CN-121992678-A - Circular screen pressure shaper with automatic throat opening adjustment function and automatic throat opening adjustment method

CN121992678ACN 121992678 ACN121992678 ACN 121992678ACN-121992678-A

Abstract

The application relates to a cylinder pressure shaper with automatic throat opening adjustment and a throat opening automatic adjustment method. The former comprises a lower lip plate, an upper lip plate capable of swinging, a balance mechanism and an automatic adjusting system. The automatic regulating system acquires technological parameters such as the inlet flow of the pulp distributor, the running speed of the cylinder mould and the like through a parameter acquisition module, and acquires the target throat opening through feedforward calculation of a control module, and simultaneously acquires the actual throat opening through a displacement detection device. The control module compares the difference value of the two to output a control instruction, and controls the actuating mechanism to adjust the stress state or position of the balance mechanism, so as to drive the upper lip plate to swing. The application combines feedforward calculation and closed-loop control, overcomes the hysteresis of traditional passive compensation, realizes active and accurate adjustment of the opening of the throat to ensure constant pulp discharge, and simultaneously realizes decoupling of opening positioning and pressure pulse buffering by utilizing a rigid-flexible combined structure, thereby effectively reducing mechanical abrasion.

Inventors

WEN HAIPING
CHENG HONGYU
ZHOU LINQUAN
ZHU ZHE

Assignees

轻工业杭州机电设计研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20260409

Claims (10)

1. The utility model provides a laryngeal opening automatically regulated's cylinder mould pressure former, includes cloth thick liquid ware, forming unit and cylinder mould, forming unit includes lower lip and articulated the last lip that sets up of wobbling, go up the lip with lower lip reaches form the laryngeal between the cylinder mould, it is connected with balance mechanism to go up the lip, its characterized in that still includes: The parameter acquisition module is used for acquiring forming process parameters, wherein the forming process parameters at least comprise inlet flow of the pulp distributor and running speed of the cylinder mould; The displacement detection device is arranged on the forming unit and is used for detecting a position signal of the upper lip plate to obtain the current actual laryngeal opening; The control module is respectively connected with the parameter acquisition module and the displacement detection device in a communication way, and is used for calculating a target throat opening according to the forming technological parameters and outputting a control instruction according to a difference value between the target throat opening and the actual throat opening; And the executing mechanism is in communication connection with the control module, is in transmission connection with the balancing mechanism or is in gas circuit connection, and is used for adjusting the stress state or position of the balancing mechanism according to the control instruction so as to drive the upper lip plate to swing and adjust the opening of the throat.
2. The automatic laryngeal opening adjusting cylinder pressure shaper of claim 1, wherein an opening calculation model is preset in the control module, and a calculation formula of the target laryngeal opening h is as follows: ; Wherein, Q is the inlet flow of the pulp distributor, Q 1 is the return flow of the pulp distributor, Q 2 is the lip slurry amount of the shaper, v Net is the cylinder mould running speed, r is the set pulp screen speed ratio, and B is the shaping width of the shaper.
3. The automatic laryngeal opening adjusting cylinder pressure shaper of claim 1, wherein the balancing mechanism comprises a first air bag and a second air bag which are respectively arranged on two sides of the upper lip plate, the executing mechanism comprises a first air bag and a second air bag, the first air bag and the second air bag are respectively communicated with the first air bag and the second air bag, an electric proportional valve and a pressure sensor are respectively arranged on the first air bag and the second air bag, and the electric proportional valve and the pressure sensor are respectively electrically connected with the control module.
4. The rotary screen pressure shaper for automatically adjusting the opening of a throat opening according to claim 1, wherein the balancing mechanism comprises a containing cavity, a first air bag and a second air bag which are arranged in the containing cavity side by side, the actuating mechanism comprises a sliding partition plate arranged between the first air bag and the second air bag and a sliding block fixedly connected with the sliding partition plate, the sliding block is arranged on a guide rail in a sliding mode, the sliding direction of the sliding block is parallel to the tangential direction of swing of the upper lip plate, and the actuating mechanism further comprises a driving device electrically connected with the control module, and the driving device is in transmission connection with the sliding block.
5. The automatic throat opening adjusting cylinder pressure former according to claim 4, wherein the driving device is a servo motor or a stepping motor, and is in transmission connection with the sliding block through a worm gear screw lifter or a gear rack mechanism.
6. The automatic laryngeal opening adjusting cylinder pressure shaper of claim 1, 3 or 4, wherein the displacement detection device is a displacement sensor, and the displacement sensor is mounted on the upper lip plate or is parallel to the linear motion direction of the actuator.
7. A method for automatically adjusting the throat opening of a cylinder mould pressure former according to any one of claims 1 to 6, comprising the steps of: S1, obtaining forming technological parameters, wherein the forming technological parameters at least comprise inlet flow of a pulp distributor and running speed of a cylinder mould; s2, the control module calculates the opening of the target throat according to the forming process parameters; s3, acquiring the current actual laryngeal opening through a displacement detection device; s4, the control module compares the target laryngeal opening with the actual laryngeal opening to generate a control instruction; And S5, the executing mechanism acts according to the control instruction, adjusts the balance mechanism and drives the upper lip plate to swing until the actual laryngeal opening reaches the target laryngeal opening.
8. The automatic laryngeal opening adjustment method according to claim 1, wherein in step S2, the calculation formula of the target laryngeal opening h is: ; Wherein, Q is the inlet flow of the pulp distributor, Q 1 is the return flow of the pulp distributor, Q 2 is the lip slurry amount of the shaper, v Net is the cylinder mould running speed, r is the set pulp screen speed ratio, and B is the shaping width of the shaper.
9. The automatic laryngeal opening adjustment method according to claim 7, wherein when the balance mechanism comprises a first air bag and a second air bag, and the execution mechanism comprises electric proportional valves for respectively controlling the first air bag and the second air bag, the steps S4 and S5 specifically comprise that when the actual laryngeal opening is judged to be smaller than the target laryngeal opening, the control module outputs a decompression instruction to the electric proportional valve corresponding to the air bag close to the laryngeal opening, and decompresses the air bags until the actual laryngeal opening reaches the target laryngeal opening.
10. The automatic throat opening adjusting method according to claim 7, wherein when the balancing mechanism comprises a first air bag and a second air bag, the executing mechanism comprises a sliding partition plate arranged between the two air bags and a driving motor, and step S5 specifically comprises the step that the driving motor acts according to a control instruction to drive the sliding partition plate to slide along the tangential direction of the swing of the upper lip plate, and the pressure difference is generated by extruding the first air bag or the second air bag to drive the upper lip plate to swing.

