GB2462466A

GB2462466A - Explosion blast protection apparatus

Info

Publication number: GB2462466A
Application number: GB0814521A
Authority: GB
Inventors: Justin Jones
Original assignee: Portasilo Ltd
Current assignee: Portasilo Ltd
Priority date: 2008-08-08
Filing date: 2008-08-08
Publication date: 2010-02-10
Anticipated expiration: 2028-08-08
Also published as: GB0814521D0; GB2462466B

Abstract

An explosion blast protection apparatus (10, fig 1) comprises a plurality of elongate parallel members (louver blades) 20 being moveable between an open condition (fig 5) through which a gas can pass and a closed condition (fig 6) in which the members 20 block the passage of the gas. The members 20 are biased when in the open condition and may be a plurality of springs 30 attached to the members 20 and a frame (12 - 15), with one spring 30 for each member 20. The members 20 may overlap an adjacent member 20 in a closed condition. Each member 20 may have lugs (23 - 25, fig 4) supported in openings 27 in frame members (13a, 17 - 19, 15a, fig 2), with the openings 27 having sides 28, 29 that limit movement of the members 20 and define the extent of the open condition. The members 20 may be pivotable.

Description

Title: Blast Protection Apparatus

Description of Invention

This invention relates to a blast protection apparatus.

Blast protection apparatus are required to be used in systems through which there is flow of gas, e.g. air, if there is a likelihood that the system may be subjected to sudden increases/decrease in gas pressure. Examples of such systems include air-conditioning or ventilation systems or air intakes for machinery/equipment.

Sudden increases in gas pressure may be caused by an explosion, within or external to the system. As the explosion release energy, the pressure of the gas near the explosion increase nearly instantaneously which gives rise to a pressure shock wave of highly compressed gas. If the shock wave of high pressure gas is permitted to move into an area where there are people or pressure sensitive equipment, this can give rise to injuries to those people or damage to the equipment.

Some prior art blast protection apparatus (one example of which can be seen in WO 07/1 41574-Wozair Limited) while providing sufficient gas admittance, do not react quickly enough in the event of a blast, as a result of the heavy components used. Other prior art apparatus (such as the PV-KK blast valve as manufactured by Temet Oy) close sufficiently quickly but cannot provide, during normal conditions, the required gas admittance, as a result of the complex and convoluted internal workings.

The present invention has therefore been devised to address these shortcomings of the prior art, to provide a blast protection apparatus which permits high volume gas flow therethrough, but also provides quick blast response.

According to the present invention, we provide a blast protection apparatus including;-a plurality of elongate blocking members which are positioned substantially parallel with each other, the blocking members each being moveable between an open condition, in which gas can pass through spaces between the blocking members, and a closed condition in which the blocking members block or substantially block the passage of gas, wherein the apparatus includes means for biasing the blocking members towards their open condition.

The apparatus may include a plurality of biasing means, one for biasing each blocking member towards its open condition.

The blocking members may be configured such that flow of gas at a predetermined pressure effects movement of the blocking members to their closed condition.

When the blocking members are in their closed condition, each blocking member may overlap an adjacent blocking member.

The blocking members may be supported in a frame and the biasing means may be connected to the frame and to the blocking members.

Each blocking member may be supported at at least two positions between its ends.

Each blocking member may be supported in openings in the frame.

The openings may limit movement of the blocking members.

The openings may define the extent of the open condition of the blocking members.

The elongate blocking members may each be pivotally moveable between their open and closed positions.

Examples of the invention will now be described by way of example only, with reference to the accompanying figures, of which:-Figure 1 is a front perspective view of a blast protection apparatus in accordance with the present invention; Figure 2 is a rear perspective view of a blast protection apparatus in accordance with the present invention; Figure 3 is an exploded rear perspective view of a blast protection apparatus in accordance with the present invention; Figure 4 is a perspective view of a blocking member of the blast protection apparatus as shown in figures 1 to 3; Figure 5 is a side view of blocking members of the apparatus in a closed condition; and Figure 6 is a side view of blocking members of the apparatus in an open condition.

