SU198716A1 - AIR FLOW REGULATOR - Google Patents

Description

The invention relates to air flow regulators for use in the systems of non-pneumatic conveying of powdered materials in various sectors of the national economy, especially in the cement and chemical industries.

Regulating devices are known for continuous or position regulation of liquid and gaseous media in conjunction with actuators, by means of which a direct influence on the flow of the controlled medium is carried out in accordance with the command given to the valve actuator. Such devices include control valves, naimimer, with pneumatic diaphragm actuators, manufactured with normally closed or normally open valves. Iodobny devices include a housing, a control valve, a shield, a spring, and an actuator membrane. They cannot be used as air flow regulators for pneumatic conveying and aeration systems, since they do not react simultaneously to pressure fluctuations in the network and changes in operating modes of pneumatic conveying systems. By their principle of operation and design, they can be either completely open or completely closed, which is unacceptable for the operation of pneumatic conveying systems.

In the proposed controller, in order to increase the accuracy of controlling the amount of air supplied to the monitored object in accordance with its mode of operation, the piston valve is provided with openings, some of which are designed for minimum flow, are made at the end of the valve and are constantly open, while others are working and performed on the side of his surface.

FIG. 1 depicts the described air flow regulator (longitudinal section); pas figs. 2 - diagram of the installation of the regulator on the pneumatic screw pump.

The air flow regulator consists of a body / controller, a spring body 2 regulating the ..: 1; hat 3, zeitrizing ring 4, rod 5 of the clan, spring 6, support ring 7, adjusting nuts 8, indicator 9 of the stem and viewing trenches 10. Valve 3 is a cylindrical tumbler turned upside down, made of stainless material (steel, bronze, brass).

The control valve has a number of holes 11, which are openly open to allow air to flow from the network to the consumer. The area of their cross section is chosen on the basis of ensuring the minimum allowable raskhopri in the latter idle or at low loads. On the cylindrical part of the valve 3 there are holes 12, the magnitude of the opening of which depends on the operating mode of the pneumatic conveying devices and the air pressure in the network, i.e., on the pressure differential acting directly on the valve. The cross section and the opening value of the openings 12 are selected on the basis of the passage of air to the consumer in required quantities depending on the increase in the load of the pneumatic conveying systems. The spring 6 is designed to lift the valve 3, its maximum compressive force is calculated on the maximum pressure drop across the valve, depending mainly on the maximum air pressure in the network. The nuts 8 serve to regulate the initial compression of the spring, the force of which in this case should be equal to the force acting on the valve 3 with a minimum pressure drop (on the order of 0.1 atm). The holes 13 are intended to communicate the cavity in which the spring 6 and the end of the rod 5 are located, with the valve space above. With their help, the pressure in these cavities is equalized, thus compensating for the error due to the influence of the cross-sectional area of the rod 5 on the force acting from above the valve 3. The air flow regulator operates as follows. The powdery material from the hopper 14 with the pinch 15 enters the pump chamber 16, and from there, moving with air passed through the nozzles 17, is transported under pressure P "but the pipeline 18 to the silo 19. The air flow regulator is installed in the immediate vicinity of the pump manual valve 20 on the supply air duct 21. When installing the regulator, the nozzles 17 are not restrictive; their flow area is chosen as large as possible in order to minimize the pressure loss in them. If the pneumatic-pneumatic unit is idling, for example, when starting or before stopping it, as well as with a small load not exceeding - - 0.4, the openings 12 in valve 3 are completely closed, since in this case the maximum pressure drop A acts on the valve max -P1- „„ p and the spring 6 is compressed to the maximum. In this case, only the openings 11 remain open, through which the minimum amount of air required for normal operation passes to the consumer. If the pneumatic conveying installation starts to work with greater performance, the resistance of the transport line increases, consequently, the air pressure PZ behind the regulator, and if the air pressure P in the network remains unchanged, the pressure drop across valve 3 decreases. Spring 6, the impact ring 7 and a rod 5, lifts the valve. As a consequence, part of the openings 12 are concealed to allow additional airflow to the consumer. The valve 3 raises until the force acting down on the valve as a result of the steady-state pressure drop compares with the force of the spring 6. If the pneumatic transport unit starts operating at lower rates for any reason, the resistance of the transport line decreases, reducing and the pressure P .2 air behind the valve. In this case, the pressure drop over the valve increases, and the valve is lowered, thus reducing the flow area of the openings 12, and hence the amount of air entering the consumer. Thus, the regulator continuously and automatically responds to changes in the resistance of the transport system, i.e., the capacity of the installation, the passage to it of a certain amount of air, depending on the magnitude of the performance. The extreme upper position of the valve 3, when the holes 11 and 12 are fully open, corresponds to the moment at which the pneumatic conveying system operates at maximum intensity. Similarly, the regulator also works when the air pressure in the network changes, i.e., in front of the valve that is affected by pressure P. If the pressure drops and the resistance of the transport system remains unchanged, the pressure drop on valve 3 decreases. 6 is raised upward, the flow area of the openings 12 is increased, but the air flow remains constant, as the pressure PI decreases. In this case, if the air pressure in the network and the resistance of the transport network are simultaneously changing, the regulator reacts to these changes simultaneously. The subject matter of the invention is the air flow regulator, comprising a housing, a sensing element in the form of a norsh valve with a spring-loaded stem, adjustment elements installed in the housing, and an inlet and outlet pipes, characterized in that with its mode of operation, the piston valve is provided with openings, some of which are designed for minimum flow, are made at the end of the valve and are constantly open, while others are working they are made on the side of its surface.