BUILDING MATERIAL COMPRESSED AIR CONVEYOR

Description

FIELD OF APPLICATION AND STATE OF THE ART

[0001] The invention relates to a building material pneumatic conveyor.

[0002] DE 38 20 710 A1 discloses a method and a device for blowing empty conveyor lines of a pneumatic slow conveyor system, each of which is supplied with a conveying medium from at least one pressure vessel in parallel and is each equipped with at least one material feed device in the form of a rotary valve. Pneumatic conveyor lines must sometimes be cleared of all material residues after conveying has ended. This is necessary, for example, before an intended change of conveyed material, since the product at the destination is generally pure, i.e., one that is not contaminated with residues of the previously conveyed material. Such cleaning is also often required during operational interruptions, for example, particularly in the food industry after conveying perishable contaminants.

[0003] WO 2016 / 034644 A1 discloses a building material pneumatic conveyor according to the preamble of claim 1. TASK AND SOLUTION

[0004] The object of the invention is to provide a building material pneumatic conveyor which conveys building material quickly and / or has low energy consumption.

[0005] The invention solves this problem by providing a building material pneumatic conveyor having the features of claim 1. Advantageous developments of the invention are described in the dependent claims.

[0006] The building material compressed air conveyor according to the invention has a building material unit for providing building material and a compressed air unit. The building material unit is designed to provide thick material. The compressed air unit has an air compressor unit, an air pressure accumulator, an accumulator inlet, an accumulator outlet and a bypass line. The air compressor unit is designed to generate compressed air. The air pressure accumulator is designed to store compressed air. The accumulator inlet is designed for a flow of compressed air from the air compressor unit into the air pressure accumulator. The accumulator outlet is designed for a flow of compressed air from the air pressure accumulator into the building material unit to promote a flow of building material out of the building material unit using compressed air.The bypass line is designed for a flow of compressed air from the air compressor unit around the air pressure accumulator into the building material unit to promote a flow of building material out of the building material unit by means of compressed air.

[0007] When the air pressure accumulator is filled and a flow of building material is conveyed out of the building material unit by means of compressed air, the bypass line makes it possible to introduce compressed air past the air pressure accumulator or without passing through the air pressure accumulator, in particular directly, into the building material unit.

[0008] Due to the typically relatively lower pressure in the building material unit compared to the pressure in the, especially filled, air pressure reservoir, the compressed air unit, in particular its air compressor unit, can provide significantly more air volume for conveying at the same power consumption or save energy with the same air volume. This can be particularly true compared to a building material compressed air conveyor without the bypass line, in which compressed air can flow from the air compressor unit into the building material unit exclusively via the air pressure reservoir.

[0009] In detail, due to the technical fact that, with a constant air flow rate, the power consumption increases in proportion to the pressure, the air compressor unit can be operated in a relatively lower pressure range thanks to the bypass line. Due to the reduction in power consumption, larger air volume flows can be generated, especially with low-performance pneumatic conveyors. This can be used to increase the performance of the pneumatic conveyor for building materials and / or to reduce the power consumption of the pneumatic conveyor for building materials.

[0010] Consequently, the building material pneumatic conveyor enables fast conveying of building material and / or low energy consumption.

[0011] The building material unit is designed to provide thick materials, such as mortar, cement, screed, concrete, and / or plaster. Additionally, the building material unit can be designed to provide sand, gravel, and / or gravel. In particular, the building material unit can have a conveyor hopper, which can be designed to provide building material in a conveyable state. Additionally, the conveyor hopper can be designed as a mixing tank, which can be designed to mix building material.

[0012] The air compressor unit may have only a single compressor or a common compressor for the reservoir inlet and the bypass line. Alternatively, the air compressor unit may have a first compressor for the reservoir inlet and a second compressor, different from the first, for the bypass line. The air compressor unit may be referred to as an air compressor unit.

[0013] The air pressure accumulator does not need to be suitable or designed for building materials, in particular not for the provision of building materials. In other words, the air pressure accumulator can be designed such that if building material gets into it, the air pressure accumulator can be damaged or already damaged. In other words, the air pressure accumulator can be suitable or designed only for compressed air. The air pressure accumulator can have a storage volume of at least 100 liters (l), in particular of at least 200 l, in particular of at least 300 l, in particular of at least 400 l, in particular of at least 600 l, and / or of a maximum of 2000 l.