Description

Circular screen pressure shaper with automatic throat opening adjustment function and automatic throat opening adjustment method Technical Field The application relates to the technical field of papermaking equipment, in particular to a cylinder mould pressure former with an automatically-adjusted throat opening and an automatically-adjusted throat opening method. Background Cylinder mould forming is one of the forming modes commonly used in paper making and fibrous web production machines. The cylinder mould pressure former is dehydrated and formed on the surface of the cylinder mould by the self static pressure of fiber suspension, and is widely applied due to high applicable working speed and large production scale. In actual production, there is inevitably pressure fluctuation in the flow system of the former feed (e.g. pressure screen drum, sizing pump impeller, etc.), causing longitudinal quantitative fluctuation of the product. To solve this problem, the conventional cylinder mould press usually has a balancing mechanism formed by springs between the upper lip and the frame. However, the above prior art still has the following significant drawbacks in practical high precision production: first, the existing balancing mechanism is essentially a passive mechanical adaptive compensation. When the slurry pressure fluctuates, the air bag or the spring only depends on the physical elasticity of the air bag or the spring to passively deform so as to absorb the pulse. The passive regulation has obvious time hysteresis, and cannot respond accurately in advance or in real time at the moment when the front-end process parameters (such as flow and vehicle speed) change, so that the slurry output still has small fluctuation. Secondly, the throat opening degree of the existing shaper is set by relying on manual experience or is adjusted by stopping a machine manually, active feedforward calculation and dynamic closed-loop control mechanisms based on core technological parameters such as inlet flow rate, reflux amount and running speed of a cylinder mould of the pulp distributor are lacked, and absolute constancy of the preset opening degree is difficult to maintain. In addition, if the rigid transmission mechanism (such as a motor directly drives the screw rod to push and pull the upper lip plate) is directly adopted to improve the opening control precision, the high-frequency pressure pulse of the sizing agent directly reversely impacts the precise transmission part, so that the cushioning effect cannot be achieved, and the serious abrasion and even damage of the mechanical structure are easily caused. Disclosure of Invention In order to solve the problems, the application provides a rotary screen pressure former capable of effectively improving the quantitative uniformity of products and automatically adjusting the throat opening and a throat opening automatic adjusting method. In order to achieve the above object, in a first aspect, an embodiment of the present application provides a cylinder mould pressure former with automatically adjustable throat opening, including a pulp distributor, a forming unit and a cylinder mould, where the forming unit includes a lower lip plate and a swingable upper lip plate hinged to the lower lip plate, a throat is formed between the upper lip plate and the lower lip plate and between the upper lip plate and the cylinder mould, and the upper lip plate is connected with a balancing mechanism, and further includes: The parameter acquisition module is used for acquiring forming process parameters, wherein the forming process parameters at least comprise inlet flow of the pulp distributor and running speed of the cylinder mould; The displacement detection device is arranged on the forming unit and is used for detecting a position signal of the upper lip plate to obtain the current actual laryngeal opening; The control module is respectively connected with the parameter acquisition module and the displacement detection device in a communication way, and is used for calculating a target throat opening according to the forming technological parameters and outputting a control instruction according to a difference value between the target throat opening and the actual throat opening; And the executing mechanism is in communication connection with the control module, is in transmission connection with the balancing mechanism or is in gas circuit connection, and is used for adjusting the stress state or position of the balancing mechanism according to the control instruction so as to drive the upper lip plate to swing and adjust the opening of the throat. Preferably, an opening calculation model is preset in the control module, and a calculation formula of the target laryngeal opening h is as follows: ; Wherein, Q is the inlet flow of the pulp distributor, Q 1 is the return flow of the pulp distributor, Q 2 is the lip slurry amount of the shaper, v Net is the cylinder mould running spee