CN100416103C - High Pressure Roots Blower - Google Patents

Abstract

A high-pressure Roots blower includes a cylinder with an air inlet, an air outlet, and an air cavity therebetween, and the cylinder and an outer cover with a space therebetween; one or more cooling air inlets are arranged on the outer cover, and one or Multiple cooling air outlets for the passage of cooling gas. One or more centrifugal cooling fans are mounted on the rotor shaft close to the inlet and outlet of the housing. Also included are run-in belt seals fitted to the two three-lobe rotors to reduce internal leakage and accidental mechanical contact. In addition, it also includes a pressure relief safety valve installed on the inner cylinder. When the internal pressure of the blower exceeds the preset pressure critical value, it will automatically open to unload and send out an audible warning signal; it also includes a raised High pressure outlet flange with sealing surface. The high-pressure Roots blower can obtain a higher pressure rise and pressure ratio, and at the same time reduce high temperature and internal leakage caused by high pressure, thereby improving the efficiency and reliability of the blower.

Description

High Pressure Roots Blower

technical field

The present invention relates to the technical field of mechanical blowers used in various industrial applications, and belongs to double-rotor vane blowers, commonly known as Roots blowers.

Background technique

Roots blowers are widely used in various industrial applications. In the language of blowers, compared to the traditional medium pressure (pressure 0.35~1.05kg/cm ² =5-15 pounds/square inch), 1.05~1.76kg/cm ² (=15-25 pounds/square inch) Pressure is often referred to as high pressure. Examples of applications for Roots blowers with high pressure capability are: deep tank aeration tanks used in modern sewage treatment plants, pneumatic conveying of thin or dense phase dispersions, or as a vacuum power source.

However, the pressure of 1.05～1.76kg/cm ² (=15-25 pounds per square inch) is usually difficult to obtain in one-stage compression, which is mainly due to the temperature rise caused by the corresponding compression ratio and the pressure caused by the pressure rise. High temperature at the outlet due to internal leakage from the outlet to the inlet, high temperature gas leaking back to the inlet raises the temperature at the inlet, further increasing the already high outlet temperature due to the higher compression ratio.

In addition, from a mechanical point of view, the increased outlet temperature reduces the gap between the cylinder and the rotor determined by the difference in thermal expansion, which may lead to contact collision of the rotor or even a seizure of the rotor. At the same time, the high temperature of the outlet gas also increases the temperature of the bearings, synchronous gears and lubricating oil, shortens their life, and eventually causes the entire machine to be scrapped.

For these reasons, in conventional designs, the pressure of Roots blowers is in principle limited to 5-15 psi. However, the Roots blower is widely loved because of its unique performance curve: variable pressure with constant flow, plus its rotary compression characteristics. This ability to vary the pressure while maintaining the same flow rate makes the Roots blower ideal for pneumatic conveying of bulk materials, because possible blockages of bulk materials can be removed by increasing the pressure. In addition, with the use of high-pressure Roots blowers, thinner pipes can be used when conveying bulk materials of the same weight, which can reduce the overall volume, weight and cost of the conveying system.

Various attempts have been made to address the above-mentioned problems related to higher temperatures. For example, spray liquid in the air flow, or add a cooling jacket in the cylinder to cool with circulating water, or use a pressure lubrication system that circulates and cools through an external radiator. However, many industrial applications prohibit the use of liquids in the gas stream to prevent contamination of the environment or the substance being conveyed. In addition, the cooling water jacket method and the pressure lubrication system increase the cost and complexity of the system. Moreover, when these common methods try to solve the high temperature problem of high pressure Roots blowers, they ignore the main cause of the problem, namely, the internal leakage of the blower.

In addition, high pressure applications also increase the possibility of leaks at the blower outlet flange. This becomes very critical when the gas is harmful to people. Traditional low-pressure flanges have sealing surfaces not only around the pipe wall but also at the screw holes. Therefore, sealing such a large surface requires a high torque torque to tighten those bolts.

