For analyzers of pH, conductivity and other chemical properties of water and steam condensate, sample preparation is required to reduce the temperature and pressure of the sample to the values ​​allowed by the analyzers. The main applications for these systems and analyzers are monitoring the parameters of the water-chemical regime at the CHP and monitoring the operation of boilers.

The structure of the measuring system (kit)

The systems have a standard configuration with slight differences depending on the input parameters.

The main elements of the systems are water heat exchangers and pressure reducers .

Heat exchangers are flow cups, inside of which there are coils from the tube through which the sample is supplied. Through the heat exchangers, a continuous supply of cooling water is carried out and as a result of this a decrease in the sample temperature and steam condensation occurs, if steam enters the system inlet. In this case, the main load falls on the coil tube, and therefore this tube is made either of stainless steel or of a special Inconel alloy, in case the sample inlet temperature exceeds + 200 ° C. Depending on the required flow rate of the sample through the heat exchanger, the heat transfer area and the length of the coil tube are calculated.

Also at the entrance to the system are installed high-temperature shut-off valves with a special seal that is resistant to high temperatures. Valves provide sample supply to the system and purge of the sampling line from scale and rust to prevent clogging of the coil and other system elements.

Pressure regulator
After the heat exchanger, a pressure regulator is installed , which reduces the pressure to an acceptable level by the analyzers. If the inlet pressure of the sample does not exceed 40 bar, then a membrane type regulator is used, similar to the regulators used for gases. If the pressure is higher than 40 bar, a special valve is used to create the necessary differential, having a very small bore and representing a rod placed in a steel tube. Due to this design, the valve is able to lower the pressure from 220 bar at the inlet, to 1 … 3 bar at the outlet.

Thermal shutoff valve
To protect analyzers from ingress of a sample with a high temperature, if for some reason the supply of cooling water has stopped, special thermal shut-off valves are provided in the systems . Inside such valves there is a cartridge with a special gel, which expands when the sample temperature rises above a predetermined value and blocks the sample flow. After the sample flow stops, it cools and the valve opens the flow. If at this point the supply of cooling water does not resume, the valve will block the flow again.

The systems also include a spring-type pressure relief valve, a strainer, a sample flow stabilizer (a pressure regulator “to oneself”, with which you can accurately set the pressure in the sample supply lines to the flow cells of the analyzers), a flow meter with a sample flow control valve, devices for indicating the pressure and temperature of the sample .

Specifications:

Maximum inlet sample temperature:	+ 550С for heat exchangers with an Inconel tube + 210С for heat exchangers with a stainless steel tube
Maximum Inlet Pressure:	220 bar
Maximum sample consumption through the system:	2 l / min (standard 0.5 l / min)
Parameters of cooling water:	Temperature from +5 to + 30C; Flow rate from 15 to 30l / min
Mounting Options:	On a panel, in a rack, in a cabinet for installation in a heated room, in a cabinet with heating for installation in an open area
Installation Area:	V-1A, V-1G, not explosive
Possible options:	High temperature alarm, N-cation exchange column for analyzing H-cation exchange, 3-way valve for laboratory analysis, drain tray
Dimensions:	Depending on the type of installation
Weight:	Depending on the type of installation