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Document Type and Number:
WIPO Patent Application WO/2016/174691
Kind Code:
The invention consists in a device for the determination of optimal diameter of the orifice of a Venturi nozzle steam trap in operation in a steam flow circuit. It is distinguished from those known because it is designed insertable in the circuit where the steam trap operates - and of which we must verify and / or restore the proper function of condensate discharge to avoid leaks of live steam in the condensate drain line - taking into account the real physical parameters that can be affected by various factors, such as: changes to the circuit system, losses from gaskets, fouling which occurred in parts of the steam circuit, etc. Furthermore, the device does not require to extract the steam trap from the circuit; operation, this, usually not always possible and often expensive, such as in complex installations for size or because of a high number of steam traps. In Fig. 1 and Fig. 2 is shown the device insertable in the circuit by means of by¬ pass valves (V1 and V2) in parallel to the discharger SC to be calibrated. The diverted fluid is directed to the tank (1 in Fig.1 ) which has the function of accumulating the condensate whose level is detected by the sensor 6. The condensate out from the accumulator is led to the block 4; here there is a rotating disk - provided with a series of orifices with varying diameters and in a predetermined range of sizes - moved by a stepper motor 5. A succession of rotations positions the disk so that the fluid, coming from the accumulator tank, flows through the orifice and returns to the circuit in C2. For each disk placement, values of condensate level L, temperature T and pressure P are detected by means of sensors placed upstream and downstream of the disk and are transmitted to the processor 8. The data processing allows to verify, for each orifice diameter and related disk position, the phase state of the fluid upstream and downstream of the disk. The rotation sequence continues or stops in base of the fluid state detected and according to the correct operation of the circuit that we want obtain: adequate condensate discharge, for the operating condition of the system, without live steam losses.

BAZZOLI, Pierino Maurizio (Piazza Garibaldi 6, Formello, 00060, IT)
BERTINI, Daniele (Via Val D'Ala 36, Roma, 00141, IT)
Application Number:
Publication Date:
November 03, 2016
Filing Date:
April 28, 2016
Export Citation:
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IMAT S.R.L. UNIPERSONALE (Via della Camilluccia, 285, Roma, 00135, IT)
BAZZOLI, Pierino Maurizio (Piazza Garibaldi 6, Formello, 00060, IT)
International Classes:
Foreign References:
Attorney, Agent or Firm:
BAZZOLI, Pierino Maurizio (Piazza Garibaldi 6, Formello, 00060, IT)
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1 ) Device for the determination of the appropriate diameter of the orifice of the Venturi nozzle steam trap without having to remove it from the circuit in which it is in operation, characterized by the following main components:

□ Two valves (V1 and V2 in Fig. 2) to realize a bypass of the circuit section (C1-C2) where the steam trap operates by diverting the fluid towards the determination device to start or stop the circulation of the fluid in the circuit, according to the requirements;

□ An accumulation tank (1 in Fig. 1) with level probe (6 in Fig.1). It is placed upstream the orifice and, inside it, the accumulated condensate is dynamically monitored, by means the level probe, at each variations of the orifice diameter of the Venturi nozzle;

□ Pressure sensors (2 in Fig.1) that detect the pressure upstream and downstream of the Venturi nozzle for each orifice diameter tested;

□ Temperature sensors (3 in Fig. 1), to check the temperatures of the fluid both upstream and downstream of the Venturi nozzle;

□ A disk system (4 in Fig. 1 and Fig. 3) with a selection of test orifices driven by a stepper motor (5 of Fig. 1) controlled, eg., by a SW which varies the orifice diameter as a function of the detected data and on the basis of the criteria stated above;

□ A processor (8 in Fig. 1) which processes the data acquired by means of dedicated acquisition modules (7 of Fig. 1) and governs the action of the motor by control module (7 in Fig. 1). 2) Device as in claim 1), characterized by the flow chart (Fig. 6), comprising the following operative steps:

□ Step 1 : Data entry of the utilizer system and calculation of the initial diameter by applying known formulas with those data;

□ Step 2: First positioning of the disk in correspondence of the calculated value of the orifice diameter, and opening of the circuit;

□ Step 2n: new positioning as a return from step 4;

□ Step 3: acquisition of the condensate level in the tank (1 in Fig. 1);

□ Step 4, Verification of when the obtained level value falls within the predetermined range and move to Step 5 or Step 2nd depending on the outcome of the verification;

□ Step 5, (Yes: the detected value lies in the range): Acquisition of the Temperature and Pressure upstream and downstream the orifice;

□ Step 6: Verification, according to the acquired values, of the presence of steam or condensate, upstream and downstream the Venturi nozzle; in the event of a positive outcome, the cycle goes to final step (END) otherwise it passes to the step 2n;

□ Step END: generation of calibration report.


