Column Sections

INTRODUCTION

Like their pipeline counterparts, Borosilicate glass column components find universal application throughout the world’s chemical, pharmaceutical, food and drink and allied industries where the advantage of using glass as a basis for the construction of complete process systems have long been recognized:

• With almost universal resistance to corrosion, a long service life is guaranteed and maintenance is kept to a minimum.

• Their transparency permits visual monitoring of the process at all times.

• Being inert, the risk of contamination is negligible.

• Smooth surfaces allow easy cleaning and sterilization and prevent the build-up of solid on the inner walls.

In many unit operations such as reaction, extraction and absorption, the transparency factor of glass column components is a particular advantage. As an example, colour changes in reaction processes are easily monitored, droplet separation in extraction processes can be observed unhindered and constant visual monitoring of hydraulic performance in packed columns is possible.

Column components are available from DN 80 to DN 450 with a smaller range of precision bore components available from DN 25 to DN 150 for specific applications where close internal tolerances are essential.

The complete range of column components is described on the following pages. All column components have standard flat buttress end connections. Further details of theses are provided in section: Technical Information.

For standard flat buttress end connections from DN25 to DN300, it is possible to achieve a 3° deflection in the joint by using a flexible gasket. Details of these and all other couplings and gasket can be found in section Couplings. 

DN refers to the nominal bore. Unless otherwise stated all dimensions are given in mm.

For permissible operating conditions, unless otherwise stated in the individual description, please see section Technical Information.

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Applications of internals

Columns used for reaction, absorption and extraction processes can be fitted with many different internals such as packed beds, structured packing and sieve or bubble-cap trays. The typical operating characteristics, as well as the recommended and possible areas of application for each of these internals, are detailed in this section: the processes beuing limited to gas/liquid operation in the form of rectification and absorption processes.

Packed beds or structure packing are used to create the surface required for mass transfer by increasing the area of contact at the surface of the liquid when it flows over the internals as a film. Irregular packed beds have a relatively high pressure drop. Figure 1 shows the pressure drop for ceramic saddles . a very significant reduction in pressure drop, particularly in regard to vacuum rectification, can be achieved by the introduction of structured packing. Figure 2, for example shows the pressure drop values for SULZERKERAPAK. A clear reduction in pressure drop is discernible here.

Applications of internals

In plate columns the boundary surface for mass transfer is created by the liquid phase flowing across the trays being penetrated by the gas or vapour rising from the plate below. The main distinctions here are between bubble cap trays and sieve trays. Plate columns have higher pressure drop then packed columns. To illustrate this, Figure 3 on the previous page shows the pressure drop of the buyer low-rise tray. The pressure drop of the tray is about the same as for 1 meter packing of 25mm ceramic saddles.

The suitability of internals to a particular process is really determined by the process conditions in each case. If a low pressure drop is required, then structured packing are the main ones to choose. In all other cases the permissible operating range of the various internals for a particular application is the determining factor. Packed and plate columns have different operating ranges as a result of the different type of boundary surface creation. The terms operating range here refers to the range of gas and liquid flows within which problem-free operating of the column is possible. 

Figure 4 shows typical load characteristics of a packed column with the operating range shaded. This is mainly limited by the so-called upper load limit, designated by flooding, against higher flow. The lower load limit designated by minimum wetting stems from the requirements that the packing has to have an even film of liquid to achieve the desired separation. It can also be seen from Figure 4 that it is possible to individual cases, however, the achievable separation effect should be checked.

Plate columns have different operating characteristics. As the load characteristics in Figure 5 show, several factors limiting the operating range have to be taken into consideration with this design. It must be emphasized in particular that turndown of the liquid load is much greater for the plate column.

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Column Sections

DN (mm)	L (mm)	Volume (L)	Volume Stacked Rings (L)	Free Area	Minimum Packing Diameter (mm)	Maximum weight of packing (kg) (lbs)
80	1000	4		50%	7	20	45
100	1000	8		60%	10	30	65
150	1000	16		65%	15	60	130
225	1000	32		75%	20	90	200
225	1500	51		75%	20	90	200
300	1000	60		75%	25	150	330
300	1500	95		75%	25	150	330
450	1500	186	14	75%	25	250	550

The figures in liters are the volumes available for packing above the supports or, Where applicable, above the two rows of stacked rings. 
Columns are fundamental to many process plants and a range of column components in borosilicate glass is available in nominal bores up to 1000mm. 

