WOODWARD 9904-820

الوصف

The WOODWARD 9904-820 is a mechanical-hydraulic speed droop governor specifically designed for steam turbines. It belongs to the TG-13 Screw (TG13S) series and is configured for high-speed applications, typically up to 4000 rpm. A key characteristic of this model is its stainless steel construction for enhanced corrosion resistance, and its speed setting is adjusted via a screw mechanism.

WOODWARD 9904-820: Stainless Steel Mechanical-Hydraulic Speed Droop Governor (TG-13S, 4000 rpm, Screw, Counterclockwise)

The WOODWARD 9904-820 is a robust, self-contained control device crucial for the reliable operation of small to medium-sized steam turbines. It’s particularly suited for applications where stable speed control with a defined droop characteristic is sufficient, rather than precise constant-speed (isochronous) operation. Its “Screw” designation indicates a specific mechanical interface for speed setting, and “SS” (Stainless Steel) signifies enhanced durability in challenging environments.

Product Overview

The 9904-820 operates as a mechanical-hydraulic governor. It continuously senses the turbine rotor speed and compares it to an internal setpoint. Based on this comparison, it precisely adjusts the turbine’s governor valve to regulate the inlet steam flow, thereby controlling the turbine’s speed.

• Product Type: Mechanical-Hydraulic Speed Droop Governor
• Manufacturer: Woodward
• Series: TG-13S (Screw-operated, Stainless Steel)
• Application: Small to medium steam turbines (e.g., driving pumps, compressors, generators).
• Key Feature: Speed droop control (not isochronous).
• Rated Speed: Designed for operation up to 4000 rpm.
• Speed Setting Mechanism: Screw-operated (for fine, manual adjustment).
• Drive Shaft Rotation: Counterclockwise (CCW) rotation.
• Output: 16 N·m (12 ft-lb) rotary output.
• Material: Stainless Steel construction for improved corrosion resistance.
• Environmental Certification: ATEX certified (suitable for potentially explosive atmospheres).
• Rated Speed @ 2° Droop: 3910 rpm (a specific configuration point for droop).

Detailed Product Description

The WOODWARD 9904-820 provides a reliable and cost-effective solution for steam turbine speed control, especially in environments where corrosion resistance is beneficial. It’s part of the well-established TG-13 governor series, offering specific configurations for different speed ranges and mechanical interfaces.

Here’s a breakdown of its features and how it functions:

• Mechanical-Hydraulic Operation: This governor is a self-contained unit. It senses turbine speed using an integrated driveshaft-driven ball head assembly. An internal, driveshaft-driven oil pump generates the necessary hydraulic pressure to create the force required to move and control the turbine’s governor valve. This mechanical-hydraulic design makes it inherently robust and minimizes reliance on external electronic components for its core speed sensing and actuation.
• Speed Droop Control: The 9904-820 operates on a speed droop principle. This means that as the load on the turbine increases, its speed will slightly decrease (or “droop”) proportionally. This characteristic is often desirable in applications where load sharing among multiple prime movers is needed, or where a slight, predictable speed variation under load changes is acceptable.
• Direct Turbine Connection: The governor directly couples to the steam turbine’s rotor or an auxiliary shaft to sense the turbine’s speed. Its rotary output terminal shaft directly connects to the turbine’s governor valve, precisely controlling the inlet steam flow.
• Higher Speed Capability (4000 rpm): A significant feature of the 9904-820 is its suitability for turbines operating at higher rotational speeds, up to 4000 rpm. This extends its applicability to a broader range of industrial steam turbine installations.
• Screw-Operated Speed Setting: The “S” in TG-13S and the part number imply that the speed setpoint is adjusted via a screw mechanism. This allows for precise and stable adjustment of the desired turbine speed, often preferred for applications requiring infrequent or fine tuning.
• Counterclockwise (CCW) Rotation: The 9904-820 specifically features a counterclockwise drive shaft rotation and output shaft rotation. This is a critical mechanical specification for ensuring compatibility with the turbine’s interface.
• Stainless Steel Construction: The “SS” in its common description indicates that key components are made from stainless steel. This significantly enhances the governor’s resistance to corrosion, making it ideal for harsh, humid, or chemically aggressive industrial environments.
• Rugged Construction and ATEX Certification: Built for demanding industrial environments, these governors feature robust construction and a self-contained sump. The ATEX certification confirms its suitability for use in potentially explosive atmospheres common in industries like oil & gas, petrochemical, and power generation.
• Output Work Capacity: The governor’s output terminal shaft delivers a significant 16 N·m (12 ft-lb) of rotary work capacity, which is sufficient to operate various turbine governor valves.

In essence, the 9904-820 provides a reliable, robust, and corrosion-resistant solution for steam turbine speed control, especially for higher speed applications where a mechanical-hydraulic, screw-operated governor with counterclockwise rotation is required.

Technical Specifications (General)

Typical Applications

The WOODWARD 9904-820 is primarily used in industrial settings that employ small to medium steam turbines for mechanical drive or power generation, especially where:

• Higher Speeds are Present: Turbines operating at or around 4000 rpm.
• Corrosive Environments: Where the benefits of stainless steel construction are critical for longevity and reliability (e.g., chemical plants, offshore platforms, or humid industrial settings).
• Speed Droop Control is Desired: For load sharing or applications tolerant of slight speed variation with load changes.
• Mechanical-Hydraulic Simplicity: Preference for a self-contained, robust mechanical governor over electronic systems.
• Screw-Based Speed Adjustment: For precise, stable, and less frequent adjustments to the speed setpoint.
• Counterclockwise Rotation: Where the turbine’s mechanical drive interface requires CCW rotation for the governor.
• Applications include:
  • Pumps: Controlling steam turbines that drive process pumps.
  • Compressors/Turboexpanders: Regulating the speed of steam turbines used to drive compressors.
  • Generators: Controlling the speed of steam turbines connected to generators for power generation.
  • Fans: Managing steam turbines that power large industrial fans.