Differential Pressure Transmitter In Oil Tank Application - Transmission, Transmitter, Transducer -

1 Introduction   In the current design of oil tank level measurement, the more popular is the use of radar level gauge or a float, buoy, strip-type liquid level gages. Although the accuracy of radar level gauge, but costs are high, buoy, float level gauge, etc., installation, maintenance, too much trouble. Differential pressure gauge, airtight container in the boiler so widely used, but the measurements are not really liquid, so the design of the tank liquid level measurement was seldom applied. In fact, the exact oil tank level, not important, users do not actually want to understand the level, but by measuring the level to understand the actual number of tanks in the oil (or tonnes), thus preventing full overflow. From this analysis method used to measure the level of differential pressure (the actual number for the MT) would be a good option. Because the current application of differential pressure transmitter is very mature, such as 1151,3051, and differential pressure transmitter EJA, technology is perfect accuracy up to 0.075, and the price plummeted, performance, higher prices.

2 Design Principles Name suggests differential pressure type level gauge measured the pressure difference between the results is that P = g h. And because often the cylindrical tank, the cross section area of a circle S is constant, then the weight G = P? S = g h? S, S constant, G and P is proportional. As long as the accurate detection of P value, you can get the actual oil inventory G, from the formula also know these density and height of h is inversely proportional to the temperature change, although the oil volume expansion or reduced, the actual liquid bit higher or lower, the detected pressure is always constant. If the user needs to show the actual level, the introduction of medium temperature compensation can be resolved.

3 practical applications Oil depot project in Wenzhou in the new century, the author applied this idea to the actual design.

Design conditions: 2000m3 tank, diameter d = 14.5m, height h = 14m.
A table: use of Wenzhou City, Bethel's Instrumentation BTL-1151LT Flanged Flameproof Pressure Transmitter, selected flange is to prevent sediment and dirt can plug the end of joining pipe, Transducer Range 0 ~ 140kPa.

Second table: use WP Series Smart Bar Display Alarm, universal signal input range can be arbitrarily changed, with the Bar Display level, with the figures show the number of tons of oil products. Case of 6 # cans, S = × r2 = 3.14 × 7.252 = 165m2, high as 14m.

In the tank top, a liquid level alarm device designed to prevent oil overflow, as a double insurance. As in the application of the tonnage measured directly, so the storage tank regardless of what kind of oil, the second table shows the value of the tonnage of oil within the tank, avoiding the need to convert measured density of the trouble.

General, oil from storage is often used to pump through the oval gear flowmeter, flowmeter accuracy is limited because the maximum 0.2 only, needs to measure the density calculation, the results are often quite different from, and thus cause measurement disputes. Now, because oil tank measurement of tonnage of the results, and precision can reach 0.2 or even 0.1, therefore, compared with the volumetric flow meter, measure the results more accurate. Although a small number of oil out of storage, due to resolution reasons, the results of the absolute error of measurement of large quantities of oil in a large warehouse, its high accuracy and small relative error, is the other measuring instruments can not match, especially for monthly, quarterly and annual inventory. Practice shows that the main advantages are: easy installation and maintenance; intuitive readings are straightforward and can be directly read out the stocks of oil; eliminates the determination of density and conversion.

4 attention problems (1) design and installation of oil tank at the bottom of the check should be considered as lower opening pressure in order to eliminate errors caused by temperature changes, if necessary, the introduction of temperature compensation.

(2) level in the tank of tank cross-section ranging from the case (as small under the large), to consider compensation measures. If the second table use WP-H80 Series Level - Capacity control device.

(3) In order to achieve a certain precision, such as the oil tank at the top with breathing valve, differential pressure transmitter must be used and not by pressure transmitter. Of the exposure tank or less precision, the pressure transmitter can be directly used to facilitate the installation.

(4) the second table as a smart table, can easily change the range, to achieve temperature compensation.

(5) installation of negative pressure differential pressure transmitter room to install the catchment, and to always sewage, so as not to affect the accuracy of water. [Popular Keywords]: Transmitter   Transmitter   Inverter Comment Large   In   Small

By: imagecreatefrom

Article Directory: http://www.articledashboard.com

We are high quality suppliers, our products such as STC12C56 , STC12C5A Manufacturer for oversee buyer. To know more, please visits STC Micro.