GB2497140A - Boiler condensate drain monitoring apparatus - Google Patents

Abstract

An apparatus 10, for monitoring the flow of boiler condensate through a condensate drain pipe, comprises: a fitting 12 having an inlet 16 and an outlet 18 for connection in a condensate drain pipe, the fitting have a passage 20 extending from between the inlet and the outlet to a float chamber 36; a switch 44; and a float 40 located in the chamber and adapted to actuate the switch. Communication means 50 are provided for relaying a signal from the switch to a remote switch for switching off an electrical supply to the boiler when the float is raised by a rising condensate level in the float chamber. The communication means are also provided for relaying a change in status of the signal from the switch to the remote switch for switching on the electrical supply to the boiler when the float is lowered by a falling condensate level in the float chamber. The switch may be a micro-switch, a reed switch or an optical switch. An alarm may be connected to the switch, where the alarm preferably comprises a transducer creating an audible alert, which may be muted, or a visual display, such as an LED or LCD.

Description

CONDENSATE DRAIN MONITORING APPARATUS

The present invention relates to an apparatus and method for monitoring the flow of condensate in a condensate drain.

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BACKGROUND TO THE INVENTION

Modern gas boilers are typically condensing boilers, which utilise the heat in the waste gases of combustion by condensing them, thereby achieving an improvement in efficiency of around 10%. The condensate is slightly acidic and is typically piped away from the boiler in a pLastics pipe, into a drain. Usually the pipe extends through an external wall and into an external drain or soak away. Ideally the pipe should extend directly into the drain and preferably below ground. In the UK, it is recommended that the drain pipe extends 25mm below ground. The reason for this is 1 5 to try and prevent freezing of the condensate in the drain pipe. Boiler condensate tends to freeze at a slightly higher temperature than, for example, water and therefore is prone to freezing in frosty conditions.

If the condensate freezes, it can block the condensate pipe causing the boiler to fail.

In very cold conditions, even if the condensate pipe is insulated, the condensate may still freeze. In some cases this can cause damage to the boiler. Furthermore, in cold conditions when the condensate is likely to freeze, the need for thc boiler to operate is even greater, because without a boiler, homes and offices can be left with no other heating and can quickly become cold. This can have serious consequences if homes are without heat for some time. Usually, in a cold period, the condensate pipes of large numbers of domestic boilers freeze at the same time and there is often a shortage of service engineers to service the boilers and attend to problems caused by the condensate freezing. For example, for engineers to receive around 10,000 reported faults per day is not unusual in a frosty cold period in the UK.

It is an object of the invention to provide an apparatus for monitoring the status of the condensate drain which reduces or substantially obviates the above mentioned problems.

STATEMENT OF INVENTION

According to the present invention, there is provided an apparatus for monitoring the flow of boiler condensate through a condensate drain pipe comprising a fitting having an inlet and an outlet for connection in the condensate drain pipe, the fitting having a passage extending from between the inlet and the outlet to a float chamber, a switch, and a float disposed in the chamber and adapted to actuate the switch, means for relaying a signal from the switch to a remote switch for switching off an electrical supply to the boiler when the float is raised by a rising condensate level in the float chamber, and means for relaying a change in status of the signal from the switch to the remote switch for switching on an electrical supply to the boiler when the float is lowered by a falling condensate level in the float chamber.

The benefit of the apparatus is that should the condensate drain pipe become blocked, for example, due to external freezing temperatures, the condensate backs up in the condensate drain. The condensate rises in the float chamber and raises the float, which actuates the switch and the condensing boiler switches off automatically, thereby preventing potentially significant damage to the boiler and its components.

Should the homeowner or caretaker not be present, the boiler will remain switched off until such a time as the condensate drain pipe thaws and the water drains away, lowering the float. As such, the boiler is protected from condensate, even when, for example, the homeowner is away at work or on holiday. Furthermore, the boiler automatically restarts when the condensate level drops.

A time delay circuit may be provided for delaying the relay of the signal to the remote switch.

A siphon store on the boiler may release condensate in shots of up to 150m1, perhaps up to 10 times per hour. By providing a time delay, this prevents switching off of the boiler due to temporary high flow rate through the condensate drain.

A time delay circuit may be configured to delay the relay of the signal to the remote switch for up to 120 seconds.

The switch may be a conductive type switch, such as a micro-switch or a reed switch, or optical switch. The remote switch may be a relay.

Alarm means may be connected to the switch.

By alarming the switch, a person can be alerted to the fact that the condensate pipe has frozen or become othei-wise blocked, and take appropriate remedial action.