Description of the industrial invention having the following title:

"Device that allows to assign the correct orifice of a Venturi nozzle steam trap without removing it from the circuit in which it is inserted".

The present invention - subject of international patent application under the Patent Cooperation Treaty (PCT) - is a device that allows to assign the optimum orifice diameter of a Venturi nozzle steam trap in its operating conditions.

To assign the correct diameter of the orifice, this device allows to not disconnect the Venturi nozzle steam trap from the circuit in which it is inserted.

The device can be connected to that circuit, by means of two bypass valves, so that the condensate flow is diverted inside the device where a rotating disk - provided with a series of orifices of different diameter - allows to choose the diameter in function of pressure and temperature by sensors properly positioned and, also, in function of the condensate level accumulated in a tank positioned upstream the rotating disk.

This rotating disk can be controlled manually or by means of a stepper motor.

There are different types of steam traps: thermostatic, float, thermodynamic, inverted bucket and Venturi nozzle steam traps.

Steam traps are installed where water steam is used in processes like: heating, sterilization, humidification and cooling; processes typically used in industries such as food, chemical, pharmaceutical, laundries or power plants, refiners, distilleries, and so on. The correct functioning of a steam trap has to be always ensured in order to avoid undesirable steam leaks and harmful condensate accumulation.

Venturi nozzle steam traps have no mechanical moving parts and, usually, have the orifice with predetermined and fixed diameter. They can also have calibrated and interchangeable orifice.

In Venturi nozzle steam traps, the orifice diameter represents the crucial factor that affects their correct functioning.

Determining the proper diameter of the orifice allows to avoid the most common drawbacks like steam leaks and condensate accumulation up in the utilizers. Condensate accumulation leads to efficiency losses and water hammers.

There are many solutions that allow to avoid those critical issues; among these there is adopting a nozzle steam trap with interchangeable orifice or structuring the inner fluid path with an articulated geometry simulating the Venturi effect.

A research report issued by the European Patent Office (EPO) shows some patent documents that describe steam traps for which arises the problem of the adoption of the most suitable diameter of the orifice; those documents are the following:


• abstract; figures 1-4e

• page 2. lines 12-18

• page 3, lines 10-26 • page 5, line 11 - page 7, line 12

D2) US 2010/294377 A1 (AIONI YEHOSHUA [IL] ET 1 ,2 AL) 25 November 2010 (2010-1 1-25)

• abstract; figure 2

• paragraphs [0014] - [0016]. [0083][0094], [011 1 J - [01 13]

D3) US 5 687 755 A (FARQUHAR KEITH ROBERT [GB] 1 ,2 ET Al) 18 November 1997 (1997-1 1-18)

• abstract; figure 1

• column 2. line 31 - column 5, line 45

None of these documents describes or suggests solutions that allow to determine the suitable diameter of the orifice of a Venturi nozzle steam trap operating in a condensate drain line when load conditions are changed.


D1 shows a Venturi nozzle steam trap that includes an interchangeable body with different size orifices.

D2 and D3 propose programmable steam traps according to temperature and pressure variations for which, however, are neither supplied Venturi nozzle or rotating disk. The device that is going to be described proposes innovative solutions regarding those adopted by D1 , D2 and D3 and it is not obtainable from any combination of D1 and D2 or D3.


the device is characterized by the fact that it has systems that allow to insert it in the circuit where the steam trap operates and for which we have to calibrate the diameter of the orifice - by means of physical parameters that are characteristic of the operating conditions in progress - without removing the steam trap.

