Improved concrete stirring device

Abstract

The invention relates to the technical field of stirrers, and discloses an improved concrete stirring device which comprises a stirrer shell and a pair of stirring shafts, a pair of arc-shaped shells are fixed to the arc-shaped outer wall of the stirrer shell, heat exchange cavities are formed by the arc-shaped shells and the outer wall of the stirrer shell, and the bottom of each heat exchange cavity is connected with a branch water inlet pipe; the first water pump is communicated with the first layer of the water tank through a first pipe; a water outlet pipe is connected to the top of the heat exchange cavity and communicates with the second layer of the water tank. A heat exchange cavity is formed in the stirring shaft, and the two ends of the stirring shaft are each rotationally connected with a water inlet and outlet connector; the water inlet and outlet joints on the front side are connected with a second pipe; the second pipe is communicated with the second layer through a second water pump and a third pipe; the water inlet and outlet connectors on the rear side are connected with a fourth pipe which is communicated with the third layer of the water tank. Through double waste heat recovery and graded heat storage of the shell and the stirring shaft, stepped heating of mixing water is achieved, and the concrete production requirement in winter is met.

Description

Technical Field

[0001] This invention relates to the field of mixer technology, and in particular to an improved concrete mixing device. Background Technology

[0002] In the concrete production process, the mixer is the core equipment. Concrete raw materials are vigorously mixed inside the mixer by the high-speed rotation of the mixing shaft. During this process, a large amount of frictional heat is generated between the mixing blades, the mixing shaft and the concrete, and between the concrete and the inner wall of the mixer casing, causing the mixer casing temperature to rise. This heat is usually directly dissipated into the environment, resulting in energy waste.

[0003] During the concrete mixing process, the friction between the mixer casing and the material, and the shearing action between the mixing shaft and the concrete, generate a large amount of waste heat. This heat is usually wasted through natural heat dissipation or forced air cooling, which not only reduces energy efficiency but may also affect the service life of the equipment due to overheating.

[0004] Concrete production faces greater challenges in the low-temperature environment of winter: First, the hydration reaction is slow: when the ambient temperature is below 5℃, the cement hydration rate decreases significantly, the concrete setting time is prolonged, the early strength growth is slow, and it is susceptible to frost damage (internal free water freezes and expands, causing structural cracking).

[0005] Second, the cost of heating the mixing water is high: traditional solutions require heating the mixing water by electric heating or gas boilers, and the energy cost accounts for 15%-20% of the total production cost in winter. In addition, the heating process has problems such as large heat loss and low temperature control accuracy.

[0006] Third, the waste heat recovery technology is insufficient: the existing waste heat recovery devices for mixers are mostly designed for motor heat dissipation, and do not make full use of the frictional heat of the shell and the mixing shaft. Summary of the Invention

[0007] The purpose of this invention is to provide an improved concrete mixing device that achieves stepped heating of mixing water through dual waste heat recovery from the shell and mixing shaft, and staged heat storage, thereby meeting the needs of concrete production in winter.

[0008] The above-mentioned technical objective of the present invention is achieved through the following technical solution: An improved concrete mixing device includes a mixer housing and a pair of mixing shafts rotatably connected to the mixer housing. One end of each mixing shaft is connected to a drive mechanism that drives it to rotate. A pair of symmetrically arranged arc-shaped shells are fixed on the arc-shaped outer wall of the mixer housing. The arc-shaped shells and the outer wall of the mixer housing form a heat exchange chamber. A branch water inlet pipe is connected to the bottom of each heat exchange chamber. The two branch water inlet pipes are connected to a main water inlet pipe through a tee joint. The other end of the main water inlet pipe is connected to the outlet of a first water pump. The suction end of the first water pump is connected to a first pipe. The other end of the first pipe is connected to the first layer of the water tank. The top of the heat exchange chamber is connected to a water outlet pipe, which is connected to the second layer of the water tank.

[0009] Through the above technical solution, when the mixer is mixing concrete, the friction between the concrete and the inner wall of the mixer shell generates heat. The first layer of the water tank stores room-temperature water. The water in the tank is pumped into the main inlet pipe by a first water pump, and then splits into two branches through a three-way connector. The water in the branch branches enters the bottom of the heat exchange chamber and flows upwards along the chamber, exchanging heat with the mixer shell during its flow, thus raising the water temperature. Finally, the water flows through the outlet pipe to the second layer of the water tank for storage, thereby completing the heating of the water, the recovery and utilization of excess heat from the mixer, and the cooling of the mixer. In summer, the mixer can be cooled by the water flow. In winter, the heated water participates in the concrete mixing, which can increase the concrete's outlet temperature and the temperature before it enters the formwork.