At present, Roots blowers have two safety protection design schemes, both of which use plug structure, one is temperature sensing, the other is pressure sensing, when the temperature or pressure reaches or exceeds the preset critical value, the membrane The tablet will crack or open.

In the case of thermal plugs, the diaphragm is made of a welded material. This material has a predictable melting temperature designed to coincide with the maximum allowable temperature of the blower. In pressure-sensitive plugs, the diaphragm is a thin sheet that will rupture when the pressure difference exceeds the stress limit of the material.

However, these heat-sensitive or pressure-sensitive plugs currently used are all disposable. Once they rupture after being triggered, the blower will not work properly for quite some time before a new plug is installed. In addition, there is a lack of audible signals for early warning of failures.

Therefore, we expect to provide a new design and structure of high-pressure Roots blower to achieve higher pressure and pressure ratio, safer, higher efficiency and reliability, and at the same time solve the problems existing in those traditional Roots blowers.

Contents of the invention

The technology of the present invention refers to a high-pressure Roots blower, which includes a one-piece cooling fan on the rotor shaft, a high-pressure outlet flange, a "friction-good" running-in belt seal layer on the rotor surface, and an audible warning on the cylinder body and release device.

An object of the present invention is to provide a new and unique design and construction of a high pressure Roots blower which can achieve higher pressure rise and pressure ratio than conventional blowers without using liquid cooling methods.

Another object of the present invention is to provide a brand-new and unique design and structure of high-pressure Roots blower, which effectively reduces the high temperature caused by high pressure by using the integrated cooling fan on the rotor shaft.

Another object of the present invention is to provide a new and unique design and structure of high pressure Roots blower with smaller clearance and good contact to improve blower efficiency and reliability.

Another object of the present invention is to provide a new and unique design and construction of high pressure Roots blower with raised flange surface which can be tightened without high torque while sealing higher internal pressure more effectively .

Another object of the present invention is to provide a new and unique design and construction of a high-pressure Roots blower, with a reusable pressure-sensitive plug that is activated when the internal pressure of the blower exceeds a predetermined pressure threshold. Uninstallation can be opened automatically.

Another object of the present invention is to provide a new and unique design and structure of a high pressure Roots blower which gives an audible warning signal after the pressure relief plug is triggered.

The high-pressure Roots blower of the present invention includes a cylinder body with an airflow inlet, an airflow outlet, and an air cavity therebetween, and the cylinder body and the outer cover. There is a space therebetween for cooling gas to pass through, and one or more cooling air is arranged on the outer cover. an air inlet, and one or more cooling air outlets for the passage of cooling gas. The high-pressure Roots blower of the present invention also includes two parallel three-leaf rotors installed in the cylinder, and the two rotors are positioned with synchronous gears, and rotate in reverse to push the airflow from the inlet to the outlet. One or more centrifugal cooling fans are mounted on the rotor shaft and located close to the inlet and outlet of the housing to circulate cooling air between the housing and the cylinder block. The high-pressure Roots blower of the present invention further includes a running-in sealing layer installed on the two multi-lobed rotors to reduce internal leakage and accidental mechanical contact. In addition, the present invention also includes a decompression safety valve installed on the cylinder body. When the internal pressure of the blower exceeds the preset pressure critical value, it will automatically open to unload and send out an audible warning signal. blower, and a high-pressure outlet flange with a raised sealing surface. The high-pressure Roots blower of the present invention can obtain higher pressure rise and pressure ratio, and at the same time reduce high temperature and internal leakage caused by high pressure, thus improving the efficiency and reliability of the blower.