Another characteristic is due to the presence of sensors properly positioned; these lead to the determination of the suitable diameter of the orifice through the acquisition of temperature and pressure parameters giving the position of the fluid state in the condensate phase.

Innovative characteristic is represented by the presence of a condensate tank in which a sensor level provides useful data to avoid steam leaks and allows to determine the orifice diameter in function of this parameter as well.

Innovative characteristic is also the presence of a rotating disk provided with different size orifices; its rotation and positioning is made in function of measures of Temperature, Pressure and condensate Level. Through a second research report issued by the European Patent Office (EPO) some other anteriorities have been identified; those more related to the same object of invention are the following:

01 JP 2001 050486 A (TLV CO L TO) 23 February 2001 (2001-02-23)

02 JP 2004 218724 A (TL V CO L TO) 5 August 2004 (2004-08-05)

03 EP 0426199 A2 (TLV CO LTO [JP]) 8 May 1991 (1991-05-08)

From these considerations the conclusion expressed in the report follows: the subject of the invention meets the requirements of novelty.

The opinion expressed in the report is that, about these anteriorities, the scope of the invention does not meet the inventive activity requirements.

It's obvious that these documents do not recall and do not suggest solutions that are at the base of the subject of invention that will be described; solutions that are not inferable by any expert in the field of above-mentioned anteriorities.

Synthetically, the most relevant anteriorities in the second above-mentioned report issued by the EPO are:

• The JP2004218724 and JP200150486 anteriorities provide multiple orifices (specifically 3 orifices) that have predetermined diameters positionable by turning a switch without any relation to the values of temperature, pressure and of the real level of condensate of the steam trap; differently from the device that will be described where, for one of the innovative characteristics, the disk provided with orifices with differentiated diameter operates as a function of the detected data, in the dynamic state of the fluid, through the relative sensors and suitably processed.

• The JP 2010281372 anteriority relates to a particular method of construction of the known "Labyrinth" steam trap. This kind of steam trap is described in all the texts of heat engineering; It exploits the principle of repeated flash steam in expansion of the fluid after passing through predetermined orifices. It isn't diffused on the market for the construction complexity and limitations in the services offered. It is evident the absence of any connection with the constructive and functional characteristics with the object of the invention.

• The EP 0426199 A2 anteriority relates to a data processing method to determine the operating diameter of a steam trap; this method provides a phase of DATA ENTRY, a second phase of Data Base searching, then an ordinary calculation with the application of well-known physical laws and, finally, an output on a monitor that makes available the processed data to the steam traps designer. No example is proposed.

Usually, steam traps as those described in these anteriorities, are designed to be inserted permanently in the condensate drain line.

Therefore, the solutions adopted by the described steam traps are specific for this kind of devices and are not transferable to devices that have the purpose to evaluate steam circuits with steam traps for which we want to determine the orifice diameter in function of the operating physical parameters (Temperature and pressure) typical of complex systems for which these values need to be detected and processed. Synthetically, the main feature of the subject of invention is the possibility to be inserted, through by-pass valves, in any facility or equipment in order to carry out the determination of the orifice diameter according to the actual operating conditions of the circuit under test. This is made possible by implementing a methodology that relates the orifices test with the flow dynamic conditions of the fluid represented by its physical parameters T and P (Temperature and Pressure) and by the condensate level L. Pressure (P) and temperature (T) data are collected through the suitably positioned sensors and the level L is detected by a sensor in the auxiliary tank where the condensate accumulates. The collected data of P, T and L are, finally, compared with the water phases diagram and processed to determine the optimal diameter of the orifice.

This qualifying characteristic of the invention to be protected with this patent application, cannot be inferred from the method described in EP 0426199 A2

Among the anteriorities related to the above-mentioned technical issues, it has to be mentioned the patent application on behalf of Bazzoli Pierino Maurizio No. RM2013A000304 of 24 May 2013 of a Venturi nozzle steam trap with calibrated and interchangeable orifice.

In said application the invention is proposed as a steam trap innovated in the orifice interchangeability as a standalone component and replaceable without having to replace the entire steam trap or one of its complex components.

The invention that will be described is included in the problematic reported in said patent application with the aim of providing a method, and related instrumentation, to determine the diameter of the outlet orifice of the condensate in Venturi nozzle steam traps with interchangeable calibrated orifice, as those present, for example, in devices utilized in systems that use steam.