[0014] The accumulator inlet is designed for compressed air flow from the air compressor unit into the air pressure accumulator. The accumulator inlet does not need to be suitable for the building material.

[0015] The accumulator outlet is designed for a flow of compressed air from the air pressure accumulator into the building material unit.

[0016] Storage discharge does not need to be suitable for building material.

[0017] The bypass line is designed to allow compressed air to flow from the air compressor unit around the air accumulator into the building material unit. The bypass line can be referred to as a bypass line. The bypass line does not need to be suitable for building material.

[0018] The accumulator inlet, the accumulator outlet and / or the bypass line can each be designed or constructed for compressed air with a maximum pressure of 30 bar.

[0019] To promote a flow of building material out of the building material unit using compressed air, the compressed air can act on the building material, in particular, have direct contact with the building material, and / or the building material unit or its conveying container, if present, can be designed for this purpose. The compressed air can be referred to as conveying air.

[0020] The compressed air unit does not need to be suitable for building materials.

[0021] The building material compressed air conveyor has a control unit. The control unit is designed to control the building material compressed air conveyor, in particular automatically, such that before a flow of building material is conveyed out of the building material unit by means of compressed air, the air compressor unit fills the air pressure accumulator with compressed air. Furthermore, the control unit is designed to control the building material compressed air conveyor, in particular automatically, such that for a flow of building material out of the building material unit by means of compressed air, at least initially, compressed air flows out of the air pressure accumulator and compressed air flows from the air compressor unit through the bypass line into the building material unit, in particular simultaneously.

[0022] In a building material compressed air conveyor without a bypass line, the air pressure accumulator would have to be refilled with compressed air at the start of the conveyor when compressed air flows out of the air pressure accumulator. Since there can typically be an enormous pressure difference between the air pressure accumulator and the building material unit, especially at the start of the conveyor, the air compressor unit would have to work against a relatively high pressure. The bypass line can significantly reduce the power consumption of the air compressor unit at the start and thus throughout the entire conveyor process. Due to the performance characteristics of the air compressor unit in combination with the corresponding compressed air line or compressed air duct, the performance curve of the air compressor unit can be ideally adapted to the conveyor requirements using the bypass line. At the same time, the air pressure accumulator enables the building material to be conveyed quickly at the start of the conveyor.

[0023] In particular, the control unit can be designed to control the air compressor unit to generate compressed air, in particular automatically.

[0024] The control unit can be a computer, microcontroller or a mechanical circuit.

[0025] In particular, the conveying or a conveying process can have three temporal conveying phases. In particular, the conveying can have a duration of 120 seconds (s) to 180 s. In a first conveying phase, a pressure or pressure value or pressure level, in particular of compressed air, in or within the building material unit, in particular in the conveying container or within the conveying container, if present, can rise or build up. In particular, the first conveying phase can have a duration of 30 s to 40 s. In a second conveying phase, in particular different from the first and / or subsequent to the first, the pressure in the building material unit can be constant, in particular with the exception of minor fluctuations. In particular, the second conveying phase can have a duration of 60 s to 100 s.In a third conveying phase, in particular one that is different from the first and / or second and / or subsequent to the first and / or second, the pressure in the building material unit can drop or decrease or be reduced. In particular, the third conveying phase can have a duration of 30 s to 40 s.

[0026] At least at the beginning of the pumping operation can mean that, at least during the first pumping phase, compressed air flows out of the air pressure accumulator at least temporarily, in particular the entire time, and that, at least temporarily, in particular the entire time, compressed air flows from the air compressor unit through the bypass line. In particular, temporarily can mean at least 50 percent (%), in particular at least 65%, in particular at least 80%, in particular at least 95%, of the duration of the first pumping phase.

[0027] In a further development of the invention, the air pressure accumulator is designed to store compressed air with a maximum operating pressure of more than 8 bar, in particular a minimum of 10 bar, in particular a minimum of 12 bar, in particular a minimum of 14 bar, and / or a maximum of 30 bar. If the maximum operating pressure is exceeded, the air pressure accumulator does not need to be damaged or already damaged, since the air pressure accumulator can be designed for a test pressure that is relatively higher than the operating pressure. Typically, a test pressure can correspond to 1.3 times the operating pressure. The operating pressure of the air pressure accumulator can be referred to as the accumulator operating pressure.