The present invention has many novel and unique features and advantages. It offers a new and unique design and manufacture of high pressure Roots blowers capable of obtaining higher pressure rises and pressure ratios than conventional blowers without using conventional liquid cooling methods. It also has tighter clearances and good contact for improved blower efficiency and reliability. The high-pressure Roots blower of the present invention effectively reduces the temperature of bearings, gears and lubricating oil through a connected cooling fan. In addition, by using raised sealing surfaces, it can be tightened without high torque while sealing higher internal pressures more effectively. It goes a step further by providing a reusable pressure relief valve that emits an audible warning signal when triggered by pressure.

These and other novelties, as well as objects of the invention, will become more apparent from the following detailed description with respect to the drawings and text.

Description of drawings

The purpose of referring to the relevant diagrams is for illustration only, but not limited to the diagrams, which are explained as follows:

Fig. 1 (prior art) is a cross-sectional view showing a typical arrangement of a conventional Roots blower;

Fig. 2 (prior art) is a left side view, represents the typical arrangement of a traditional Roots blower;

Fig. 3 is a cross-sectional view showing a best implementation of the high-pressure Roots blower of the present invention;

Fig. 4 is a left side view, represents a best realization scheme of high pressure Roots blower of the present invention;

Fig. 5 (prior art) is a perspective view, represents the rotor of a traditional Roots blower;

Fig. 6 (prior art) is a partially enlarged view, represents a part of the rotor of a traditional Roots blower;

Fig. 7 is a three-dimensional view, represents a best implementation scheme of the high-pressure Roots blower of the present invention: the running-in belt sealing layer positioned at the end of the rotor;

Fig. 8 is an enlarged view of the left side, representing a best implementation of the high-pressure Roots blower of the present invention: the running-in belt sealing layer positioned on the curved surface and top of the rotor blade;

Fig. 9 is an enlarged view of the left side, representing a best implementation of the high-pressure Roots blower of the present invention: another running-in belt sealing layer positioned at the end of the rotor;

Fig. 10 (prior art) is a partial diagram, represents the connection flange on the traditional Roots blower;

Fig. 11 (prior art) is a left side view, represents the connection flange on the traditional Roots blower;

Fig. 12 is a partial diagram showing the high-pressure connecting flange on the high-pressure Roots blower of the best implementation of the present invention;

Fig. 13 is a partial left view showing the high-pressure connection flange on the high-pressure Roots blower of the best implementation of the present invention;

Fig. 14 is a cross-sectional view showing the audible decompression safety valve used on the high-pressure Roots blower of the best implementation of the present invention: the valve is in the open position;

Fig. 15 is a cross-sectional view showing the audible decompression safety valve used on the high-pressure Roots blower of the preferred embodiment of the present invention: the valve is in the closed position;

Detailed ways

Although the specific implementation solutions of the present invention will be described below with reference to relevant drawings, it should be understood that the implementation solutions here are only examples and illustrations, and there are many other solutions that can be implemented according to the principle of the present invention. Obviously, for those skilled in these arts, various changes and modifications within the scope of the present invention will be considered to belong to the spirit, scope and consideration of the present invention, which will be further defined in the appended claims .

As a brief introduction, the high-pressure Roots blower of the present invention includes a cylinder with an air inlet, an air outlet, and an air cavity therebetween, and the cylinder and the outer cover. There is a space between them for cooling gas to pass through. There is a One or more cooling air inlets, and one or more cooling air outlets for passage of cooling gas.

The high-pressure Roots blower of the present invention also includes two parallel multi-leaf rotors installed in the cylinder body, the two rotating shafts are supported by bearings in the cylinder body, positioned by synchronous gears, and the two rotors rotate in reverse to push the air flow from the inlet to the outlet . One or more centrifugal cooling fans are mounted on the rotor shaft and located close to the inlet and outlet of the housing to circulate cooling air between the housing and the cylinder block.

The high-pressure Roots blower of the present invention further includes a running-in sealing layer installed on the two multi-lobed rotors to reduce internal leakage and accidental mechanical contact.

