Cooling requirement absorption

Ideal Performance and Cooling Requirements. Eree carriers can be excited by the thermal motion of the crystal lattice (phonons) as well as by photon absorption. These thermally excited carriers determine the magnitude of the dark current,/ and constitute a source of noise that defines the limit of the minimum radiation flux that can be detected. The dark carrier concentration is temperature dependent and decreases exponentially with reciprocal temperature at a rate that is determined by the magnitude of or E for intrinsic or extrinsic material, respectively. Therefore, usually it is necessary to operate infrared photon detectors at reduced temperatures to achieve high sensitivity. The smaller the value of E or E, the lower the temperature must be. 

In order to dissipate the recoil energy Mossbauer was the first to use atoms in solid crystal lattices as emitters and also to cool both emitter and absorber. In this way it could be shown that the 7-ray emission from radioactive cobalt metal was absorbed by metallic iron. However, it was also found that if the iron sample were in any other chemical state, the different chemical surroundings of the iron nucleus produce a sufficient effect on the nuclear energy levels for absorption no longer to occur. To enable a search for the precisely required absorption frequency, a scan based on the Doppler effect was developed. It was noted that a velocity of 102 ms-1 produced an enormous Doppler shift and using the same equation (7) it follows that a readily attainable displacement of the source at a velocity of 1 cms-1 produces a shift of 108 Hz. This shift corresponds to about 100 line-widths and provides a reasonable scan width. 

A refrigeration unit is required for the cooling of plant make-up water and also for cooling the absorption tower cooling water. The cooling duty required from the refrigeration unit is estimated to be 325 kl/V. 

As in alkylation, the time required for the absorption step is determined largely by the cooling required and the efficiency of the contacting. The two contactors used in the pilot unit gave a contact or residence time of about one hour in each contactor, which is probably far in excess of what is needed. 

The key to making a quantum logic gate is to provide conditional dynamics that is, we desire to perform on one physical subsystem a unitary transformation which is conditioned upon the quantum state of another subsystem [46]. In the context of cavity QED, the required conditional dynamics at the quantum level has recently been demonstrated [50,51]. For trapped ions, conditional dynamics at the quantum level has been demonstrated in verifications of zero-point laser cooling where absorption on the red sideband depended on the motional quantum state of the ion [11,12]. Recently, we have demonstrated a CN logic gate in this experiment, we also had the ability to prepare arbitrary input states to the gate (the keyboard operation of step (2a) below). 

Mol% Carbon Dioxide in the Vapor Stream Sent to the Absorption Tower Heating Requirement in the Desorption Tower and Cooling Requirement of the Recirculation Liquid [kcal/kmol Vapors Sent to Absorption ... 

In a typical batch operation, carbon disulfide is added to four molar equivalents of 25—30 wt % aqueous ammonia in a stirred vessel, which is kept closed for the first one to two hours. The reaction is moderately exothermic and requires cooling. After two to three hours, when substantially all of the disulfide has reacted, the reaction mixture is heated to decompose dithiocarbamate and trithiocarbonate and vented to an absorption system to collect ammonia, hydrogen sulfide, and any unreacted carbon disulfide. 

The absorption is carried out by countercurrent passage of ethylene through 95—98% sulfuric acid in a column reactor at 80°C and 1.3—1.5 MPa (180—200 psig) (41). The absorption is exothermic, and cooling is required (42) to keep the temperatures down and thereby limit corrosion problems. The absorption rate increases when ethyl hydrogen sulfate is present in the acid (43—46). This increase is attributed to the greater solubiUty of ethylene in ethyl hydrogen sulfate than in sulfuric acid. 

Steam and cooling water requirements for ammonia absorption refrigeration systems are shown in Table 1 for single-stage and two-stage units. The tables are based upon cooling water to the condenser of 85°F with 100°F condensing temperature. Water from the condenser is used in the absorbers. 

Steam and Cooling Water Required for Ammonia Absorption Refrigeration Systems... 

---