[0028] In a further development of the invention, the building material pneumatic conveyor has an electric motor for driving the air compressor unit or is designed to drive the air compressor unit. In particular, the building material pneumatic conveyor or its electric motor can be designed for connection to a 400 volt (V) power connection with a maximum current load limited to 16 amperes (A) or 32 A or 63 A. The bypass line can enable optimal use of the available electrical power. The control unit, if present, can be designed to control the electric motor for driving the air compressor unit, in particular automatically. Additionally or alternatively, the building material pneumatic conveyor can have an internal combustion engine, in particular a diesel engine, for driving the air compressor unit.

[0029] In a further development of the invention, the compressed air unit has a pressure reducer. The pressure reducer is arranged or designed at the accumulator outlet to limit the compressed air flow from the air pressure accumulator into the building material unit to a maximum operating pressure of 8 bar, in particular 6 bar, in particular 4 bar, in particular 2 bar. This makes it possible to protect the building material unit, which typically does not need to be designed for a higher operating pressure, from damage caused by higher pressure. The operating pressure of the building material unit can be referred to as the building material unit operating pressure. The pressure reducer does not need to be suitable for building material.

[0030] In a further development of the invention, the compressed air unit has a bypass release and shut-off valve. The bypass release and shut-off valve is arranged or designed on the bypass line to release or shut off a flow of compressed air from the air compressor unit through the bypass line into the building material unit. When shut off, this can make it possible to control or restrict a flow of compressed air to the accumulator inlet and / or the accumulator outlet. The control unit, if present, can be designed to control the bypass release and shut-off valve for release or shut-off, in particular automatically. The bypass release and shut-off valve does not need to be suitable for building materials.

[0031] In a further development of the invention, the compressed air unit has an accumulator release and shut-off valve. The accumulator release and shut-off valve is arranged or designed on the accumulator outlet to release or shut off a flow of compressed air from the air pressure accumulator through the accumulator outlet into the building material unit. When shut off, this can make it possible to control or restrict a flow of compressed air to the accumulator inlet and / or the bypass line. In particular, when the accumulator release and shut-off valve and the bypass release and shut-off valve, if present, are shut off, this can make it possible to fill the air pressure accumulator with compressed air from the air compressor unit without compressed air being able to flow out of the air pressure accumulator through the accumulator outlet.The control unit, if present, can be designed to control the accumulator release and shutoff valve for release or shutoff, in particular automatically. The accumulator release and shutoff valve does not need to be suitable for the building material.

[0032] In a further development of the invention, the compressed air unit has an accumulator check valve. The accumulator check valve is arranged or designed at the accumulator inlet to block the flow of compressed air from the air pressure accumulator through the accumulator inlet into the air compressor unit, in particular up to the air compressor unit, and / or into the bypass line, in particular up to the bypass line. This makes it possible to prevent compressed air from flowing out of the, in particular filled, air pressure accumulator through the accumulator inlet. The accumulator check valve does not need to be suitable for building materials.

[0033] In a further development of the invention, the building material pneumatic conveyor has at least one check valve. The check valve is arranged or designed on the building material unit to block the flow of building material from the building material unit into the compressed air unit, in particular up to the compressed air unit. This makes it possible to protect the compressed air unit from damage caused by building material. The check valve can be referred to as a building material check valve.

[0034] In a further development of the invention, the building material compressed air conveyor has a compressed air conveying line. The compressed air conveying line is suitable or designed for a flow of compressed air, in particular from the compressed air unit, into the building material unit for conveying a flow of building material out of the building material unit by means of compressed air. The accumulator outlet and the bypass line open into the compressed air conveying line, in particular within the compressed air unit. This enables the compressed air unit to be fluidly connected to the building material unit by just a single line for compressed air, the compressed air conveying line. In other words: the accumulator outlet and the bypass line, or respective line ends of these, can be fluidly connected to the building material unit via the compressed air conveying line, in particular for a flow of compressed air into the building material unit.The compressed air delivery line does not need to be suitable for building materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Further advantages of the invention will become apparent from the claims and the following description of preferred embodiments of the invention, which are explained below with reference to the figures. In the figures: Fig. 1 a circuit diagram of a building material pneumatic conveyor according to the invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The building material compressed air conveyor 10 according to the invention has a building material unit 20 for providing building material and a compressed air unit 30, as in Fig. 1 each indicated by dashed lines. The compressed air unit 30 has a, in particular electrically controllable, air compressor unit 35, an air pressure accumulator 40, a storage inlet 41, a storage outlet 42, and a bypass line 50. The air compressor unit 35 is designed to generate compressed air. The air pressure accumulator 40 is designed to store compressed air. The storage inlet 41 is designed for a flow of compressed air from the air compressor unit 35 into the air pressure accumulator 40, as shown in Fig. 1 indicated by an arrow P1. The accumulator outlet 42 is designed for a flow of compressed air from the air pressure accumulator 40 into the building material unit 20 to promote a flow of building material out of the building material unit 20 by means of compressed air, as shown in Fig. 1 indicated by an arrow P2. The bypass line 50 is designed for a flow of compressed air from the air compressor unit 35 around the air pressure accumulator 40 into the building material unit 20 to promote a flow of building material out of the building material unit 20 by means of compressed air, as in Fig. 1 indicated by arrows P3.

