GB2425739A

GB2425739A - Condensate treatment

Info

Publication number: GB2425739A
Application number: GB0606324A
Authority: GB
Inventors: David William Armfield
Original assignee: SALAMANDER
Current assignee: SALAMANDER
Priority date: 2005-04-07
Filing date: 2006-03-30
Publication date: 2006-11-08
Also published as: GB0606324D0; GB0507079D0

Abstract

Condensing boilers generate an undesirable by-product in the form of an acidic condensate that has to be piped away to a drain or soak-away but should not pass into the sewers untreated, as this could cause difficulties if a large number of condensing boilers were put into commission. A method of neutralizing a condensate from a condensing boiler comprises passing said condensate through a neutralizing unit comprising a housing 20 which contains a solid neutralizing agent, characterized in that the neutralizing unit is adapted to be in the form of a readily replaceable unit. The neutralizing unit is easy to fit and replace and can be fitted 'in-line' for easy servicing if required. The neutralising agent is calcium carbonate chippings held in place by a mesh arranged inlet and outlet. The unit is attached by screw threads 21,22 and a collar 27,31 so that it may be easily replaced.

Description

The invention relates to the treatment of acidic aqueous solution,

particularly the condensate that is generated as a by-product of a central heating boiler of the condensation type i.e. a so-called condensing boiler'.

A condensing boiler is a high efficiency modern boiler that incorporates an extra heat exchanger so that much of the energy of the hot exhaust gases is used to pre-heat the water in the boiler system. When working at peak efficiency, the water vapour produced in the combustion process condenses back into liquid form releasing the latent heat of vaporisation. A side effect is that this aqueous solution, known as condensate, which is usually acidic, has to be piped away to a drain or soak-away.

Typically the condensate comprises sulphuric acid with a pH around 3.5 and should not pass into the sewers untreated, as this could cause difficulties if a large number of condensing boilers were put into commission, as such boilers may produce around I to 2 litres per hour per boiler. In addition, correct disposal of the condensate is important for the overall efficiency of the boiler.

An object of this invention is to provide a neutralizing treatment system which is highly effective on acidic aqueous solution e.g. condensate, gives a consistent water treatment over a period, can be easily fitted / replaced and is cost-effective. The aim would be to treat the acidic aqueous solution so that it is substantially neutral i.e. has a pH of 7.

According to one aspect of the present invention a neutralizing unit suitable for attachment to the condensate outlet of a condensing boiler comprises a housing which contains a solid neutralizing agent, characterized in that the neutralizing unit is adapted to be in the form of a readily replaceable unit.

According to another aspect of the present invention a method of neutralizing a condensate from a condensing boiler comprises passing said condensate through a neutralizing unit comprising a housing which contains a solid neutralizing agent, characterized in that the neutralizing unit is adapted to be in the form of a readily replaceable unit.

An example of an acidic aqueous solution suitable for treatment according to the present invention would be the condensate from a central heating boiler of the condensing type, where the condensate is usually a very dilute solution of acid in water and is treated under substantially atmospheric conditions i.e. not pressurized.

Preferably the solid neutralizing agent is in particulate form, e.g. chippings or granular such as spheres, and having a maximum dimension in the size range 2 to 5mm. The aim would be to use as the neutralizing agent a material or mixture of materials which does not dissolve too quickly, is readily and cheaply available and which does not produce (in combination with the condensate) compounds which would be detrimental to the environment or to the surrounding medium e.g. the pipe work.

Examples of suitable neutralizing agents may include one or more carbonates or oxides (hydroxide) of calcium with or without one or more magnesium salts.

Preferably the neutralizing agent comprises calcium carbonate on its own or with a sparingly soluble calcium salt.

The unit will have a finite life, as the neutralizing agent will react with the condensate.

