Sampler for Condensing Phases in Steam and Other Gases

Products

4313 Nebraska Court

Pomfret, MD 20675

USA

Phone: (301) 934-5605

Fax: (301) 934-5606

The Sampler is used for troubleshooting corrosion and water and steam chemistry problems in steam turbines, feedwater heaters, BWR reactors, PWR steam generators, heat exchangers, piping, and geothermal systems. It can also be used for any other two-phase fluids (oil and gas, hydrocarbons, acids, etc.) for pressures up to 600 psi (4 MPa) and 600F (315C).

This instrument was originally developed for sampling moisture (early condensate, first condensate) from the wet steam regions of LP turbines and the extraction piping. Impurities and water treatment chemicals in the steam redistribute between the gas and liquid, often acidifying the water drops and film. The Sampler (Figure 1) samples wet steam from an extraction pipe and passes it through a high efficiency Moisture Separator (99.9%). The separated moisture contains the same concentration of impurities as is present in the liquid film that forms on LP turbine blades in the wet stages of the LP turbine.

The purpose of the sampling and chemical analysis of the steam moisture is to determine its corrosivity on the surfaces of LP turbine and other components which are in the wet steam regions, particularly the turbine blades and blade attachments and heat exchanger and piping surfaces. When used with on-line or grab sample analysis, the Moisture Sampler can be used to determine the pH, conductivity and concentration of impurities in the moisture.

The Sampler (Figure 1) collects samples of the moisture in the wet steam. The steam is removed from the piping at an isokinetic sampling rate. It then passes through a moisture separator that removes 99.9% of the moisture and water droplets greater than 1 micron while allowing the steam to pass. The separated moisture drains through the bottom of the separator, passes through a sample cooler and can then be sent to on-line analyzers, directly sampled, or sent to a drain. The saturated steam exits the separator and passes through a condenser after which it is sent to drain. Flowmeters are installed on the condensed steam and separated moisture drain lines in order to calculate the % moisture in the sampled steam.

In order to achieve the greatest accuracy, it is recommended to sample the wet steam using an EPRI Isokinetic Sampling Nozzle. This will result in a sample that is representative of the conditions in the pipe. If a surface tap is used, the surface liquid film on the inside diameter of the pipe will be sampled.

Figure 1. Sampler for Condensing Phases

Serving the power industry since 1983

Specializing in Sampling and Instrumentation, Corrosion,

Water and Steam Chemistry, and Failure Analysis

Jonas, Inc.