Rotary slurry test

Figure 9.16 Rotary abrasive slurry test setup [86].

The General Electric in-duct scmbbing (IDS) process involves the atomization of a slaked lime slurry, using a rotary disk atomizer A test at the 12 MWe scale at the Muskingum River Station of Ohio Power, performed in a duct with a 4.3-m cross section, achieved 50% SO2 removal with good lime utilization... 

A slurry pump operating at 1 atm must be selected to transport a coal slurry from an open storage tank to a rotary drum filter, at a rate of 250 gpm. The slurry is 40% solids by volume and has an SG of 1.2. The level in the filter is 10 ft above that in the tank, and the line contains 400 ft of 3 in. sch 40 pipe, two gate valves, and six 90° elbows. A lab test shows that the slurry can be described as a Bingham plastic with v = 50 cP and t0 = 80dyn/cm2. 

A rotary drum filter 6 ft in diameter and 8 ft long is to be used to filter a slurry. The drum rotates at 0.5 rpm, and one-third of the drum s surface is submerged in the slurry. A vacuum is drawn in the drum so that a constant pressure drop of 10 psi is maintained across the drum and filter cake. You test the slurry in the lab by pumping it at a constant filtrate rate of 20 gpm through 1 ft2 of the drum filter screen and find that after 1 min the pressure drop is 8 psi and after 3 min the pressure drop is 12 psi. How long will it take to filter 100,000 gal of filtrate from the slurry using the rotary drum ... 

A rotary drum filter is used to filter a slurry. The drum rotates at a rate of 3 min/cycle, and 40% of the drum surface is submerged in the slurry. A constant pressure drop at 3 psi is maintained across the filter. If the drum is 5 ft in diameter and 10 ft long, calculate the total net filtration rate in gpm that is possible for a slurry having properties as determined by the following lab test. A sample of the slurry was pumped at a constant flow rate of 1 gpm through 0.25 ft2 of the filter medium. After 10 min, the pressure difference across the filter had risen to 2.5 psi. The filter medium resistance may be neglected. 

A slurry is to be filtered with a rotary drum filter that is 5 ft in diameter and 8 ft long, rotates once every 10 s, and has 20% of its surface immersed in the slurry. The drum operates with a vacuum of 20 in.Hg. A lab test was run on a sample of the slurry using 1/4 ft2 of the filter medium at a constant flow rate of 40 cm3/s. After 20 s the pressure drop was 30 psi across the lab filter, and after 40 s it was 35 psi. How many gallons of filtrate can be filtered per day in the rotary drum ... 

A rotary drum filter is to be installed in your plant. You run a lab test on the slurry to be filtered using a 0.1 ft2 sample of the filter medium at a constant pressure drop of 10 psi After 1 min you find that 500 cm3 of filtrate has passed through the filter, and after 2 min the filtrate volume is 715 cm3. If the rotary drum filter operates under a vacuum of 25 in.Hg with 25% of its surface submerged, determine ... 

You want to filter an aqueous slurry using a rotary drum filter, at a total rate (of filtrate) of 10,000 gal/day. The drum rotates at a rate of 0.2 rpm, with 25% of the drum surface submerged in the slurry, at a vacuum of 10 psi. The properties of the slurry are determined from a lab test using a Buchner funnel under a vacuum of 500 mmHg, using a 100 cm2 sample of the filter medium and the slurry, which resulted in the lab data given below. Determine the total filter area of the rotary drum required for this job. 

A slurry containing 40 per cent by mass solid is to be filtered on a rotary drum filter 2 m diameter and 2 m long which normally operates with 40 per cent of its surface immersed in the slurry and under a pressure of 17 kN/m2. A laboratory test on a sample of the slurry using a leaf filter of area 200 cm2 and covered with a similar cloth to that on the drum, produced 300 cm3 of filtrate in the first 60 s and 140 cm3 in the next 60 s, when the leaf was under pressure of 84 kN/m2. The bulk density of the dry cake was 1500 kg/m3 and the density of the filtrate was 1000 kg/m3. The minimum thickness of cake which could be readily removed from the cloth was 5 mm. 

A continuous rotary filter is required for an industrial process for the filtration of a suspension to produce 0.002 m3/s of filtrate. A sample was tested on a small laboratory filter of area 0.023 m2 to which it was fed by means of a slurry pump to give filtrate at a constant rate of 0.0125 m3/s. The pressure difference across the test filter increased from 14 kN/m2 after 300 s filtration to 28 kN/m2 after 900 s, at which time the cake thickness had reached 38 mm. What are suitable dimensions and operating conditions for the rotary filter, assuming that the resistance of the cloth used is one-half that on the test filter,... 

A new plant requires a large rotary vacuum filter for the filtration of zinc sulfite from a slurry containing 1 kg of zinc sulfite solid per 20 kg of liquid. The liquid contains water, sodium sulfite, and sodium bisulfite. The filter must handle 8000 kg of slurry per hour. What additional information is necessary to design the rotary vacuum filter How much of this information could be obtained from laboratory or pilot-plant tests Outline the method for converting the test results to the conditions applicable in the final design. 

An example of a solid-liquid phase separation - often referred to as a mechanical separation - is filtration. Filters are also used in gas-sohd separation. Filtration may be used to recover liquid or sohd or both. Also, it can be used in waste-treatment processes. Walas [6] describes many solid-hquid separators, but we will only consider the rotary-drum filter. Reliable sizing of rotary-drum filters requires bench and pilot-scale testing with the slurry. Nevertheless, a model of the filtering process will show some of the physical factors that influence filtration and will give a preliminary estimate of the filter size in those cases where data are available. 

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