Preferably a useful life' indicator would be provided on each unit so that the user would know when to change the unit. For example where a unit has a life of 12 months, then when the unit is fitted the date that is in twelve months' time would be put on the unit. Alternatively, an automatic clock could be incorporated to perform this function, with an alarm to indicate time for replacement. The unit may then be refilled for re-use or exchanged for a new unit. Usually, in accordance with good practice the unit will be positioned so that it slopes downwards from the condensate inflow (falls away) towards the outlet whether that is a soil pipe or soak-away or drain. Preferably the neutralizing unit defines a single generally linear path through which the aqueous solution passes in contact with the neutralizing agent. Preferably the unit is fitted in line' i.e. no additional pipe work is required. A convenient form for the unit would be an elongate cartridge which can be easily fitted and replaced with ease.

In a preferred embodiment the unit is in the form of a readily replaceable cartridge (e.g. of plastic) fitted with a quick release means so that when the unit is ready to be changed, this can be done quickly and easily. For example it could be a plastic cylinder with an inlet at one end and an outlet at the other, fitted at each end with an attachment means. An example of a quick release connection means suitable for connecting a neutralizing unit of the present invention to a pipe comprises an external screw thread provided at one end of the unit and a complementary internal screw thread provided on a collar movably attached to the pipe in line with the pipe and the unit, arranged such that the collar can be screwed onto the unit when fitting the unit and unscrewed for removal of the unit. Usually there would be two such quick release connection means provided, one each end of the unit. Conveniently, the unit is elongate and preferably fitted with fluid permeable retention means at each end e.g. a mesh. This retention means stops the solid neutralizing unit from falling out of the unit but allows the aqueous solution (e.g. condensate) to flow through it.

Embodiments of the present invention illustrating the combined in line' and single pass' use of new neutralizing units will now be described with reference to the accompanying drawings in which: Figure 1 is a side view of a neutralising unit according to one embodiment of the present invention, in use; Figure 2 is a side view of the components of Figure 1 prior to assembly or on removal of the neutralizing unit; and Figure 3 is a side perspective view of a neutralizing unit according to a second embodiment of the present invention, in use.

Referring to Figure 1, a neutralizing unit comprises a cylindrical plastic housing 10 contains solid particulate neutralizing agent (not shown) and is provided with caps 11, 12 which in turn define inlet 13 and outlet 14 provided with external screw threads.

To a standard plastic pipe 15 leading from a boiler (not shown) is attached a compression fitting 16 comprising a fitting provided with an external screw thread 17 which is tightened on to pipe 15 by means of a wheel 18. The screw thread 17 corresponds to that of 13 and 14. A collar 19 has an internal screw thread complementary to that of 1 7, 13 and 14 and screws on to thread 17 and 13, thus attaching pipe 15 to neutralizing unit 10. A similar assembly can be used to connect outlet 14 to standard plastic pipe, as required.

Referring to Figure 2, in order to attach housing 10 to pipe 15 a compression ring 20 is pushed on to the thread 1 7 and then collar 19 is screwed on to thread 17 until about halfway on. Housing 10 is then attached by means of engaging screw thread 13 into collar 19 until it abuts thread 17. Removal of the unit e.g. when neutral ising agent is exhausted is simply achieved by screwing collar 19 further on to screw thread 17 until thread 13 is free. The same quick-release means can be used to detach thread 14 at the outlet end. A new unit can then be inserted by the reverse process.

En use, acidic condensate from a boiler flows within pipe 15 and through housing 10.

The condensate is neutralized by the neutralizing agent within the housing 10 and the resulting neutral solution flows out through outlet 14 to a drain, soil pipe or whatever is selected.

Although Figures 1 and 2 show the unit and pipe 15 in a horizontal configuration, in practice they would slope downwards from the boiler.

Referring to Figure 3, a neutralizing unit comprises a cylindrical plastic housing 20 in the form of a rigid plastic cartridge which contains solid granular neutralizing agent (not shown) and is provided with a narrowed inlet 21 and narrowed outlet 22, each provided with exterior screw threads. At each end of the inlet 21 and outlet 22 is an elastomeric compression ring (not shown). To a standard copper pipe 23 leading from the outlet of a condenser boiler is attached a compression fitting 24 consisting of a cylindrical portion 25 provided with an external screw thread which is tightened Onto the pipe 23 by means of an internally threaded collar 26 screwed onto the cylindrical portion 25 in the direction shown by an arrow. The fitting 24 is also provided with a collar 27 slidable along a spindle 28. The collar 27 has an internal screw thread corresponding to the external screw thread on inlet 21. By screwing the collar 27 onto the screw thread on inlet 21, a rigid 0' ring (not shown) at the end of spindle 28 is pushed against the compression ring at the end of inlet 21, thus providing a fluid-tight seal. The same fittings (collars 29 & 31, fitting 30) are used at the outlet 22 of the unit 20.

