Device for dynamically measuring bubble content of flowing liquid

#The present invention relates to a device for dynamically measuring the bubble content of a flowing liquid. More particularly, the invention relates to a device provided in a conveyance passage for a flowing liquid, as may be used in the chemical or mechanical industries, or provided in a simple bypass for the conveyance passage, so that the bubble content of the flowing liquid and the bubble quantity of dissolved gas in the flowing liquid can be dynamically measured without extracting any of the liquid therefrom.

#When a liquid such as a lubricating oil and a liquid containing a polymer, a surface active agent or the like flows through a passage with agitation, bubbles are likely to be produced in the liquid. The bubbles contained in the liquid are likely to cause various problems, such as an inaccurate measurement of the flow rate of the liquid, or, in the case that the liquid is a lubricating oil, a drop in the efficiency of operation of a hydraulic apparatus operated by the liquid and abnormal wear of the lubricated sliding surfaces of the machine. Although it is often necessary to dynamically, quickly and accurately measure the bubble content of a liquid, no appropriate measuring device has heretofore been available. Conventionally, a sample of the liquid has been extracted from a passage for the liquid and subjected to a gas chromatography or a static separation process. However, such procedures are time consuming, the bubbles in the liquid are likely to disappear, and it is difficult to accurately measure the bubble content of the liquid.

#Accordingly, to overcome the above problems, a method and a device for dynamically measuring the bubble content of a flowing liquid without extracting any of the liquid from a passage were disclosed in U.S. Pat. No. 5,041,990. The device is installed in a conveyance passage of a bubble-containing liquid or in a bypass of the passage. The device includes a density sensor sensitive to the density of the bubble-containing liquid, a pressure sensor, a temperature sensor, a pressure calculation circuit, a temperature calculation circuit, a bubble content calculation circuit, a control panel, and a bubble content display panel. The density of the liquid, which changes depending on the bubble content of the liquid, is first measured. The pressure calculation circuit, the temperature calculation circuit, and the bubble content calculation circuit then carry out calculations in accordance with a predetermined formula and an instruction from the control panel to determine the bubble content of the flowing liquid at a standard pressure and a standard temperature. The bubble content determined in this manner is indicated on the bubble content display panel.

#FIG. 1 is a cutaway view of an integrated-type device of the invention for dynamically measuring the bubble content of a flowing liquid, which is directly installed in a conveyance passage for the liquid;

#FIG. 2 is a block diagram of the device of FIG. 1;

#FIG. 3 is a cutaway view of a separate type device for dynamically measuring the bubble content of a flowing liquid, which is installed in a bypass for the liquid;

#Two preferred embodiments of the present invention are hereafter described. However, the invention is not confined to these embodiments.

#One of the two preferred embodiments is an integrated-type device intended for dynamically measuring the bubble content of a flowing liquid and which is installed in the mixed oil conveyance passage of a mixer for mixing a lubricating oil with a polymer. The device includes a pressure sensor 5, a pressure calculation circuit 6, a temperature sensor 7, a temperature calculation circuit 8, a volumetric flowmeter 9, a volumetric flow amplifier 30, a mass flowmeter 10, a mass flow amplifier 31, pressure regulation valves 11, passage changeover valves 12, a bubble content calculation circuit 13 which operates in accordance with bubble content calculation formulae (1) and (2) above, a control panel 14, a bubble content display panel 15, a pressure display panel 16 and a temperature display panel 17, as shown in FIGS. 1 and 2. These components are provided in housing box 18. The pressure sensor 5, the temperature sensor 7, the volumetric flowmeter 9, the mass flowmeter 10, the pressure regulation valves 11 and the passage changeover valves 12 are connected to each other by pipes as shown. The housing 18 is provided in the conveyance passage 1 of the mixer in such a manner that the pipes of the device are connected to the passage by pipe joints A. The sensors 5 and 7, the flowmeters 9 and 10, the flow amplifier 30 and 31, the calculation circuits 6, 8 and 13, and the panels 14, 15, 16 and 17 are electrically coupled together by wires. The control panel 14 can be manipulated in front of the device. The values shown on the bubble content display panel 15, the pressure display panel 16 and the temperature display panel 17 can be seen in front of the device.

#The second embodiment is a separate type device intended for dynamically measuring the bubble content of a flowing liquid and which is installed in a bypass of the lubricating oil conveyance passage of a 2,000 cc four-cycle engine for a motor vehicle. The device includes a pump 3 having a function of circulating the liquid in the pump, a connection pipe 4, a high-pressure section including a pressure sensor 5, a pressure calculation circuit 6, a temperature sensor 7, a temperature calculation circuit 8, a volumetric flowmeter 9, a volumetric flow amplifier 30, a pressure regulation valve 11, a bubble content calculation circuit 13 operating in accordance with calculation formula (1) above, a bubble content display panel 15, a pressure display panel 16 and a temperature display panel 17, a low-pressure section including a pressure sensor 5, a pressure calculation circuit 6, a temperature sensor 7, a temperature calculation circuit 8, a volumetric flowmeter 9, a volumetric flow amplifier 30, a pressure regulation valve 11, a bubble content calculation circuit 13 operating in accordance with calculation formula (2), a bubble content display panel 15, a pressure display panel 16 and a temperature display panel 17, a mass flowmeter 10, a mass flow amplifier 31, and a control panel 14, as shown in FIGS. 3 and 4. These components are provided in housing boxes 18. Two tapped holes are provided in the lubricating oil conveyance passage 1 of the engine. The bypass 2 is connected to the passage by pipe joints A screw-engaged in the tapped holes. The sensors, the calculation circuits, the flowmeters, the flow amplifiers and the panels are electrically coupled together by wires so that the device is composed of a bubble content measuring detector 19 connected to the bypass 2, and a bubble content measuring data processor 20 electrically coupled to the detector.