SI9700147A - Combination of axial diaphragm controller with damper and control valve - Google Patents

Abstract

The combination of an axial diaphragm throughput or differential pressure controller with damper and control valve, where the pressure drop inside the damper and the control valve but also in the load has an effect on the diaphragm to withstand the spring pressure and moves the valve seat, which together with the valve plate controlling the flow or differential pressure. The combination consists of three complete valves, separated from each another and operating independently, located in a common compact enclosure in the following order: damper, control valve, diaphragm control valve. Due to the independence of valves it is possible to achieve several function combinations with the same components and insignificant changes. The concept and adjustment of the damper is very simple and permanently reliable. By the axial version of the diaphragm controller and a moving pipe valve seat a great level of compactness at low cost with ample accuracy is achieved.

Description

COMBINATION OF AXIAL MEMBRANE CONTROLLER WITH STAMP AND STEERING VALVE

The subject of the invention is a combination of an axial diaphragm regulator of differential pressure or flow of liquids and gases, with a control valve and throttle, which is simple and compact and allows different combinations of functions at low cost. Such a combination is particularly suitable for district heating and air-conditioning distribution networks and in district heating stations. The diaphragm regulator regulates the flow or differential pressure. With the control valve, however, the temperature or other parameters, or only serves to manually close it. The throttle is used to adjust the flow regulator or as a manual throttle only.

This invention solves four technical problems.

Problem 1. The utmost universality of the controller is required. It should be possible to perform as many different functions and combinations of functions with the same elements. It should be possible to use temperature and other drives from different manufacturers. Typically, valves for different functions differ significantly in component parts and have a drive connector tailored to a single product.

Problem 2.

A compact, small size design with the highest accuracy and low cost is required. But a normal membrane regulator works more accurately if it has a large membrane, which means more price and size.

Problem 3.

The flow adjustment should be simple, durable, transparent and separate and independent of other functions.

Problem 4.

The design must be such that no additional protection of the choke is required with a built-in safety valve.

The known solutions to these problems are as follows.

Problem 1.

a) Combination for flow and temperature control.

The diaphragm flow controller has a throttle when made so that it is moved by the actuator for temperature control. Manually adjusting and limiting the maximum throttle stroke, thereby setting the maximum flow. The disadvantage of this design is that the flow adjustment is opaque and the design is complicated. Parts that restrict flow move and are exposed to wear and tear. Over time, wear and tear may cause an accidental change in flow setting. In addition, it is mandatory to protect the throttle against excessive force due to the large pressure difference. Because in the case of leaks in the valve seat and simultaneous tightness of the throttle, the throttle may be loaded with maximum differential pressure in the system. The force required in this case to open the throttle may be greater than the force exerted by the actuator. The throttle would thus remain permanently closed. The consumer would be left without flow. The pressure relief of the throttle is usually carried out with a small safety valve fitted to the damper. However, if the capacity of the small safety valve is less than the leakage of the ventilation seat, the situation does not work again reliably. In addition, the small safety valve may become clogged or permanently leaky. The temperature actuator connector is usually adapted to only one specific actuator from the same manufacturer.

b) Combination for flow and temperature control. The throttle is free and the additional actuator acts directly on the valve plate. The disadvantage is that the actuator must overcome the force of the spring to regulate the flow. Stronger drive required than solution a) But no additional safety load on the choke is required.

c) Combination of flow control and manual closing or differential pressure and manual closing. In the known embodiments, manual closure is typically performed with a spindle that presses onto the diaphragm plate and closes the valve through it. The disadvantage is that the flow regulator requires many significantly different internal parts and housing than the differential pressure regulator.

Problem 2.

In the known embodiments of the combinations, a straight or oblique shut-off valve on which the diaphragm actuator is mounted is always used. The bright diameter of the vent seat must be relatively large in order for the resistances to be reasonably small. The diaphragm must be large enough to overcome the friction on the unloaded piston of the vent plate and thus provide sufficient accuracy. This means large dimensions and a higher price.

Problem 3.

The disadvantages of the known designs of flow-control chokes for combined controllers are already described in problem 1. under a).

Problem 4.

The disadvantages of the known embodiments of combined controllers, which require the installation of an additional safety valve in the throttle, are already described in problem 1. under a).

Solution to the problem 1.

The universality problem is solved by installing the following stand-alone elements in series in the same housing: throttle, control valve and complete diaphragm regulator. The throttle can be used to manually suppress the flow or to set the maximum flow rate on the diaphragm regulator. The control valve is easy to close manually or with the aid of a suitable actuator, to regulate the temperature or other parameters. The actuator connection is of such a shape and dimension that almost all actuators for thermostatic valves from different manufacturers can be connected to it. The diaphragm flow regulator differs from the differential pressure regulator only by the force of the spring and by the fact that it has a V + pulse inside the housing, in the form of a bore. The differential pressure regulator, however, has a dP + impulse performed externally.

Solution to the problem 2.

The problem of compactness is solved by the fact that three otherwise independent valves are mounted in a common housing and the diaphragm regulator is made in the axial form known from Slovenian patent 9500294. Due to the small deviation of the direction of flow, the pressure drop in the seat of the axial regulator is relatively small. Therefore, the bright diameter of the valve seat and, consequently, the diaphragm and housing may be small. With low pressure consumption, high accuracy and low cost are possible.

Solution to the problem 3.

