JP2884285B2 - Automatic control valve for steam temperature - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve for controlling the temperature of steam for heating an object to be heated, and more particularly, to a valve capable of setting an upper limit of the temperature of heated steam using a pressure reducing valve. Related. When heating an object to be heated with steam, especially when the object to be heated is a food, a chemical product, a medical product, etc., a slight change in the steam temperature can cause the object to be heated to deteriorate or cause thermal damage. In addition, the steam temperature must be maintained with high accuracy, and these heated objects often undergo rapid deterioration or thermal damage when the heating temperature exceeds a certain limit value.

[0002]

2. Description of the Related Art Conventionally, when heating such a product as described above, a combination of a so-called automatic control valve, a temperature sensor and a temperature controller has been used. By sensing the heated temperature of the object to be heated by the temperature sensor and adjusting the automatic control valve via the temperature controller, the amount of the steam to be supplied to the object to be heated is controlled and the object to be heated is controlled. By heating at a predetermined temperature and setting and inputting a heating limit temperature, for example, a heating upper limit temperature, to a temperature controller, the object to be heated is heated so that the temperature of the heated object does not exceed the upper limit temperature. It heats things.

[0003]

In the above-mentioned conventional apparatus, there is a problem that when the amount of the object to be heated changes, the temperature of the object to be heated fluctuates or exceeds the limit temperature. This is because even if the amount of supplied steam is constant, the amount of heat supplied from the steam to the object to be heated changes due to the change in the amount of the object to be heated, and the temperature of the object to be heated fluctuates. It is because. For example, when a certain amount of steam is supplied from the automatic control valve to the object to be heated, if the amount of the object to be heated decreases, the amount of heat supplied per unit amount of the object to be heated increases, and Is higher than a predetermined value.

[0004] Therefore, the technical problem of the present invention is that even if the amount of the object to be heated fluctuates, the heating temperature of the object to be heated does not fluctuate, and the heating temperature does not exceed the heating limit temperature. An object of the present invention is to provide an automatic steam temperature control valve capable of reliably preventing deterioration and thermal damage of an object to be heated.

[0005]

Means for Solving the Problems The technical means of the present invention taken to solve the above technical problem is to receive a secondary fluid pressure on one surface of a pressure responsive member and apply an elastic member of an elastic member to the other surface. under the force, the displacement of the pressure responding member consists pressure reducing valve for opening and closing the main valve to flow down the steam, saturated steam into the pressure reducing valve
A set temperature adjusting means for adjusting the elastic force of the elastic member based on the relationship between the pressure and the temperature of the elastic member; a storage unit for storing a relationship between the elastic force of the elastic member and the set temperature; and a set temperature input means for inputting the set temperature. Te, in which is provided a drive control unit for driving desired amount setting temperature adjusting means from the relationship between the input value and the storage unit from the set temperature inputting means, a limit elastic force of the elastic member is set input to the drive control unit Steam pressure and steam
A temperature limit value input means capable of setting a limit value such as an upper limit or a lower limit of the steam temperature from the relationship of the steam temperature is provided.

[0006]

The operation of the above technical means is as follows.
Steam (more precisely, saturated steam) has a one-to-one relationship between pressure and temperature, and when the steam pressure is determined, the steam temperature is automatically determined. Therefore, when the set temperature of the pressure reducing valve is input by the set temperature input means, the elastic force is calculated to be the set temperature from the set temperature in the storage unit, that is, the relationship between the pressure and the elastic force of the elastic member, and the elastic force is generated. Thus, the set temperature adjusting means is driven, the pressure reducing valve is set, and the steam pressure, that is, the temperature on the secondary side is maintained at the set temperature.

By maintaining the steam pressure on the secondary side, that is, the temperature, at the set temperature by the pressure reducing valve, the steam is supplied in accordance with the consumption of the steam on the secondary side, and the amount of the object to be heated fluctuates. Even so, the amount of supplied steam also fluctuates, so that the heating temperature of the object to be heated does not fluctuate.

In the drive control section, a temperature limit value input means capable of setting and inputting a limit elastic force of the elastic member of the pressure reducing valve to set a limit value of the steam temperature is provided. A limit value such as a value or a lower limit value can be set. In this case, since the temperature limit value is set via the elastic force of the elastic member, the temperature limit value is not exceeded even when the amount of the object to be heated changes.

[0009]

An embodiment showing a specific example of the above technical means will be described (see FIG. 1). A pressure reducing valve 1, a steam supply pipe 2 for supplying steam to the pressure reducing valve 1, a pressure reducing steam pipe 3 for supplying reduced pressure steam to a device using steam (not shown), a drive control unit 7 and a temperature limit value input unit 6. Constitutes an automatic control valve for the steam temperature.

