment failure being compressor failure/water upset/chloride upset. 

During the system analysis, it was necessary to determine a time to compressors failure. Using the method of maximum likehood, it was determine that the time to compressors failure is driven by WeibuUs distribution (Fig. 6). More information about the system analysis may be found in (Gala 2007). 

Table 2 defines control laws with respect to variable p. Once the pressure drops under 6.2 bars, it means that the main compressor failure occurred. The backup compressor is switched ON when pressure value reaches 5.5 bar. The state when the pressure in the pipeline moves between 5.5 and 5.8 bars is now being modeled. 

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. 

Supplied-air respirators are effective protection against a wide range of air contaminants (gases, vapors, and particulates) and can be used where oxygen-deficient atmospheres are present. Where concentrations of air contaminants could be immediately dangerous to life, such respirators can be used provided (1) the protection factor of the respirator is not exceeded and (2) the provisions of OSHA s Respiratory Standard (which indicates the need for a safety harness and an escape system in case of compressor failure) are not violated. 

Compressor failure improper interpretation of console instmments loss of coolant flow loss of solvent flow refrigerant tank pressure regulator failure unacceptable coolant and/or solvent temperatures... 

Depressurization (Primary) Core Heat-up, air ingress, Over-speed/failure of turbo machine/compressor failure of magnetic bearings... 

The refrigerator does not function well e.g. a specific part has broken down (thermostat switch, ventilator, automatic thawing mechanism or compressor failure). 

Section (d)(2)(ii) deals with compressors used to supply breathing air through an air line. A breathing air-type compressor shall be used. Compressors shall be constructed and situated to avoid entry of contaminated air into the system, and suitable inline air-purifying sorbent beds and filters installed to further a.ssure breathing air quality. A receiver of sufficient capacity to enable the respirator wearer to escape from a contaminated atmosphere in the event of compressor failure, as well as alarms to indicate compressor failure and overheating. 

For the non-pressurized tank, the total surveillance time would be a better indicator of data quality. If this is large and the failures few, it only means that reliability is high. For the compressor, failures are more frequent, and a sufficiently high amount may be reached long before surveillance time equals that of the tanks. Sufficient in this case expresses the amount which gives the analyst confidence that the lifetime distribution derived from the data is suitable and accurate for predicting the reliability of similar equipment. Hence, depending on the equipment class, there should be a balance between total surveillance time and amount of failures. 

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