US3211376A - Steam heating apparatus - Google Patents

Description

Filed July 23, 1964 INVENTOR AUSTIN F'- MCCORMACK JR.

BY MJM 555%@ ATTORNEYS United States Patent 3,211,376 STEAM HEATING APPARATUS Austin F. McCormack, Jr., 1414 Bella Vista Drive, Dallas, Tex. Filed July 23, 1964, Ser. No. 384,628 Claims. (Cl. 237-68) This application is a continuation-in-part of my prior U.S. application Serial No. 181,115, led March 20, 1962, now U. S. Patent No. 3,147,920 and relates to steam heatying system apparatus and, more particularly, to such apparatus employing a plurality of deaerating steam traps for removing non-condensible gases from steam condensate. As is pointed out in my prior application, steam traps are conventionally used in steam heating systems and are automatically operated to trap or retain steam in the heating apparatus yor piping system until its latent heat has been dissipated and then to permit the condensate from the steam to accumulate for discharge to the return line of the heating system. A particular disadvantage to such a system is the continuous expense of replacing piping because of corrosion. This corrosion is principally caused by the presence of carbon dioxide in the condensate as well as oxygen and other non-condensible gases. The continuous forming of corrosion results in a corresponding continuing decrease in the overall eiciency of the heating system.

It is recognized from my prior application that the noncondensible gases are lighter than the steam vapor and will collect at the top of the condensing column whence they are thermostatically vented to the atmosphere. It has been further discovered that the percentage of the non-condensible gases freed from the condensate is a function of the amount of steam flashed in the steam trap.

It is, therefore, an object of the present invention to control the amount of steam flashed in a deaerating steam trap.

Another object of the present invention is to minimize the amount of steam flashed in a deaerating steam trap.

Another object of the present invention is to provide a deaerating steam trap with an orifice of predetermined size at the trap outlet.

The present invention has another object in that steam heating apparatus is provided with a plurality of deaerating steam traps which vent to a single condenser unit.

It is another object of the present invention to provide a single condenser unit for a plurality of deaerating steam traps in a heating system.

A further object of the present invention is to obtain useful heat from the single condenser unit connected to a plurality of deaerating steam traps in a heating system.

In practicing the present invention, a steam trap having inlet and outlet means separated by a liquid collecting chamber is provided with valve means for releasing the collected liquid from the chamber in the form of iiashed steam, means disposed upstream of the outlet means including separation chamber means for separating corrosive gases from condensate released by the valve means and including vent means for the separated gases, and means controlling the amount of flashed steam whereby a maximum percentage of the corrosive gases is separated. In addition, a plurality of such steam traps in a steam heating system are provided with a single condenser means connected to each separation chamber whereby the separated gases are combined for venting to the atmosphere. Other objects and advantages of the present invention will become apparent from the following description of a preferred embodiment taken in connection with the accompanying drawing wherein:

FIGURE 1 is a Vertical section view of a steam trap ice and its associated elements embodying the present invention;

FIGURE 2 is a schematic arrangement of a plurality of the steam traps of FIGURE 1 combined into a steam heating system; and

FIGURE 3 is a cross section of a detail of FIGURE 1.

As is illustrated in FIGURE 1 of the drawing, the steam trap comprises a generally hollow body 10 having an inlet 12 with an orifice plug 13 and a pair of outlets 14 and 16 with outlet 16 including an orifice plug 17. The interior of the body 10 forms a condensate collection chamber 18 that is separated by a partition wall 20, the lower portion of which is provided with a removable filter plug unit 22 so positioned as to iilter the flow from the inlet 12 to the chamber 18.

The condensate collection chamber collects condensed moisture from the steam entering the inlet 12 and such condensate supports a bucket 24 in a buoyant manner. A valve plate 26 is integrated to the bottom of the bucket 24 as by a plurality of mounting studs and nuts 28 (only one being shown). The upper end of each mounting stud 28 is pivoted to a strap 30 fixed to the valve plate 26 which is thus assured of aligned seating even through the bucket 24 may be slightly tilted due to the buoyant forces.

The upper part of chamber 18 is defined by a partition wall 32 centrally formed with a downwardly extending hollow tubular member 34, the lower edge of which forms a valve seat 36 for the valve plate 26. The top surface of partition wall 32 and the opposite interior surfaces of the body 10 define a condensate outlet chamber 38 which communicates with the outlets 14 and 16.

