High Pressure Trail Concrete Pump

The primary pump circuit is one of a concrete boom pump's most crucial parts. This circuit controls the parallel hydraulic drive cylinders and features the following components.
Piston pump: The main hydraulic power pump gets its power from a variable displacement axial piston pump complete with a swashplate design. Adjusting the swashplate angle changes the stroke length of the pistons, and this process changes the concrete displacement. The more flow, the larger the swashplate angle becomes. Operators can adjust the swashplate angle using the load sense feature and the volume control.
Motor: An engine or electric motor powers the main hydraulic pump. When the engine operates like usual, the pump switches off, minimizing the pressure on the pump and providing enough power to keep the pump lubricated.
Valve manifold: A valve on the main circuit controls flow, the relief valve, the check valve and the pilot-operated directional valve.
Throttle control: To energize the pump circuit, the operator sets the speed to maximum RPM using the throttle control.
Cycling circuit: Once the pump switches on, it immediately triggers the cycling circuit. This circuit generates an electrical signal and activates the directional valves.
Material cylinders: The two parallel cylinders alternately pump the concrete. Proximity sensors trigger the material pumping action, sending the signal from the sensors to the logic controller.
Relief valve: This valve protects the primary pump circuit from extreme pressure. When the system pressure reaches the maximum allowed, the relief valve opens to let oil return to the tank.

This circuit controls the function for shifting the S-tube from one cylinder to the other during pumping. As there's a single outlet for pumping material, there must be a method to transfer concrete from the cylinder to the outlet and then onto the delivery line.
The hopper has an S-tube to ensure task completion. There's one S-tube for two cylinders, so it must be easy to shift from one cylinder to another. We can explain this circuit by considering each of the following components.
Tandem pump: To meet pressure and flow requirements, a tandem pump installed in a single section of the shift circuit connects to the main hydraulic pump, which drives it.
Manifold block: Just like the main hydraulic circuit, there are manifold blocks in the shift circuit.

The agitator's hydraulic function is part of the auxiliary unit. The circuit controls the operation of the agitator and other additional equipment.
The agitator rotates to mix the concrete in the hopper and feed the cylinders. The tandem pump on the main circuit serves the auxiliary circuit. A solenoid cartridge or dump valve is a safety mechanism to prevent flow to the auxiliary circuit when the operator activates the emergency stop circuit.
One of the most significant functions of the auxiliary circuit is to assist in pumping concrete high in the air and over long distances. The main components of this system include the following.
Elbow with wear-detecting holes: These holes in the concrete pump elbows consist of quench casting material. They smooth the ready-mixed concrete flow and increase safety and durability.
Outrigger: This component hangs at an oblique angle and widens the overhanging area for more significant stable movement.
U-shaped bottom of the hopper: This part facilitates the initial movement of the liquid concrete from the hopper into the intake port. Cleaning is more accessible due to the efficient flow of the ready-mixed concrete, as it reduces the remaining volume.
Power-operated vacuum pump: This battery-powered vacuum pump minimizes pulsation and discontinuity in concrete flow. This component creates a more homogeneous mixture.

The spraying arm positions the concrete flow at the correct location. Telescopic elevation platforms and scaffolding are unnecessary, as the component can spray for distances up to 56 feet. The spraying head mixes concrete, elevators and air. The nozzle dimensions and overall design are vital for ensuring minimal rebound and correctly incorporating the concrete.

The air compressor gives the concrete the kinetic energy to spray and compact. A specific velocity is necessary for shotcrete to impact the site's surface, achieved with the compressor's airflow and the correct nozzle diameter.

The accelerator meets the requirement for early strength development by speeding up the hardening of the concrete. The dosage depends on the concrete flow at all times. A synchronized dosing device, combined with the concrete pump, performs this function.

The motorized chassis transports the concrete pump to the desired location. The chassis design is crucial, as it needs to be able to turn in relatively small spaces and operate on uneven terrain.

The control panel allows for ease of operation and confirms the condition of the ready-mixed concrete inside the hopper. Operators can control the pumping speed based on the operation's needs. The digital display indicates when to perform maintenance checks or replacements.

