# Results for: “P.S.Sona”

1 eBook

## Ch_18_F |
P.S.Sona | Laxmi Publications | |||||

74 A Practical Manual of Pharmaceutical Engineering Where, d rs ro g = Diameter of the particle (m) = Density of the particle(g/cc) = Density of liquid (g/cc) = Acceleration due to gravity (m/s2) From this equation it is possible to determine the terminal velocity of particles of known diameter. Say suppose particle of size 40 mm, 20 mm etc. If a suspension taken in a container of known volume, let the height of the suspension in the container is Ho. It is possible to determine the velocity of settling, V = Ho/t � (Eq: 18.2) After rearranging the equation one can find out the settling time for particles of interest. By applying this concept it is easy to separate particles of different size by pre calculating the time for them to settle completely. This experiment allows an easy mode of separation of particle of interest by performing simple decantation procedure. PROCEDURE 1. Prepare slurry of calcium carbonate in water (5 g/100 ml). 2. Add this slurry into a beaker (I) and make up to the mark depending upon the capacity of the beaker. See All Chapters |
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## Ch_28_F |
P.S.Sona | Laxmi Publications | |||||

Determination of Relative Humidity by Sling Psychrometer EXPERIMENT 111 28 DETERMINATION OF RELATIVE HUMIDITY BY SLING PSYCHROMETER AIM To determine the relative humidity by wet bulb depression method using sling psychrometer. REQUIREMENTS Sling psychrometer (1) Humidity chart (wet bulb depression Chart) (1) PRINCIPLE (Refer the previous experiment). In this experiment relative humidity is determined by sling psychrometer. It consists of two thermometers fixed on a metallic frame (Refer the Fig. 28.1) which can be rotated by a handle. One of the thermometers (wet bulb) is covered with cloth sack which can be dipped in water. (See the Fig. 28.1) the second thermometer (dry bulb) is free and exposed to the air. The sling psychrometer is whirled for some seconds until the reading in the wet bulb thermometer reaches equilibrium. After reaching equilibrium it is noticed that the reading in the wet bulb thermometer is always lower than the dry bulb thermometer. The amount of cooling at the wet bulb and the fall in the reading depends upon the rate of evaporation. The rate of evaporation interns depends on the relative humidity of the air. See All Chapters |
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## Appdiex_XVI |
P.S.Sona | Laxmi Publications | |||||

## Appdiex_I |
P.S.Sona | Laxmi Publications | |||||

## Ch_3_F |
P.S.Sona | Laxmi Publications | |||||

12 A Practical Manual of Pharmaceutical Engineering q = mc cpc (Tcb � Tca) Where, q mc cpc Tcb Tca � (Eq: 3.1) = Rate of heat transfer = Mass flow rate of cold water (liter/sec) = Specific heat of cold water (J/kg) = Temperature of the leaving cold water (°C) = Temperature of the entering cold water (°C) Rate of heat transfer, based on the area of heating surface (tube) can be determined as follows, dq /da = UDT � (Eq: 3.2) dq/da = Local flux, DT = Over all local temperature difference (Th � Tc , where Th is the average temperature of the hot fluid, Tc is the average temperature of the cold fluid) U = Local overall heat transfer coefficient Since DT can vary considerably from point to point along the tube, the heat flux is proportional to DT. To apply this equation for the total surface area, the equation must be integrated. This can be done with some simple assumption that, the overall coefficient U is a constant, the specific heat of hot and cold fluids are constant, the flow is steady in both parallel or counter current. After integration and proper arrangement the equation becomes, q= See All Chapters |