Whistle systems

The production of polymeric resins involves heating acids and glycols to a high temperature then adding styrene as the temperature is reduced. It is the styrene which takes part in curing when the activator is added. In a process developed by Scott Bader at Wellingborough in the UK, the styrene is added and mixed with a traditional stirrer. 

The underlying mode of action, involving as it does the flow induced vibration of a steel blade, immediately suggests the problem of erosion by particulate matter - the sand blasting effect. Despite this apparent drawback a whistle has been used in this Scott Bader process over several years without blade replacement. 

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There are numerous different types of equipment available for use as sonochemical reactors. The initial source of ultrasound comes from transducer devices which convert alternating electrical impulses to mechanical vibrations. Generally these are constructed of either piezoelectric or magnetostrictive material (p. 5). A purely mechanical low-frequency emitter is the whistle system, not frequently used by sonochemists, but of widespread usage in food processing (p. 311). Several set-ups are used to produce low-frequency ultrasoimd, from the simple cleaning baths to much more sophisticated emitters, sometimes using two... 

In order to transform the kinetic energy of a fluid into ultrasonic waves, siren and whistle systems are used. In siren systems, the fluid is forced to pass across a hole and depending on its velocity, the fluid flux will generate turbulence that constitutes the mechanical wave. In whistles, the fluid is forced across a thin blade which causes the blade to vibrate. For each vibrational movement, the leading face of the blade creates a pressure wave (Mason, 1998). 

Siren and whistle systems are not widely used in industrial applications. In liquid applications, the whistles constitute a powerful tool for mixing and homogenization (Mason and Lorimer, 2002), and for this reason they have been applied to cheese-making processes or in the sauce industry to achieve stable emulsions, such as mayonnaise or ketchup (Mason, 1998). Sirens are very rarely applied in a gas medium, most likely due to the fact that the working frequency of these systems is within the human hearing range, so that noise makes the industrial operation difficult. An example was provided by Da Mota and Palau (1999), who used a siren system to improve onion drying at low frequencies (1.6 and 3.2 kHz). 

Leicester Steam whistle, after train hit horse 1885 J. van Depoele Single overhead wire system for... 

The practising chemist has four types of laboratory ultrasonic apparatus which are commercially available. One of these, the whistle reactor, relies on mechanical generation of ultrasonic power whereas the other three - the bath, probe and cup-horn systems - are driven by electromechanical transducers. The construction of such systems is discussed below and a summary of their relative advantages (and disadvantages) in sonochemical usage are summarised in Tab. 7.1. 

An alarm system for notifying personnel of an emergency in progress and for communicating action required, such as information only, shelter-in-place, or evacuate. This could include bells, sirens, whistles, horns, or public address systems. 

A system for reporting fires and alerting the plant fire brigade and the municipal fire department should be provided. This system should be as simple as possible to minimize the potential for confusion in emergencies. The preferred design is a multiplex system that alarms in the control room or some other 24-hour constantly attended location and activates visual devices, such as strobes or beacons, and audible notification devices, such as a steam whistle, air horn, or tone generator. Complete systems are available from recognized vendors. 

Failure of bellows can be detected by medium leaking via the bonnet vent. As this is not always evident and detection systems not always very reliable, people have become very inventive in trying to detect bellows failure by putting whistles on the bonnet vent in order to detect leakages from the bonnet vent. The bottom line, however, is that bellows are a very vulnerable but, for its correct operation, very critical part of a spring-operated SRV. Bellow balanced valves need more frequent maintenance or at least checking in order to assure proper operation. The system might have an SRV installed but with the bellows invisibly ruptured, the SRV has no purpose whatsoever. 

Of the four types of laboratory ultrasonic apparatus commercially available for practising chemists in general (namely, whistle reactors, ultrasonic cleaning baths, probes and cup-horn devices) analytical chemists, except for a few specialists working in (or with) ultrasound detectors, use mainly cleaning baths and probes both of which are usually operated at a fixed frequency dependent on the particular type of transducer, that is usually 20 kHz for common probe systems and 40 kHz for baths. Both types of devices are described below. 

It is basically a simple system with few bells and whistles and was designed for bare bones instruction. 

Such bells and whistles are great when everything works the way it should. If not, then you have to understand the system in order to get it back in working order. This means having the knowledge to test and analyze and of course you also need to be able to get replacement parts, or fabricate your own. If you have a basic understanding of micro controllers, sensors and the basics of DC power units you will have a head start. 

Among the reasons for this extreme cost growth is that the American vendors of mass burning systems do not have as many "bell and whistle" design features as the European systems. The American purchaser has not previously feared corrosion enough to demand protective features. The American buyer often concentrates more on the lowest bid while the European buyer prefers a reliable system of which he and the community can be proud. 

A verbal presentation was made and submitted in writing by Gary Harris, a former employee and whistle-blower at the Chemical Agent Munitions Disposal System (CAMDS) facility and at TOCDF, at the committee s meeting of October 18, 2001. 

Many of these meters will, at the flip of a switch, show instantaneous voltage or current values or even both in the same display. The price goes up as more features—low-volt-age disconnect, alarms, load shunting, etc.—are added in other models. These aren t bells and whistles. They re the eyes and ears of your system, and will help you make good decisions and spot trouble early. At best, it will make you master of your energy-generating system. At least, it provides a solid sense of security when it comes to energy matters. 

Conditions C4 and C5 also strike me as problematic. As formulated, they are too strong for it to be reasonable to require that they be satisfied (along with C1-C3) for an engineer to have a FERE2-based ethical responsibility publicly to blow the whistle on an engineering product or system. 

Moreover, the government entities most heavily involved in investigating and adjudicating federal employee whistle-blowing claims - the Office of Special Counsel, the Merit Systems Protection Board (MSPB), and the Federal Circuit Court of Appeals (FCCA) - have rarely decided in favor of whistle-blowers. 

Require an alarm system that includes voice communication or sound signals such as bells, whistles, or horns. 

The preferred means of alerting employees to a fire onergency must be part of the plan. An employee alarm system must be available throughout the woikplace complex and must be used for emergency alerting for evacuation. The alarm system may be voice communication or sound signals such as bells, whistles, or horns. Employees must know the evacuation signal. 

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