Pump, proportioning

The ACTIV-OX chlorine dioxide system evaluated in this trial overcomes many of the problems associated with chlorine dioxide for the small water user. A chlorine dioxide precursor solution and a dilute acid solution are mixed in a 1 1 ratio immediately prior to injection into the water to be treated. The dose rate of chlorine dioxide is controlled by water meter signal to two proportioning pumps. The mixing of the two chemicals immediately produces a chlorine dioxide solution which is diluted to the required strength by injection into the water to be treated (Fig 3). 

Figure 12.6 illustrates the outline of such an analysis. An automatic pipette extracts a preset volume of the liquid sample (or solution) from a cup presented to it on a turntable. The measured sample is mixed with the reagents in the appropriate proportions, and propelled through the instrument by the peristaltic proportioning pump. This pump operates by means of moving bars, attached to a chain drive, which sequentially compress the plastic sample and reagent tubes to drive the liquids forward through the instrument. The incorporation of a succession of air bubbles at... 

This particular section of the Auto Analyzer consists mainly of the sampler, proportioning pumps, and programmer. First, the sampler introduces a fixed quantity of serum sample into the analysis train , which varies from one instrument to another instrument supplied by different manufacturers. For instance, the SMA-12 Survey Auto Analyzer possesses 12 analysis trains or streams as illustrated in Figure 2.7. 

The proportioning pump controls the rate of advancement, viz 10 inch/minute, of each sample through the analysis stream. Hence, a fixed length of tubing is equivalent to a fixed amount of time. Each analysis stream is made of transparent plastic flexible tubing, and each patient-sample is separated from one another by an air-bubble. 

Fig. 5.14. The principles of CFA and FIA. For details see the text. 1 - sampling device 2 - proportioning pump 3 - mixing spiral,...

The emulsifying equipment has been set up as a self-contained trailer-mounted unit. The unit used at the 1975 field trial in Lufkin, Texas is designed to accept molten sulfur and hot asphalt from road tankers. The sulfur and asphalt flow rates are controlled by two proportioning pumps driven by a sprocket and chain arrangement from a common shaft. This arrangement enables the sulfur content of the binder to be varied from 20% to 50%. 

This included storage tankage, feed lines, proportioning pumps, automatic controls and injector for the introduction of our proprietary chemicals into the boiler. 

PROPORTIONING PUMP DATA RFCIPROCATING PUMP DATA ... 

The injection point of the sulfuric acid is in the pump bay, or as near as possible to water intake. The sulfuric acid pump is normally a motor-driven proportioning pump, and an electric motor is connected to a pH analyzer installed on the cooling water supply header so that the pump starts and stops, depending on the pH in the circulating water. Table 8.2 summarizes various chemical treating agents for cooling water towers. 

Agglomerating liquid is supplied from tank (5) by a proportioning pump through spray injectors to the granulator. 

Initially, when the mixer (4) is started water may be fed to its cylinder by a proportioning pump, which is done to increase flow of the material. Water is supplied through a hole in a kneading tooth of the screw. The quantity of water is decreased as the equipment picks up steady-state operating conditions. The water contained in the mixer is then evaporated and may be removed from the connecting shaft by means of a vacuum pump. 

Method. A diagram of the apparatus is shown in Fig.4.29. Any suitable liquid chromatograph may be used. The AutoAnalyzer is modified such that the liquid sampler is fitted to the end of the chromatographic column. The proportioning pump is by-passed. The set-up of the AutoAnalyzer is the same as that for normal measurements of cholinesterase. The application of this technique to the determination of CGA 18809 in plum-leaf extract is shown in Fig.4.30. A comparison is made with UV analysis of the same extract. The limit of detection for CGA 18809 is c . 20 ng at a 3 1 signal to noise ratio. The relative inhibitions of several organophosphates and carbamates are compared in Table 4.9. Diazoxon may be detected in low picogram quantities. 

An early spectrophotometric method [ 1 ] for aluminium in soil involves the use of a Technicon sample changer, proportioning pump and automatic colorimeter. The method is based on the measurement of the rate of colour development in the reaction between aluminium and xylenol orange in ethanolic media. The calibration graph is rectilinear up to 2.7 mg/1 aluminium and the coefficient of variation is 4.5%. 

This method is automated and the autoanalyser manifold used is shown in Fig. 7.4. A Technicon sampler plate and proportioning pump were used in conjunction with a Cecil CE 212 ultraviolet monitor and a Servoscribe RE 511 recorder. Glass tubing must be used to make connections from the double... 

In place of the diluent (or in addition to it, using more channels) one can add a buffer to obtain the optimum pH for the most efficient extraction. Or, one can add a reagent (or two, or more) and perform a pre-column derivatization, if that is required to improve separation or sensitivity. Multi-channel proportioning pumps are available with up to 28 channels, with pump tubes which can handle acids, bases, and most solvents at flow rates ranging from about 50 microliters per minute up to nearly four milliliters per minute. 

Solution is withdrawn from the bottom of the fiow column with a Ruska proportioning pump. The pump is capable of pumping or withdrawing fluid at a rate of 10 to 1200 cc/hr. by the action of a 500 cc piston in a cylinder, powered by a 1/4 horsepower drive motor. 

Hypochlorinators are most suited for smaller installations. For installations serving about ten people, it is possible to use drip-fed hypochlorinators. For up to 100 people, orifice-controlled feeders using a constant head tank mounted overhead and fed by gravity can be used successfully. The most satisfactory means of feeding hypochlorite solutions is through the use of low capacity proportioning pumps. 

Change in the position of the sorption front, which is in the part of the column positioned between electrodes, results in bridge imbalance that is registered by a potentiometer. Divergence of the needle, as a result, breaks the contact and a relay reacts. Resistance is increased if the sorption front has risen. If the front has lowered, resistance is reduced. Response of the electric motor of the proportional pump controlling solution flow in response to such signaling with respect to sorption front... 

---