A valve stem 48 has its lower end adjustably threaded through the valve plate 26 as is apparent from the crosssection seen through the rectangular opening in the strap 30. The valve stem 40 is disposed in the tube 34 and has a conical valve member 42 xed on its upper end. The valve 42 cooperates with an orifice fitting 44 threaded into the partition 32 so as to be in axial alignment with the outlet 14. The valve plate 26 and the valve 42 are simultaneously moved in response to the rise and fall of the bucket 24 whose vertical movement is stabilized about its central axis by means of a plurality of stabilizing pins 46 (only one being shown) which are adjustably threaded into the undersurface of partition 32. Each pin 46 extends into the bucket 24 so as to be slightly spaced from the interior of the bucket 24.

In addition to communicating with the collection chamber 18, the steam and condensate inlet 12 also communicate with the condensate outlet chamber 38 by means of a bypass orifice 48 which is controlled by a bellows type valve 50. A mounting plug 52 carries the bellows valve 50 in axial alignment with the orice 48 and in such a location as to be responsive to steam entering the inlet 12. The orifice 48 and valve 50 constitute an air bypass to condensate outlet chamber 38, which is thermostatically controlled. The valve 50 is expanded to a closed position in response to the inlet temperature of the steam; conversely a reduction of the inlet temperature causes contraction of the bellows valve 50 and permits air to pass directly to the condensate outlet chamber 38.

A vertically disposed conduit, forming a separation chamber 54, has one end connected to the outlet 14 and an opposite end connected to -a capillary coil 56 made of any `suitable thin walled tube such as copper tubing. The capillary coil 56 forms a condenser coil that cornmunicates with a thermostatic release Valve 58 which is automatically operated at a predetermined temperature to expel non-condensible gases to the atmosphere. In this particular installation, the thermostatic release valve 58 includes a bellows type valve member 60 that is normally closed on a valve seat 62 and is moved away from such seat upon contraction in response to a predetermined temperature.

The present invention is particularly adaptable for use in a steam heating system and, in such operation, the inlet 12 is connected to a steam condensate connection and the outlet 16 is connected to the return line of the system. The steam trap performs the basic function of preventing the steam from passing through the trap itself While permitting the collected condensate to be dumped into the return line. This collected condensate includes such non-condensible gases as oxygen, carbon dioxide and nitrogen; the oxygen and carbon dioxide are basic causes of return line corrosion in steam heating systems but such corrosive elements are eliminated as will become more apparent in the following description of the sequence of operation.

In operation, the condensate will collect in the chamber 18 from which it spills over into the bucket 24. As the bucket 24 begins to iill with condensate, its buoyancy is overcome and the bucket 24 begins to sink. The downward movement of the bucket 24 simultaneously moves valve plate 26 away from valve seat 36 and conical valve 42 away from orifice seat 44. The condensate in the bucket 24 is then forced by the steam pressure acting on its surface to rush up through the hollow tube 34 and is discharged through the oriiice iitting 44.` The valve member 42 and valve seat 44 constitute a variable orifice or atomizing valve which increases the velocity and decreases the pressure of the discharged condensate. Because of the axial alignment of the outlet 14 with the orice 44, the discharged condensate is projected into the conduit chamber 54 and because of the atomizing operation, the condensate is discharged with its non-condensible gases commencing to separate from the condensate. The high velocity of this sprayed discharge into the separation chamber 54 accomplishes the separation of the noncondensible gases and the condensate. The condenser coil 56 collects the non-condensible gases which are intermittently expelled to the atmosphere by the automatic thermostatic valve 58 whenever the temperature reaches a predetermined point. The condensate falls back down the conduit chamber S4 to the condensate outlet chamber 38 whence it is delivered to the condensate outlet 16 in a condition subtsantially free of non-condensible gases so that the return piping of the heating system is not subjected to any corrosive action by the condensate.

