Skimmer system

FIGURE 7.16 Schematic of a rope (a) and belt (b) skimmer system. 

The momentum separator can be considered as a two-stage differentially-pumped nozzle-skimmer system, thus featuring a nozzle, a skimmer, and a colhmator. In this respect, the FBI resembles an atmospheric-pressure ionization system (Ch. 5.4). However, in the FBI, the analyte is sampled from a closed desolvation chamber, and the analyte is transferred to the high-vacuum region prior to ionization Generally, little attention is paid to the design characteristics of the momentum separator with respect to optimized molecular-beam performance. 

An electrodynamic ion furmel interface, positioned between the outlet of a heated stainless-steel capillary and an RF-only octapole ion guide, thus replacing the skimmer, was described by Shaffer et al. [41-42]. The ion furmel interface consists of a series of ring electrodes with decreasing internal diameter. Both RF and DC voltages are apphed to these electrodes. The device provides a more effective focussing and ion transmission. Abont ten-fold sensitivity improvement over a conventional nozzle-skimmer system was demonstrated. 

Skimmer system. Debris and other species floating on the water surface of fuel storage pools should be removed by a skimmer system or other means. This material can settle on the surfaces of fuel cladding and cause pitting corrosion. 

In the ion source, a supersonic beam of noble gas is generated and the sample is seeded into it (e.g., by laser desorption). Together with the beam, the sample is carried through a skimmer system that allows only the isentropic core to enter the vacuum chamber where the ions are generated by two tunable lasers. The technique is still in the development stage. 

In early GC with packed columns several tens of milliliters of carrier gas per minute were eluted. Thus, most of the flow had to be separated before entering the ion source to prevent the mass spectrometer vacuum system from breakdown [4,33,38]. Flow reduction was either effected by a simple split to divide the effluent in the inlet system by a factor of about 1 100 or by means of a more elaborate separator, the jet separator being the best-known of those [57,58]. The advantage of separators over a simple split is the enrichment of the analyte relative to the carrier gas in case of the jet separator this effect is based on a principle related to that of the nozzle-skimmer system in ESI (Chap. 12.2.1). 

The Supersonic or skimmer system is more costly and more difficult to use but it gives many advantages on the capillary transfer line no condensation in the transfer line, no collision between the molecules and with the transfer line wall, possibility to detect high mass species (above 500 amu)... 

Ions and neutral molecules headed for skimmer orifice, drawn mainly by the vacuum system... 

Sanitizers. Spa and hot-tub sanitation is dominated by chlorine- and bromine-based disinfectants. Public spas and tubs usually employ automatic feeders, eg, CI2 gas feeders, to maintain a disinfectant residual. Private or residential spas and tubs can use automatic chemical feeding or generating devices, or they can be sanitized manually with granular or liquid products. The most widely used products for private spa and tub sanitation are sodium dichloroisocyanurate and bromochlorodimethylhydantoin. Granular products are normally added before and after use, whereas solids, eg, stick-bromine, are placed in skimmers or feeders. Bromine generating systems can also be used and are based on oxidation of bromide ions (added to the water as sodium bromide) by peroxymonosulfate, chloroisocyanurates, hypochlorites, or ozone to generate the disinfectant HOBr. 

Inertial collectors for mists and droplets are widely used. They include cyclone collectors, baffle systems, and skimmers in ductwork. Inertial devices can be used as primary collection systems, precleaners for other... 

System component A small mixing tank, two chemical feed tanks, a mixer, and a large tank equipped with an oil skimmer and a sludge pump. The mixing tank has a retention time of 15 min and the oil skimming tank has a retention time of 2.5 h. 

Fig. 1. Schematic diagram of the multimass ion imaging detection system. (1) Pulsed nozzle (2) skimmers (3) molecular beam (4) photolysis laser beam (5) VUV laser beam, which is perpendicular to the plane of this figure (6) ion extraction plate floated on V0 with pulsed voltage variable from 3000 to 4600 V (7) ion extraction plate with voltage Va (8) outer concentric cylindrical electrode (9) inner concentric cylindrical electrode (10) simulation ion trajectory of m/e = 16 (11) simulation ion trajectory of rri/e = 14 (12) simulation ion trajectory of m/e = 12 (13) 30 (im diameter tungsten wire (14) 8 x 10cm metal mesh with voltage V0] (15) sstack multichannel plates and phosphor screen. In the two-dimensional detector, the V-axis is the mass axis, and V-axis (perpendicular to the plane of this figure) is the velocity axis (16) CCD camera.

Rope and belt skimmer units are quite efficient at removing thin layers of LNAPL from both open-trench wells and larger surface areas (ponds, or even manholes). Recent developments include development of belts that are sufficiently narrow to use in open wells. Both smooth flexible-tube and belt systems rely upon continuous rotation of a flexible closed-loop tube (or belt) constructed of an oleophilic material (Figure 7.16). The automatic unit draws the oil-covered tube (or belt) through scrapers and returns it to the surface to gather more oil. 

Ions, formed in the source, are transported into the high-vacuum system of the mass spectrometer by the use of a nozzle-skimmer arrangement. This acts as a momentum separator and heavier sample molecules tend to pass through, while lighter solvent and drying gas molecules can be more readily pumped away in this... 

TOOOl 3M Company, 3M Empore Extraction Disk T0003 Abanaki Corporation, Active Belt Oil Skimmers T0005 Active Environmental Technologies, Inc., TechXtract T0009 Advanced Environmental Services, Inc., System 64MT Low-Temperature Thermal Desorption... 

If the oil or grease congeals or solidifies at ambient temperatures, the tank and/or skimmer will require heaters to maintain fluid flow. This is especially true at temperatures where water freezes. The use of rust inhibitors, high temperatures, and variable pH levels can affect the efficiency of oil skimmers. Turbulent waters may emulsify the water and oil and limit the system effectiveness. All information is from the vendor and has not been independently verified. 

The PetroTrap is available from the vendor at a cost of 885.00 per unit. The standard system includes a PetroTrap skimmer assembly (2- or 4-inch-diameter model), a 25-ft suspension hose, and a locking well cap (D17074L, p. 4). 

---