Suction Jet Pump Pressure Control for Gas Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas analyzers using infrared absorption spectroscopy face challenges with pressure fluctuations and high propellant gas consumption, leading to inaccurate measurements and increased maintenance costs, particularly when dealing with hot and humid exhaust gases from combustion engines.
Innovation Solution
A device with a proportional control valve in the propellant gas line of an ejector pump adjusts the propellant gradient to maintain constant pressure in the analysis cell, reducing pressure fluctuations and propellant gas consumption by regulating the driving pressure as a direct function of the delivery pressure, and optionally using a pressure sensor for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If a suction jet pump is used to convey sample gas through the analysis cell, then the gas can be conveyed without moving parts and maintenance is reduced, but pressure fluctuations occur that negatively impact measurement quality
Solution Approach 1:
A control valve is arranged in the propellant gas line that responds to pressure changes in the delivery line by automatically adjusting the propellant gas flow. When pressure increases, the valve restricts flow; when pressure decreases, the valve opens further. This feedback mechanism stabilizes pressure fluctuations while maintaining the maintenance-free operation of the ejector pump.
2Measurement precision
If the propellant gas pressure is increased to maintain constant delivery pressure, then measurement stability improves, but propellant gas consumption increases
Solution Approach 1:
The control valve dynamically adjusts the propellant gas flow based on real-time pressure conditions in the delivery line. Instead of maintaining constantly high pressure, the system adapts the propellant flow to match actual demand, opening the valve further when pressure drops and restricting it when pressure is sufficient. This dynamic adjustment stabilizes delivery pressure while minimizing propellant gas consumption.
3Measurement precision
If the analysis cell is operated at reduced pressure to avoid cross-sensitivities, then spectral overlap of gas components decreases, but additional vacuum pump components and maintenance are required
Solution Approach 1:
The system changes the pressure parameter dynamically by adjusting propellant gas flow through the control valve. By responding to pressure changes in the delivery line, the system maintains optimal negative pressure conditions for spectral resolution without requiring complex vacuum pump systems. The ejector pump with control valve provides simplified vacuum generation while achieving the desired pressure conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution provides stable and accurate gas concentration measurements with reduced propellant gas usage, minimizing maintenance and operational costs, while allowing operation at high temperatures and avoiding condensation issues.
Implementation Method 1
Device and method for determining the concentration of at least one gas in a sample gas stream by means of infrared absorption spectroscopy
Implementation Method 2
The infrared radiation is in the range of the vibration level of molecular bonds, which are excited to vibrate by absorption
Implementation Method 3
a suction jet pump which is arranged downstream of the analysis cell and via which the measurement gas can be conveyed through the analysis cell and the conveying line
Data Source
Figure 1
Figure 2
AI summary
Devices are known for determining the concentration of at least one gas in a sample gas stream by means of infrared absorption spectroscopy, comprising an infrared radiation source (12), the radiation of which is directable through an analytical cell (16), a sample gas stream being directable by means of a feed line (34) into the analytical cell (16) and out of the analytical cell (16), and a detector (22) capable of measuring an absorption spectra generated in the analytical cell (16), and a suction jet pump (30) arranged downstream of the analytical cell (16) by means of which the measurement gas can be conveyed through the analytical cell (16) and the feed line (34). Frequently, however, measuring errors occur due to pressure fluctuations within the analytical cell, or increased maintenance- and manufacturing costs arise. In order to prevent these, the present invention provides a control valve (60) that is arranged in a propellant gas line (48) leading to a propellant gas connection (44) of the suction jet pump (30), by means of which the pressure in the propellant gas line (48) can be regulated so that the propellant pressure in the propellant gas line (48) and in the propelling nozzle (52) of the suction jet pump (30) is regulated as a direct function of the feed pressure within the analytical cell (16) or in the feed line (34).