The alarm means may include a transducer for creating an audible alert.

A mute button may be provided for muting the audible alert.

Once alerted, a person can mute any audible alarm, which otherwise may become an annoyance.

The alarm means may include a visual display.

The visual display may be an LED or LCD.

A drain port may be in fluid communication with the float chamber.

The drain port may include a valve which can be opened and closed manually.

Alternatively, it can be opened and closed by electrical actuation.

Conveniently, the chamber can be drained manually using the drain port. Condensate can be drained into a container, temporarily, such as a bucket, bottle or the like. This enables the boiler to be restarted, although the container will need to be emptied regularly. Condensate may be drained through a flexible tube, of which one end may be attached to the drain port and the other end may be terminated in a large capacity vessel, an internal drain or domestic waste drain.

DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which: Figure 1 shows a perspective front view of the apparatus, and shows, in particular, a user-interface of the invention; Figure 2 shows a perspective rear view of the apparatus of Figure 1, showing in particular a fitting of the invention in a horizontal orientation; Figure 3 shows a perspective rear view of the apparatus with the fitting of Figure 2 now in a vertical orientation; Figure 4 shows a front view of the apparatus of Figure 1, with the user interface predominantly removed for clarity; Figure 5 shows a cross sectional view of the apparatus through the line A-A indicated in Figure 4; and Figure 6 shows a cross sectional view of the apparatus through the line B-B indicated in Figure 4.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring firstly to Figure 1, an apparatus for monitoring the flow of boiler condensate through a condensate drain pipe is indicated generally at 10. The apparatus comprises a pipe fitting 12 for connection in the condensate drain pipe, and an operations controller, indicated generally at 14, for detecting a build up of condensate in the condensate drain pipe, due to the condensate failing to drain away, for example, duc to the pipe freezing.

With reference to Figures 2 and 3, the fitting 12 is generally tee' shaped, having an inlet 16 and an outlet 18 and a passage or conduit 20 extending laterally outwardly from between the inlet 16 and the outlet 18. The fitting 12 is symmetrical or substantially symmetrical and can be fitted in the condensate drain pipe either way around, ie it is reversible. Threaded connections 22 are provided at the inlet 16 and the outlet 18 to facilitate a sealed connection with the condensate drain pipe, though any suitable fitting for making a seal could be used instead. Typically, condensate drain pipe is 21.5mm outside diameter uPVC/ABS.

The fitting 12 is rotatably mounted to the operations controller 14 about an axis which extends in parallel with the longitudinal extent of the passage 20. As best seen in Figure 5, a tubular boss 24 extends outwardly from a housing 26 of the operations controller 14 and engages in the conduit 20 of the tee fitting. A flange 28 extends radially outwardly from a free end of a tubular section forming the conduit 20 of the tee. A retaining element 30, connected to the housing 26, locates over the flange 28 and maintains the flange 28 in contact with the housing 26. A cut-away 32, best seen in Figure 3, is provided in the flange 28 and is configured to allow the retaining element 30 to pass there-through. When the cut-away 32 is in angular alignment with the retaining element 30, the cut-away 32 can pass over the retaining element 30 and the fitting 12 can be assembled to or released from the operations controller 14. 0-ring seals are provided to seal between the housing and tee.

The ability to rotate the fitting 12 relative to the operations controller 14 permits the orientation of the fitting 12 to be changed from vertical or substantially vertical, to horizontal or substantially horizontal, or any angle there-between, without the fitting 12 becoming detached from the operations controller 14. This adjustability is advantageous because it enables the apparatus to be fitted, for example, to vertical or horizontal pipe work, with the operations controller maintaining a vertical position.

This ensures correct operation of a level sensing switch, described below.

The operations controller 14 will now be described with reference to Figures 4, 5 and 6. A collection or float chamber 36, best seen in Figure 5, is provided in fluid communication with the passage 20 and the tubular boss 24. A float switch 38 is disposed within the collection chamber 36. The float switch 38 comprises a preferably annular float member 40 moveably mounted about a support stem 42, and a switch 44 adapted to be actuated by the float member 40. A pair of support shoulders 46a, 46b extends laterally outwardly from the support stem 42. The support shoulders 46a, 46b are spaced apart along a longitudinal extent of the support stem 42, and are therefore referred to as upper and lower support shoulders 46a, 46b when the operations controller 14 is oriented as indicated in the drawings. Effectively, the upper and lower support shoulders 46a, 46b define alert and rest positions respectively for the float member 40.

