Gas and Liquid Sampling Device

8/8/2019 Gas and Liquid Sampling Device

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AC Liquefied Gas & Gas SamplingDevice


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AC Liquefied Gas & Gas Sampling Device

Hardware section

Page 2 of 13Version 2004/4.0

Introduction

The AC Liquefied and Gas Sampling Device is a sampling module that allows the user to

reproducibly introduce gaseous and liquefied (LPG) samples into a gas analyzer. A built-

in heated vaporizer vaporizes the liquefied samples, so they are introduced into the gas

chromatograph in the gaseous state. The unit is placed adjacent to the gas

chromatograph and connected to the gas sample loop(s) of the gas analyzer. It is

configured with a heated vaporizer, two rotameters, a selection valve and a clamp to

hold the sample bombs.

Partnumber Description

68100.000 Gas and Liquid Sampling Device excluding vaporizer

68100.001 Gas and Liquid Sampling Device including 110 V vaporizer

Options :

- low temperature (24-104C) *

- high temperature (104-194C) *

68100.002 Gas and Liquid Sampling Device including 220 V vaporizer

Options :

- low temperature (24-104C) *- high temperature (104-194C) *

* NOTE: Temperature adjustable inside the vaporizer, depending on the desired

temperature.


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Configuration

The sampling device is a separate unit configured with a heated vaporizer, a rotameter,

a clamp to hold the sample bombs, two selection valves and the necessary plumbing

material. The schematic overview can be found in figure 1.

Heated Vaporizer

to Gas SamplingValve GC

L

G

out

in

Gaseous Sample in

Liquefied Sample in

from Gas SamplingValve GC

Selection Valve

rotameter

Vent

Needle valve

Outlet pressureadjustment

2

10

4

3

7

1

5 6

8

9

Selection Valve13

13

12

A

B

Figure 1 Schematics

Principle

Both Liquefied and gaseous samples can be mounted on the device. With the Selection

Valve A, the proper position is chosen.

So for gaseous samples, position 3 (of selection valve A) is selected. The sample from

the sample bomb directly flows via Selection Valve A through the gas sample valve of

the gas chromatograph. It then goes through the rotameter to Vent. The effluent flow canbe adjusted with the needle valve (8) underneath the rotameter.

For Liquefied samples the Selection Valve A must be put in the Liquid position (4) and

selection valve B in position (12). So the liquefied sample is introduced in the Heated

Vaporizer. Here it is vaporized. The effluent gas goes to the gas sampling valve of the

gas chromatograph and finally again through the needle valve to vent. The effluent flow

should be adjusted with the outlet pressure adjustment (10), a special tool to adjust the

outlet pressure is delivered with the system.

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Configuration

Figure 2 Over view

1. Gas Sample In (male Swagelok 1/8)

2. Rotameter

3. Selection Valve A Position: Gas (3)

4. Selection Valve A Position: Liquid (4)

5. To Gas Sampling Valve Gas Chromatograph (male Swagelok 1/8)

6. From Gas Sampling Valve Gas Chromatograph (male Swagelok 1/8)7. Liquefied Sample in (male Swagelok 1/8)

8. Needle Valve Rotameter

9. Vent (male Swagelok 1/8)

10. Outlet pressure adjustment Heated vaporizer (5/32 Allen wrench)

11. Power supply

12. Selection Valve B Position: to GC (12)

13. Selection Valve B Position: to vent (13)

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Power supply Configuration

Figure 3 Front and Rear view

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Installation

The Sampling device must be placed adjacent to the gas chromatograph on the

lefthandside. The Gas sampling valve of the chromatograph must then be connected to

the Sampling device.

Using 1/16 Stainless steel capillary tubing, position 5 is connected to the Gas Sample

in from the gas chromatograph. Position 6 is connected to the Gas sample out from the

gas chromatograph.

It is recommended to connect a length of 1/8 tubing from the Vent position (9) on the

rear side of the device to a fume hood.

The power plug can be plugged in, this is the power supply of the heated vaporizer.

Please refer to figure 4 for the location of the temperature adjusting screw. This screw is

used to set the temperature of the heated vaporizer depending on the boiling point range

of the sample.

