The lining material should be selected according to the corrosiveness, wear and temperature of the tested medium:
First, natural rubber (soft rubber)
1, better elasticity, wear resistance and tearing force
2, resistant to general weak acid, weak alkali corrosion
3. Water and sewage
Second, acid-resistant rubber (hard rubber)
It can withstand the corrosion of hydrochloric acid, acetic acid, oxalic acid, ammonia water, phosphoric acid and 50% sulfuric acid, sodium hydroxide and potassium hydroxide at normal temperature, but it is not resistant to corrosion by strong oxidants.
It can measure general acid, alkali and salt solutions.
Third, neoprene (Neoprene)
1, excellent elasticity, high tearing force, good wear resistance
2, resistant to general low concentration of acid and alkali, salt solution corrosion, but not resistant to oxidation of the medium, and temperature requirements <80 ° C;
It can measure water, sewage, mud and pulp.
Fourth, Polyurethane (Polyurethane)
1, excellent wear resistance
2, poor acid and alkali resistance, temperature requirements <40 ° C
Measure medium-strongly worn coal slurry, mud and slurry
Five, polytetrafluoroethylene (PTFE)
1. Boiling hydrochloric acid, sulfuric acid, nitric acid, aqua regia, concentrated alkali and various organic solvents
2, good wear resistance, poor bonding performance, temperature requirements -80 ~ +180 ° C;
Measuring concentration, concentrated alkali strong corrosive solution and sanitary medium
Second, gas turbine flowmeter measurement characteristics
1. Gas turbine flowmeter is one of the main types of flowmeters. Its working principle is: the gas entering the gas turbine flowmeter is accelerated by the fluid, and the accelerated gas acts on the blades of the turbine through the inlet passage. The impulse causes the turbine of the flow meter to rotate in the flow path, and within a certain flow range, the number of revolutions of the turbine is proportional to the volume of the gas flowing therethrough. By mechanical or electromagnetic induction, the number of revolutions f of the turbine can be obtained, so that the flow rate Q of the gas flowing through the flow meter can be obtained.
2. Gas turbine flowmeters are widely used in the measurement of gas flow or total gas volume, and are widely used in natural gas flow measurement at home and abroad. The theoretical research and practical experience of gas turbine flowmeters are very mature, and there are corresponding international standards. Countries also have corresponding national standards. China also adopts international standards. In Europe and the United States, gas turbine flow meters are the most important gas flow meters, and the Netherlands alone uses more than 2,600 gas turbine meters on natural gas pipelines.
Selection of measurement types for special industrial and commercial users
2. Case 2: A heavy machine tool factory
The main gas plant of the heavy-duty machine tool factory is 13 production kiln, and there is also a machine repair workshop and 63 mobile burners. The total gas load of all gas facilities is 1837m3/h. See Table 1 for details. The customer promised that all gas facilities could not be fully activated at the same time, the maximum gas consumption required was 1200m3/h, and the minimum pressure required before the furnace was 0.055MPa. The pressure regulator used in the on-site pressure regulating metering box is opened and ready, and the flow meter is in the form of a G1600 turbine table plus bypass.
When debugging the kiln, it was found that the flowmeter in the pressure regulating metering box had a stop-and-go phenomenon. If only some of the kiln was opened or only some of the kiln was used, there would be a phenomenon that the flowmeter did not measure or the measurement error was large.