FEATURE FLOW, LEVEL & CONTROL
Screening efficiency levels
T
he screen house of a quarry is where the aggregates are processed and
graded, and sorted into size ready for coating, stockpiling or loading onto transport. The environment, however, features dust, noise and vibration from the screens and associated machinery. E&JW Glendinning was using
ultrasonic level sensors at its quarry in Devon, but these were giving false indications resulting in both lost time and productivity during lorry loading and at the infeed control. As an example, the plant operator
would start to load out to a lorry based on the initial level reading of a particular grade, then be unable to complete the loading process due to the bin running empty and the lorry then having to be topped up by a loading shovel from the quarry stockpiles. So, with regular maintenance,
cleaning and adjustment needing to be carried out, the company turned to the VEGAPULS 69 contactless bulk solids radars. Radar technology uses microwave signals to measure level and is unaffected by the in-flight dust, air movement, pressure, temperature or filling noise that often affect ultrasonic sensors.
SENSOR SOLUTIONS The sensors are deployed across nine bins; and the materials being measured range in size from 0-4mm inside the bins, where there are very high levels of dust, to 60mm where high levels of filling noise can also be encountered. The plant has a 600TPH load out
capacity for road going lorries, and internal dumpers feed the ready-mix and block production plants. So, an accurate ‘picture’ for the operators is a key component for efficient running of the plant. According to the company,
installation in the screen house was easy. The sensors were supplied with flanges to match the current sensor
can easily avoid the build-up on the sides of the bins and focus just on the product level – from top to bottom. The higher frequency is also unaffected by even very large amounts of build-up from aggregate dust on the transducer face, which again can quickly attenuate ultrasonic sensor signals.
The quarry screen house, where the aggregates are
processed and graded
The SCADA screen shows an accurate representation of bin levels
Contactless bulk solids radar level sensors from
VEGA Controls have been selected for the screen house of a UK quarry, where they are resulting in high levels of efficiency while coping with dust, vibration and noise
locations and they were also able to utilise the same cabling. Of additional benefit, the new
80GHz radar solution has a measuring range span from just a few hundred centimetres up to 120m, enabling its use in silos, hoppers, crushers, mobile stockpile levels and even fast change response for conveyor positioning. Its sister device, an 80GHz radar for liquids, is also suitable for Bitumen tank levels. The new radar has excellent focussing, with a 3.5˚ beam angle being typical, so it
Of additional benefit, the latest generation radar devices are safe. They conform to EN LPR (Level Probing Radar) standards, so they can be used both inside or outside the plant with absolutely no risks to personnel.
“The new 80GHz radar solution has a measuring range span from just a few hundred centimetres up to 120m, enabling its use in silos, hoppers, crushers, mobile stockpile levels and even fast change response for conveyor positioning”
14 OCTOBER 2016 | INSTRUMENTATION
AN INCREASE IN THROUGHPUT Since the installation of the new sensors, Glendinning have seen an increase in plant throughput with the operators being able to control and trim bin levels efficiently. The level increase and decrease is followed in a smoother, more accurate manner, offering a truly ‘analogue or dynamic’ representation. In addition, because there are no false high level alarms, the plant does not unnecessarily place the infeed on hold either, as the operators are able to trust the levels seen on the SCADA screens. Of further benefit, there has been a decrease in the extra traffic movements when directing lorries to the plant or stockpiles. The reduced pressure on stock loader shovels frees them to load the products they are designated for, while lower demands on electrical, control and instrument engineers frees their time for projects and proactive maintenance, as well as reducing risk from working in these areas. Another set of sensors has been purchased for the course screens. This site is now also testing a new VEGA innovation: a Bluetooth sensor set up and maintenance tool. Using Smart phone, tablet or PC with Bluetooth, all VEGA devices can be easily and safely commissioned, and simply monitored.
VEGA Controls T: 01444 870055
www.vega.com/uk
/ INSTRUMENTATION
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176 |
Page 177 |
Page 178 |
Page 179 |
Page 180 |
Page 181 |
Page 182 |
Page 183 |
Page 184 |
Page 185 |
Page 186 |
Page 187 |
Page 188 |
Page 189 |
Page 190 |
Page 191 |
Page 192 |
Page 193 |
Page 194 |
Page 195 |
Page 196 |
Page 197 |
Page 198 |
Page 199 |
Page 200 |
Page 201 |
Page 202 |
Page 203 |
Page 204 |
Page 205 |
Page 206 |
Page 207 |
Page 208 |
Page 209 |
Page 210 |
Page 211 |
Page 212 |
Page 213 |
Page 214 |
Page 215 |
Page 216 |
Page 217 |
Page 218 |
Page 219 |
Page 220 |
Page 221 |
Page 222 |
Page 223 |
Page 224 |
Page 225 |
Page 226 |
Page 227 |
Page 228 |
Page 229 |
Page 230 |
Page 231 |
Page 232 |
Page 233 |
Page 234 |
Page 235 |
Page 236 |
Page 237 |
Page 238 |
Page 239 |
Page 240 |
Page 241 |
Page 242 |
Page 243 |
Page 244 |
Page 245 |
Page 246 |
Page 247 |
Page 248 |
Page 249 |
Page 250 |
Page 251 |
Page 252 |
Page 253 |
Page 254 |
Page 255 |
Page 256 |
Page 257 |
Page 258 |
Page 259 |
Page 260 |
Page 261 |
Page 262 |
Page 263 |
Page 264 |
Page 265 |
Page 266 |
Page 267 |
Page 268 |
Page 269 |
Page 270