[0010] The present invention is further configured such that: a heat exchange cavity is provided inside the stirring shaft, and a water inlet / outlet connector is rotatably connected to each end of the stirring shaft; the water inlet / outlet connectors on the front side of the two stirring shafts are connected to a second pipe, the second pipe is connected to the outlet end of the second water pump, the end of the second pipe away from the second water pump is sealed, and the suction end of the second water pump is connected to a third pipe, which is connected to the second layer. The inlet and outlet water connectors on the rear side of both agitator shafts are connected to the fourth pipe, which is connected to the third layer of the water tank. The end of the fourth pipe away from the water tank is sealed.

[0011] Through the above technical solution, the water that has been initially heated in the second layer enters the second pipe through the third pipe and the second water pump, and then splits into two paths to enter the two inlet and outlet water connectors on the front side. The water in the inlet and outlet water connectors enters the heat exchange cavity to exchange heat with the stirring shaft. After the water has been heated again, it enters the fourth pipe through the inlet and outlet water connectors on the rear side, and then enters the third layer for storage.

[0012] The present invention is further configured such that: a third water pump is fixed on the upper part of the water tank, the suction end of the third water pump is connected to a fifth pipe, the fifth pipe extends into the third layer; the outlet end of the third water pump is connected to a sixth pipe, the sixth pipe extends into the mixer housing, and a flow meter is connected to the sixth pipe, the flow meter being electrically connected to the controller.

[0013] Through the above technical solution, the third water pump pumps hot water into the sixth pipe through the fifth pipe, and then the hot water enters the mixer through the sixth pipe for mixing. The flow meter can accurately control the amount of water entering the mixer.

[0014] The present invention is further configured such that: the third pipe is bypassed and connected to a seventh pipe, and the other end of the seventh pipe is connected to the first pipe; A first solenoid valve is connected to the first pipe, and the first solenoid valve is located on the upstream side of the seventh pipe; The seventh pipe is connected to a second solenoid valve. Both the first and second solenoid valves are electrically connected to the controller, which controls the first, second, and third water pumps.

[0015] With the above technical solution, the first solenoid valve is closed and the second solenoid valve is opened. The water in the second layer enters the first pipe through the third pipe and the seventh pipe. Then, it can re-enter the heat exchange chamber for heat exchange by the action of the first water pump, thereby allowing the water in the second layer to be heated a second time.

[0016] The present invention is further configured such that: a water level sensor and a first temperature sensor are each provided in the first layer, the second layer and the third layer; The heat exchange chamber is connected to a second temperature sensor. The water level sensor, the first temperature sensor, and the second temperature sensor are all electrically connected to the controller. The water level sensor and the first temperature sensor are used to monitor the water level and water temperature of each layer of water. The second temperature sensor is used to monitor the temperature of the heat exchange chamber. If the water temperature in the second layer is lower than the temperature in the heat exchange chamber, the water in the second layer can be reheated. Otherwise, it is not necessary.

[0017] The invention is further configured such that: the first layer is connected to a supply pipe. When the water level in the first layer is detected to be low, municipal water or recycled water can be introduced into the first layer through the supply pipe.

[0018] The invention is further configured such that: an electric heater is provided at the bottom of the third layer, and the electric heater is electrically connected to the controller. If the temperature of the mixing water is not high enough, the water in the third layer can be heated by the electric heater to reach the required temperature before being pumped into the mixer for mixing.

[0019] The present invention is further configured such that: a heat insulation layer is provided between the first layer and the second layer, and between the second layer and the third layer.

[0020] The insulation layer reduces heat exchange between layers. Additionally, placing high-temperature water in the upper layer and low-temperature water in the lower layer also reduces heat exchange.

[0021] The invention is further configured such that a support strip is sandwiched between the inner wall of the arc-shaped shell and the outer wall of the mixer shell, and the support strip is formed with a plurality of water passage holes.