The problem of simplicity of the damper is solved so that the damper is made in the form of a completely independent spindle, which is permanently stationary after the adjustment is completed. The position of the adjustment is clearly visible and precisely determined by the scale at the front of the damper. The setting is secured with a lock nut.

Solution to the problem 4.

The problem of protecting the throttle against too much pressure difference in case of leakage at the seat of the control valve is solved so that the damper is independent and fixed. However, depending on the direction of flow of the medium, the control valve is mounted so that the pressure difference on the control valve plate acts in the direction of opening it. Thus, in the event of a leak in the seat of the controller, the control valve only leaks properly if the actuator force is no longer sufficient to close it tightly. However, there can be no closure and permanent interruption of flow.

DESCRIPTION OF THE CONSTRUCTION SOLUTION

1 is a combination of the invention with a flow controller

2 is a combination of the invention with a differential pressure controller

Figure 1

In the common housing (1), in view of the flow direction, a damper (7) is mounted first, then a control valve (19) and finally a diaphragm regulator (22) of the axial design. The inlet is indicated by (2), the middle outlet by (18), and the outlet by (8). The throttle valve seat is indicated by (3) and the control valve valve seat by (21). The throttle valve plate is (4) and the control valve valve plate is (20). The impulse bore (V +) leads from the inlet (2) to the chamber (14) in front of the diaphragm (13). The impulse bore (17) conducts pressure (V-) from the middle opening (18) through the tubular portion (15) of the diaphragm plate (16) into the diaphragm space. The spring (12) presses against the diaphragm and moves the valve seat (10) away from the fixed valve plate (9). The valve seat (10) is sealed with a gasket (11). The throttle is secured against unscrewing with a guard (5) and a nut (6).

The flow medium enters from the pipeline into the inlet port (2), then passes through the opening between the vent plate (4) and the vent seat (3), and further through the opening between the valve plate (20) and the valve seat (21) of the control valve (19). ). Then, through the middle opening (18) and the opening between the valve plate (9) and the valve seat (10), the flow regulator flows into and out of the discharge port (8). The pressure of the medium from the inlet, acting through the impulse hole (V +) and the chamber (14) to the membrane (13), against the force of the spring (12) and the pressure from the middle opening (18) acting on the membrane through the impulse hole (17), (V-). The flow at which the flow regulator (22) starts to close (maximum flow) is adjusted by closing the throttle (7) with the control valve (19) fully open. if the control valve then closes, the pressure in the middle orifice drops and the flow regulator (22) is closed accordingly. The control valve and the flow controller always operate simultaneously in the same sense. The control valve always works against the very small pressure difference on the valve plate. As much as necessary to overcome the force of the spring with the diaphragm. That's about 10 to 20 kPa. All residual pressure drop is dried in the flow regulator. The maximum possible flow is determined by the position of the damper and the spring force (12). The current flow rate, however, depends on the opening rate of the control valve (19). The control valve closes and can open any actuator depending on any parameter (temperature, pressure, etc.).

Figure 2

The differential pressure control combination differs from the flow control combination only in that it does not have an internal impulse (V +) but an external impulse (dP +) through which pressure is exerted before the consumer on the membrane (13). The pressure behind the consumer and at the same time for the throttle and control valve acts from the middle opening (18) through the impulse hole (17) as (dP—) to the back of the diaphragm. The maximum flow rate is determined by the position of the throttle. The maximum possible differential pressure (difference between dP + and dP-) is determined by the force of the spring (12). Current flow, however, depends on the opening rate of the control valve (19).

Claims (5)

PATENT APPLICATIONS 1. The combination of an axial diaphragm flow regulator with a throttle and a control valve in which the pressure drop in the throttle and the control valve acts on a spring-loaded diaphragm and moves the valve seat which, together with the valve plate, regulates the flow, characterized by three complete, separate and self-acting valves which are housed in a compact common housing (1) wherein the first valve in the direction of the medium flow is in the form of a manually adjustable throttle (7) and the second valve in the direction of flow is in the form of a control valve (19) which is suitable for connecting different control actuators or for manually closing the flow, and the third valve in the direction of the flow of the medium is in the form of an axial diaphragm flow regulator (22) whereby the pressure difference on the diaphragm (13) required for the operation of the diaphragm regulator (22) is generated in the throttle ( 7) and the control valve (19). Combination according to claim 1, characterized in that the control valve (19) is mounted with respect to the direction of flow of the medium so that the force due to the pressure difference on the plate (20) of the control valve (19) acts in the direction of its opening. Combination according to claim 1, characterized in that the pressure from the inlet opening (2) in front of the choke (7) is guided through the internal impulse hole (V +) to the front of the diaphragm (13) and the pressure (V-) from the middle opening ( 18) for the throttle (7) and the control valve (19) through a pulse hole (17) in the diaphragm plate (16) to the rear of the diaphragm (13) with the flexible tubular valve seat (10) attached to the diaphragm plate (16) and sealed with gasket (11) and the valve plate (9) is fixed in the housing (1). Combination according to claim 1, characterized in that it does not have an internal impulse bore (V +) and pressure in front of the consumer through the external impulse pipe (dP +) through the outer impulse conduit (dP +) and an axial diaphragm control valve (22), depending on sums of pressure drops in the consumer and the throttle (7) and the control valve (19). Combination according to claim 4, characterized in that it does not have an inductor (7).