Figure 4 Wiring diagram

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Gaseous Samples

To inject gaseous samples, the gas sample bomb must be vertically mounted in the

clamp. The top outlet valve must be connected to the gas sample in (1) position on the

device and the selection valve A must be switched to the Gas position. (3)

Now with the needle valve of the rotameter (8) in the closed position (turned entirely

clockwise) the outlet valve of the sample bomb is opened. Then slowly the rotameter

needle valve is opened until a constant flow is obtained. (2 on scale corresponds with

about 30 mLs/minute)

The sample loop in the gas chromatograph is now being flushed. After one minute the

analysis can be started.

To obtain proper results, it is important to introduce and analyse samples and calibration

blends in the same way. Therefore if analysis is done whilst the sample loop is being

flushed, the flow through the gas sample loop must always be identical for sample and

calibration analyses.

If atmospheric injection is preferred, care must be taken to allow the same wait time after

the flow through the sample has been stopped for both sample and calibration runs.

(The stopwatch function of the GC display can be helpful in this)

Heated Vaporizer

L

out

inLiquefied Sample in


Selection Valve

rotameter

Vent

Needle valve


2

10

4

7

6

8

9

Selection Valve13

13

12

A

B


G

Gaseous Sample in

3

1

5

Figure 5 Flow path gaseous samples

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Liquefied Samples

To inject liquefied samples, the sample bomb must be mounted in the clamp, and the

bottom valve must be connected to the Liquefied Sample in position of the device*.

The selection valve A must be switched to the Liquid position. (4), selection valve B

must be in position (12).

The outlet pressure adjustment (10) can be adjusted with the special tool supplied with

the system.

Now with the outlet pressure adjustment (10) in the closed position and the needle valveof the rotameter (8) opened, the outlet valve of the sample bomb is opened. Then slowly

the outlet pressure adjustment (10) is opened until a steady flow (about 30 ml/minute) is

obtained. (2 on scale corresponds with about 30 ml /minute). The sample loop in the gas

chromatograph is now being flushed. Several minutes of time must be allowed to pass in

order to properly flush the vaporizer and to obtain a homogeneous sample.

Prior to analysis, selction valve B must be switched to position (13) in order to vent

excess sample. The pressure in the sample loop now becomes atmospheric.

To obtain proper results, it is important to introduce and analyse samples and calibrationblends in the same way. Therefore if analysis is done whilst the sample loop is being

flushed, the flow through the gas sample loop must always be identical for sample and

calibration analyses.

Please refer to figure 6.


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Heated Vaporizer


L

G

out

in

Gaseous Sample in

Liquefied Sample in


Selection Valve

rotameter

Vent

Needle valve


2

10

4

3

7

1

5 6

8

9

Selection Valve1312

A

B

Figure 6 Flow path liquefied samples

NOTE: A too high sample flow can be the cause of a not totally evaporated sample in

the sample loop.

NOTE: If the sample bomb is equipped with a diptube then the liquid out of the diptube

must be connected to the Liquefied Sample in position of the device!

NOTE: To vent excess sample, selection valve B must be switched to position (13).

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Heated Vaporizer

The heated vaporizer is built in to vaporize the liquefied samples. It consists of a heat

exchanger and a pressure control section. The liquefied sample enters the heated body,

where it is vaporized. The outlet pressure is controlled by a regulator (10) which can be

accessed at the back of the sampling device.

Figure 7 Heated vaporizer

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Part numbers:

28024.210 Heated Vaporizer (220V) 24 104 C



28124.221 Heated Vaporizer (110V) 104 194C

Standard Specifications

Body: Stainless steel

Model:/Port configuration: Side entry

Seat: Peek

Temp range: 75 F to 220 F (24 C to 104 C)

215 F to 380 F (104 C to 194 C)

Outlet range: 0-10 Psi

Power: 100 watt

Max pressure inlet: 2000 Psi

Typical applications are

Vaporize liquid hydrocarbons Ethylene, LPG, Butane. Natural gas sampling

Heated gas samples to prevent condensable drop out

Installation and Usage

Installation Vaporizer involves plumbing lines and electrical connection, use only

with AC applications.

Use instructions regarding connections as described below:

Allways check the connection for leaks.


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General mounting instructions

Disconnect power before servicing or replacement.

Plug in the power cord to the specified voltage.

Adjusting the proper temperature

Disconnect power.

Remove left cover from unit.

Open the vaporizer cylindrical cover plate to get access to the power cable.

Adjust the proper temperature setting. (position 1-6)

Documents

Gas and Liquid Sampling Device