[0037] In detail, the building material unit 20 is designed to provide thick material, in particular mortar. The building material unit 20 has a conveyor container 21, which is designed to provide building material in a conveyable state. Additionally, in the illustrated embodiment, the conveyor container 21 is designed as a mixing container, which is designed for mixing building material. In alternative embodiments, the conveyor container need not be designed as a mixing container.

[0038] Furthermore, the building material unit 20 has a vent valve 22, which is arranged on the conveyor container 21 for venting the conveyor container 21, in particular when the conveyor container 21 is being filled with building material. In detail, the building material unit 20 or its conveyor container 21 has a filling opening (not shown) through which the conveyor container 21 can be filled with building material, in particular discontinuously. After filling, the filling opening can be closed, and the conveyor container 21 can be filled or pressurized with compressed air.

[0039] The air compressor unit 35 has a common compressor in the form of a screw compressor for the storage inlet 41 and for the bypass line 50.

[0040] In the illustrated embodiment, the air pressure accumulator 40 has a storage volume of 400 l. In alternative embodiments, the air pressure accumulator may have a storage volume of at least 100 l.

[0041] Furthermore, in the illustrated embodiment, the air pressure accumulator 40 is designed to store compressed air with a maximum operating pressure of 12 bar. In alternative embodiments, the air pressure accumulator can be designed to store compressed air with a maximum operating pressure of more than 8 bar. In addition, in the illustrated embodiment, the compressed air unit 30 has a safety valve 46, which is arranged on the air pressure accumulator 40 to limit the maximum operating pressure of the air pressure accumulator 40 to 12 bar.

[0042] The compressed air unit 30 further includes a pressure reducer 45. The pressure reducer 45 is arranged at the accumulator outlet 42 to limit the compressed air flowing from the air pressure accumulator 40 into the building material unit 20 to a maximum operating pressure of 8 bar.

[0043] In addition, the compressed air unit 30 has a bypass release and shutoff valve 55, in particular an electrically controllable one, in the form of a 2 / 2-way valve. The bypass release and shutoff valve 55 is arranged on the bypass line 50 to release or shut off a flow of compressed air from the air compressor unit 35 through the bypass line 50 into the building material unit 20.

[0044] Furthermore, the compressed air unit 30 has a, in particular electrically controllable, accumulator release and shutoff valve 44 in the form of a 2 / 2-way valve. The accumulator release and shutoff valve 44 is arranged at the accumulator outlet 42, in particular between the air pressure accumulator 40 and the pressure reducer 45, to release or shut off a flow of compressed air from the air pressure accumulator 40 through the accumulator outlet 42 into the building material unit 20.

[0045] In addition, the compressed air unit 30 has an accumulator check valve 43 in the form of a flap valve. The accumulator check valve 43 is arranged at the accumulator inlet 41 to block the flow of compressed air from the air pressure accumulator 40 through the accumulator inlet 41 into the air compressor unit 35 or into the bypass line 50.

[0046] Furthermore, the building material compressed air conveyor 10 has a compressed air conveying line 60. The compressed air conveying line 60 is designed for a flow of compressed air, in particular from the compressed air unit 30, into the building material unit 20 to convey a flow of building material out of the building material unit 20 by means of compressed air, as shown in Fig. 1 indicated by arrows P4. The accumulator outlet 42 and the bypass line 50 open into the compressed air supply line 60, particularly within the compressed air unit 30.

[0047] In addition, the building material pneumatic conveyor 10 has at least one check valve 25a, 25b in the form of a check valve. The at least one check valve 25a, 25b is arranged on the building material unit 20 to block the flow of building material from the building material unit 20 into the compressed air unit 30, in particular into the compressed air conveyor line 60.