The optimal operation of a steam trap depends on the ability to perfectly retain the steam and, at the same time, to discharge fully and quickly the condensate without losing live steam.

To ensure that optimum operation, the calculation operation of the orifice diameter must take into account the parameters measured in the real and specific condition in which the steam trap operates.

In fact, for the application of the known formulas for the calculation of the orifice diameter of Venturi nozzle, arising from Bernoulli's theorem, it is assumed they refer to a liquid that operates in ideal conditions; and not in the real ones that we are interested in.

Therefore, if from the knowledge of the operating parameters values, we arrive at the calculation of the orifice diameter of the Venturi nozzle inlet, (in this way the proposed method operates to compute a first approximated value of the diameter from which to start), it remains the problem of how to take account of deviations caused by physical conditions in which the steam trap operates. Physical conditions that can be affected, for example, by steam harmful counterthrusts present downstream the condensate, before the Venturi nozzle and /or close to its output. To give technical solution to this problem, that is, to determine quickly and with extreme precision the proper orifice diameter for the user load conditions, it has been developed the innovative device under consideration.

Such a device - connected hydraulically in parallel with the Venturi nozzle steam trap in operation - measures the characteristic parameters of the fluid, upstream and downstream of the Venturi nozzle.

The orifice diameter of the device is sequentially varied, making a succession of tests until it is identified the value corresponding to the optimum operation of the plant system.

The change of the orifice diameter is obtained from a disk handling system, equipped with suitable holes, positioned - step by step - in correspondence of the Venturi nozzle of the device. This feature allows the device to operate in a succession of different orifices and to evaluate the respective physical parameters (condensate Level, Temperature and Pressure) which define the state of the circuit operation.

The functional and structural characteristics of the device are highlighted as innovative for the following reasons:

1. it operates in parallel to the system circuit in question, without having to extract the steam trap that is into operation;

2. it determines the value of the orifice diameter of the steam trap in the actual physical condition of the plant and with the real condensate flow rate; the condensate load value is monitored dynamically by means of a specific tank present in the device;

3. it detects the physical parameters determining the correct operation of the condensate drain line and processes them to determine the obtaining of such proper functioning.

The functional and structural characteristics of the device will be highlighted in relation to the attached drawings, where:

• Fig.1 - Page 1/3 shows the scheme of the device for the determination of the orifice diameter;

• Fig.2 - Page 1/3 shows the part of the circuit under test where the device is placed in operating conditions upstream and downstream of the Venturi nozzle steam trap SC to calibrate;

• Fig.3 - Page 2/3 shows the section of the device where the rotating disk and the Venturi nozzle operate;

• Fig.4 - Page 2/3 shows the section of the rotating disk with orifices and fitted with a motor connectable stem for pivotal movement;

• Fig. 5, Page 2/3 shows the arrangement of the holes (orifices) on the disk;

• Fig. 6 - Page 3/3 shows the flow chart with the sequences of the device operating loop.

The device, which operates according the sequences referred to Fig. 6, implemented by means of a HW/SW system for controlling and processing, is composed of the following main components (Refer to the attached drawings): 1. Two valves (V1 and V2 in fig. 2); they allow to perform a by-pass by the C1- C2 circuit to the device and must be operated for the start or the interruption of the circulation of the fluid in the circuit, according to the requirements;

2. An accumulation tank (1 in Fig.1) with level probe (6 in fig. 1) in which accumulates condensate upstream of the orifice and that keeps dynamically track - with the same level probe - of the level changes in relation to the various diameters of Venturi nozzle orifices which succeed with the different positions of the rotating disk;

3. Pressure sensors (2 in Fig. 1) that detect the pressure upstream and downstream of the Venturi nozzle with the trial orifice diameter;

4. Temperature sensors (3 in Fig. 1), to verify the fluid temperature upstream and downstream of the Venturi nozzle.

5. A disk system (4 in Fig. 1 and Fig. 3) with a selection of trial orifices driven by a stepper motor controlled, for example, by a software that changes the orifice dimeter according to the collected data and in base to the above- mentioned criteria.