Column Sections 

Column sections are supplied complete with the appropriate size of packing support. In type C columns, two rows of stacked glass Ranching rings immediately above the support provide a firm base on which the dumped packing is supported. 
Type C column sections can be supplied with a side branch (for example for thermometer pocket) on special order. This is located near the top of the column section. 

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Packing Supports

DN (mm)	L (mm)	Free Area	Maximum Load (kg) (lb)		Minimum Packing Diameter (mm)	Type	Cat Ref
80	15	50%	20	45	7	A	GLB3
100	20	60%	30	65	10	A	GLB4
150	30	65%	60	130	15	A	GLB6
225	30	75%	90	200	20	A	GLB9
300	30	75%	150	330	25	A	GLB12
450	70	75%	250	550	25	B	GHD450

Type A supports are glass
Type B supports are glass and PTFE

Glass packing supports are supplied as part of the column section assembly. They are normally only ordered separately when required as replacements. 
They are seated on a PTFE crescent ring which is supplied with the support. Two rows of stacked glass rings are also supplied with type B supports. 

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Perforated Plates

DN (mm)	L (mm)	Free Area	Type	Material	Cat Ref
80	11	22%	A	glass	GCP3
100	16	30%	B	glass	GCP4
150	16	30%	B	glass	GCP6
225	16	37%	B	glass	GCP9
300	16	32%	B	glass	GCP12

These plates are fitted at the top of columns as restrainers for column packing where there is a risk of damage to other parts of the installation. 
They are clamped between buttress ends and a gasket is required on each side. Longer bolts than usual are required in the flanges used with the glass plates. 

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Support Ring, TFE-Covered

DN (Glass) (mm)	D (O.D.) (mm)	D1 (I.D.) (mm)	D2 (Gasket) (mm)	D3 (Bolt Circle) (mm)	Holes (No./ Size) (mm)	L (Thickness) (mm)	Cat Ref
150	260	102	194	241	8/11	11	GTCSR6
225	343	194	267	310	8/11	11	GTCSR9
300	419	244	349	394	12/11	11	GTCSR12
450	616	397	540	584	12/14	11	GTCSR450

This support ring is made of steel covered with a TFE machined envelope over a compressed fiber gasket. Clamp the support ring between two column sections. For 225 mm size and over, we recommend using a TFE Crescent Ring Gasket (Cat. Ref. TR) on each side of the plate. This makes it easier to get a tight seal, and you can reuse the support ring when you wish. 
The ring supports either the ceramic packing support plate or the ceramic distributor plate. This ring lets you remove an entire packed section without having to remove the packing first. 
For bromine service please check with GARG. 

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Packing Support Plate, Ceramic

DN (Column) (mm)	D (Plate) (mm)	L (mm)	Minimum Packing Size (mm)	Cat Ref
225	216	114	10	GPSP9
300	292	114	13	GPSP12
450	438	178	13	GPSP450

Plates are made from white unglazed chemical porcelain in the riser-type "gas injection" design. All ceramic plates have greater than 50% free area. All sizes of these plates can easily accommodate a 3-meter (10 ft) height of any conventional packing material. Consult GARG Process Systems about heights greater than this. 
To install these plates, center one on top of a TFE-covered support ring; then raise the plate and ring together to meet the column section above. The ceramic plate stays on the edge completely inside the column. Caution: do not try to slide the ceramic plate down from the top of the column section--it may get stuck.

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Distributor Plate, Ceramic

DN (Column) (mm)	D (mm)	D1 (mm)	L (mm)	Flow Rate Range (L/hr.)	Cat Ref
150	127	140	76	170-450	GLD6M
225	203	215	89	510-1130	GLD9M
300	229	290	89	680-1590	GLD12M
450	356	445	133	1590-3630	GLD450

This plate is made in one piece from white unglazed chemical porcelain. The gas risers in the center of the plate effectively reduce the pressure drop across the plate and so retard velocity so as to lower the hydraulic gradient effect on the liquid, thereby giving more uniform liquid distribution. 
For smaller-size distributor plates, simply use a glass packing support plate (in this catalog). For distributor plates capable of handling either lower or higher flow rate ranges, check with GARG Process Systems for plates available on special order. 

