Circulation systems

The HILL-SCAN 30XX boards can be used in different PCs. Desktop- and tower-PCs as well suited for laboratory uses. For in-field inspections rugged notebooks and portable PCs are advantageous. A typical portable system is shown in Fig. 2 (USPC 3010), used in MUSE (Mobile Ultrasonic Equipment). This portable PC not only contains the boards for ultrasonic testing but also a controller with power supply for stepper motors, so that a manipulator can be connected directly. The MUSE system is enlarged with a water circulation system which enables a local immersion technique" for in-field inspections. A typical result is shown in Fig. 3, which presents a D-scan of a CFRP- component in RTM-techniques. The defect area caused by an impact is clearly indicated. The manipulator is described in [3]. 

A static leaf filter is used for cleaning machine tool coolants. These are used on the suction side of a pump circulating system, with the same pump employed for withdrawal of the filtrate as for backdushing the filter elements. SoHds in this case are removed from the sump by a scraper conveyor. 

The modern HF alkylation processes are also differentiated primarily by the reactor system that is used. The Phillips process employs a gravity acid circulation system and a riser reactor (19). The UOP process uses a pumped acid circulation system and an exchanger reactor (20). 

Cla.riGers. Pool water may occasionally contain metallic impurities such as copper, iron, or manganese which enter the pool with the makeup water or by corrosion of metallic parts in the circulation system. These dissolved metals can discolor the water and cause stains. Chlorine oxidizes soluble Fe and to the highly insoluble Fe(OH)3 and MnO which can be removed by filtration. Water-soluble, high molecular weight polymers can be... 

Preparation is accompHshed by simple blending of the diluent into the hot base asphalt. This is generally accompHshed in tanks equipped with coils for air agitation or with a mechanical stirrer or a vortex mixer. Line blending in a batch circulation system or in a continuous fashion (40) is used where the volume produced justifies the extra faciUties. A continuous, line-blending system is appHcable to the manufacture of cutback asphalts and asphalt cements (Fig. 8). 

Axial-Flow (Propeller) Pumps (Fig. 10-44) These pumps are essentiahy very-high-capacity low-head units. Normally they are designed for flows in excess of 450 mVh (2000 gal/min) against heads of 15 m (50 ft) or less. They are used to great advantage in closed-loop circulation systems in which the pump casing becomes merely an elbow in the line. A common installation is for calandria circulation. A charac teristic cui ve of an axial-flow pump is given in Fig. 10-45. 

In the forced-circulation-type crystallizer (Fig. 19-43) primaiy control over particle size is exercised by the designer in selecting the circulating system and volume of the body. From the operating standpoint there is little that can be done to an existing unit other than supply external seed, classify the discharge ciystals, or control the shiny... 

Steam-Generator Circulation System Circulation systems for utility application are generally classified as natural circulation and forced or pump-assisted circulation in drum-type boilers, and as once-through now in subcritical- and supercriticaf-pressure boilers. The... 

FIG. 27-41 Circulation systems a) natural circulation (h) pump-assisted circulation. 

Forced Circulation System—Using foreed eireulation in a waste heat reeovery system allows the use of smaller tube sizes with inherent inereased heat transfer eoeffieients. Flow stability eonsiderations must be addressed. The reeireulating pump is a eritieal eomponent from a reliability standpoint and standby (redundant) pumps must be eonsidered. In any event, great eare must go into preparing speeifieations for this pump. 

The thermosyphon is a good system for remote areas where utilities are limited, but requires some careful design to ensure proper operation. This is a circulating system with the motive force derived from the change in densiiy of the cooling fluid from the hot to the cold sections of the sysieni. API dl8 pennits this system for discharge gas temperatures below 210 F or a temperature rise across the compressor of 150°F or less. 

Ring current (Section 13.5) Electric held associated with circulating system of -tr electrons. 

The horizontal natural circulation systems do not use a kettle design exchanger, but rather a 1-2 (1 shell side, 2 tube-side passes) unit, with the vaporized liquid plus liquid not vaporized circulating back to a distillation column bottoms vapor space or, for example, to a separate drum where the vapor separates and flows back to the process system and where liquid recirculates back along with make-up feed to the inlet of the horizontal shell and tube reboiler. See Figures 10-96A-C. 

The kelly cock and lower kelly valve are manually operated valves in the circulating system. 

Mud pumps consume more than 60% of all the horsepower used in rotary drilling. Mud pumps are used to circulate drilling fluid through the mud circulation system while drilling. A pump with two fluid cylinders, as shown in Figure 4-99, is called a duplex pump. A three-fluid-cylinder pump, as shown in Figure 4-100, is called a triplex pump. Duplex pumps are usually double action, and triplex pumps are usually single action. 

Maximum Drilling Rate. In fast drilling operations (soft formations), the maximum penetration rate is limited by the maximum pressure available at the bit. This is the maximum allowable standpipe pressure minus the total losses in the circulating system. 

Note that the drill pipe pressure is a sum of all the pressure losses in the circulating system. 

Total Pressure Loss. Since bit life is not an issue in a short deviation control motor run operation, it is desirable to operate the positive displacement motor at as high a power level as possible during the run. The motor has a maximum pressure loss with which it can operate. This is 580 psi (see Table 4-114). It will be assumed that the motor will be operated at the 580 psi pressure loss in order to maximize the torque output of the motor. To obtain the highest horsepower for the motor, the highest circulation flowrate possible while operating within the constraints of the surface mud pump should be obtained. To obtain this highest possible, or optimal, circulation flowrate, the total pressure losses for the circulation system must be obtained for various circulation flowrates. These total pressure losses tabulated in the lower row of Table 4-117 represent the surface standpipe pressure when operating at the various circulation flowrates. 

Rock bit type (tooth shape, journal angle, cone offset, fluid circulation system)... 

HPj = hydraulic horsepower dissipated through the remaining circulating system... 

Range 1 of the mud pump performance characteristic is defined by the performance of the smallest liner, and range 2 is defined by the remaining liners. The pressure loss in a circulating system, except for bit (p ), can be estimated from numerous theoretical formulas or from a flowrate test. Data obtained from a flowrate test can be approximated using a curve-fitting technique by the following function ... 

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