Inlet elbow

If the probe is in the meter run, the placement should be away from the inlet elbow and as far downstream of the orifice plate as possible. 

In initial test evaluation, a low nss value of 22,000 was unfavorably realized for 450 gpm at 6000 rpm, as indicated in Fig. 3, The integrally cast guide vanes within the pump-inlet elbow-type bell were then partially machined away. The corresponding reduction of inlet losses resulted in an nss of 150,000 at 450 gpm. This was equivalent to a favorably low liquid level of 10 in. above the inlet edge of the pump, as indicated in Fig. 4. 

The inlet elbow has to be connected in a positive and restraint-free manner to the kiln. Variations in length both parallel and perpendicular to the kiln have to be compensated, and the forces due to heating and deformation must not be transmitted across the joint. 

Fig. 40 shows various designs for the inlet elbows to the cooling tubes. The form of construction in which the elbow is placed somewhat off-centre in the direction of rotation, and that in which a bridge or weir is provided as an internal fitting in the elbow, have proved most suitable (Figs.41 a and 41 b). 

Poor performance can result from fan inlet eccentric or spinning dow, and discharge ductwork that does not permit development of hiU fan pressure. Sometimes inlet restrictions starve a fan and limit performance. To obtain rated performance, the air must enter the fan uniformly over the inlet area without rotation or unusual turbulence. This allows all portions of the fan wheel to do equal work. If more air is distributed to one side of the wheel, such as with an elbow on the inlet, the work performed by the lightiy loaded portions of the wheel is reduced and capacity is decreased by 5—10%. The use of an inlet box duct on a fan can reduce capacity by as much as 25% unless there are turning vanes in the duct. Use of the vanes reduces the capacity loss to around 5%. 

Example 1 Force Exerted on a Reducing Bend An incompressible fluid flows through a reducing elbow (Fig. 6-5) situated in a horizontal plane. The inlet velocity Vj is given and the pressures pi and measured. 

On all rotating diyers, the vapor-outlet tube is stationary it enters the shell through a rotating gland and is fitted with an elbow and an upward extension so that the vapor inlet, usually protected by a felt dust filter, will be at all times near the top of the shell. 

Favored locations for erosion-corrosion are areas exposed to high-flow velocities or turbulence. Tees, bends, elbows (Fig. 11.5), pumps, valves (Fig. 11.6), and inlet and outlet tube ends of heat exchangers (Fig. 11.7) can be affected. Turbulence may be created downstream of crevices, ledges (Fig. 11.8), abrupt cross-section changes, deposits, corrosion products, and other obstructions that change laminar flow to turbulent flow. 

In cases where bellows failure would release flammable, toxic or corrosive liquids through the vent, a short nipple and elbow should be used to direct leakage to an open funnel which is piped to grade and ties into a catch basin or manhole with a sealed inlet connection. 

Example The maximum flare load of a system is 1,000,000 Ibs/hr of vapor. The pressure at the base of the flare stack is 2 psig, the average molecular weight of the vapor is 50, at a temperature of 200°F at the combined header to the flare stack. The distance from the drum to the stack is 500 ft. The line consists of two 90° welding elbows and an orifice for a flow controller. The total pressure drop at the knock-out drum is 0.5 psi. Determine the pressure at the inlet of the knock-out drum. 

Crude oil with a viscosity of 12.5 cP and SG = 0.88 is to be pumped through a 12 in. sch 30 commercial steel pipe at a rate of 1900 bbl/hr. The pipeline is 15mi long, with a discharge that is 250 ft above the inlet, and contains 10 standard elbows and four gate... 

A pneumatic transfer line has 300 ft of straight pipe, two long radius elbows, and a lift of 50 ft. A two-stage cyclone is at the receiving end. Solid with a density of 125 lb/cuft is at the rate of 10 tons/hr and the free air is at 5000ft/min. Inlet condition is 27psia and 100°F. Investigate the relation btween line diameter and power requirement. 

Example 1 Force Exerted on a Reducing Bend An incompressible fluid flows through a reducing elbow (Fig. 6-5) situated in a horizontal plane. The inlet velocity Vl is given and the pressures pl and p. are measured. Selecting the inlet and outlet surfaces 1 and 2 as shown, the continuity equation Eq. (6-9) can be used to find the exil velocity Vz = VjA/A. The mass flow rate is obtained by m = p V. A. ... 

FIGURE 7.12 Laboratory assembled modular canister setup composed of (a) ionic exchange column, (b) pump, (c) inlet valve, (d) elbow, (e) T connection, and (f) column valve. 

Tourills are in principle Wolff s ceramic (stoneware) bottles, provided with two large connections at the top in which elbow pipes are fixed and sealed by a mixture of asbestos and water glass. The pipes serve for inlet and outlet of the gases (see Fig. 118). 

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