In addition, the present invention also includes a decompression safety valve installed on the cylinder body. When the internal pressure of the blower exceeds the preset pressure critical value, it can automatically open and unload, and send out an audible warning signal. The present invention also includes High pressure outlet flange with raised sealing surface.

The high-pressure Roots blower of the present invention can obtain higher pressure rise and pressure ratio, and at the same time reduce high temperature and internal leakage caused by high pressure, thus improving the efficiency and reliability of the blower.

Referring to Figures 1 and 2, a typical prior art Roots blower 10 is shown. Generally speaking, Roots blower 10 has two parallel rotors 12 mounted on shafts 14 and 16, respectively. Drive shaft 12. The rotor 12 of the Roots blower 10 is wrapped by the cylinder 20, the two rotating shafts 14 and 16 are supported by the bearing 24 in the cylinder, the bearing 24 is supported by the bearing box 22, and the seal 26 is next to it.

The distance between the two ends of the rotor 12 and the cylinder 20 is called "end gap" 30, the gap between the two rotors 12 is called "blade gap" 32, and the gap between the top of the rotor 12 and the cylinder The gap between bodies 20 is referred to as the "top gap" 34 .

Due to the impetus of the rotor 12 , the arrows in the figure show the flow direction of the airflow from the inlet 36 to the outlet 38 of the blower 10 .

Referring to Figures 3 and 4, there is shown a preferred solution for realizing the high pressure Roots blower 100 of the present invention. The high-pressure Roots blower 100 of the present invention has two parallel multi-leaf rotors 112 respectively installed on the rotating shafts 114 and 116, where the rotating shaft 114 is driven by an external device (not shown), and through a pair of synchronous gears 118 in the absence of The shafts 112 are driven in contact to facilitate the flow of air from the inlet 136 to the outlet 138 of the blower 100 .

The rotor 112 of the high-pressure Roots blower 100 of the present invention is wrapped by the cylinder 120, and the two rotating shafts 114 and 116 are supported by the bearing 124 in the cylinder. There is a space between the cylinder body 120 and the outer cover 128 for cooling gas to pass through, and the air flow direction is shown by the arrow in FIG. 3 .

As an important novelty and uniqueness of the present invention, centrifugal cooling fans 140 are installed at both ends of the blower to provide intensive cooling. The cooling fan is installed on the extension end of the shaft 114, close to the position of the air inlet 142 of the housing 128, for sucking cooling air. As shown by the arrows in FIG. 3 , these gases flow through the space between the outer cover 128 and the inner cylinder 120 and are discharged from the gas outlet 144 on the outer cover 128 .

Usually, the outlet temperature of the blower is not only affected by the leakage backflow (especially for high pressure), but also proportional to the pressure ratio. This external heat will add to the internal heat generated by the internal friction of the gears and bearings. Therefore, the cooling fan 140 of the present invention connected to the rotating shaft 114 is simple in structure and can forcefully remove heat from the blower 100, unlike the more expensive pressure oil lubrication method or liquid spray cooling used in conventional designs.

Another novel and unique feature of the present invention is the use of multiple wear-in-strip seal layers on the rotor 112 .

As shown in Figures 1, 2, 5 and 6, on the Roots blower 10 of the prior art, the leakage flow occurs in the end gap 30 between the end faces 50 of the rotor 12 and the cylinder 20, and between the two rotors. The interblade gap 32 at the mesh 52 between the rotor 12 and the top gap 34 between the top 54 of the rotor 12 and the cylinder 20.

The high pressure Roots blower 100 of the present invention uses a new and unique break-in belt seal to reduce leakage problems. As shown in FIGS. 7 to 9 , in the best implementation, it is a running-in belt sealing layer 162 on the curved surface 152 of the rotor 112 , which is a toothed surface.

In addition, or as another option in the best implementation solution, a running-in belt sealing layer 164 on the top of the rotor 112 is used on the top 154 of the rotor 112, and the running-in belt sealing layer 164 is rib-shaped. As a further supplement, or as an option in another optimal implementation solution, a running-in belt sealing layer 160 at the end of the rotor is used on both ends 150 of the rotor 112 , and the running-in belt sealing layer 160 is planar.

