Calibration Tables - Plastic Profiles
Plastic material that has been melted and degassed in the extruder is processed into continuous profiles on the calibrating table. Typically, these profiles are made into pipes or various technical profiles for windows, cable ducts, medical tubing, etc. The plastic material is suctioned into a mold. For cooling and lubrication purposes, a film of water is generated between the inside of the mold and the continuous workpiece and is continuously extracted by the vacuum pump.
Cement Conveying and Handling
NASH WITTIG rotary vane products deliver reliable performance for the handling of raw cement materials as they move from one location to another, for example from a delivery truck to a silo or other storage container. Our products offer short start-up times, constant minimum reserve oil levels, and efficient performance.
General "pick and place" (chucking) operations are frequently handled with NASH equipment. Pre-engineered package systems are also available.
During processing, thermoplastics are melted in an extruder and degassed in the extruder's screw section. A vacuum is used to extract gaseous and vaporous components from the melt. All low-molecular substances are extracted to obtain optimal quality thermoplastic with a smoother surface, more strength, better insulating properties and a lower offgassing rate.
When producing hollow glassware large volumes of compressed air and vacuum are required. High quality and reliability of all units and components is of prime importance. For continuous 24-hour operation, NASH WITTIG rotary vane compressors and vacuum pumps offer ideal solutions.
Compressed air is used to fill in the blanks on production machines. A compressed air system is needed to control the various shaping devices and the general air supply of the factory.
Rotary vane vacuum pumps are used to evacuate the glass molds. This ensure high product quality and increasing the number of pieces per hour poses no problem for our WITTIG pumps.
Sterilization of various devices and equipment is a vital necessity in all medical practices, hospitals, laboratories and pharmaceutical facilities. Sterilizers run through 3 distinct cycles:
Fractionation: Air serves as an isolation layer and prevents the hot steam from actually coming into direct contact with the objects to be sterilized - which is why it must be extracted from the vessel. For fractionation, air pressure is reduced to 100 mbar (27"HgV) and hot steam is then injected. This procedure is repeated 3 to 4 times.
Sterilization: Steam is injected into the vessel at a pressure of 2 to 3 bar (30-45 psi) and a temperature of 121 to 134°C (250 to 275°F) and kills all the germs. The vacuum pump does not run during sterilization.
Drying: When the actual sterilization is complete, the vacuum pump expels the air from the vessel until a final vacuum of 50 mbar (28.5"HgV) is created, thus drying the sterilized objects
In this application, the moisture from the filtrate receiver of a vacuum filter is collected and fed back into the system. If a system upset occurs, such as the failure of the filtrate pump, slugs of liquid can carry over into the vacuum system. Soft solids from the filter can also enter the vacuum system. In both cases, the liquid and soft solids will not damage the liquid ring vacuum pump, improving the overall reliability of the vacuum filtration system. A variety of seal liquids compatible with the process vapors may be selected in order to minimize contamination of gases extracted during the filtration process.
In this application, vacuum pumps are used to maintain a prime in cooling water systems. Maintaining a prime allows water circulating pumps to maintain design water flows with minimum power consumption. Single stage liquid ring pump packages, often supplied with priming valves, are ideal for this application because they prevent ingesting of water slugs into the pumps.
Wood Treating - Impregnation
Raw timber is treated to prevent decay in unprotected environments. In order to do this, the wood is loaded into large, air-tight vessels. Once loaded, liquid ring pumps are used to draw vacuum on the tank to extract water vapor from the wood. Chromated Copper Arsenate (CCA) or some other preservative is then injected into the tank. The pumps are now used as compressors to pressurize the tank and to impregnate the wood with the desired concentration of preservative. Nash products are very tolerant of the resinous components and vapors from the preservative chemicals.