Compressors booster

Gas compression (primary- and secondary compressor, booster compressor) 8.7 11.5... 

Most gas-fired, heavy-duty gas turbines installed as of 1996 operate at gas pressures between 1.2 and 1.7 MPa (180—250 psig). However, aero derivative gas turbines and newer heavy-duty units can have such high air-inlet compression ratios as to require booster compressors to raise gas inlet pressures, in some cases as high as 5.2 MPa (750 psig). 

In some cases, blade-type rotary compressors are used in low temperature appHcations as high volume, low stage, or booster compressor (Fig. 9). These booster compressors are appHed at suction conditions varying from —87 to —20°C with compression ratios of 7 1 using CFC-12, HCFC-22, or ammonia. 

Continuous-Flow Compressors Continuous-flow compressors are machines where the flow is continuous, unlike positive displacement machines where the flow is fluctuating. Continuous-flow compressors are also classified as turbomachines. These types of machines are widely used in the chemical and petroleum industiy for many services. They are also used extensively in many other industries such as the iron and steel industry, pipeKne boosters, and on offshore platforms for reinjection compressors. Continuous-flow machines are usually much smaller in size and produce much less vibration than their counterpart, positive displacement units. 

Most ethylene plants operate continuously with the expanders operating at or near design conditions. If necessary, due to their unique design characteristics, radial inflow turboexpanders can accommodate a wide range of process conditions without significant losses in thermal or mechanical efficiency. Expanders may be loaded with booster compressors, gear-coupled generators, dynamometers, or other in-plant mechanical equipment such as pumps. In ethylene plants, turboexpanders are typically used in eitlier post-boost or pre-boost applications. 

Figure 4-6. Ammonia combustion and absorption at air compressor discharge pressure of 3-12 bar (Process 2, elevated pressure), a = medium pressure, 3-6 bar b = high pressure, 6-12 bar, with interceding or booster compressor.

In pre-boost applications, an integral booster compressor feeds an expander and the complexity of interactions is different than in postboost applications where the integral booster compressor is downstream from the turboexpander. 

The methane warms to 10°C. It then passes through the booster compressors on the expansion turbine shaft, increasing in pressure from 325 psi to 375 psi before being introduced into other gas compressors tliat boost the pressure back up to 600 psi. This is the pressure needed for reintroduction of the natural gas back into the TransCanada pipeline. This 50 psi boost, which makes use of available energy from the expansion turbines, provides a significant savings in electrical power. 

The sliding-vane compressor is widely used as a vacuum pump as well as a compressor, with the largest volume approximately 6,000 cfm. The lower end of the volume range is 50 cfm. A single-stage compressor with atmospheric inlet pressure is limited to a 50 psi discharge pressure. In booster service, the smaller units can be used to approximately 400 psi. 

The problem is to calculate the suction conditions for a proposed booster compressor. Values to calculate are flow in cfra at the flowing... 

In some applications (usually high pressure compressors using oil film seals) alternative pump schemes should be considered. It may be that the desired seal pressure is not achievable by one set of pumps or the quantity required by the seal is small relative to the main pump capacity. There are (imes when booster pumps are needed however, if the reason is energy, it would be worth reviewing the economics very carefully, because reliability tends to suffer with the booster. The booster pumps are paired into a main and standby and are configured to take suction fro lower pressure system. Sufficient interlocks have to be supplied drivers so that if the main pumps shutdown, the boosters come ... 

I ween the tubing and the casing. When it is economical to recover this j >, or when the gas must be recovered for environmental reasons, a . asinghead gas compressor will be installed. These are somei called casing vapor recovery (CVR) units or just vapor recovery (VRU). Casinghead compressors are typically characterized by low tion pressure (0 to 25 psig). They often discharge at low pressure (50 to 300 a booster or flash gas compressor or into a... 

The flare valve also allows production to continue momentarily if a compressor shuts down automatically. Even in booster service it may be beneficial to allow an operator to assess the cause of the compressor shutdown before shutting in the wells. In flash gas or gas-lift service, it is almost always beneficial to continue to produce the liquids while the... 

Poppet valves are typically used for low compression ratio applications, such as pipeline booster compressors. As the pressure differential increases across each of the individual poppets, they lift and allow gas to pass through the flow openings in the stop plate. 

When specifying compressor packages to API 1 IP, it may be necessary to specify certain sections of API 618 to ensure satisfactory installations. An example of this would be the supply of multiple compressors to be located in pipeline booster stations. In this case, an analog or digital pulsation and vibration study per API 618 Section 3.9 would be advisable to improve reliability and to minimize system problems and potential damage caused by gas pulsations and interaction between the individual compressor packages. 

In air drilling operation, large compressors and usually a booster compressor are used to compress atmospheric air and supply the required volumetric flowrate to the standpipe in much the same way that mud pumps supply mud for drilling. The volumetric flowrate of compressed air needed (which is usually stated in SCFM of air) depends upon the drilling rate, the geometry of the borehole to be drilled and the geometry of the drill string to be used to drill the hole [64,65]. 

The booster, which can compress air coming from the primary compressors to higher levels (i.e., on the order of 1,000 psig or higher), is always a piston-type compressor capable of variable volumetric flow and variable pressure output. 

Bring one compressor and booster on line to aerate the fluid pumped downhole approximately 100 to 150 scfm/bbl of fluid should be sufficient for aeration. 

If the air volume used is too high, standpipe pressure will exceed the pressure rating of the compressor (and/or booster). Therefore, the compressor must be slowed down until air is mixed with the fluid going downhole. 

J in. bit will have three open orifices and each orifice has an opening of 0.80 in. in diameter. The inside diameter of drill pipe is 3.640 in. The surface compressors and booster available at the drilling location are... 

Thus the primary compressors will have sufficient pressure capability to drill the interval from 8,500 to 10,000 ft. A third primary compressor should be on site and hooked up for immediate service in the event of downhole problems or the necessity to shut down one of the operating compressors. Also, the booster should be hooked up for immediate service in the event of downhole problems. For more information and engineering calculations pertaining to compressors and boosters see reference 64. 

It is additionally recommended in the British Gas publication Guidance Notes on the Installation of Gas Pipework, Boosters and Compressors in Customers Premises (lM/16) that for buildings containing plant over 2 MW total heat input and being supplied with gas at pressures above 1 bar, a remotely operable valve shall be fitted in the gas supply to the building. In the case of large boiler houses, provision for remote operation of the valves shall be provided both inside and outside the building. 

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