The switch 44 is disposed at or proximate the upper support shoulder 46a and is actuated by the float member 40 when the float member 40 is in the alert position. The switch 44 may be a micro-switch, reed switch or a type of optical switch. The switch 44 is in electrical communication with control circuitry on a printed circuit board 48.

The control circuiny is operable to transmit a continuous or intermittent signal from the apparatus 10 to a remote switch (not shown), which in the presence of the signal, is configured to switch off an electrical supply to the boiler. The control circuitry includes connection or communication means 50 adapted to relay the signal to the remote switch.

The signal may be transmitted to the remote switch wirelessly or by electrical wire. If transmission occurs wirelessly, the wireless transmission protocol may be a suitably designed "Wi-Fi", infra-rcd, Bluetooth RTM protocol, or it may include any other wireless transmission protocol selected as being suitable for the application.

The control circuitry may be configured such that the signal is transmitted to the remote switch only after the float member 40 has made contact with the switch for a pre-determined period of time. This period of time is preferably 80 seconds. Many commercially available condensing boilers have a condensate trap incorporating a siphon drain or trap. The siphon trap permits intermittent and controlled discharge of condensate from the boiler into the property's drainage system. This reduces the likelihood of the condensate in any externally run discharge pipe from freezing when temperatures drop. Typically, condensate will be discharged from a siphon store within the boiler (up to 5Oml) at intervals of as much as ten times per hour.

However, the batch flow from the siphon trap might otherwise cause premature and temporary activation of thc switch inside the collection chamber. The preferable time delay of 80 seconds between actuation of the switch and the transmission of the signal overcomes this problem, since any condensate filling the chamber will drain away in this time ensuring only the presence of a real blockage within the condensate drain pipe actually sets off deactivation of the boiler.

When the float member 40 is no longer in contact with the switch 44, the status of the signal by the connection means 50 is changed. Optionally, there may be a pre-determined time delay, for example of 40 seconds, between the switch 44 being released and the change in status. The change in status may be provided by the signal transmission being halted.

A bypass drain or drain port 52, best seen in Figures 2, 3 and 6, extends from a base 54 of the collection chamber 36. A bypass valve 56 is disposed within the drain 52 and can be opened and closed manually by a user from the user interface 34. In the present embodiment, a key is required to turn a lock or tap 58 at the user interface 34 in order to open and close the valve 56. However, alternative means of operating the bypass valve 56 are envisaged, for example, a rotary dial or a slidable selector switch.

The valve 56 itself may alternatively be electronically controllable, but its operation must require a user input.

When the tap 58 is in the open position, the valve 56 in the drain 52 is open, and condensate is able to drain from the collection chamber 36, for subsequent collection or draining off elsewhere. When the tap 58 is in the closed position, the valve 56 in the drain 52 is consequently closed, and condensate is effectively trapped within the collection chamber 36 and within the condensate drain pipe above the blockage.

The user interface 34, provided on an external surface of the housing 26, includes a plurality of visual status indicators 60a, 60b, 60c for conveying information to the user about the status of the condensate drain pipe, the bypass drain 52 and the boiler.

The visual status indicators 60a, 60b, 60c are all typically light emitting diodes of various colours, which may flash or remain lit up continuously as and when required.

The user interface 34 may additionally or alternatively include a display screen for disp'aying alphanumeric or symbolic type messages.

A first visual indicator 60a indicates that the operations controller 14 is powered up and active, ready to detect a blockage in the condensate drain pipe. The first visual indicator 60a is preferably green in colour. A second visual indicator 60b may visually alert the homeowner or caretaker that the bypass drain is in use and bypass valve 56 is in the open position. Additionally or alternatively, the second visual indicator 60b may flash intermittently at a predetermined frequency when the bypass valve 56 is open. To facilitate this, a sensor may be placed in the drain 52 or on the valve 56 to detect when the valve 56 is open. The sensor may be one or more optical sensors or microswitehes. The second visual indicator 60b is preferably amber. It will be appreciated that any colour of indication can be utilised. A third visual indicator 60c is operable to indicate when the electrical supply to the boiler has been isolated.

The third visual indicator 60c is preferably red.

An electro-aeoustic device, for example, a buzzer 62 (shown in Figure 5), may sound when the float member 40 is in contact with the switch 44 in the collection chamber 36. The buzzer 62 provides an audible indication to the homeowner or caretaker that the electrical supply to the boiler has been shut down. This is particularly useful if the boiler is located behind panels, for example, in a cupboard or control room, or is remote from the normal everyday transit of people. The buzzer 62 is concealed behind a grill portion 64 of the housing 26.

