US3685731A - Large capacity steam trap - Google Patents

Abstract

This invention relates to an improvement of a large capacity steam trap, wherein certain disadvantages of a composite valve mechanism, which is opened and closed by utilizing the buoyancy of a float or the like, are eliminated by the addition of a bellows mechanism or the like, to obtain a steam trap which is accurate in operation, low in cost and easy to handle and maintain, as well as being capable of discharging a large quantity of condensed water.

Description

United States Patent [151 3,685,731 Aug. 22, 1972 Fujiwara [54] LARGE CAPACITY STEAM TRAP [72] Inventor: Katsuii Fuiiwara, 191, Nishitani Hiraoka-cho, Kakogawa-shi, l-lyogoken, Japan [22] Filed: Dec. 4, 1970 [211 Appl. No.: 95,235

30 Foreign Application Priority Data Dec. 6, 1969 Japan ..44/98119 [52] US. Cl ..236/53, 236/56 [51] Int. Cl. ..F16t H10 [58] Field of Search ..236/53, 56, 58

[56] References Cited UNI ED TAT SPA ENTS 895,073 8/ 1908 Chisolm ..236/53 2,043,074 6/1936 Simpson ..236/53 Primary Examiner-Edward J. Michael Attorney-MeGlew and Toren [57] ABSTRACT This invention relates to an improvement of a large 4 Clains, 1 Drawing Figure PATENTED M1822 I972 INVENTOR KATSUJI Fuzn WARR 1 LARGE CAPACITY STEAM TRAP SUMMARY OF THE INVENTION In a large capacity steam trap of the usual type, when the valve is opened the valve body is attracted by the drop of dynamic pressure caused by high velocity fluid flowing at the valve portion of a composite valve mechanism, according to Bemoullis theorem. Thus, the valve port is throttled, so that a large quantity of condensation could not be discharged in spite of the valve port having a larger aperture.

An object of the present invention is to eliminate such a drawback and to assure an instant discharge of a large quantity of condensed water by keeping the valve port always opened maximally when the valve is opened.

Such an object may be attained, according to the present invention, by providing the composite valve mechanism with a bellows mechanism which operates thermostatically such that in the valve opening operation, the pressure at the valve portion of said composite valve mechanism is raised by the condensed water flowing out from the valve port of said bellows mechanism to prevent the valve body of said composite valve mechanism from being attracted to the valve seat. Thus, there is no fear of throttling of the valve port and of decreasing the flow quantity of discharge, but it is always possible to keep the valve port opened maximally and yet the condensed water may be discharged also by said bellows mechanism, so that a large quantity of condensed water may be discharged in a short time. And, at the time of starting, said bellows mechanism is in the opened valve condition, so that air and cold condensed water in the piping and the apparatus may be discharged in a short time.

Further, in the steam trap according to the present invention, when the condensed water is accumulated, first the float will rise to open the composite valve. When the composite valve is opened, the pressure within the valve chamber will rise and .come close to the pressure on the inlet side (primary pressure), so that the difference between the primary pressure acting on the bellows mechanism and the secondary pressure on the outlet side will disappear. Thus, the bellows may be promptly contracted to open the valve due to .a slight temperature drop and pressure drop accompanied therewith.

BRIEF DESCRIPTION OF THE DRAWING A better understanding of the present invention will be had by reference to the following detailed description of the preferred embodiments thereof taken in connection with the accompanying drawing which is'a longitudinal sectional view of a steam trap embodying the present invention.

DESCRIPTION or THE PREFERRED EMBODIMENTS In the drawing, a trap body 1 having an inlet 2 and an outlet 3, and defining a condensed water sump 6 is formed with an upper cover 4 and a side cover 5. On the side communicating with said outlet 3 of the inner wall of said condensed water sump 6, a valve box having upper and lower valve seats 7, 8 is fixed to form a valve chamber 9.

An upper valve body 11 comprises slide rods l2, l3, and a lower valve body 14 comprises slide rods l5, l6. Said upper valve body 11 and said lower valve body 14 are so adjusted that said valve bodies ll, 14 will seat simultaneously on said valve seats 7, 8 respectively by coupling said slide rods l3, 15 together with screw means secured by a bolt 17 and a nut 18.

A valve body holder 19, a bushing 20 and a snap ring 21 are also provided. On said slide rod 12 of the upper valve body 11, a float 22 is connected. Said valve box 10 is provided with a bellows unit comprising a bellows 23, a bellows holder 24, a valve 25, a valve holder 26, a plug 27, a valve seat 28, a bellows receiving cylinder 29 and a snap ring 30.