Referring to figure 1 to 3 there is shown a blast protection apparatus 10 in accordance with the present invention. The blast protection apparatus 10, in this example, is for connection to an air intake for a housing (not shown) in which is supported machinery/equipment. It should be appreciated, of course, that the blast protection apparatus 10 may be utilised in many other applications, eg. in an air-conditioning system. Essentially, the apparatus 10 in accordance with the present invention may be utilised in any environment where it is necessary to protection something, e.g. equipment or persons, from sudden increases in gas pressure.

The apparatus 10 is substantially squared-shaped in front view and includes a peripheral frame including four frame members 12, 13, 14, 15 which are connected to each other, e.g. by welding or any other appropriate means to provide a square frame. Each frame member 12, 13, 14, 15 includes an outwardly directed flange, each including a plurality of apertures 16, for permitting connection of the apparatus 10 to the intake (not shown).

Supported inside the frame 12, 13, 14, 15 is a plurality of blocking members 20, which are positioned parallel to each other. As will be described in greater detail below, the blocking members 20 are moveable between an open condition (figure 5), in which gas can pass through spaces between the blocking members 20, and a closed condition (figure 6) in which the blocking members 20 block or substantially block the passage of gas.

As can be seen in figures 2 and 3, the blocking members 20 are supported by five internal frame members 13a, 17, 18, 19, 15a, which are positioned in between, and substantially parallel to, the frame members 13, 15. The frame member I 3a abuts an internally facing surface of the frame member 13, and is connected thereto by appropriate means, e.g. welding or by fasteners. The frame member I 5a abuts an internally facing surface of the frame member 15 and is connected thereto by appropriate means, e.g. welding or by fasteners.

The remaining internal frame members 17, 18, 19 are positioned at regular intervals between the frame members 13a, 15a, and are connected to the frame members 12, 14, with the frame member 18 being positioned substantially halfway between the frame members 1 3a, 1 5a. A rear end of the frame member 18 supports an elongate spring support member 35. The member 35 has a plurality of apertures 36, each of which provides a connection point for an end of respective spring 30 (discussed in greater detail later). A frame part 12a is provided, connected to an internally facing surface of the frame member 12. The frame part 12a serves to cover a gap between the frame part 12 and the uppermost blocking member 20.

Turning to figure 4, this shows a perspective view of a blocking member 20 of the present invention. The blocking member 20 is elongate and is comprised of two elongate substantially planar sections 21, 22 which are inclined at an obtuse angle to each other. The section 21 is positioned towards a front of the apparatus 10, and the section 22 is positioned towards a rear of the apparatus 10. In this example the sections 21, 22 are inclined at an angle of 135° to each other, although it should be appreciated that other angles of inclination may be utilised. A free edge of the section 22 is provided with a plurality of lugs 23, 24, 25, which support the blocking member 20 relative to the frame members 13a, 17, 18, 19, 15a. In more detail, a lug 23 is provided at each end of the section 22, the lugs 23 each extending perpendicularly upwardly away from the section 22. A lug 25 is provided positioned substantially midway between the lugs 23, the lug 25 also extending perpendicularly upwardly away from the section 22. Finally, two further lugs 24 are provided, one positioned at either side of the lug 25, substantially midway between the lug 25 and the lug 23. The lugs 24 also extend perpendicularly upwardly away from the section 22. The lug 25 includes an aperture 26 which provides a connection point for an end of a respective spring 30.

As shown in figures 5 and 6, the lugs 23, 24, 25 are supported in openings 27 in the frame members 13a, 17, 18, 19, 15a. Each opening 27 is, in side view, shaped substantially as a sector of a circle, with straight sides 28, 29, with its radius being equal to or slightly longer than the length of the lugs 23, 24, 25.