A mute button 66 may be provided in or on the user interface 34 so that the user of the apparatus 10 is able to mute the buzzer 62 for a period of time, or until such a time as the device is reset and a further blockage is detected.

A test button 68 (shown in phantom in Figure 1) may also be provided in or on the user interface 34. Once pressed or depressed, the test button 68 initiates a check routine to establish that the system is frmnetioning correctly. The check routine is broadly as follows: a signal is sent to the remote switch, causing the electrical supply to the boiler to be discontinued. The third visual indicator 60c is consequently illuminated, and the buzzer 62 is sounded. Once the check routine has been completed, the system resumes its normal operation, with power to the boiler being restored and the first visual indicator 60a being illuminated in pacc of the third visual indicator 60c. The check routine should ideally take no Longer than 60 seconds to complete.

It is envisaged that the operations controller 14 may be configured to transmit a text message alert, for example, to the mobile telephone or computer of the homeowner, caretaker or a plumbing engineer under contract, to notify them that the electrical supply to the boiler is discontinued.

In use, when the condensate drain pipe becomes blocked, for example, due to freezing of the pipe, condensate from the boiler begins to back up into the passage 20 and then the collection chamber 36. As the volume of condensate in the collection chamber 36 increases, the float member 40 floats on the condensate and rises and eventually actuates the switch 44 at the upper support shoulder 46a. The switch 44 directly triggers transmission of the signal to the remote switch, and the boiler is consequently switched off This functionality prevents the boiler from failing or going into a lock out' mode.

When the condensate drain pipe becomes unblocked or as condensate drains from the collection chamber 36 via the bypass drain 52, the condensate level in the chamber drops and the float member 40 drops back to the lower support shoulder 46b to its rest position. The control circuitry is consequently deactivated and the remote switch, sensing a change in status of the signal, then re-establishes electrical power to the boiler once more. In this way, the integrity of the boiler is assured and the homeowner or caretaker maintains absolute control over the operation of the bypass drain 52.

It will be appreciated that by the fitting 12 of the apparatus 10 of the invention, freezing of condensate from domestic and commercial boilers can be detected during periods of cold weather and damage to boilers can be prevented thereby preventing discomfort and distress to many people at home and in work.

Claims (1)

1. <claim-text>CLAIMS1. Apparatus for monitoring the flow of boiler condensate through a condensate drain pipc comprising a fitting having an inlet and an outlet for connection in the condensatc drain pipe, the fitting having a passage extending from between the inlet and the outlet to a float chamber, a switch, and a float disposed in the chamber and adapted to actuate the switch, and means for relaying a signal from the switch to a remote switch for switching off an electrical supply to the boiler when the float is raised by a rising condensate level in the float chamber, and means for relaying a change in status of the signal from the switch to the remote switch for switching on an electrical supply to the boiler when the float is lowered by a falling condensate level in the float chamber.</claim-text> <claim-text>2. Apparatus as claimed in claim 1, in which a time dday circuit is provided for delaying the relay of the signal to the remote switch.</claim-text> <claim-text>3. Apparatus as claimed in claim 2, in which the time delay circuit is configured to delay the relay of the signal to the remote switch for up to 120 seconds.</claim-text> <claim-text>4. Apparatus as claimed in any preceding claim, in which the switch is a micro-switch, reed switch or optical switch.</claim-text> <claim-text>5. Apparatus as claimed in any preceding claim, in which alarm means is connected to the switch.</claim-text> <claim-text>6. Apparatus as claimed in claim 5, in which the alarm means includes a ntnsdueer for creating an audible alert.</claim-text> <claim-text>7. Apparatus as claimed in claim 6, in which a mute button is provided for muting the audible alert.</claim-text> <claim-text>8. Apparatus as claimed in any one of claims 5 to 7, in which the alarm means includes a visual display.</claim-text> <claim-text>9. Apparatus as claimed in claim 8, in which thc visual display is an LED or LCD.</claim-text> <claim-text>10. Apparatus as claimed in any preceding claim, in which a drain port is in fluid S communication with the float chamber.</claim-text> <claim-text>11. Apparatus as claimed in claim 10, in which a valve in the drain port is manually actuable.</claim-text> <claim-text>12. Apparatus as claimcd in claim 10, in which a valve in the drain port is electrically actuable.</claim-text> <claim-text>13. Apparatus substantially as described herein with reference to and as illustrated in Figures Ito 6 of the accompanying drawings.</claim-text>