Throttle plate

This equation can be used for an orifice plate introduced into pipework as a measuring, throttling or balancing device, and for a jet discharging gas into the injector of a burner at atmospheric or sub-atmospheric pressure. 

Inspect in areas in which the piping is anticipated to have experienced metal loss because it was affected by velocity or turbulence. Prime inspection areas include the outer surfaces of piping bends and elbows, areas around tees, piping around reducers, orifice plates, and throttling valves and the piping downstream from them. 

Cavitation is not exclusive of ultrasound. Thus, hydrodynamic cavitation can simply arise from passage of the liquid through a constrictor such as a throttling valve, orifice plate, Venturi tube, etc. On passage through the constrictor, the kinetic energy — velocity — of the liquid increases at the expense of the pressure. Various types of hydrodynamic cavitation reactors have been reported and their most salient features reviewed [17]. Also, the effects of ultrasound and hydrodynamic cavitation on oxidation processes have recently been compared [18]. 

The liquid passes through a throttling valve, orifice plate or any other mechanical constriction (Figure 3.12a). If the pressure in vena contractu falls below the cavitation pressure (usually the vapor pressure of the medium), millions of microcavities will be generated. Those cavities will subsequently collapse as the liquid jet expands and pressure recovers. 

A fast stream of Ns Is introduced until all air is displaced. The Ns stream is throttled down to a few bubbles, and the aspirator and the hot plate are turned on. Evaporation to 300 ml. is carried out at 40°C. The temperature should not exceed 45°C. The cooled liquid is poured into a wide-neck Erlenmeyer flask, which is then well stoppered and placed in a Dry Ice-acetone bath. After crystallization, which sometimes must be started by scratching the walls, the flask is allowed to stand for 12 hours at about 5°C. At that point the liquid should constitute 30-40% of the flask contents. Further operations must be carried out in a refrigerated space. The crystals are quickly filtered through filter paper and the filtrate is discarded. The crystals are pressed dry and placed in a crystallizing dish, in which they are allowed to stand until about 20-30% of the contents liquefy. The residue is filtered off and the process is repeated. The almost pure residue (about 10% yield) is stored over Mg(C104)3 in a vacuum desiccator in a refrigerated room. To obtain large crystals, the material can be recrystallized from n-butanol. 

A mechanical resistance is introduced into the flow and the resulting pressure drop is measured. Thus, flow measurement is transformed into the measurement of pressure difference. An orifice guage or standard orifice plate is generally used (Figure 2.8-5). Other types of throttle are the standard jet, the standard Venturi jet, and the spiral tube, which have the advantage over the standard orifice plate of a lower permanent pressure drop. This measurement principle is applicable over a wide measuring range, requires... 

After the condensing process, a throttling device such as a valve, orihce plate, or capillary tube is used to expand the liquid refrigerant in order to reduce the pressure of the refrigerant liquid level to a boiling temperature below that of the heat source. After the expansion process, the refrigerant enters the evaporator in a two-phase state. 

If a centrifugal pump with high discharge capacity is being used to feed a process unit with manual operation control, then provide a recirculation line (to the feed tank on inlet side of the pump) with an orifice plate and a throttle valve. 

Thermal Conductivity. Conductivity measurements were made of tape candidates to determine whether or not they would satisfy the cable design requirements listed in Table I. The measurements were made for BNL by Jelinek of BCL using the apparatus illustrated in Fig. 7. The method was a modified steady-state conductivity technique where a temperature gradient was established between two copper plates separated by four layers of polymeric film. (Multilayer measurements were always made to approximate the series interfacial resistivity that would be present in lapped cable configurations.) One plate was attached to a controlled heat sink and a measured quantity of heat was added to the other plate by means of an electric heater. With the use of a liquid helium throttling dewar, the ambient temperature could be controlled to within 1 K. (Complete details of the conductivity measurement method are included in Appendix II of this paper.)... 

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