[0048] In detail, the building material unit 20 has an upper air line or container inlet 23 for a flow of compressed air from the compressed air conveying line 60 into the conveying container 21 for conveying a flow of building material out of the conveying container 21 by means of compressed air, as shown in Fig. 1 indicated by an arrow P5.

[0049] Furthermore, the building material unit 20 has a building material conveying line 26 for a flow of building material out of the conveying container 21 by means of compressed air, as shown in Fig. 1 indicated by arrows P7.

[0050] In addition, the building material unit 20 has a sub-air line or building material conveying line inlet 24 for a flow of compressed air from the compressed air conveying line 60 into the building material conveying line 26 for conveying a flow of building material through the building material conveying line 26 by means of compressed air, as in Fig. 1 indicated by an arrow P6.

[0051] The compressed air supply line of the embodiment shown can be referred to as a compressed air supply distribution line.

[0052] Furthermore, the building material unit 20 has a sub-release and shut-off valve 27, in particular an electrically controllable one, in the form of a 2 / 2-way valve. The sub-release and shut-off valve 27 is arranged on the sub-air line 24 to release or shut off a flow of compressed air from the compressed air supply line 60 through the sub-air line 24 into the building material supply line 26.

[0053] In the illustrated embodiment, the compressed air conveyor 10 for building materials has two check valves 25a, 25b. One of the check valves 25a is arranged on the upper air line 23 to block the flow of building material out of the conveyor container 21 through the upper air line 23 into the compressed air conveyor line 60. The other of the check valves 25b is arranged on the lower air line 24, in particular between the building material conveyor line 26 and the lower release and shut-off valve 27, to block the flow of building material out of the building material conveyor line 26 through the lower air line 24 into the compressed air conveyor line 60.

[0054] In addition, the building material pneumatic conveyor 10 has an electric motor 80, in particular an electrically controllable one, for driving the air compressor unit 35. In detail, the electric motor 80 is designed for connection to a 400 V power supply and a maximum current load limited to 32 A. Additionally, in the illustrated embodiment, the electric motor 80 is designed to drive the building material unit 20 or its conveyor container 21. In alternative embodiments, the electric motor need not be designed or provided to drive the building material unit.

[0055] Furthermore, the building material compressed air conveyor 10 has a control unit 90, in particular an electrical one. The control unit 90 is designed to control the building material compressed air conveyor 10 such that, before a flow of building material is conveyed out of the building material unit 20 by means of compressed air, the air compressor unit 35 fills the air pressure accumulator 40 with compressed air. Furthermore, the control unit 90 is designed to control the building material compressed air conveyor 10 such that, for conveying a flow of building material out of the building material unit 20 by means of compressed air, at least initially, compressed air flows out of the air pressure accumulator 40 and compressed air flows from the air compressor unit 35 through the bypass line 50 into the building material unit 20.

[0056] In addition, in the embodiment shown, the building material compressed air conveyor 10 has a pressure transducer or pressure sensor 91, in particular an electrically readable one, which is arranged on the air pressure accumulator 40 to measure an actual pressure of compressed air within the air pressure accumulator 40.

[0057] Furthermore, in the embodiment shown, the building material compressed air conveyor 10 has a pressure transducer or pressure sensor 92, in particular an electrically readable one, which is arranged on the conveyor container 21 to measure an actual pressure of compressed air within the conveyor container 21.

[0058] In addition, in the embodiment shown, the building material pneumatic conveyor 10 has a user-operable control panel 95 for operating the building material pneumatic conveyor 10.

[0059] In the embodiment shown, the control unit 90 is coupled, in particular electrically, to the air compressor unit 35, the bypass release and shut-off valve 55, the accumulator release and shut-off valve 44, the sub-release and shut-off valve 27, the electric motor 80, the pressure sensor 91, the pressure sensor 92 and the control panel 95, as shown in Fig. 1 indicated by dotted lines. In detail, the control unit 90 is designed to control the air compressor unit 35, the bypass release and shutoff valve 55, the accumulator release and shutoff valve 44, the sub-release and shutoff valve 27, and the electric motor 80.

[0060] Before a flow of building material is conveyed out of the building material unit 20 using compressed air, the control unit 90 controls the bypass release and shutoff valve 55 and the accumulator release and shutoff valve 44, each to shut off. Furthermore, the control unit 90 controls the electric motor 80 and the air compressor unit 35, each such that the air compressor unit 35 fills the air pressure accumulator 40 with compressed air to 12 bar, and in particular, does not fill it any further unnecessarily. This is enabled by the pressure sensor 91.