The pressure reducing valve 1 has a main valve 8 for blocking the passage of steam.
A piston 9 cooperating with the main valve 8, a pilot valve portion 11 for supplying and shutting off high-pressure steam on the primary side to the upper chamber 10 of the piston 9, and a diaphragm 12 as a pressure responsive member for driving the pilot valve portion 11. , A secondary pressure introducing passage 14 for introducing a secondary fluid pressure into the lower chamber 13 of the diaphragm 12
A coil spring 15 acting as an elastic member acting on the upper surface of the diaphragm 12, an adjusting screw 16 acting as a set temperature adjusting means for adjusting the elastic force of the coil spring 15, and a motor 17 acting as a drive unit for driving the adjusting screw 16. And reduction gear 1
8 and a set temperature input means (not shown) for setting the secondary temperature of the pressure reducing valve to a desired temperature, and a storage unit (not shown) for storing the relationship between the set temperature and the elastic force of the coil spring 15. ) Are built in the drive control unit 7. Although not shown, the set temperature input means and the temperature limit value input means 6 may be any as long as they can input arbitrary values using a numeric keypad or the like.

In this embodiment, the coil spring 15 as the elastic member has been described as an example in which the elastic force acts downward of the diaphragm 12. However, when the steam below the atmospheric pressure is reduced, the elastic force is in the opposite direction. That is, a coil spring acting in the upward direction can be used.

The pressure reducing valve 1 has a separator 20 for separating condensed water contained as condensed water contained in the high-pressure steam supplied from the steam supply pipe 2, and a condensate separated by condensing water. A steam trap 23 comprising a float 22 for opening and closing the valve port 21 is integrally attached.

Next, the operation will be described. When the set pressure, that is, the temperature of the pressure reducing valve, is input by the set temperature input means in the drive control unit 7, the elastic force of the coil spring 15 with respect to the set temperature is calculated by the storage unit in the drive control unit 7, and this elastic force is generated. Only the motor 17 is rotated and the coil spring 15 is compressed. Accordingly, the steam supplied from the steam supply pipe 2 is throttled by the main valve 8 and flows down to the secondary-side reduced-pressure steam pipe 3 as steam reduced in pressure to the set pressure, that is, the temperature. In this case, when the amount of the object to be heated (not shown) increases, the amount of steam condensed by applying heat to the object to be heated also increases, so that the steam in the reduced-pressure steam pipe 3 decreases and the pressure decreases. The pilot valve 11 is opened by being depressed by the elastic force of the coil spring 15, and the high pressure steam on the primary side is supplied to the upper piston chamber 10 so that the piston 9 is displaced downward. Steam is further supplied to the steam pipe 3. Therefore, the temperature of the object to be heated does not change because the amount of the heating steam also changes in accordance with the change in the amount of the object to be heated.

Further, by providing the temperature limit value input means 6, it is possible to set the limit value of the heating temperature of the object to be heated, and to reliably prevent the object to be heated from being altered or thermally damaged due to abnormal temperature rise or fall. Can be prevented. In this case, even if the amount of the object to be heated changes, the amount of the supplied steam also changes, so that the object to be heated does not exceed the temperature limit value.

[0015]

According to the present invention, even if the amount of the object to be heated fluctuates, the amount of steam supplied from the pressure reducing valve also fluctuates. Since the limit value can be set, the object to be heated is not heated beyond the heating limit temperature, and the object to be heated can be surely prevented from being deteriorated or damaged.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional configuration diagram of an embodiment of an automatic steam temperature control valve of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure reducing valve 2 Steam supply pipe 3 Pressure reducing steam pipe 6 Temperature limit value input means 7 Drive control unit 8 Main valve 12 Diaphragm 15 Coil spring 16 Adjustment screw 17 Motor

Claims (1)

(57) [Claims] 1. A pressure reducing valve that receives a secondary fluid pressure on one surface of a pressure responsive member and receives an elastic force of an elastic member on another surface, and opens and closes a main valve through which steam flows down by displacement of the pressure responsive member. A setting temperature adjusting means for adjusting the elastic force of the elastic member based on the relationship between the pressure and the temperature of the saturated steam is attached to the pressure reducing valve, and a memory for storing the relationship between the elastic force of the elastic member and the set temperature. Unit and a set temperature input means for inputting a set temperature,
A drive control unit is provided for driving the set temperature adjusting unit by a desired amount based on the relationship between the input value from the set temperature input unit and the storage unit.
In this case, the limit elastic force of the elastic member is set and input to the drive control unit, and a temperature limit value input capable of setting a limit value such as an upper limit or a lower limit of the steam temperature from the relationship between the steam pressure and the steam temperature. An automatic control valve for steam temperature, characterized in that a means is provided.