Flushing Fluid

When abrasive solids are present and it is not permissible to introduce appreciable quantities of a secondary flushing fluid into the process, double internal seals are sometimes used (Fig. 10-114). Both sealing faces are protected by the flushing fluid injected between them even though the inward flow is negligible. 

Throttle bushings (Fig. 10-117) are commonly used with single internal or external seals when sohds are present in the fluid and the inflow of a flushing fluid is not objectionable. These close-clearance bushings are intended to serve as flow restric tions through which the maintenance of a small inward flow of flushing fluid prevents the entrance of a process fluid into the stuffing box. 

DEAD-ENDED SEAL CHAMBER WITH NO CIRCULATION OF FLUSHED FLUID. 

A294 Flush fluid name FLUSH FLUI C 20 ... 

Low-permeability soils are difficult to treat with soil flushing. Surfactants can adhere to soil and reduce effective soil porosity. Reactions of flushing fluids with soil can reduce contaminant mobility. 

The potential of washing the contaminant beyond the capture zone and the introduction of surfactants to the subsurface may cause problems. The technology should be used only where flushed contaminants and soil flushing fluid can be contained and recaptured. 

Answer—there is an error in the design of this pump. The error is that this is a self-flushed pump. The mechanical seals on centrifugal pumps require a lubricant or seal flush material to keep the seal faces from touching and rubbing. In most pumps, this seal flush fluid comes from the discharge of the pump itself. Such pumps are called self-flushed pumps. 

When a self-flushed pump is running, the space between the seal faces is filled with the seal flush fluid. When the pump is shut down, the space between the seal faces is filled with the fluid in the suction of the pump. However, if the pressure at the suction of the pump is below atmospheric pressure, then air is drawn through the seal faces and into the suction of the pump. This air displaces the water in the pump s case and, with time, causes the pump to lose its prime. 

BALANCED. YES/NO TANK SHUTOFF. YES/NO.FLUSH FLUID-SEAL DESICN PRESS--------------------TEMP.. 

Permeability and hydraulic conductivity are the controlling factors in the effectiveness of in situ treatment technologies. The ability of soil flushing fluids to contact and remove contaminants can be reduced by low soil permeability. Low permeability can lessen the volatilization of VOCs in soil vapor extraction or limit the effectiveness of in situ vitrification by slowing vapor releases. 

To evaluate the effects of cosolvent on surfactant delivery and PCE recovery, Box B was flushed with 4% Tween 80 + 5% EtOH at a Darcy velocity of 4.8 cm/hr. The surfactant/cosolvent mixture, which had a density of 0.994 g/cm3, was also representative of a neutral buoyancy flood solution (Shook et al, 1998). It is important to recognize that "neutral buoyancy" refers to density of flushing fluid after solubilization of the DNAPL. Thus, the initial density of the surfactant formulation must be less than that of the resident aqueous phase. Figure 5b shows the location and shape of the 4% Tween 80 + 5% EtOH front after flushing Box B with 0.5 pore volumes of solution. The lower density of the 4% Tween 80 + 5% EtOH solution (0.994 g/cm3) relative to the density of resident pore water (0.998 g/cm3) caused the injected solution to flow preferentially along the top of Box B (Figure 5b). This effect can become severe at low flow rates (Taylor, 1999). The... 

A flushing fluid is a special hydrocarbon liquid designed specifically for flushing out mechanical pumps. It can be obtained from most mechanical pump, and mechanical pump oil manufacturers and suppliers. Do not use a hydrocarbon solvent, such as acetone because you will destroy your pump. 

The liner has a porous or near porous structure generating a uniformly distributed source of cooling or hot flushing fluid that keeps Tw of the liner cool or reduces the concentration of corrosives species in the wall boundary layer G. 

Legend to Fig. 5 a corrosive/hot, reacting fluid, y cooling/flushing fluid, L Liner,... 

BALANCED.YES/NO TANK SHUTOFF.YES/NO. FLUSH FLUID-SEAL DES I GNi PRESS.— TEMP------... 

The water circulation pump must be of sanitary design and may be equipped either with a single or a double mechanical seal. In the latter case, the purified water from the pump s discharge is used as a seal flush fluid (Fig. 5). If a spare circulation pump is installed for reliability, it is important to ensure that it does not constitute a long dead leg. This can be avoided either by valving it off and draining it free of water... 

BALANCED. YES/NO TANK SHUTOFF. YES/NO.FLUSH FLUID-SEAL DESIGN PRESS TEMP.. 

Dead-ended seal chamber with no circulation of flush fluid. 

Grouting Units shall be so arranged that flushing can be accomplished with grout intake valves closed, flushing fluid supply valves open, and the pump operated at full speeds. 

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