Pneumatic tube system

Steige, H., and Jones, J. D. Evaluation of pneumatic tube system for delivery of blood specimens. Clin. Chem. 17, 1160-1164 (1971). 

For such purposes, facilities such as a "Jiffy probe system" In the cyclotron or a "pneumatic tube system" In the atomic reactor have been used. 

Pneumatic tube systems are also useful for rapid transference of samples irradiated In a reactor (17 ). In one such facility the sample to be Irradiated Is placed In lusteroid or polyethylene capsules and Is Inserted In a polyethylene rabbit which runs through the pneumatic tube to the side of the reactor. After Irradiation, the rabbit is returned to a hood in which chemical operations can be performed, is quickly opened and the sample removed. The pneumatic tube system la operated by vacuum rather than by compressed air to minimize... 

Although transport of specimens from the patient to the clinical laboratory is often done by messenger, pneumatic tube systems have been used to move the specimens more rapidly over long distances within the hospital. Hemolysis may occur in these systems unless the tubes are completely filled and movement of the blood tubes inside the specimen carrier is prevented. The pneumatic tube system should be designed to eliminate sharp curves and sudden stops of the specimen carriers, because these factors are responsible for much of the hemolysis that may occur. With many systems, however, the plasma hemoglobin concentration may be increased, and the serum activity of red cell enzymes, such as lactate dehydrogenase, may also be increased. Nonethe-... 

Several methods may be used to deliver specimens to the laboratory, which is often in a location distant from the patient. These include courier service, pneumatic tube systems, electric track vehicles, and mobile robots. In some laboratories, phlebotomists may also bring specimens with them as they return to the laboratory. 

Pneumatic tube systems provide rapid specimen transportation and are quite rehable when installed as point-to-point services. However, when switching mechanisms are introduced to allow carriers to be sent to various locations, additional mechanical problems may arise and cause carriers to be misrouted. Although pneumatic tubes have been reported to damage specimens because of rapid acceleration or deed-... 

Green M. Successful alternative to alternate site testing use of a pneumatic tube system to the central laboratory. Arch Pathol Lab Med 1995 119 943-7. 

Greendyke RM, Banzhaf JC, Pelysko S, Bauman B. Immunologic studies of blood samples transported by a pneumatic tube system. Am J Chn Pathol 1977 68 508-10. 

Pragay DA, Fan P, Brinldey S, Clulcote ME. A computer directed pneumatic tube system its effects on specimens. Clin Biochem 1980 13 259-61. 

Despite these refinements, the vertical rods could not be used for certain isotopes that had a very short half-life because their radioactivity might well be gone by the time the sample was unloaded. Tints elements like sodium, which had a half-hour half-life, had to be made in the self-serve mechanisms. In order to speed them on their way to the laboratory, a pneumatic tube system was installed between the NRX building and adjacent labs to permit rapid delivery of isotopes in small quantities. 

WHICH ONE of the following gases is used to propel the rabbit in the pneumatic tube system ... 

Figure 10.30 illustrates a multiple-stage exhauster and smooth-flow duct (pneumatic tubing) components. It also includes pictures of air cleaner-exha uster-motor installations located outside of buildings and connected to LVHV (or central vacuum cleaning) systems inside the buildings. 

A pneumatic conveyer system consists of a long tube or duct to carry air at high velocities, an induced draft fan to propel the air, a suitable feeder for addition and dispersion of particulate solids... 

Where water supplies are inadequate for conventional firefighting and foam making, automatically activated fixed clean agent or CO2 systems may be considered for seal fire protection. The agent should be discharged into the seal area below the secondary seal. Fire detection options for these automatic systems include reusable thermal wires and pneumatic tube devices. Thermal wire is typically the more economical choice. 

Where water will create a serious fire or personnel hazard, a suitable nonwater automatic extinguishing system should be considered. Penetrations through fire-rated floor, ceiling, and wall assemblies by pipes, conduits, bus ducts, cables, wires, air ducts, pneumatic tubes and ducts, and similar building service equipment should be protected in accordance with NFPA 101 , Life Safety Code. All floor openings should be sealed or curbed to prevent liquid leakage to lower floors. Door assemblies in 1 -hour rated fire barriers should be y4-hour rated. Door assemblies in 2-hour rated fire barriers should be 1 V2-hour rated. 

M4. McClellan, E. K., Nakamura, 11. M., Haas, W., Moyer, D. L., and Kunitake, G. M., Effect of pneumatic tube transport system on the validity of determinations in blood chemistry. Amer. J. Clin. PaihoL 42, 152-155 (1964). 

Figure 2.7 shows a typical pneumatic nebulization system for a premixed flame. The sample is sucked up a plastic capillary tube. In the type of concentric nebulizer illustrated here, the sample liquid is surrounded by the oxidant gas as it emerges from the capillary. The high velocity of this gas, as it issues from the tiny annular orifice, creates a pressure drop which sucks up, draws out and shatters the liquid into very tiny droplets. This phenomenon is known as the venturi effect and is illustrated in Fig. 2.8. 

Rate-of-rise Alarm System One of the systems installed for detecting fire by an abnormal rate of increase of heat operates when a normal amount of air in a pneumatic tube expands rapidly when heated and exerts pressure on diaphragms. 

If operated on clean, dry plant air, pneumatic controllers offer good performance and are extremely reliable. In many cases, however, plant air is neither clean nor dry. A poor-quality air supply will cause unreliable performance of pneumatic controllers, pneumatic field measurement devices, and final control elements. The main shortcoming of the pneumatic controller is its lack of flexibility when compared to modem electronic controller designs. Increased range of adjustability, choice of alternative control algorithms, the communication link to the control system, and other features and services provided by the electronic controller make it a superior choice in most of todays applications. Controller performance is also affected by the time delay induced by pneumatic tubing mns. For example, a 100-m run of 6.35-mm ( -in) tubing will typically cause 5 s of apparent process dead time, which will limit the control performance of fast processes such as flows and pressures. 

The pneumatic tubes shown in (c) relies on a continuous supply of air into the system. The air is purged into the bottom of the tank. As the liquid level in the tank rises, more pressure is needed to push the air into the bottom of the tank. Thus, the pressure required to push the air into the system is a measure of the liquid level in the tank. As shown in the figure, the indicator and recorder may be cahbrated to read levels in the tank directly. 

In contrast with the limited ability to reconfigure conveyor belt systems and their limited ability to handle different sized specimen containers, mobile robots are easily adapted to carry various sizes and shapes of specimen containers,. and can be reprogrammed to travel to new (and distant) locations with changes in laboratory geometry. Limitations of mobile robots include their requirement of having to batch specimens, and their difficulty in interfacing mechanically with laboratory analyzers so that specimens are introduced directly from the mobile robot onto the analyzer. In many situations, laboratory personnel are still required to place specimens onto or remove specimens from the mobile robot at each stopping place. Mobile robots have been used to return conveyor belt specimen carrier racks to the central dispatch area and for transport of specimens within and outside the laboratory. In the latter application, mobile robots may be a useful alternative to pneumatic tube defiv-ery systems. 

Deterioration of specimens as a result of delays in transport from wards to the laboratory has focused attention on the possible advantages of pneumatic tube communication systems. A technical memorandum (M8) discussed the financial and operational factors to take into consideration before deciding to install such a system, which can be undertaken economically only as part of a building program, and McClellan et al. (M6) reported data on the adverse effects of one such transport system on the validity of chemical determinations on blood samples. 

M8. Ministry of Health, Pneumatic Tube Communication Systems, Hosp. Tech. 

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