|Title of Invention||
A STEAM TRAP FOR DISCHARGE OF CONDENSATE
|Abstract||A steam trap for discharge of condensate is disclosed. The steam trap includes a chamber, a first orifice and at least one other orifice. Each of the orifices has closing elements. The closing elements of all orifices are connected to an interlinked lever arrangement operated by a float. The orifices open in response to level of condensate in the chamber of the trap.|
|Full Text||THE PATENTS ACT 1970
(39 of 1970)
THE PATENTS RULES, 2003
(See section 10 and rule 13)
FLOAT OPERATED STEAM TRAP
SPIRAX MARSHALL PVT LTD
An Indian Company
Of PB No. 29, Mumbai - Pune Road, Kasarwadi, Pune- 34
The following specification describes the invention.
The invention relates to a steam trap.
Steam traps are automatic valves that release condensed steam (condensate) from a steam space while preventing the loss of live steam. They also remove air and non-condensable particles from the steam space. Steam traps are design to maintain steam energy efficiency by performing specific tasks such as maintaining heat for process and the like. Once steam is trapped it gets converted into hot water, it is removed by the trap from the steam side as condensate and either returned to the boiler via condensate return lines or discharged to the atmosphere. Many types of steam traps are known in the art with their varied applications. Steam traps are broadly classifies on the basis of their generic operations i.e. "continuous flow" and "intermittent flow".
In the continuous flow type traps, there is a continuous discharge of condensate. These are generally float, thermostatic and fixed orifice traps. Intermittent traps work in open and closed cycles. They have a pattern of hold-discharge-hold. These traps are generally of the thermodynamic, inverted bucket and bimetallic type.
Float type steam traps are traditionally known along with their varied functions. The main function of a float type steam trap is to drain condensate from the steam line. The conventional design of the float type steam trap has single orifice which in turn is operated by a float and lever mechanism. These single orifice float type steam traps are sized on the basis of running condensate loads & differential pressures across the trap. Initially the
condensate load is higher and the single orifice is not able to handle the higher condensate load. To overcome this problem, two traps are required to be installed in parallel. This results in over sizing of the trap, bulky installation, and higher cost.
Background of Invention
Float type steam traps are installed on process vessels to remove condensate. The steam consumption in processes varies with time, which causes variation in the condensate load. At startup, when all processes & steam lines are cold, the rate of condensation is high. In this startup period, the trap has to handle high condensate load. Float type steam traps are sized on basis of running condensate loads & differential pressure across trap. Hence the steam trap selected is not able to remove condensate at startup effectively. If steam traps are sized on startup condensate loads & differential pressures across trap, it makes steam trap oversized. This results in requirement of more space, extra cost, and bulky installation.
Condensate loads from some processes are high, which may lie beyond the condensate handling capacity of a single orifice float trap. Two steam traps are needed to handle these high condensate loads. This needs more space, cost & the installation is bulkier.In addition there are several other limitations which exists in the known arts.
A bell-float type steam trap having a double-action trapping unit with a draining valve and a pilot valve is disclosed in US Patent No. 3877479 wherein a large draining capacity is ensured through the draining valve while accurately controlling the draining operation by the pilot valve. Wear
and tear of the pilot valve is prevented by diverting its striking impact through a shoulder portion having a comparatively wider contact area, which is separate from the contact area of the conic pilot valve.
A steam trap assembly is disclosed in US Patent No. 430588 wherein the said assembly is formed with a casing defining a valve chamber therein with an inlet for introducing fluid generally consisting of condensate and steam into said chamber and with an outlet for discharging condensate from the chamber. This invention seeks to overcome the limitations of the known arts.
A Steam trap assemble is disclosed in US Patent No. 4276354 wherein the said assembly relates to a housing in which any one of a plurality of steam trap valve assemblies may be installed and which may be machined to accommodate a plurality of different inlet and outlet conduit configurations. The housing includes a main body through which a central cylindrical passage extends. Flanges extend radially outward from the main body at opposite ends of this passage and serve to connect the main body with the top and bottom members.
The invention seeks to overcome the limitation of the existing prior arts.
Thus, the object of the invention is to overcome the difficulty of selection & sizing of single orifice float trap.
Another object of the invention is to increase the handling capacity of poor condensate at Startup.
Yet another object of the invention is to optimize the float type steam trap in order to sustain high condensate load.
Further, the object of the invention is to reduce the cost and the bulk of installations.
This invention envisages a two orifice float type steam trap:-
Typically the two orifice means are operated by a single float and lever mechanism.
Typically the two orifices means are installed in a vertical or in a horizontal plane or in any inclined plane mounted on a base in which this operation can be done.
The two orifice means increase the condensate discharge capacity of the trap.
Typically the operating mechanism of orifice design can be of various types.
In the preferred embodiment the float trap has two orifice means i.e. Main orifice & Pilot orifice operated using a single float & lever mechanism. This helps in optimizing the float trap sizing & selection. The construction facilitates the installation of a trap as per regular trap installation having inlet & outlet as per type of end connection provided which can be either on a base or on the cover.
Typically the use of said float trap can enhance the condensate discharge capacity as well as reduce the space requirement. Due to compact installation of float type steam trap assembly along with single float and lever mechanism there can be a certain amount of reduction in the cost.
The invention will now be described with reference to the accompanying drawings, in which figure 1 is a sectional view of the steam trap, in accordance to this invention when there is no condensate load;
Figure 2 is a sectional view of figure 1 when condensate enters the trap.
Figure 3 is the sectional view of figure 2 in which both orifices are open.
Referring to the drawing there is provided a steam trap in accordance with this invention having the following components -
3. Main Orifice
4. Pilot Orifice
6. Main Lever
7. Pilot Lever
In figure 1 there is no condensate load, float is at bottom position and both the orifices are in closed position.
As seen in figure 2, when condensate enters the trap, the float rises up and opens the main orifice allowing condensate to discharge through main orifice (3). Pilot orifice is still in closed condition.
Finally as seen in figure 3 when condensate load increases further, the float rises to its topmost position. The main orifice is operated by main lever and the pilot orifice is operated by pilot lever. Discharge capacity is improved as condensate is discharges through two orifices.
While considerable emphasis has been placed herein on the structures and structural interrelationships between the component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.
Dated47y April 2006
MOHAN DEWAN of R K Dewan & Co. Applicant's Patent Attorney.
|Indian Patent Application Number||600/MUM/2006|
|PG Journal Number||48/2013|
|Date of Filing||17-Apr-2006|
|Name of Patentee||SPIRAX MARSHALL PVT. LTD.|
|Applicant Address||PB NO.29, MUMBAI-PUNE ROAD, KASARWADI, PUNE.|
|PCT International Classification Number||F16T1/20|
|PCT International Application Number||N/A|
|PCT International Filing date|