6. A computer (8 in Fig. 1) which processes the data collected through an acquisition card (7 in Fig. 1) and controls the stepper motor by means of a control card (7 in Fig. 1).

The two 3-way valves (V1 and V2 in Fig. 1) allow to exclude the steam trap in service, by diverting the fluid flow from the inlet of the steam trap SC towards the tank inlet of the device and, then, by directing the condensate in V2, downstream the trap SC towards the condensate drain line.

The characteristic of the invention - that operates in parallel to the steam trap that is in service - is particularly qualifying and innovative if we take into account that in complex systems is not always easy and/or appropriate the extraction of the steam trap to operate directly on it.

The invention, operating in parallel with the steam trap, takes into account the characteristics of the steam trap which operates in the circuit under test. This special feature will be highlighted later when the role of individual components in the test procedure will be illustrated.

To operate in parallel, besides, it seems essential to create the simulation conditions of the condensate drain system carried out by the steam trap SC in the operative cycle. For this reason, it is crucial the function performed by the condensate accumulation tank (1 in Fig. 1).

The condensate accumulation tank - which is a peculiar characteristic of innovation of the invention - is used to determine how the steam trap SC can work, in operating conditions, at correct scheme without live steam losses and, therefore, without lowering the heat exchange efficiency of the plant.

As it will be shown later, the level value L detected by the sensor (6 in Fig. 1) is a key parameter to determine the orifice diameter in the Venturi nozzle to act in accordance with that essential condition of operation.

The innovative feature of the present invention is represented by the introduction of said component 1 in combination with its probe 6 which allows to monitor whether the level of condensate to drain is positioned in the predetermined range as a constraint for a regular regimen of the condensate drainage in the specific circuit where it is inserted.

As shown in Fig.1 , the condensate, in output from the tank 1 , it is conveyed at the unit 4 where a disk is driven by the stepper motor (5 in Fig.1). This group is represented in Fig. 3 where a Venturi nozzle operates. The fluid enters in I and exits in a U through the orifice O.

In the embodiment shown, by way of example and not binding, in Fig. 3 two plates (1 and 2) tightened with screws 3 and properly sealed are showed with, inside them, the disk 4 equipped with motorized axle and holes of different diameters (Fig.5). The holes have a predetermined configuration according to predetermined values, as it will be explained later; they are circularly arranged so that with the rotation of the disk they follow each other allowing a verification cycle of the physical parameters at stake (P, T and condensate level) by comparing them with the values comprised in a predetermined range.

The evaluation procedure starts from a value of first approximation and ends when it results as the optimal orifice of the Venturi nozzle.

The first positioning is calculated using well-known formulas on the basis of the input values that describe the plant system concerned; Indeed, it is assumed that the restoration of the proper functioning or adaptation to any change that occurred in the system should fall within a predetermined range around the first approximation value.

The disk rotation for the positioning of the orifices is governed by the control unit of the input data processing and / or output cards (7 and 8 in Fig. 1).

To determine the orifice diameter suitable to the system, in which the Venturi nozzle steam trap is inserted, the device operates following a series of steps (See Flow Chart Fig. 6): • Step 1 , Data Entry - entry of the plant system data and computation of the first orifice diameter by applying the known formulas with said data;

• Step 2 - the first positioning of the orifice disk in correspondence with the calculated diameter, and circuit opening;

• Step 2n - new positioning as result of negative answer of step 4 or 6;

• Step 3 - acquisition of the condensate level in the tank (1 in Fig. 1);

• Step 4 - test if the acquired condensate level value falls within the predetermined range; it moves to Step 5 or to Step 2n according the test outcome;

• Step 5 - If the answer to the 4th step is affirmative, the device acquires Temperature and Pressure upstream and downstream of the orifice;

• Step 6 - test, in function of all acquired values, the absence of steam close to the Venturi nozzle, upstream and downstream. If the test is positive, the loop passes to the END final step; otherwise it goes to the step 2n;

• Step END, generation of calibration report.

For example, a study that involves 1000 cases, has allowed to prepare a reference table which has been implemented in the software. The table can be accessed by the computer system for checks provided in steps 4 and 6.