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Raschig Rings

Size (mm)	kg/ liter	Packing Factor (F)	m2/m3	Cat Ref
8 x 8	0.68	700	500	GFC8
10 x 10	0.58	530	450	GFC10
15 x 15	0.44	300	300	GFC15
20 x 20	0.28	220	280	GFC20
25 x 25	0.27	145	200	GFC25
40 x 40	0.29	90	160	GFC40
50 x 50	0.320	65	120	GFC50

One standard type of glass column packing is available: Raschig rings. It is especially suitable for use in glass columns because of its low bulk density. 

Selection and use of column packing 
1. The ratio of column diameter to packing diameter should not be less than 8:1. 

2. Where smaller sizes of packing are used, it is sometimes advisable to use a small layer of larger packing immediately above the support to prevent the smaller packing falling through. 

3. In vacuum operations and applications involving high vapor velocities glass packing--because of its low weight--may tend to be lifted away from the top of the column sections and may cause damage to other parts of the installation. This can be prevented by fitting a suitable form of restraint (for example a perforated plate) above the column section. 

4. Various methods can be used for the random distribution of packing in a column. One method is to fill the column section with water, then dump in the packing. If this is used, care must be taken not to exceed the maximum pressure permissible in the column. 

5. Column packings other than the standard glass ones can be used but bulk density should be taken into consideration and the maximum permissible load on the support should not be exceeded. 

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Precision Bore Pipe Sections

DN (mm)	D1 (mm)	L (mm)	L1 (mm)	Cat Ref
25	25.4	1000	900	GPPS1/1000
40	38.0	1000	890	GPPS1.5/1000
50	47.3	1000	880	GPPS2/1000
80	72.45	1000	870	GPPS3/1000
100	100.4	1000	840	GPPS4/1000
150	152.4	1000	820	GPPS6/1000

L1 is the approximate length of the precision bore zone of the pipe. The bore of the remaining pipe is not less than the minimum bore of the precision zone. Where the inside diameter of a column must be within closely controlled limits (for example to accommodate sieve plate assemblies), precision bore pipe sections are used. 

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PTFE Redistributors

DN (mm)	d (mm)	Type	Cat Ref
80	55	A + B + C	GTLCF3
100	80	A + B + C	GTLCF4
150	100	A + B + C	GTLCF6
225	175	A + B + C	GTL9
300	215	A + B + C	GTL12
450	365	A + B + C	GTL45

DN is the nominal bore of the column in which the redistributor is used Type A and Type B redistributors are clamped between buttress ends and no gasket is required. Type C redistributors fit between the packing support and the glass shelf built into the column section. 

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Liquid Seal

DN (mm)	DN1 (mm)	L (mm)	L1 (mm)	Cat Ref
25	25	160	205	GLS1
40	25	315	305	GLS1.5

This device prevents vapors from passing directly into the after cooler and receiver. Install it on the product exit line from the reflux splitter, which also has a 10° pitch. A valve branch DN1 permits sampling and draining. Glass Valves are covered in another section of this catalog. 

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Column Adaptors

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Column Adaptors - Flat Top

DN (mm)	DN1 (mm)	L (mm)	L1 (mm)	L2 (mm)	Type	Cat Ref
150	40	155	165	110	A+B	GFH 6/1.5
225	40	165	200	120	A+B	GFH 9/1.5
300	40	190	240	140	A+B	GFH 12/1.5
450	40	285	300	175	A+B	GFH 450/1.5

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Column Feed Pipes

DN (mm)	DN1 (mm)	DN2 (mm)	d (mm)	L (mm)	L1 (mm)	Cat Ref
80	40	25	13	100	115	GFP 3
100	40	25	13	125	115	GFP 4
150	40	25	13	150	115	GFP 6
225	40	25	13	185	115	GFP 9
300	40	25	13	230	115	GFP 12
450	80	40	25	320	150	GFP 450

DN is the nominal bore of the column in which the feed pipe is used. PTFE/Steel Construction
These feed pipes have a fused-in distribution tube which directs the process fluid down onto the center of the column packing. They are designed for use with unequal tee pieces .

