GB2159927A

GB2159927A - Condensate discharge device for combustion apparatus

Info

Publication number: GB2159927A
Application number: GB08513661A
Authority: GB
Inventors: John Paul Eising
Original assignee: AO Smith Corp
Current assignee: AO Smith Corp
Priority date: 1984-06-04
Filing date: 1985-05-30
Publication date: 1985-12-11
Also published as: FR2565326A1; NL8501614A; DE3519593A1; CA1242953A; GB8513661D0; BE902570A

Abstract

A housing 4 has an inlet 3 in its upper end connected to a combustion conduit 2 containing the waste gases of combustion. The upper end of an outlet tube 7 in the lower end of the housing in alignment with the inlet projects a substantial distance above the lower surface of the housing and provides a seat 9 for a hollow plastic ball 10 which rests on the seat to prevent escape of gases from the housing. Condensate generated by cooling of the combustion gases flows into the housing and when the condensate accumulates to a level above the seat, the ball will float to permit the discharge of the condensate while preventing discharge of the gaseous products of combustion. <IMAGE>

Description

SPECIFICATION Condensate Discharge Device for Combustion Apparatus In high energy efficient water heaters and furnaces, waste gases of combustion are passed in heat transfer relation with water or air to extract heat from the combustion gases. Cooling of the combustion gases through heat transfer results in the production of substantial quantities of condensate and it is necessary to discharge the condensate without allowing escape of the combustion gases into the surrounding building.

In the past, various types of condensate discharge devices have been employed in steam or compressed air systems to permit the discharge of condensate while preventing escape of the gas. One form of condensate discharge device, as used in the past, has been an S-trap. While devices of this type are effective to discharge condensate without permitting the gas to enter the environment, foreign materials or contaminants tend to collect in the trap and eventually clog the line and prevent proper operation.

Other types of condensate discharge devices are complicated structures requiring numerous moving parts which can be subject to corrosion by contaminates in the waste gas.

The invention is directed to an improved condensate discharge device for a combustion apparatus which automatically drains condensate from the combustion system, while preventing escape of gaseous products of combustion into the environment.

In accordance with the invention, such a device comprises a housing having an inlet for connection to a conduit containing waste gases of combustion, a tubular member disposed within an opening in the lower end of the housing, with the inner end of the tubular member projecting above the lower end of the housing and defining an outlet, and a spherical float disposed within the housing and disposed to seat on the outlet to prevent flow therethrough.

Condensate generated by cooling of the combustion gases in the combustion system will flow through the inlet into the housing and when the condensate accumulates to a level above the outlet, the float will lift from the outlet to permit the discharge of the condensate while preventing the discharge of the waste gases of combustion.

The device is of simple and inexpensive construction having only a single moving part, which is the float, and no adjustment is required for its operation.

The housing, outlet tube and float are preferably formed of plastic material so that the entire unit is non-corrosive.

The space between the upper end of the outlet tube and the lower end of the housing defines a sump wherein contaminants are collected, thereby preventing the contaminants from accumulating on the valve seat and ensuring proper sealing of the float valve to the seat.

Due to the design of the unit, the float is selfcentering, and after discharge of the accumulated condensate, the float will automatically re-seat itself on the upper end of the outlet tube.

An example of condensate discharge device in accordance with the invention will now be described with reference to the accompanying drawings, in which: Figure lisa vertical section of the device as associated with a combustion system; and Figure 2 is a sectional view taken along line 2-2 of Figure 1.

The drawings illustrate a condensate discharge device 1 which is connected to a conduit 2 containing waste gases of combustion. The conduit 2 can take the form of a combustion chamber, heat exchanger, flue or the like, through which the waste gases of combustion are passed to the atmosphere.

A nipple 3 connects the lower end of the conduit 2 to the device 1 and condensate generated by cooling of the waste gases in conduit 2 will flow through nipple 3 into the device 1.

The discharge device 1 includes a cup-shaped housing 4 having an open end which is closed by a plug 5 which is bonded to the open end of the housing by an adhesive or the like. Plug 5 is provided with a threaded opening 6 which receives the lower end of nipple 3.