With further reference to Figure 8, it should be noted that each toothed rotor must mate or mesh with another smooth or non-toothed rotor. This is because if both rotors have a toothed profile, they will lock to each other due to relative sliding on the meshing surfaces and cause damage to the rotors.

Due to the use of run-in belt seals 160, 162 and 164, surface discontinuities are created in the sliding direction, reducing the potential contact area. Thus, a large sealing surface becomes a narrow sealing line. The new interface makes better contact, and an accidental contact will only cause some wear, not rotor seizure.

In addition, through the use of run-in belt seals 160, 162, and 164, the high pressure Roots blower 100 of the present invention enables the use of smaller spacings compared to conventional Roots blowers. As a result, internal leakage is reduced, outlet pressure is increased, and the mechanical reliability of the blower is greatly improved.

Another novel and unique feature of the present invention is the use of a high pressure flange to connect the high pressure Roots blower 100 .

Referring to Fig. 10 and Fig. 11, the surface sealing surface 72 of the outlet flange 70 of the conventional Roots blower is flat. When the blower outlet flange 70 is connected to the outlet pipe (not shown), it needs to be fastened with fastening bolts (not shown) inserted into the surrounding threaded holes 76. However, since the sealing surfaces of those flanges are flat, a large torque is required for tightening those bolts.

Referring to Fig. 12 and Fig. 13, the present invention uses a high-pressure outlet flange 170, and the middle part 174 on its sealing surface 172 has a protrusion. In this new design, the end sealing surfaces 172 are concentrated in the middle. Thus, such a flange can more effectively seal the high pressure at the blower outlet, requiring less torque to tighten the bolts (not shown). These bolts are inserted into the surrounding threaded holes 176, and are tightened to connect the Roots blower outlet flange 170 with the outlet pipe (not shown).

Another novel and unique feature of the present invention is the use of a reusable and audible pressure relief valve on the high pressure Roots blower 100 of the present invention.

Referring to Fig. 14 and Fig. 15, as the best implementation plan, the audible decompression safety valve 180 used in the high-pressure Roots blower 100 of the present invention is shown. The audible pressure relief valve 180 is pressure activated and reusable. Its shell 182 has thread 184 outside, so that be installed on the outlet end cylinder block of Roots blower.

When the pressure from the inlet 186 of the pressure reducing safety valve 180 exceeds the preset pressure limit, this pressure will act on the valve ball 190 in the pressure reducing safety valve 180 to overcome the force of the internal spring 192 to move the valve ball 190 thereby opening the relief port 188 to relieve the internal pressure. The decompression port 188 is made into a narrow shape to produce a whistle, and when the high-pressure fluid (as shown by the arrows in Fig. 14 and Fig. 15 ) passes through the decompression port 188, an audible alarm signal is generated.

The top of the audible decompression safety valve 180 on the high-pressure Roots blower 100 of the present invention is provided with a nut 194 for adjusting trigger pressure for different applications. A scale can be installed at the extreme end of the nut 194, and the pressure value after calibration is arranged above.

The speed of the high-pressure Roots blower 100 of the present invention can reach 5000 rpm, the outlet pressure can reach 1.76kg/cm ² (=25 psi), and the outlet temperature can often reach 400F.

The high pressure Roots blower of the present invention has many advantages. It is able to achieve higher pressure rise and pressure ratio than conventional blowers without using liquid spray cooling or oil lubrication methods. The cooling fan connected to the gear shaft effectively reduces the high temperature caused by high pressure. It also uses run-in tape seals on the rotor top, end and airfoil surface, so that the gap can be smaller and the contact is good. In addition, it also uses a high-pressure outlet flange with a raised sealing surface, which can effectively seal higher internal pressure without requiring a large torque. These improved seals and additional protection against higher outlet temperatures add to the blower's efficiency and reliability. Moreover, the high-pressure Roots blower of the present invention can send out an audible warning signal after the decompression safety valve is triggered. After the high-pressure gas is released, the decompression safety valve can still be used again.