[0022] The support bars can support the arc-shaped shell to ensure the shape of the heat exchange chamber; the water passage holes can ensure water flow, but the support bars can slow down the water flow speed so that the water can fully exchange heat.

[0023] The outstanding effects of this invention are: Compared with existing technologies, this invention incorporates an arc-shaped shell forming a heat exchange chamber on the outer wall of the mixer casing and a heat exchange cavity inside the mixing shaft, constructing a two-stage series heat exchange system. Cold water first flows through the heat exchange cavity outside the mixer casing, absorbing the heat generated by the friction between the concrete and the casing. Subsequently, the initially heated water is pumped into the heat exchange cavity inside the mixing shaft, absorbing the heat generated by the friction between the mixing shaft and the concrete, as well as the heat generated during transmission. This achieves tiered and deep recovery of waste heat from the mixer's main heat source, resulting in high thermal energy utilization. It also cools the mixer, achieving different effects in different seasons.

[0024] The recovered heat is directly used to heat the mixing water, which can replace traditional coal, gas or electric heating methods in winter, greatly reducing energy consumption and greenhouse gas emissions, and saving production costs. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 for Figure 1 A sectional view of AA; Figure 3 for Figure 1 A magnified view of a portion of B; Figure 4 for Figure 2 A magnified view of a portion of C; Figure 5 for Figure 2 A magnified view of a portion of D.

[0026] Reference numerals: 1. Mixer housing; 2. Mixing shaft; 21. Heat exchange cavity; 22. Inlet / outlet water connector; 3. Drive mechanism; 4. Arc-shaped shell; 6. Support bar; 61. Water passage hole; 51. Branch inlet pipe; 52. Main inlet pipe; 53. First water pump; 54. First pipe; 55. Water tank; 551. First layer; 552. Second layer; 553. Third layer; 554. Insulation layer; 56. Outlet pipe; 57. Second pipe; 58. Second water pump; 59. Third pipe; 510. Fourth pipe; 511. Third water pump; 512. Fifth pipe; 513. Sixth pipe; 514. Seventh pipe; 515. First solenoid valve; 516. Second solenoid valve; 517. Flow meter; 518. Water level sensor; 519. First temperature sensor; 520. Second temperature sensor; 521. Supply pipe; 100. Heat exchange cavity. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0028] The following is for reference Figures 1 to 5 The present invention will be described as follows: An improved concrete mixing device includes a mixer housing 1 and a pair of mixing shafts 2 rotatably connected to the mixer housing 1. One end of each mixing shaft 2 is connected to a drive mechanism 3 that drives it to rotate. A pair of symmetrically arranged arc-shaped shells 4 are fixed on the arc-shaped outer wall of the mixer housing 1. The arc-shaped shells 4 and the outer wall of the mixer housing 1 form a heat exchange chamber 100. The bottom of each heat exchange chamber 100 is connected to a branch water inlet pipe 51. The two branch water inlet pipes 51 are connected to a main water inlet pipe 52 through a T-joint. The other end of the main water inlet pipe 52 is connected to the outlet end of a first water pump 53. The suction end of the first water pump 53 is connected to a first pipe 54. The other end of the first pipe 54 is connected to the first layer 551 of a water tank 55. The top of the heat exchange chamber 100 is connected to an outlet pipe 56, which is connected to the second layer 552 of the water tank 55.

[0029] The stirring shaft 2 is provided with a heat exchange cavity 21 inside. Each end of the stirring shaft 2 is rotatably connected to a water inlet / outlet connector 22. The water inlet / outlet connectors 22 on the front side of the two stirring shafts 2 are connected to the second pipe 57. The second pipe 57 is connected to the outlet end of the second water pump 58. The end of the second pipe 57 away from the second water pump 58 is sealed. The suction end of the second water pump 58 is connected to a third pipe 59. The third pipe 59 is connected to the second layer 552. The inlet and outlet water connectors 22 on the rear side of the two stirring shafts 2 are connected to the fourth pipe 510. The fourth pipe 510 is connected to the third layer 553 of the water tank 55. The end of the fourth pipe 510 away from the water tank 55 is sealed.

[0030] A third water pump 511 is fixed to the upper part of the water tank 55. The suction end of the third water pump 511 is connected to a fifth pipe 512, which extends into the third layer 553. The outlet end of the third water pump 511 is connected to a sixth pipe 513, which extends into the mixer housing 1. A flow meter 517 is connected to the sixth pipe 513, and the flow meter 517 is electrically connected to the controller.