[0061] Typically, the actual pressure within the conveying tank 21 before conveying is 0 bar, especially after the conveying tank 21 has been filled with building material. The control unit 90 detects the actual pressure via the pressure sensor 92. Thus, the control unit 90 can detect the situation, namely 12 bar in the air pressure accumulator 40 and 0 bar in the conveying tank 21. The control unit 90 can control the conveying accordingly.

[0062] In detail, the control unit 90, for conveying a flow of building material out of the building material unit 20 by means of compressed air, at least initially activates the bypass release and shutoff valve 55 and the accumulator release and shutoff valve 44, respectively. Furthermore, the control unit 90, at least initially, each activates the electric motor 80 and the air compressor unit 35 such that the air compressor unit 35 generates compressed air.

[0063] As the illustrated and explained embodiments make clear, the invention provides an advantageous pneumatic construction material conveyor that conveys building material quickly and / or has low energy consumption.

Claims

1. Building material compressed-air conveyor (10), comprising: - a building material unit (20) for providing building material, - a compressed-air unit (30) comprising: - an air compressor unit (35) for generating compressed air, - an air pressure store (40) for storing compressed air, - a store inlet line (41) for a flow of compressed air from the air compressor unit (35) into the air pressure store (40), - a store outlet line (42) for a flow of compressed air out of the air pressure store (40) into the building material unit (20) for conveying a flow of building material out of the building material unit (20) by means of compressed air, - a bypass line (50) for a flow of compressed air from the air compressor unit (35) around the air pressure store (40) into the building material unit (20) for conveying a flow of building material out of the building material unit (20) by means of compressed air, and - a control unit (90), which is designed to control the building material compressed-air conveyor (10) in such a way - that before a flow of building material is conveyed out of the building material unit (20) by means of compressed air, the air compressor unit (35) fills the air pressure store (40) with compressed air, characterized in that the building material unit (20) is designed to provide thick material, and in that the control unit (90) is designed to control the building material compressed-air conveyor (10) in such a way that, for conveying a flow of building material out of the building material unit (20) by means of compressed air, at least at the start compressed air flows out of the air pressure store (40) and compressed air flows from the air compressor unit (35) through the bypass line (50) into the building material unit (20).

2. Building material compressed-air conveyor (10) according to Claim 1, - wherein the air pressure store (40) is designed to store compressed air at a maximum operating pressure of more than 8 bar.

3. Building material compressed-air conveyor (10) according to either of the preceding claims, comprising: - an electric motor (80) for driving the air compressor unit (35).

4. Building material compressed-air conveyor (10) according to one of the preceding claims, - the compressed-air unit (30) comprising a pressure reducer (45), which is arranged on the store outlet line (42) to limit compressed air flowing out of the air pressure store (40) into the building material unit (20) to a maximum operating pressure of at most 8 bar.

5. Building material compressed-air conveyor (10) according to one of the preceding claims, - the compressed-air unit (30) comprising a bypass release and shut-off valve (55), which is arranged on the bypass line (50) to allow or shut off a flow of compressed air from the air compressor unit (35) through the bypass line (50) into the building material unit (20).

6. Building material compressed-air conveyor (10) according to one of the preceding claims, - the compressed-air unit (30) comprising a store release and shut-off valve (44), which is arranged on the store outlet line (42) to allow or shut off a flow of compressed air out of the air pressure store (40) through the store outlet line (42) into the building material unit (20).

7. Building material compressed-air conveyor (10) according to one of the preceding claims, - the compressed-air unit (30) comprising a store check valve (43), which is arranged on the store inlet line (41) to block a flow of compressed air out of the air pressure store (40) through the store inlet line (41) into the air compressor unit (35) and / or into the bypass line (50).

8. Building material compressed-air conveyor (10) according to one of the preceding claims, comprising: - at least one check valve (25a, 25b), which is arranged on the building material unit (20) to block a flow of building material out of the building material unit (20) into the compressed-air unit (30).

9. Building material compressed-air conveyor (10) according to one of the preceding claims, comprising: - a compressed-air conveying line (60) for a flow of compressed air into the building material unit (20) for conveying a flow of building material out of the building material unit (20) by means of compressed air, - wherein the store outlet line (42) and the bypass line (50) open into the compressed-air conveying line (60).