Broadly speaking, the present invention is a kind of high pressure Roots blower, comprises: (a) there is a cylinder body that has airflow inlet, airflow outlet and therebetween is air chamber, and cylinder body and outer cover, there is space therebetween, for cooling gas Through, there is at least one cooling gas inlet and outlet on the outer cover; (b) two parallel multi-lobed rotors installed in the cylinder, the two rotating shafts are positioned by synchronous gears, and counter-rotate to promote the flow of air from the inlet to the outlet; (c) at least one centrifugal cooling fan on both rotor shafts positioned proximate to at least one inlet of the outer casing to circulate cooling air between the outer casing and the inner cylinder; and (d) run-in band seals on the two multi-lobe rotors to reduce Internal leakage and accidental mechanical contact; (e) This high-pressure Roots blower can obtain a higher pressure rise to pressure ratio while reducing high temperature and internal leakage caused by high pressure, thus increasing the efficiency and reliability of the blower.

Of course, the present invention is not limited to any particular form or configuration, or any specific implementation and any specific use, disclosed herein, without departing from the spirit of the application of the present invention as shown and described above or scope, the same substance may be altered in various details or relationships. The device or method shown here is only for illustrating and disclosing the best form of implementation, but not showing all the different forms or modifications in which the invention may be implemented or operated.

In full compliance with patent laws and regulations, the present invention has been described in considerable detail to provide disclosure of at least one of its embodied technical disclosures. However, such detailed description is not intended to limit in any way the broad features or principles of the invention.

Claims (8)

1. high pressure roots blower, it is characterized in that: it comprises:

A. there is one to have airflow inlet, flow outlet and be the cylinder body of air cavity therebetween, and cylinder body and outer cover, having living space therebetween, cooling but gas passes through, and has a cooled gas import and outlet on the outer cover at least;

B. be installed in two parallel leafy rotors in the cylinder body, two rotor shafts are by the synchromesh gear location, and counterrotating promotes air-flow flowing from import to outlet;

C. have a centrifugal cooling fan at least on two rotor shafts, its position is near at least one import of outer cover, with the cooling air that circulates between outer cover and cylinder body;

D. on two leafy rotors break-in band sealing layer is arranged, contact with accidental mechanicalness to reduce internal leakage.

2. high pressure roots blower according to claim 1, it is characterized in that: it further comprises a centrifugal cooling fan at least in addition on two rotor shafts, its position is near at least one outlet of outer cover, to strengthen the cooling air that circulates between outer cover and cylinder body.

3. high pressure roots blower according to claim 1 is characterized in that: described break-in band sealing layer comprises at least one break-in band sealing layer, is used on each leafy epitrochanterian end face.

4. high pressure roots blower according to claim 1 is characterized in that: said break-in band sealing layer comprises at least one break-in band sealing layer, is used on two leafy epitrochanterian each blade profile curved surfaces.

5. high pressure roots blower according to claim 1 is characterized in that: said break-in band sealing layer comprises at least one break-in band sealing layer, is used in two leafy epitrochanterian tops.

6. high pressure roots blower according to claim 1, it is characterized in that: further comprise a pressure regulator that is installed on the cylinder body, when the internal pressure of blower surpassed predefined pressure threshold, it was opened automatically and unloads, and sends the audible early warning signal.

7. high pressure roots blower according to claim 6 is characterized in that: described pressure regulator is provided with a nut, is used for determining the pressure threshold when said pressure regulator is activated.

8. high pressure roots blower according to claim 1 is characterized in that: further being included in has the high-pressure outlet flange on the blower export, its sealing surfaces middle part projection.

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