[0031] The third pipe 59 is bypassed and connected to the seventh pipe 514, and the other end of the seventh pipe 514 is connected to the first pipe 54. A first solenoid valve 515 is connected to the first pipe 54, and the first solenoid valve 515 is located on the upstream side of the seventh pipe 514. The seventh pipe 514 is connected to a second solenoid valve 516. The first solenoid valve 515 and the second solenoid valve 516 are electrically connected to the controller, which controls the first water pump 53, the second water pump 58 and the third water pump 511.

[0032] Each of the first layer 551, the second layer 552, and the third layer 553 is equipped with a water level sensor 518 and a first temperature sensor 519. The heat exchange chamber 100 is connected to a second temperature sensor 520. The water level sensor 518, the first temperature sensor 519, and the second temperature sensor 520 are all electrically connected to the controller. The water level sensor 518 and the first temperature sensor 519 are used to monitor the water level and water temperature of each layer. The second temperature sensor 520 is used to monitor the temperature of the heat exchange chamber 100. If the water temperature in the second layer 552 is lower than the temperature in the heat exchange chamber 100, the water in the second layer 552 can be reheated. Otherwise, it is not necessary.

[0033] The first layer 551 is connected to a supply pipe 521. When the water level in the first layer 551 is detected to be low, municipal water or recycled water can be introduced into the first layer 551 through the supply pipe 521.

[0034] The bottom of the third layer (553) is equipped with an electric heater, which is electrically connected to the controller. If the mixing water temperature is not high enough, the water in the third layer can be heated by the electric heater to reach the required temperature before being pumped into the mixer for mixing.

[0035] A heat insulation layer 554 is provided between the first layer 551 and the second layer 552, and between the second layer 552 and the third layer 553. The heat insulation layer 554 can reduce the heat exchange between the layers. At the same time, the high-temperature water is placed in the upper layer and the low-temperature water is placed in the lower layer, which can also reduce the heat exchange.

[0036] A support strip 6 is sandwiched between the inner wall of the arc-shaped shell 4 and the outer wall of the mixer shell 1. Several water passage holes 61 are formed on the support strip 6. The support strip 6 can support the arc-shaped shell 4 to ensure the shape of the heat exchange chamber 100; the water passage holes 61 can ensure the flow of water, but the setting of the support strip 6 can slow down the flow speed of water so that the water can fully exchange heat.

[0037] Working Principle: Primary Heating / Cooling: Room temperature makeup water enters the first layer 551 of water tank 55 through makeup pipe 521. The controller opens the first solenoid valve 515, closes the second solenoid valve 516, and starts the first water pump 53. Cold water is pumped out from the first layer 551 through the first pipe 54, and enters the two heat exchange chambers 100 from the bottom through the main inlet pipe 52 and two branch inlet pipes 51. After absorbing the frictional heat of the mixer shell 1 in the heat exchange chambers 100, the cold water temperature rises and flows out from the top outlet pipe 56, eventually flowing into the second layer 552 of water tank 55 for storage. The support bar 6 and its water passage holes 61 create turbulent water flow, enhancing heat exchange.

[0038] Secondary heating / cooling: The controller activates the second water pump 58. Warm water in the second layer 552 is pumped into the second pipe 57 via the third pipe 59, and then flows evenly into the inlet / outlet connectors 22 at the front ends of the two stirring shafts 2, entering their heat exchange chambers 21. As the water flows through the high-speed rotating stirring shafts 2, it fully absorbs the frictional heat generated by the shafts, further significantly increasing the water temperature. The final hot water flows out from the inlet / outlet connectors 22 at the rear ends of the stirring shafts 2, enters the fourth pipe 510, and flows into the third layer 553 of the water tank 55 for storage. The insulation layer 554 effectively reduces interlayer heat exchange.

[0039] Used as mixing water: Hot water supply: When the mixer needs water, the controller starts the third water pump 511. The high-temperature hot water in the third layer 553 is pumped into the sixth pipe 513 through the fifth pipe 512. The flow meter 517 monitors the flow rate in real time and feeds it back to the controller. The controller then controls the operation of the third water pump 511 or the opening of the valve to achieve a precise and quantitative supply of hot water to the mixer, thereby increasing the outlet temperature of the concrete.

