Floating suction

Tank settling as a means of contaminant removal is not very efficient with fuels having the viscosity of kerosene. It is common practice to design tanks with cone-down drains and floating suctions to facilitate water and solids removal. 

Install the feedwater distribution tube with distribution header and remove the floating suction device. Add 200-300 lb of sodium fluoride directly to the tank. (Various graduations of sodium fluoride can be used, from coarse crystal to fine crystal to powder, but fine crystals will produce less dust than powder and dissolve better than coarse crystal.)... 

A sudden drop in furnace feed temperature is commonly caused by a slug of bottoms sediment and water (BSJ crude charge. This happens when a tank in the crude supply system has been cleaned. The silt and waxy dirt were flushed down the crude line to the refinery. A floating suction in the refinery s crude charge tank minimizes the effects of these incidents. 

For low pressure pipelines that have ports open to the atmosphere, eg, sewers or closed effluent culverts, samplers are designed to sample through manholes. In a typical system, the Hquid is lifted through a suction line into the sampling chamber under vacuum. When filled, the vacuum shuts off, and the sample drains into a sample jar. A secondary float prevents any Hquid from reaching the vacuum pump. The suction line then drains by gravity back to the source. 

Condenser tail pipes, used tvith any condenser, are sealed with a 34-foot leg into a sump, or with a condensate pump operating under vacuum on suction. With surface-type condensers, the level may be sealed in a receiver with a float or other type of level control. 

Should a float control fail, the level in the shell may rise and liquid pass into the compressor suction. To warn of this, a second float switch is usually fitted at a higher level, to operate an alarm and cut-out. 

For solids which float, or which are added from the top, a vortex action helps to draw the material down into the impeller. Often a draft tube is used to serve as a suction entrance for the impeller. Uniform suspensions are difficult to maintain when the tank liquid height is much greater than the tank diameter. The impeller is normally placed A of liquid depth off the bottom [21]. 

The pump will be placed on a floating dock that is just a few feet above the river level, so that the net positive suction head (NPSH) will be adequate. The maximum height from the bottom of the barge to the pump will be 20 ft. 

Pnmps shall be designed to float with the suction... 

Automatic refilling using an automatic float valve should be provided. A maximum refill time of 8-hours is recommended (NFPA 22). Low-level alarms to protect the pumping unit should be provided. Suction pits associated with reservoirs should be monitored by level alarms to detect suction screen plugging. 

Pumps shall be designed so that they may either float with the suction and discharge pipe, or be bolted to a pad or foundation. 

After being heated for about 20 min., the odor of alcohol will disappear, indicating the completion of the reaction. A pasty mass containing a mixture of the soap, glycerol, and excess sodium hydroxide is obtained. Use an ice water bath to cool the flask with its contents. To precipitate or salt out the soap, add 150 mL of a saturated sodium chloride solution to the soap mixture while stirring vigorously. This process increases the density of the aqueous solution therefore, soap will float out from the aqueous solution. Filter the precipitated soap with the aid of suction and wash it with 10 mL of ice cold water. Observe the appearance of your soap and record your observation on the Report Sheet. 

When, at the end of about a week, the mass has changed to a pure red color, wash it by decantation (see Note 5 (6), page 10) in a 600-cc. beaker. Most of the excess of sulphur is floated off. Then rinse the red sulphide back into the evaporating dish, leaving behind in the beaker any lumps of black sulphide or globules of mercury. Boil the red sulphide with 50 cc. of saturated sodium sulphite solution to remove the last of the uncombined sulphur wash by decantation with boiling water and collect the mercuric sulphide on a suction filter. Dry the product on the hot plate and preserve it in a 2-ounce cork-stoppered bottle. 

It turned out that this nozzle produces coarse bubbles which are not able to float very fine or strongly hydrophilic flocks. A nozzle which displays a channel with a constant hydraulic cross-sectional area, Sh Da2 - D,2, see Fig. 56 b, serves this purpose better [81]. It also exerts a stronger suction and produces a larger gas throughput. This has to be throttled in order to prevent tiny gas bubbles to coalesce... 

---