Moisture Control System

Modulus, 247 set also Retention modulus Moisture content of eluents, 80, 83 control of, 80-82 determination of, 80 Moisture control, 106 Moisture control system, for eluent, 81-83 Molar surface area, 171, ... 

Temperature and moisture control systems for dry bulk materials... 

According to IPCS (1999), the analyzer system consists of an analyzer as well as sample preconditioning components fitted with a moisture control system such as the Non-Dispersive-Infrared (NDIR) analyzer. The infrared absorption near 4.6 pm, characteristic of CO, is used to measure its concentration. The most sensitive analyzers can detect CO concentrations as low as 0.05 mg/m (0.044 ppm). The NDIR analyzer designed by Luft (1962) is considered appropriate because it is little affected by flow rate, requires no wet chemicals, has a short response time, and is sensitive over wide concentration ranges. 

The retention of 46 alkylbenzenes was studied on an alumina column (A = 254 nm) at 25°C using a pentane mobile phase [597]. Retention times and V values were tabulated for mobile phases with 0.5% and 1.0% water. At 0.5% water the k values ranged from 0.2 (sec-butylbezene, time = 2.4min) to 3.2 (hexamethylbenzene, time = 8.6 min). The authors used a moisture control system set at 0.5% and 1.0% water. What value this really translates to is unclear since water is soluble in pentane only to the 0.009% level. Perhaps the water level refers to that on the alumina itself. Regardless of this, the authors state that the reproducibility of the retention decreases with decreasing water content due to increased heterogeneity of the alumina. 

To study the effect of sorbed water on the dynamic viscoelastic properties of hydrophilic polymers, we previously developed a moisture control system [41] as shown in Fig. 38. The moisture control system consists of two heat exchangers, denoted I and II, which are held at temperatures Tj and T2, respectively, a hot-water reservoir, a glass-filled column, and a water pump. The water in the reservoir is kept at about 90°C. Steam is fed into heat exchanger II, which is held at the dew point temperature Tj necessary to obtain the desired relative humidity at (temperature of the test chamber). 

Fig. 38 A moisture control system for dynamic viscoelastic measurements as a function of relative humidity. (From Ref. 41.)...

Moisture control systems can be divided into chemical and cooling methods. The chemical method reduces ambient humidity by absorbing moisture from air using an activated charcoal rotary or lithium chloride solution. In this method, it is necessary that the charcoal or absorption solution remove the absorbed moisture cyclically if continuous operation is needed. Energy is needed to recycle these materials. Figure 3 shows the... 

The KDF filter was first tested in prototype on a coal mine in northern Germany. It was installed in parallel with existing vacuum filters and it produced filter cakes consistendy lower in moisture content by 5 to 7% than the vacuum filters. Two production models have been installed and operated on a coal mine in Belgium. The filter is controlled by a specially developed computer system this consists of two computers, one monitoring the function of the filter and all of the detection devices installed, and the other controlling the filtration process. The system allows optimization of the performance, automatic start-up or shut-down, and can be integrated into the control system of the whole coal washing plant. 

The control system requires the values of T and AT obsei-ved during the first minutes of operation to be stored as the basis for the above calculation of end point. When the exhaust temperature then reaches the value calculated, diying is terminated. Coefficient K can be estimated from models but requires adjustment on-hne to reach product specifications repeatedly. Products having different moisture specifications or particle size will require different settings of K, but the system does compensate for variations in feed moisture, batch size, air moisture, and inlet temperature. Some exhaust air may be recirculated to control the dewpoint of the inlet air, thereby consei-v-ing energy toward the end of the batch and when the ambient air is especially diy. 

Mist eliminators are widely used in air polluhon control systems to prevent free moisture from entering the atmosphere. Usually, such mist eliminators are found downstream from wet scrubbers. The recovered mist is returned to the liquid system, resulhng in lowered liquid makeup requirements. 

Applicability/Limitations Liquid injection incineration can be applied to all pumpable organic wastes including wastes with high moisture content. Care must be taken in matching waste (especially viscosity and solids content) to specific nozzle design. Particle size is a relevant consideration so that the wastes do not clog the nozzle. Emission control systems will probably be required for wastes with ash content above 0.5 percent (particulate control) or for halogenated wastes (acid gas scrubbers). 

The type of control system and instrumentation to be selected will depend on its location (e.g., the danger of fire, explosion, pollution, moisture, the conditions of temperature and its variations). The control equipment can be classified as... 

This necessitates plant capable of control of temperature by being able to add or subtract heat from the air and control of humidity by being able to add or subtract moisture. The system also comprises fan(s), filtration, and a distribution system and may include noise control. Other terms such as cooling or comfort cooling may be met and these can be taken to mean an ability to lower the temperature of the air by refrigeration but without full control of humidity. Moisture may be removed as an incidental characteristic of the cooling coil. The term air conditioning is sometimes used where control of humidity is not included. It is essential to employ clear specifications of performance. 

The pressurized air goes to an air receiver for storage and then is processed for use by passing through filters, dryers and, in some cases, lubricators. This pressurized air is normally classified as instrument air when it is used in control systems. This air must be moisture and oil free to prevent the control devices from clogging up. 

Moisture Instrumentation , Buyers Guide Issue, Instruments Control Systems (1973)... 

Cost Costs were estimated at 4.5 million, which includes soil importation, revegetation, quality control and assurance, construction management, and installation and operation of moisture monitoring systems. 

Figure 26.32 illustrates two moisture control options in gas-collector systems. Gas-collector systems will tolerate a large amount of moisture before air transmissivity is affected. Condensates from the gas-collector layer that form beneath the clay and FMC can also be taken back into the waste, since most hazardous wastes are deposited very dry. 

---