[0040] Reheating Circulation: The controller compares the readings of the second temperature sensor 520 (casing temperature) and the temperature sensor (water temperature) of the second layer 552 in real time. If it is determined that the heat exchange chamber 100 has excess heat capacity but the water temperature of the second layer 552 is not as expected, the controller closes the first solenoid valve 515 and opens the second solenoid valve 516. At this time, the second water pump 58 pumps the warm water from the second layer 552 directly back to the inlet of the first pipe 54 through the third pipe 59 and the seventh pipe 514, so that it flows through the heat exchange chamber 100 again for "secondary heating", thereby deeply exploiting the excess heat, increasing the final water temperature, and maximizing energy utilization efficiency.

[0041] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications assumed above should also be considered within the scope of protection of the present invention.

Claims

1. An improved concrete mixing device, comprising a mixer housing (1) and a pair of mixing shafts (2) rotatably connected to the mixer housing (1), characterized in that: A pair of symmetrically arranged arc-shaped shells (4) are fixed on the arc-shaped outer wall of the mixer housing (1). The arc-shaped shells (4) and the outer wall of the mixer housing (1) form a heat exchange chamber (100). Each heat exchange chamber (100) is connected to a branch water inlet pipe (51) at the bottom. The two branch water inlet pipes (51) are connected to the main water inlet pipe (52) through a three-way connector. The other end of the main water inlet pipe (52) is connected to the outlet end of the first water pump (53). The suction end of the first water pump (53) is connected to the first pipe (54). The other end of the first pipe (54) is connected to the first layer (551) of the water tank (55). The top of the heat exchange chamber (100) is connected to a water outlet pipe (56), which is connected to the second layer (552) of the water tank (55).

2. The improved concrete mixing device according to claim 1, characterized in that: The stirring shaft (2) is provided with a heat exchange cavity (21) inside. Each end of the stirring shaft (2) is rotatably connected to a water inlet / outlet connector (22). The water inlet / outlet connectors (22) on the front side of the two stirring shafts (2) are connected to the second pipe (57). The second pipe (57) is connected to the outlet end of the second water pump (58). The suction end of the second water pump (58) is connected to the third pipe (59). The third pipe (59) is connected to the second layer (552). The inlet and outlet water connectors (22) on the rear side of the two stirring shafts (2) are connected to the fourth pipe (510), and the fourth pipe (510) is connected to the third layer (553) of the water tank (55).

3. The improved concrete mixing device according to claim 2, characterized in that: A third water pump (511) is fixed on the upper part of the water tank (55). The suction end of the third water pump (511) is connected to a fifth pipe (512), which extends into the third layer (553). The outlet end of the third water pump (511) is connected to a sixth pipe (513), which extends into the mixer housing (1).

4. The improved concrete mixing device according to claim 3, characterized in that: A flow meter (517) is connected to the sixth tube (513).

5. The improved concrete mixing device according to claim 2, characterized in that: The third pipe (59) is bypassed by a seventh pipe (514), and the other end of the seventh pipe (514) is connected to the first pipe (54); A first solenoid valve (515) is connected to the first pipe (54), and the first solenoid valve (515) is located on the upstream side of the seventh pipe (514); The seventh pipe (514) is connected to a second solenoid valve (516).

6. The improved concrete mixing device according to claim 5, characterized in that: Each of the first layer (551), the second layer (552), and the third layer (553) is equipped with a water level sensor (518) and a first temperature sensor (519). The heat exchange chamber (100) is connected to a second temperature sensor (520).

7. The improved concrete mixing device according to claim 6, characterized in that: The first layer (551) is connected to a supply pipe (521).

8. The improved concrete mixing device according to claim 6, characterized in that: An electric heater is provided at the bottom of the third layer (553).

9. The improved concrete mixing device according to claim 2, characterized in that: A heat insulation layer (554) is provided between the first layer (551) and the second layer (552), and between the second layer (552) and the third layer (553).

10. The improved concrete mixing device according to claim 9, characterized in that: A support strip (6) is sandwiched between the inner wall of the arc-shaped shell (4) and the outer wall of the mixer shell (1), and a number of water passage holes (61) are formed on the support strip (6).

Images