Mounted within an opening in the lower end of housing 4 is a generally L-shaped outlet tube 7. The inner end of tube 7 projects a substantial distance above the lower surface 8 of housing 4 and defines a seat 9. A spherical float or ball 10 normally rests on seat 9 and prevents the discharge of gases from housing 1 to the exterior. Float 10 is hollow and is preferably formed of plastic material, having a specific gravity less than 1.0 so that as condensate accumulates within the housing 4, the bail will float on the condensate to open the seat 9 and permit the condensate to drain through the outlet tube. In practice, the ball is provided with a specific gravity so that it will float to open the valve seat when the condensate has accumulated to a level about 1/4 inch (6 mm) above the seat 9.

The space between seat 9 and the lower end 8 of housing 4 defines a reservoir or sump 11 and contaminates in the condensate will be collected in sump 11 and thus will not accumulate on the seat 9 to disrupt proper seating of the ball on the seat.

All the components of the discharge device, including the housing 4, outlet tube 7, float 10 and plug 5 are preferably formed of plastic material so that the entire unit is non-corrosive. The device is of simple and inexpensive construction, being gravity actuated, and includes only one moving part which is the spherical float or ball. Furthermore, the device is operable without adjustment.

The hollow plastic float being light in weight provides improved response to accumulated condensate.

The in-line construction of the inlet and outlet faciiitates plastic moulding and the incoming condensate entering the housing through nipple 3 tends to flush and rotate the float, thereby cleaning the float and removing contamination to ensure proper seating of the float on the seat 9. As a further advantage, the incoming condensate is deflected outwardly by the float and is directed toward the sump 11, thereby providing some agitation of the condensate in the sump. Agitation of the condensate results in some of the contaminants in the sump being suspended in the liquid and carried out through the outlet tube.

Claims

1.A A condensate discharge device for combustion apparatus, comprising a housing having an inlet for connection to a conduit containing waste gases of combustion, a tubular member disposed within an opening in the lower end of the housing, with the inner end of the tubular member projecting above the lower end of the housing and defining an outlet, and a spherical float disposed within the housing and disposed to seat on the outlet to prevent flow therethrough, condensate generated by cooling of the combustion gases fiowing from the conduit into the housing and an accumulation of condensate above the level of the outlet causing the spherical float to lift from the outlet to permit discharge of the condensate while preventing discharge of gas through the outlet.

2. A device according to claim 1 wherein the spherical float is a hollow plastics member.

3. A device according to claim 1 or claim 2, wherein the inlet is in the upper end of the housing and axially aligned with the outlet.

4. A device according to anyone of the preceding claims, wherein the housing is cup-shaped and has a generally cylindrical wall closed at the upper end by a plug within which the inlet is disposed.

5. A device according to claim 4, wherein the diameter of the cylindrical wall is slightly greater than the diameter of the spherical float so that the float will automatically seat itself on the outlet when the condensate has been drained through the outlet.

6. A combustion system including a conduit to conduct waste gases of combustion and having a drain opening in a lower portion thereof communicating with an inlet in the upper end of a housing, having an aperture in its lower end with an outlet tube disposed in the aperture and aligned with the inlet, the upper end of the outlet tube projecting upwardly from the bottom of the housing to provide a seat and the space between the seat and the bottom of the housing defining a sump, and a spherical float disposed within the housing and mounted to rest on the seat to prevent discharge of gas through the outlet tube, cooling of the waste gases in the conduit generating condensate which flows through the drain opening to the housing, an accumulation of condensate above the level of the seat causing the spherical float to lift from the seat to permit discharge of condensate through the outlet tube while preventing discharge of gas through the outlet tube.

7. A system according to claim 6, wherein the float is aligned beneath the inlet so that condensate entering the inlet will strike the float and be deflected outwardly toward the sump.

8. A condensate discharge device for combustion apparatus, substantially as described and as illustrated with reference to the accompanying drawing.