Compressor Process

Sealing of turboexpander and compressor process gas from die bearing housing differs for air separation and natural gas applications. The bearing housing is usually sealed in cold expanders and for cases when die process gas contains heavy hydrocarbon components, which may cause condensation in die bearing housing. 

Typical Diaphragm Compressor Process Construction Materials... 

Some common enclosures are small buildings or enclosures for utility air or process gas compressors, gas turbines, refrigeration compressors, process pumps, filters, additive systems, dust collectors, field instruments, etc. 

The starting point for the compressor process (see Fig. 6.6-9) is the condition prevailing within the separator, that means, the gaseous solvent enters directly into the compressor (1) and is pressurized to the extraction pressure (2). The use of intermediate cooled compressors is necessary, otherwise low efficiency and extremely high outlet temperatures would be reached. After compression, the extraction fluid has to be cooled to the extraction temperature (3), and under these conditions extraction takes place. Analogous to the pump process, the loaded fluid is expanded in the two-phase region (4) and heated up to gaseous conditions (1) where separation takes place. 

Figure 6.6-9. Compressor process in the temperature-entropy diagram...

Figure 8.1-8. Return on Investment (ROI) for the compressor process of fish-oil fractionation at different solvent/feed ratios, depending on variable benefits per kg of product.

Economics The advantages of this process are low equipment costs (viz. the deethanizer system and ethylene/ethane separation) and reliability of the acetylene hydrogenation due to low excess hydrogen at the reactor inlet. The refrigeration compressor benefits from low specific power and suction volume, while the cracked-gas compressor processes above-ambient-temperature gas. 

Large pipeline compressors Process compressors Small units... 

This illustration demon.strates that the sum O -I- IVy is the same for a fluid undergoing some change in a continuous process regardless of whether we choose to compute this sum from the closed-system analysis on a mass of gas or from an open-system analysis on a given volume in space. In Illustration 3.2-2 we consider another problem, the compression of a gas by two different processes, the first being a closed-system piston-and-cylinder process and the second being a flow compressor process. Here we will find that the sum Q + W s different in the two processes, but the origin of this difference is easily understood. 

Validate the entire compressor process in a multi-stage, pilot scale system. 

For a compressor process with throttling in the supercritical state of the solvent the according numbers for the necessary heat and electric energy for cases of energy recovery and without energy recovery are listed in Table 3. 

TABLE 2. Energy consumption of a compressor process. Throttling to the subciitical state. Supercritical solvent CO2. Conditions of the extraction 40 MPa. 313 K Conditions of the regeneration 5 MPa, 299 K. 

TABLE 3. Energy consumption of solvent CO2. a compressor process. Throttling in the supercritical state. Supercritical ... 

A comparison of both cycle processes is presented in Figure 31. Energy consumption of both cycles increases with extraction pressure, without much difference between either if precipitation and regeneration is carried out in the supercritical state. Differences are small even for subcritical precipitation and regeneration for an extraction pressure of around 30 MPa. At higher pressures the compressor process needs more energy, at lower extraction pressures the pump process needs more energy. 

Some advantages of the pump process are Lower investment cost for a pump than for a compressor, good control of solvent mass flow, less energy consumption than the compressor process at pressures higher than about 30 MPa. Disadvantages of the pump process are heat exchangers and condensator necessary, additional heat energy needed at low extraction pressures. 

Timer, operator, PLC Valve, pump, compressor Process unit Sensor... 

Separation of dissolved substances from the fluid is performed by precipitation. Most applications use an isenthalpic decrease of pressure and temperature to reduce the fluid density and, consequently, the solvent power of the fluid. After pressure reduction, the extraction dense gas is heated so that it reaches the gaseous state. In this phase, no solvent power is present for any substances and therefore nearly complete separation of the extracted substances takes place. The dissolved substances precipitate and can be discharged at the bottom of the separator. The solvent cycle is closed by recycling the recompressed CO2, either cooled in case of a compressor process or condensed by using the pump process. 

In 2003, NATEX Prozesstechnologie started investigations for scale-up of an industrial process. With a production capacity of 2500 tons per year, it corresponds to 500 million cork stoppers. In order to optimize the energy consumption, a careful comparison between the pump and the compressor process was executed. 

The evaluation showed economic advantages for the compressor process and in consequence design engineering was adjusted accordingly. 

In generaL it is process engineer s responsibility to specify process requirement of a compressor on a data sheet With the compressor process specification, a vendor is able to design or select a compressor to fit ihe need. Providing the compressor process specification is the first step to purchase a new compressor or to rate an existing compressor. 

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