In this context there is the need to integrate the theoretical calculation of the orifice diameter with the one that takes into account the real parameters in the operating conditions which the Venturi nozzle steam trap operates in. Therefore, the reference tables, generated by the results of experimental tests on market products, are stored in the Data Base to be used to verify the proper operation expected.

The tables could be considered, not merely as theoretical data, but auxiliary instruments of enhanced technical information about the real conditions of operation of the adopted steam traps, and let them to become basic equipment that characterizes both methodology and instrumentation objects of the present disclosure.

After the disk has been positioned in correspondence with the orifice with the diameter calculated by applying known formulas in base of the physical parameters made available by the data entry,

the 3-way valves are opened and the fluid starts moving.

Of course, it is superfluous to recall each time the movement of the two valves to start or stop the circulation of the fluid depending on the step in which the device is operating.

Once the circulation of the fluid is started, the values of P, T and condensate level are acquired; these are the parameters that show the operation of the circuit corresponding the conditions of the chosen orifice diameter.

In the flow chart it is shown an order of acquisition and the corresponding evaluation for a simple, clear and logical description.

Of course, the instrumentation may be provided of a logic of acquisition, and contextual evaluation, of the values of physical parameters to realize the "check- and-reposition" procedure that is necessary to achieve the objective of determining the value of the suitable diameter.

In this context, the next step at each re-positioning of the disk, which occurred through the Step 2n, is capturing, through a dedicated sensor, the condensate level in the tank 1. With the Step 3 it is verified if the level is or not in the "range" predetermined and fixed with the Data Entry.

And no doubt that the predetermination of the "range" is a binding condition.

The condensate to be discharged must be produced and, therefore, a minimum threshold of condensate must be respected for avoiding steam leaks.

Besides, a maximum threshold level must be provided in order to avoid an accumulation of condensate which, though it does not determine the stoppage of system, can nevertheless constitute an efficiency lowering of the plant.

The predetermination of the "optimum range of plant", for which the level of condensate cannot be a single binding value, can result from experimental verifications on steam traps to which it is mentioned above. This is why we can say that it represents an added value to the instrumentation that provides entered data enhanced by specific system tables, not exclusively derived from the technical documentation supplied with the equipment under test.

If the outcome of the evaluation carried out (step No. 4) is negative, the next step to valuate other parameters is unnecessary and, therefore, it needs to pass to the step "2n", that is, to place the disk in correspondence the new diameter value to repeat steps 3 and 4.

In case of a positive result, the temperature and pressure parameters acquired in step No. 5 are valued in step No. 6. These valuations, made following the step No. 4, highlights the role of the presence of condensate in the tank detected by the level probe.

From contextual evaluation of P and T detected upstream of the orifice, in relation to the state diagram relating to the specific fluid in the circuit, it is possible to deduce the presence or absence of condensate upstream of the Venturi nozzle - more precisely, between the condensate tank and the Venturi nozzle inlet - determined from unwanted counterthrusts of condensate and/or steam downstream.

Therefore, the positive assessment of the condensate level value performed in step n. 4 constitutes a necessary condition, but not sufficient, for the final determination of the orifice diameter.

Similarly, the evaluation of the values of pressure P and temperature T, made both upstream and downstream of the Venturi nozzle, leads to the final step "END" only in case of positive test results.

A single negative test result leads, on the contrary, to the step "2n" to rotate the disk to a new value of the orifice diameter.

The diagram above mentioned and what illustrated in the accompanying figures refer to an embodiment of the invention. However, the proposed solutions of the construction details are indicated by way of non-binding examples. In particular, in the respect of the idea of technical solution on which the device is based, the structure, the geometry of the components and their fixing and sealing systems, in combination with the relative positioning seat, may vary remaining within the scope of protection of the patent request.

Furthermore, for example, the variation of the orifice can also be performed manually, excluding the action of the stepper motor; as well as the innovation of the measurability of the physical parameters at stake, in combination with the mode of determination of the diameter, can find different embodiments without departing from the same area of patent protection.

Finally, the logical path implemented in the proposed Flow Chart is dictated by a need for clarity and, for the conclusions to be achieved, it is irrelevant whether the shown sequence, for example, provides a global data acquisition for their global evaluation.