How to measure the flow rate and liquid level of asphalt

Measuring the flow rate of asphalt: mass flow meters (which must be of the straight-tube type) or wedge flow meters can be used. Measuring the liquid level of asphalt: radar level gauges or radio frequency admittance level gauges can be employed

Is there anything wrong with using orifice plates and differential pressure transmitters?

Considering the issue of the measuring medium, for flow meters that use orifice plates and differential pressure transmitters, I have not come across any records of their use in such applications. Of course, when making a choice, from an economic perspective, one tends to opt for the measurement method suggested. In that case, you can ask the manufacturer to provide information on the use of orifice plates and differential pressure transmitters for measuring asphalt, as this can serve as a factor to consider when making a decision, thereby giving you more options to choose from.

The asphalt flow rate is measured using a Smith anti-settling flow meter. A photoconductive level gauge is used for measuring liquid levels. There will be oil and gas at the top of the asphalt storage tank, so radar will not work very well. Over time, with radio frequency admittance, asphalt can accumulate on the rod; if this accumulation is too thick, it will affect the measurements.

The viscosity of the asphalt is too high, preventing the required Reynolds number for the orifice plate from being achieved, thus making accurate measurement impossible. It could block your pressure guide tube!

For asphalt, both scraper flow meters and mass flow meters can be equipped with heating systems; the scrapers used for measuring asphalt typically come with insulation jackets

I’m not sure if a gear wheel can be used with the flow meter; it’s just a guess

If high precision is required, a photoconductive type should be used; if lower precision is sufficient, a float steel belt type can be used, as the latter is purely mechanical.

For flow rate, try a target flow meter; for level, try an electric float.

For measuring media with high viscosity such as asphalt that are highly sensitive to temperature, a target flow meter should be used, as it is both economical and practical; for measuring liquid levels, a float switch is suitable, as other options are not effective

Given the viscosity, it seems that only a scraper can be used; other types such as orifice plates, target plates, etc., won’t allow flow at all! ~

Flow rate: An ultrasonic flow meter can also be used! Ultrasonic flow meters can measure the flow rate of any liquid, especially those that are corrosive, highly viscous, or non-conductive. As for the liquid level, there are many options available – it mainly depends on your requirements regarding cost-performance! For a lower cost option, use a float ball or a steel belt; if high precision is required, go with radar wave guidance

I have worked on butane deasphalting units, where target flowmeters and differential pressure flow transmitters were used for measuring flow rates. Due to the high viscosity of asphalt, the maintenance of differential pressure flow meters is quite extensive on an annual basis; it is necessary to regularly fill them with isolation fluid and conduct insulation checks. Addressing the issue of asphalt entering the pressure transfer pipes is time-consuming and labor-intensive. Later, all the differential pressure type flow meters were replaced with wedge-type flow meters, which reduced the amount of maintenance work required. However, an accident occurred once: due to the high temperature in the asphalt processing unit (over 200 degrees) and high pressure (the maximum pressure in the unit was 6 MPa), the gaskets on the pressure-taking flanges of the wedge-type flow meters aged, resulting in asphalt leakage. At that time, operators were conducting inspections outside at night and detected the accident in time; otherwise, it could have led to a serious fire. Therefore, the issue of gaskets must be considered when selecting wedge flow meters. After replacing one of the target flowmeters with a scraper flowmeter as well, the impurities present in asphalt can easily cause the scraper to get stuck; moreover, scraper flowmeters are much more expensive. Therefore, if no transition is made, target flowmeters should continue to be used. This post was last edited by horizontal line on 2009-4-15 11:12.]