In use, acidic condensate from a boiler flows within pipe 23 and through the unit in a single pass through the linear path within the housing 20, the flow only being disturbed by the particles of neutralizing agent within the housing. The condensate is neutralized by the neutralizing agent within the housing 20 and the resulting neutral solution flows out through outlet 22 to a drain, soil pipe or whatever is selected.

Although Figure 3 shows the unit 20 and pipe 23 in a horizontal configuration, in practice they would slope downwards from the boiler to ease the flow of condensate through the unit.

Removal of the unit, e.g. when the neutralizing unit is exhausted and ceases to work efficiently, is simply achieved by unscrewing collar 27 and br 3 1, sliding back the or each collar 27/31 along its respective spindle, thus releasing the unit which can be replaced by a new unit. Fitting of a new unit is a by reversing the process of removal.

Thus a unit can be replaced without disturbing the pipe work each side of the unit.

Flanges 32 and 33 are useful for aiding grip by e.g. a spanner or handgrip tool so that not too much stress is placed on the pipe work during replacement of a unit.

It will be appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable combination.

Claims

CLAIMS: 1. A neutralizing unit suitable for attachment to the condensate

outlet of a condensing boiler comprises a housing which contains a solid neutralizing agent, characterized in that the neutralizing unit is adapted to be in the form of a readily replaceable unit.
2. A neutralizing unit according to claim I wherein the neutralizing agent is in the form ofchippings.
3. A neutralizing unit according to claim 1 or 2 wherein the neutralizing agent comprises calcium carbonate.
4. A neutralising unit according to any preceding claim wherein the housing defines a generally linear path in which the neutralizing agent is contained.
5. A neutralizing unit according to any preceding claim wherein the housing consists of an elongate cartridge.
6. A neutralizing unit according to any preceding claim wherein the housing is provided with at least one quick release means to allow quick and easy attachment and removal from a condensate outlet.
7. A neutralizing unit according to any preceding claim wherein the quick release means comprises a screw thread on the housing complementary to a screw thread provided on the condensate outlet.
8. A neutralizing unit according to any preceding claim wherein the housing is provided with fluid permeable retention means at each end to retain the particles of neutralizing agent within it.
9. A neutralizing unit according to claim 8 wherein the fluid permeable retention means comprises a mesh.
10. A neutralizing unit according to claim 1 substantially as herein described.
II. A neutralizing unit according to claim 1 and substantially as herein described with reference to any one of Figures Ito 3.
12. A method of neutralizing a condensate from a condensing boiler comprises passing said condensate through a neutralizing unit comprising a housing which contains a solid neutralizing agent, characterized in that the neutralizing unit is adapted to be in the form of a readily replaceable unit.
13. A method of neutralizing a condensate according to claim 12 wherein the condensate is treated under substantially atmospheric conditions.
14. A method of neutralizing a condensate according to claim 12 or 13 wherein the housing is positioned so that the condensate flows through it in a downward direction.
15. A method of neutralizing a condensate according to claim 12, 13 or 14 wherein the condensate passes only once through the housing.
16. A method of neutralizing a condensate according to any one of claims 12 to 15 wherein the housing defines a generally linear path through which the condensate passes.
17. A method of neutralizing a condensate according to any one of claims 12 to 16 wherein the neutralizing unit is fitted in-line.
18. A method of neutralizing a condensate according to any one of claims 12 to 17 and having the feature of any one of claims 1 to 11.
19. A method according to claim 12 and substantially herein described.
20. A method according to claim 12 and substantially as described in any one of Figures 1 to 3.