Reciprocating Plate Extractors. These extractors are also know as agitated liquid-liquid extractors. Common types of these extractors are reciprocating-plate extractors and rotating disc extractors. For both of these, backmixing, which reduces column efficiency, is a problem. Agitation is needed to increase mass transfer by dispersing one of the phases and increasing turbulence in the continuous phase. In the rotating-disc extractor, the disc is the agitator. In the reciprocating-plate extractor, it is the up-and-down motion of the plate stack. Horizontal stator rings above and below each disc or impeller reduces backmixing.
Manual Relief Valve: A valve used to limit the pressure in a vessel to a certain maximum level. Pressure is relieved by allowing pressurized media to escape out of the system. The valve is designed or is set to open at a predetermined pressure. When the pressure setting is exceeded, the relief valve becomes the "path of least resistance." The valve is forced open and a portion of the media is diverted through the auxiliary route. As the media is released, the pressure inside the vessel drops. Once it reaches the valve's re-seating pressure, the valve closes.
Ribbon Blender Dryers. These dryers consist of a U-shaped horizontal trough and a specially fabricated ribbon agitator, which is a set of inner and outer helical agitators. The outer ribbon moves materials in one direction and the inner ribbon moves the materials in the opposite direction. The ribbons rotate at approximately 300 feet per minute and moves materials both radially and laterally to ensure thorough drying in short cycle times.
Utilities, RODI Packages: RO/DI (Reverse Osmosis/Deionization) systems help to remove impurities from water, such as chlorine, chloramines, pesticides, phosphates, heavy metals and many others. Deionizing removes phosphates, silicates and nitrates.
Rotameter. A device that measures the flow rate of liquid or gas in a closed tube. It is a variable area meter, which measures flow rate by allowing the cross sectional area that the fluid travels through to vary. A rotameter consists of a tapered glass tube with a float inside that is pushed up by flow and pulled down by gravity. At a higher flow rate more area is needed between the float and the tube to accommodate the flow, so the float rises. The float is shaped so that it rotates axially as the fluid passes, allowing one to tell if the float is stuck since it will only rotate if it is free. Readings are usually taken from the top of the float.
Rotary Drum Dryers. These are industrial dryers that remove or minimize moisture from a product by putting it in direct or indirect contact with hot air. This type of dryer has a rotating cylinder through which hot air passes. The dryer is classified as an indirect heated type when it uses gas preheated by other means. This type has low risk of product contamination. A direct heated dryer uses an air steam composed of furnace fumes and air. Two types of commonly used rotary dryers are counter-current rotary dryers and co-current rotary dryers. In the first type, heated air flows in a similar path as the material. In the other type, air flow against the direction of the material. Both models expose the material to hot air heated by a source. While the drum rotates, fins that line the inner wall of the drum lift the product into the stream of air
Rotary Lobe Positive Displacement Pumps. These positive displacement pumps can handle solids, slurries, pastes, and a variety of liquids. Rotary lobe pumps use rotating lobes to push material through the pump. They offer continuous and intermittent reversible flows, and can operate dry for brief periods of time. Because the lobes do not make contact, particle size pumped can be much larger in lobe pumps than in other positive displacement types
RTD Temperature Transmitter. A measurement device that converts an RTD (Resistance Temperature Detector) resistance measurement to a current signal that can be used to operate an integrated digital or analog readout, or to control another device. The RTD component, also called a resistance thermometer, is a temperature sensor that exploits the change in electrical resistance of some materials with changing temperature.
Rupture Disc: A pressure relief device that protects a vessel or system from over pressurization. They have a membrane, usually metal foil, which fails at a fixed pressure or vacuum. Rupture discs respond quickly to an increase in system pressure, but once the membrane has failed it will not reseal. Rupture discs are often used as a backup device for a conventional safety valve. If the safety valves fails to operate (or can't relieve pressure quickly enough), the disc ruptures.