It is known that condensate at a high pressure and temperature will flash into steam as a result of a pressure drop. The decrease in pressure as the condensate passes through the variable orifice 44 may cause flashing depending upon the temperature of the condensate and the steam `pressure acting on the surface of the condensate in the bucket. Inasmuch as carbon dioxide is freely separated from iiashed steam by condensing out the steam, ,the present invention has the additional advantage of recovering the condensed steam that would normally be vented to the atmosphere. The tiashed steam is discharged into the conduit chamber 54 and is condensed as condensate by the cooling coil 56; such condensate is recoverable by falling back down the conduit chamber 54 to the condensate outlet chamber 38. The top of the coil S6 collects the non-condensible gases, e.g. carbon dioxide, from the ashed steam and cools them for release to the atmosphere by the thermostatic valve 58.

In order to separate the non-condensible -gases from the tiashed steam vapor, it is necessary to maintain the amount of steam flashed to a minimum. The amount of steam flashed is controlled by specifically selecting the size of the outlet oritice plug 17 `for the exact operating conditions such as the pressure of the heating system, the pressure drop through the inlet orice Iplug 13 and the temperature of the condensate. It is to be understood that the oriiice plugs 13 and 17 may be adjustable to diferent sizes for the particular requirements of the steam trap.

Such adjustability may be accomplished by selection from differently sized orifice plug or by utilizing an orifice plug that has a selectively variable restricltor. While any suitable type of selectively variable orifice plug may be utilized, one example is shown in FIGURE 3 as including an adjustable needle valve 17a.

In the above arrangement, the inlet orifice plug 13 is specifically selected for a particular steam condensate ow and a particular pressure drop. For example, the inlet `orifice plug may be selected to pass 280 lbs/hr. of condensate at 25 p.s.i.g. with a pressure drop of 5 p.s.i. The amount of pressure reduction required to provide suliicient ashing and velocity to the condensate is in the range of from 2-5 .p.s.i.; additional pressure reduction would only be required to get below the saturation temperature. For example, if the steam pressure was 25 p.s.i.g. but the temperature of the condensate entering the trap was consistently 250 F., the pressure would have to be reduced at least to 15 p.s.i.g. to reach the boiling condition and an additional 2-5 p.s.i. pressure drop would be required for the steam to flash. It is now ap- Iparent, that the amount of steam flashed may be kept to a minimum by controlling the pressure drop at the outlet orifice 17. Continuing the above example, the outlet orifice 17 is adjusted .to pass 280 lbs./hr. at an allowable pressure drop of 3 p.s.i.g.

Turning now to FIGURE 2, there is shown a schematic diagram of steam heating system apparatus wherein a plurality of steam traps are connected to a single condenser unit. The same reference numerals have been used in FIGURE 2 to designate the same elements already described in FIGURE l, and new reference numerals have been used for the additional elements. For instance, each of the steam traps 10 has its inlet 12 connected to a steam condensate connection and its outlet 16 connected to the condensate return line 102 of the steam heating system. Each of the conduits forming the separation chambers 54 has one end connected to the outlet 14 of the steam trap 10 as described in FIGURE 1, but the opposite ends of the chambers 54 are connected to a single condenser unit indicated generally at 104. The condenser unit 104 includes a plurality of finned conduits 106 extending between an upper expelling chamber 108 and a lower condensate chamber a plurality of thermostatic release valves 58 (as described in detail in FIGURE 1) communicates with the expelling chamber 108 and a return pipe 112 communicates with the collection chamber 110. A condensate return .trap 114, of any conventional structure, is located in the return .pipe 112 to deliver condensate therefrom to the condensate return line 102. A circulating fan 116 is disposed adjacent the condenser unit 104 to direct a ow of air onto the finned conduits 106 and thus reduce the number of cooling iins needed for each conduit.

In operation of the steam heating system apparatus shown in FIGURE 2, each steam trap 10 operates independently (as described in connection with FIGURE l), up to the point where the sprayed discharge into the separation chamber 54 accomplishes the separation of the nonacondensible gases and the condensate. The finned conduits 106 collects the non-condensible gases for delivery to the upper expelling chamber 108 whence they are intermittently expelled to the atmosphere by the automatic thermostatic valves 58. The separated condensate falls down into the lower condensate chamber 110 whence it is delivered in a condition substantially free of noncondensible gases to the return pipe 112 and is subsequently returned by the steam trap 114 to the condensate return line 102 whereby the heating system apparatus is not subjected to any corrosive action by the returning condensate.