In the operation of said steam trap, at the time of starting, the float 22 will lower and the composite valve will close, while the bellows 23 will contract or close and air and cold condensed water'within the piping and the apparatus will be discharged under the condition of an opened valve. When hot condensed water and steam flow in, said bellows 23 is expanded to close the valve. Thereupon, respective areas of the upper and lower valve bodies l1, 14 are exposed to equal pressures, so that the effect of pressure acting on said composite valve is to create equilibrium conditions. Thus, the condition of a closed valve is maintained by operation of the float 22 and the composite valve. When a large quantity of condensed water flows in, the float 22 will first promptly rise to pull up the composite valve and to open the valve. When said composite valve is opened,

the pressure within the valve chamber 10 will rise and come close to the pressure within the bellows 23 which is being cooled, so that the valve closing force due to said bellows becomes smaller. Thus, the valve is opened by the pressure drop accompanied by a slight temperature drop. After opening of the valve of said bellows mechanism, the pressure of the valve portion of said composite valve mechanism is raised and the composite valve is prevented from being attracted onto the valve seat. Thus, a large quantity of condensed water is discharged in a short time without reducing the discharge quantity due to the throttling of the valve port. As the quantity of condensed water decreases, the float 22 will gradually lose its buoyancy and the composite valve will be closed again, and at the same time, the bellows 23 is also heated by steam and will expand to close the valve. Such actions are repeated to discharge large quantity of condensation.

In the above mentioned embodiment, the composite valve and the float are directly connected. However, the present invention is byno means limited to such an example, and the same effect may be obtained by making the composite valve to open and close, through a lever mechanism actuated by ascent and descent of the float. The same effect may be obtained also, when a thermostatic bimetal mechanism is used in place of said bellows mechanism.

What is claimed is:

1. A large capacity steam trap comprising a housing defining a sump for condensate water, said housing having an inlet and an outlet therein spaced from one another, a valve body positioned within the sump in said housing and comprising a horizontally arranged tubular box, said tubular box having a first opening at one end in communication with the outlet from said housing and a second opening at its other end communicating with said sump, at least a first valve seat located in said tubular box intermediate its first and second openings, a second valve seat located at the second opening in said tubular box, first valve means associated with said first valve seat for opening and closing flow into said tubular box from said sump, a float position within said sump and in operative engagement with said first valve means for opening said first valve means in response to a predetermined increase in the level of condensate water in said sump, second valve means associated with said second valve seat and responsive to thermal conditions within said sump for opening and closing flow through said second opening into said tubular box.

2. A large capacity steam trap, as set forth in claim 1, wherein said first valve seat comprises an upper opening in said tubular box and a lower opening in said tubular box vertically aligned below said upper opening, said first valve means includes an upper valve member associated with said upper first valve seat and a lower valve member associated with said lower first valve seat and means interconnecting said upper and lower valve members and said float for simultaneously opening and closing said upper and lower first valve seats in response to the movement of said float.

3. A large capacity steam trap, as set forth in claim 2, wherein said second valve means comprises a valve support, a bellows mounted on said valve support and arranged to expand and contract in response to temperature increases and decreases within said sump, a valve attached to said bellows for movement into and out of contact with said second valve seat for controlling flow through said second opening into said tubular box.'

4. A large capacity steam trap, as set forth in claim 3, wherein said means interconnecting said upper and lower valve means comprises a vertically extending stem assembly, and the axis of said bellows disposed horizontally so that said bellows expands and contracts in the horizontally extending direction of said tubular box member.

Claims (4)

1. A large capacity steam trap comprising a housing defining a sump for condensate water, said housing having an inlet and an outlet therein spaced from one another, a valve body positioned within the sump in said housing and comprising a horizontally arranged tubular box, said tubular box having a first opening at one end in communication with the outlet from said housing and a second opening at its other end communicating with said sump, at least a first valve seat located in said tubular box intermediate its first and second openings, a second valve seat located at the second opening in said tubular box, first valve means associated with said first valve seat for opening and closing flow into said tubular box from said sump, a float position within said sump and in operative engagement with said first valve means for opening said first valve means in response to a predetermined increase in the level of condensate water in said sump, second valve means associated with said second valve seat and responsive to thermal conditions within said sump for opening and closing flow through said second opening intO said tubular box.

2. A large capacity steam trap, as set forth in claim 1, wherein said first valve seat comprises an upper opening in said tubular box and a lower opening in said tubular box vertically aligned below said upper opening, said first valve means includes an upper valve member associated with said upper first valve seat and a lower valve member associated with said lower first valve seat and means interconnecting said upper and lower valve members and said float for simultaneously opening and closing said upper and lower first valve seats in response to the movement of said float.

3. A large capacity steam trap, as set forth in claim 2, wherein said second valve means comprises a valve support, a bellows mounted on said valve support and arranged to expand and contract in response to temperature increases and decreases within said sump, a valve attached to said bellows for movement into and out of contact with said second valve seat for controlling flow through said second opening into said tubular box.

4. A large capacity steam trap, as set forth in claim 3, wherein said means interconnecting said upper and lower valve means comprises a vertically extending stem assembly, and the axis of said bellows disposed horizontally so that said bellows expands and contracts in the horizontally extending direction of said tubular box member.

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