Product Information HYGROPHIL HCDT
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Product information HYGROPHIL® HCDT Measurement system for the detection of the hydrocarbon dewpoint and the water dewpoint in natural gas BARTEC BENKE GmbH ● Schulstraße 30 ● D-94239 Gotteszell ● Phone +49 (0) 9929 301-0 ● Fax 301-112 E-Mail: gotteszell@bartec-benke.de ● Internet: www.bartec

Table of contents Contents Design of the measurement system HYGROPHIL© HCDT ______________________ 4 All rights and changes reserved. No part of this document may be reproduced, processed or distributed in any form or by any means without the prior written permission of BARTEC BENKE. Document: Revision: Product information Hygrophil HCDT Copyright © 2013 by BARTEC BENKE GmbH Schulstraße 30, D-94239 Gotteszell valid as from: 01.07 27.03.201

Product information Hygrophil HCDT

Introduction The water dewpoint is generally defined as the temperature at which water vapour begins to condense. This phenomenon can be observed on every foggy morning. The air temperature decreasing down to the dewpoint temperature, water starts to condense and gathers in small drops. Something similar happens to eyeglasses steaming up on a humid day. The cold glass cools the air temperature down below the dewpoint temperature, water condenses on the cold side of the glass. Compared to the hydrocarbon dewpoint, the water dewpoint can be determined quite easily because it is only a single...

Physical principle For the determination of the hydrocarbon dewpoint temperature, the HYGROPHIL® HCDT made by BARTEC BENKE applies the fundamental and approved standard method of the chilled mirror principle. This principle, which was discovered by Regnault in the 19th century, is based on the cooling of a mirror surface which is flowed by gas. When the dewpoint temperature has been reached, condensate is deposited on the mirror surface. Fig. 1 roughly illustrates the interrelationship between water dewpoint and hydrocarbon dewpoint Fig. 1 As can be seen in Fig. 1, in most of the cases the...

Natural gas, example phase diagram -70 -60 -50 -40 -30 -20 -10 0 10 Temperature, °C Product information Hygrophil® HCDT

Design of the measurement system HYGROPHIL© HCDT The complete measurement sytem (cf. Fig. 3) consists of the following components: HCDT sample system 5985-7x HCDT sensor 1510-11 incl. transmitter Moisture sensor L166x HYGROPHIL® F 5673 display unit HCDT sample system 5985-xx Via a heated pipe the sample system is connected to the pipeline (process). In the sample system, the natural gas is conditioned, i.e. pressures are reduced, the flowrate is regulated, and temperatures are controlled. The system includes the moisture sensor L166x for the measurement of the water dewpoint under line...

Fig. 4 shows the HCDT sample system (distance to analyzer > 20 m) Fig. 4 HYGROPHIL® F 5673 In the last 10 years, the measurement system HYGROPHIL® F 5673 with its fiber-optical sensor L166x has established itself very successfully in the field of ”moisture measurement in natural gas“. The sensor regulation (HCDT-sensor 1510-11) is performed by the analyzer HYGROPHIL® F 5673. The analyzer evaluates the sensor data, represents the data graphically and stores all available data in an integrated data logger. For the data transfer to superordinate conduct systems, not only analog outputs but...

Fig. 5 shows the display unit HYGROPHIL® F 5673 Fig. 5 Dimensions in mm Product information Hygrophil® HCDT

Channel board Analog/Digital I/O Ex Power supply module Interface module HCDT-sensor (data cable) HCDT-sensor (current) HCDT-Sensor (current) Product information Hygrophil HCDT Relay module Interface HCDT-Sensor

Sensors Measurement of the water dewpoint The measurement of the water vapour dewpoint is carried out via Hygrophil® F and the sensor type L166x. The moisture sensor type L166x consists of a robust multilayer of optically high-refractive and lowrefractive layers connected to 2 fiber-optical cables. By means of a special thermal coating technique, pores with the diameter of a water molecule (approx. 0.3 nm) are generated on the layer. Due to the equilibrium relative humidity, water is deposited in the layer. Due to the different refraction indexes (air: 1.00 / water: 1.33), this results in a...

Measurement of the hydrocarbon dewpoint For the measurement of the hydrocarbon dewpoint, the optical dewpoint sensor 1510-11 is integrated into the sample system after the pressure reduction (5…35 bar rel) (p corresponding to the cricondentherm pressure). Fig. 8 shows the sensor tip of the HCDT sensor 1510-11, Fig. 9 shows the layout with the transmitter Bild 8 Condensation range of hydrocarbons (2mm x 1mm) Product information Hygrophil HCDT

The HCDT sensor works according to the novel and patented method of internal total reflexion. Fig. 10 illustrates this measurement principle in detail. Fig. 10 Peltier element Light beam Glass substrate Photo diode The innovation consists essentially in the fact that the light signal is not conducted through the gas stream like in conventional chilled mirrors. The beam transmitted by LED is not sent to the mirror surface from above but fed into the mirror surface from below. By means of a screen, the light beam is coupled into the sensor glass under a certain angle and is totally reflected...

Measurement ranges Measurement range of moisture sensor L166x Fig. 11 Sensor L 166x, Dew-point measuring range 30 20 10 Gas temperature TT [°C] Out of calibrated range Calibratable range Function range extrapolated The sensor L 166x has a calibrated measurement range of -80 ° C ... +20 ° C DT in the pressure range up to 100 bar (200 bar per test certificate). The sensor measures with an accuracy of ± 1 K. Product information Hygrophil HCDT

Application- and measurement range of HCDT sensor 1510-11 By means of the integrated Peltier cooling and depending on the density (pressure) of the gas, a cooling up to 35 K compared to the temperature of the sensor shaft can be reached. The pre-cooling unit expands the cooling range up to 60 K. Fig. 12 shows the application- measurement range of the sensor. Via the default setting of precooling the desired dew point measurement range is selectable, depending on the ambient temperature Application- measurement range Measurement range By default setting pre-selected sensor shaft temperature...