151. To get a fine talc powder from its granules, the equipment used is
152. For a cyclone of diameter 0.2 m with a tangential velocity of 15 m/s at the wall, the separation factor is
153. Width and speed of a conveyor belt depends upon the __________ of the material.
154. Higher is the mesh number, smaller will be the aperture size of the screen. It means that the aperture size of a 200 mesh screen will be smaller than that of 20 mesh screen. This is valid for
155. Which of the following size reduction equipments employs mainly attrition for ultrafine grinding ?
156. Tank filter (e.g., Nutsch filter) is
157. In bag filters, filter fabrics are never made of
158. Use of 'grinding aids' is done in __________ grinding.
159. Height of liquid in agitation tank is normally maintained equal to the tank diameter. However, if the tank is too tall and a large liquid hold up is desired, then two or more impellers mounted on the same shaft may be used. The clearance between the tank bottom and the bottom most impeller should be about (where, D = impeller diameter)
160. Which of the following is the most suitable filter for separation of abrasive solids suspended in a corrosive liquid ?
161. All resistances during washing of cake
162. A __________ mixer resembles a ball mill without balls.
163. __________ conveyor is the most suitable for short distance transportation of non-abrasive loose materials like garbage, grain, food wastes etc.
164. As the product becomes finer, the energy required for grinding
165. Gyratory crushers compared to the reciprocating jaw crushers
166. The important dimensional group involved in the power requirement calculation in mixing operation is the __________ number.
167. At low Reynold's number, the power (P) required for agitating a fluid in a stirred tank becomes independent of inertial forces. In this limit, indicate which of the following relations is satisfied:
Po = ρ/ρN3 D5 : Power number
Re = ρ N D2/μ: Reynold's number
N is the impeller rotational speed, and D is the impeller diameter.
168. Which of the following grinding mills has the horizontally arranged rods as the grinding elements thereby delivering more uniform granular products with minimum fines ?
169. Rittinger's crushing law states that
170. Mechanical conveyors which push the material along an endless trough or tube are called scrappers. Which of the following conveying equipments comes under the category of 'scrappers' ?
171. Sphericity of pulverised coal is
172. The reduction ratio for fine grinders is
173. General mechanism of size reduction in intermediate and fine grinder is by
174. A straight line is obtained on plotting reciprocal of filtration rate vs. the volume of filtrate for __________ flow of filtrate.
175. The work index in Bond's law for crushing of solids has the following dimensions