It is to be understood that each of steam traps 10 are located adjacent a heating element such as a radiator. The entire etiiciency of the heating system apparatus is greatly increased by the use of the unitary condenser unit 104. Furthermore, the condenser unit 104 may be itself'.` utilized as a heating element in furnishing extra heat to the space in which it is located.

Inasmuch as the preferred embodiment of the present invention is subject to many variations, modifications and changes in structural details, it is intended that all matter contained in the foregoing description or illustrauted on the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In steam heating apparatus, the combination comprising a steam trap device having an inlet and an outlet and a condensate collection chamber therebetween, atomizing valve means for discharging collected condensate from said chamber at a high velocity in the form of a spray, an additional outlet means disposed upstream of said outlet to receive the discharged spray, gas separation means including condenser means and a separation chamber communicating with said additional outlet means for separating gases from the discharged spray and leaving purified condensate, means to expel the separated gases from said condenser means, means to collect the purified condensate, and means controlling the amount of steam ashed with the discharged spray.

2. The combination as recited in claim 1 wherein said last mentioned means comprises preselected pressure drop means disposed at said outlet.

3. The combination as recited in claim 2 wherein said pressure drop means comprises adjustable orilice means in said outlet.

4. In steam heating apparatus having a steam condensate connection and a condensate return line, the combination comprising plural steam trap means connected between said condensate connection and said return line, a condensate collection chamber in each steam trap means, valve means for releasing collected condensate from said chamber in the form of a discharged spray, separation means receiving the discharged spray to separate the same into non-condensible gases and puried condensate, condenser means to collect the non-condensible gases, means 5. The combination as recited in claim 4, wherein said condenser means comprises a condenser unit having a plurality of finned conduits for collecting the non-condensible gases whereby said condenser unit acts as a heating element.

6. In steam heating apparatus, the combination cornprising a plurality of steam condensate traps, each of said traps having an inlet and an outlet and a condensate collection chamber therebetween, additional outlet means for each trap disposed upstream of said outlet, valve means for each trap adapted to release collected condensate from said chamber to said additional outlet means, separation chamber means for each additional outlet means, unitary condenser means communicating with said separation chamber means to receive non-condensib1e gases and purified condensate therefrom, means to expel non-condensible gases from said unitary condenser means, means to collect the purified condensate from said unitary condenser means, and heat dissipating means on said unitary condenser means whereby said unitary condenser means acts as a heating element.

7. The combination as recited in claim 6 wherein said heat dissipating means comprises a plurality of finned conducts and wherein circulating fan means is disposed adja cent said finned conduits.

8. The combination as recited in claim 7 wherein each of said steam condensate traps is provided with means controlling the amount of steam ashed during release of the collected condensate by said valve means.

9. The combination as recited in claim 8 wherein said controlling means comprises preselected pressure drop means disposed at said outlet.

10. The combination as recited in claim 9 wherein said pressure drop means includes adjustable orifice means in said outlet to reduce the amount of steam fiashed to a minimum.

References Cited by the Examiner UNITED STATES PATENTS 1,114,609 10/14 Hatch 236-53 1,191,342 7/16 Pendleton 137--190 EDWARD I. MICHAEL, Primary Examiner.

Claims (1)

1. IN STEAM HEATING APPARATUS, THE COMBINATION COMPRISING A STEAM TRAP DEVICE HAVING AN INLET AND AN OUTLET AND A CONDENSATE COLLECTION CHAMBER THEREBETWEEN, ATOMIZING VALVE MEANS FOR DISCHARGING COLLECTED CONDENSATE FROM SAID CHAMBER AT A HIGH VELOCITY IN THE FORM OF A SPRAY, AN ADDITIONAL OUTLET MEANS DISPOSED UPSTREAM OF SAID OUTLET TO RECEIVE THE DISCHARGED SPRAY, AS SEPARATION MEANS INCLUDING CONDENSER MEANS AND A SEPARATION CHAMBER COMMUNICATING WITH SAID ADDITIONAL OUTLET MEANS FOR SEPARATING GASES FROM THE DISCHARGED SPRAY AND LEAVING PURIFIED CONDENSATE, MEANS TO EXPEL THE SEPARATED GASES FROM SAID CONDENSER MEANS, MEANS TO COLLECT THE PURIFIED

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