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Resistance Thermometers

DN (mm)	d (mm)	L (mm)	L1 (mm)	Cat Ref
25	12	250	100	GWT 1/100
25	12	290	140	GWT 1/140
25	12	430	280	GWT 1/280
40	12	295	140	GWT 1.5/140
40	12	555	400	GWT 1.5/400
40	12	705	550	GWT 1.5/550

Non-standard lengths can be supplied to special order.
Resistance thermometers are used for remote indication, recording and control of temperature of gases and liquids. They can be connected to all conventional types of instruments which work on a basic nominal resistance of 100 ohms. 
GARG resistance thermometers consist of a platinum resistance element in a borosilicate glass sheathe with a perforated glass guard to ensure additional protection from mechanical damage to the element. The sealed-in element is in direct thermal contact with the fluid. 

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Thermo well, Single-End

DN (mm)	D1 (mm)	D2 (mm)	L (mm)	Cat. Ref.
40	16	10	70	GTWS1/1
40	19	13	70	GTWS1/2
40	25	16	70	GTWS1/3
50	16	10	70	GTWS2/1
50	19	13	70	GTWS2/2
50	25	16	70	GTWS2/3
75	16	10	89	GTWS3/1
75	19	13	89	GTWS3/2
75	25	16	89	GTWS3/3

These thermo wells are made to order. Please specify the length up to 914mm (36") when ordering. 

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Thermo well, Double-End

DN (mm)	D1 (mm)	D2 (mm)	L (mm)	Cat Ref
40	16	10	150	GTWD1/1
40	19	13	150	GTWD1/2
40	25	16	150	GTWD1/3
50	16	10	150	GTWD2/1
50	19	13	150	GTWD2/2
50	25	16	150	GTWD2/3
75	16	10	150	GTWD3/1
75	19	13	150	GTWD3/2
75	25	16	150	GTWD3/3

Double-end thermo wells are especially useful for sealing out the atmosphere.
These thermo wells are made to order. Please specify the length up to 914mm (36") when ordering.

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Reflux Separators - Manually Operated

DN (mm)	DN1 (mm)	L (mm)	L1 (mm)	L2 (MM)	Cat Ref
80	25	190	115	82	GRDA3
100	25	255	145	95	GRDA4
150	25	255	145	100	GRDA6
225	25	380	150	115	GRDA9
300	25	380	150	110	GRDA12
450	40	610	275	150	GRDA18

On this type of reflux separator, a valve is fitted to the outlet pipe. When it is open the condensate flows only through the product off-take connection, but it can be partially or fully closed so that some or all of the condensate returns to the column as reflux giving coarse reflux control. 

FLOW DATA

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Reflux Separators - Automatically Operated

In applications where there is need for the reflux to be at a fixed value, then it is advisable to fit an electro-magnetically or pneumatically operated reflux separator in conjunction with a timer.

Reflux Separators - Magnetically Operated 

This type of reflux separator uses a swinging funnel mechanism. The funnel, which has a soft iron core sealed into it, is operated magnetically from outside the column so that the condensate can be removed from the column and reflux returned to the column in correct ratio. Activation of the electromagnet moves the funnel into the off-take position. 

The electromagnet (shown dotted) and timer should be ordered separately. Details can be found below. 

DN (mm)	DN1 (mm)	L (mm)	L1 (mm)	L2 (mm)	Cat-Ref
80	25	380	75	75	GRHM3
100	25	455	90	90	GRHM4
150	25	455	90	90	GRHM6
225	25	560	100	100	GRHM9
300	25	685	140	430	GRHM12

Flow Data

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Electromagnets

For use with RHM reflux separators, the RPA electromagnet can be used in hazardous areas and is certified as (Ex)s G5 in Germany.

Operating Voltage: 24V DC
Operating Current: 0.5A

They are mounted off the main tubular support structure using the adjustable fitting supplied. They should be located just clear of the glass and lined up with the marks on the body of the reflux separator.

Electromagnets

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Electronic Timers

These electronic timers are designed for use in conjunction with type RPA electromagnets shown above and magnetically operated reflux separators. 

The timer allows variations of reflux and take-off in the ration 1/99/1. 
Standard Operating voltage 240V, 1ph, 50Hz.

A flameproof version of this timer is also available. This is housed in an explosion proof enclosure EEXd IIB T6 (III A Class) and allows variations of reflux and take-off in the ration 1/100/1.