The openings 27 permits the blocking member 20 to pivot relative to the frame members 13a, 17, 18, 19, 15a, about an axis which is substantially parallel with the frame members 12, 14. The openings 27 also serve to limit pivotal movement of the blocking members 20, i.e. they define the extent of the open condition of the blocking members 20. Communicating with, and positioned beneath, each opening 27 is a further opening 31 which is substantially triangular is side view, having a upper, substantially horizontal, edge 32 and a lower inclined edge 31. The angle of inclination 8 of the edge 31 to a front edge of the frame members 13a, 17, 18, 19, 15a is substantially equal to the obtuse angle formed between the planar sections 21, 22 of the blocking member 20. Thus, in this example, that angle is 135°. This ensures that, in their closed condition, the sections 21, 22 of the blocking member 20 abut, closely, the front edge of the frame members 13a, 17, 18, 19, 15a, and thus that the section 21 is aligned substantially parallel with the front edge of the frame members 13a, 17, 18, 19, iSa.

As can be seen from figures 2 and 3, the apparatus 10 also includes a plurality of springs 30, one for each blocking member 20. Each spring is connected at one end to a corresponding aperture 36 in the member 35 and at its opposite end to the aperture 26 on a corresponding lug 25. The springs 30 are configured such that, at rest, each spring 30 biases its respective blocking member 20 to a position where gas can pass through spaces between the blocking members 20. In the closed position each blocking member 20 overlaps an adjacent blocking member 20.

The apparatus 10 operates as follows. In normal use conditions, the springs are configured such that they bias the blocking members 20 to their open positions (see figure 5). In this position, gas 40 is permitted to pass through spaces between the blocking members 20. However, if, for example, an explosion gives rises to a sudden increase in gas pressure at the front surface of the apparatus 10, the blocking members 20 of the present invention are forced by the increase in pressure to move pivotally, against the biasing force of the springs 30, to their closed condition (see figure 6), thus preventing the high pressure gas from passing through the apparatus 10. Once the pressure at the front surface of the apparatus 10 has decreased to a predetermined value, the blocking members 20 automatically move back to their open condition, as a result of the bias provided by the springs 30. Thus, the apparatus 10 automatically resets itself, without any requirement for a user to intervene.

The blocking members 20 of the present invention are advantageous over known blast apparatus, because they allow for sufficient gas admittance, but also provide for increased speed of closing of the spaces between the blocking members 20 when an increased pressure is experienced. This is due to the many number of blocking members used, and the fact that they are narrow and light-weight. It has been found that the blocking members 20 of the present invention move to their closed condition in less than lOms when experiencing a pressure increase of 0.O3bar (about 0.435psi), whilst permitting a minimum gas flow rate of 18,000m3/hour. The apparatus 10 can also withstand a pressure increase of 0.25bar (about 3.6psi), without resulting in damage thereto.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS1. A blast protection apparatus including;-a plurality of elongate blocking members which are positioned substantially parallel with each other, the blocking members each being moveable between an open condition, in which gas can pass through spaces between the blocking members, and a closed condition in which the blocking members block or substantially block the passage of gas, wherein the apparatus includes means for biasing the blocking members towards their open condition.
2. An apparatus according to any preceding claim including a plurality of biasing means, one for biasing each blocking member towards its open condition.
3. An apparatus according to any preceding claim wherein the blocking members are configured such that flow of gas at a predetermined pressure effects movement of the blocking members to their closed condition.
4. An apparatus according to any preceding claim wherein, when the blocking members are in their closed condition, each blocking member overlaps an adjacent blocking member.
5. An apparatus according to any preceding claim wherein the blocking members are supported in a frame and the biasing means is connected to the frame and to the blocking members.
6. An apparatus according to any preceding claim wherein each blocking member is supported at at least two positions between its ends.
7. An apparatus according to claim 6 when dependent on claim 5 wherein each blocking member is supported in openings in the frame.
8. An apparatus according to claim 7 wherein the openings limit movement of the blocking members.
9. An apparatus according to claim 8 wherein the openings define the extent of the open condition of the blocking members.
10. An apparatus according to any preceding claim wherein the elongate blocking members are each pivotally moveable between their open and closed positions.
11. A blast apparatus substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.
12. Any novel feature or novel combination of features described herein with reference to and/or in the accompanying drawings.