There are three main ways of piping arrangement at the pump outlet. The way must be confirmed according to the spot state.
Direct connetion: After the outlet connects with cone pipe, the pipes are set forward straight.
U-type connection: After the outlet connects with cone pipe, one 3m straight pipe is connected and two 90˚bend pipe are connected to form a 180˚horizontal bend pipe.
L-type connection: After the outlet connects with cone pipe, one 3mpipe is connected and one 90˚ bend pipe is connected.
Direct connection: Small pumping resistance, but when pumping to a larger height, concrete is easy to backflow, suitable for horizontal or below horizontal concrete conveying.
U-type connection: Large pumping resistance, but when the pumping height is large, the concrete is not easy to backflow, suitable for large height pumping.
L-type connection: The pumping resistance is between the above two, but the lateral reaction force is larger, so there should be a firm fixing at the cone pipe.

Concrete piping should never be subjected to any external tension.
Piping layout should be laid in accordance with the principle of the shortest distance and the least number of elbows.
The conveying pipeline should be arranged in an easily accessible place for personnel to clean and replace the conveying pipeline.
Connection of each pipeline is firm and steady. Bend pipe should be added firm fixed point in order to prevent pipe shaking and loosing during pumping.
Each pipe clamp shouldn't contact with ground or supporting objects. There is gap expediently dismantling and installing. Each pipe clamp is screwed up to ensure that the joints don't let out slurry and air.
The horizontal pipe shouldn't be hung in the air and should be fixed firm. When the working time is very long, the pipe must be supported by a wood pad.
At the outlet of cone pipe, bend pipe is not connected direct. At least 5m pipe is connected and then bend pipe is connected.
The pipe far from the machine 3m to 5m should be fixed by 1 to 2 m³ concrete block. The concrete block can absorb flowing counterforce to make the machine steady and the pipe vibration decreased.
Delivery pipes laying should meet the following requirement: placing concrete at the far place firstly so as to avoid pipe connection during operation.
In summer, pipeline exposed to the sunlight will cause blockage, because overheated concrete will result in losing water. So pipeline must be covered with wet grass bags or similar. In winter, when temperature is up to -5℃, pipeline should be covered with grass bags to preserve warm and ensure concrete placing temperature.
Fix the conveying pipe which is connected with the cone pipe at the outlet of machine, in oreder to conveniently dismantle pipes for cleaning after stopping operation.
Conveying pipe close to the machine and in dangerous area person has to set foot must be screened with preserve to avoid pipeline cracking and clamp loosenes damage.

The pipeline upward can be laid along elevator well, scaffold or through prefab hole of floor in order to dismantle pipeline conveniently.
Use new conveying line when laying upward pipeline; when height is big, the thickness pipes must be used at the bottem. The thickness pipes must be used on the underside and easy to dismantle. Bend pipe can't be used for vertical pipeline supporting, each pipe should be supported by 1~2 bolsters. Straight and bend pipe must be fixed on wall. Scaffold, tower or lift well in order to transfer the concrete gravity of pipeline from bolsters into the building.
As the vertical lines height rises, the delivery concrete may incline to flow backwards and give an impact to S valve. In order to reduce the shock, a certain length of horizontal pipeline should be laid between the machine and vertical pipeline to resist the concrete flowing backwards. The length of horizontal pipeline is not less than the 15% length of the vertical pipeline, and the cut-off valve should be installed at the horizontal pipeline of machine outlet, if the concrete delivery is at high level.
If the pumping distance is very high and the concrete output is large, you can carry out two group parallel pipelines. If one group line is blocked, another pipeline can continuously working.

If delivery concrete downwards, when the drop in height exceeds 6m, the pipeline should be laid as the following figure to avoid concrete segregation; When mortar is pumped, the sponge ball should be put into pipeline in different height every 20 to 30m to ensure the pumping normally.

In addition to the arrangement of the pump pipe, the arrangement of the concrete pump is also very important and you need to pay attention to the following aspects.
Once the concrete pump is delivered to the site, it should be set up away from slopes, embankments, trenches, etc. It should also consider easy access when the transport truck is loaded and shorten the pump line as much as possible.
The concrete pump must be placed on a solid and flat surface, preferably by pouring a flat concrete foundation and building a simple shed for it.
After the pump reaches the designated position, adjust its height with a jack, so that the pump walking wheel is off the ground, and fix the legs with outrigger pins. Ensure that the hopper door opens and closes freely and it is convenient to clear the material; if you do not move the pump for a long time, you can remove the tires.
Around the concrete pump work site, it should ensure that the water source is adequate, and drainage facilities are smooth, and set up the appropriate lighting devices.
There must be a working space of 1 meter around the pump for the staff to operate and maintain.
When pumping from a low pressure state to a high pressure state, the pump must be re-fixed so that it can work stably and reliably.