Provided is a gypsum-based board producing apparatus including: a mixer configured to prepare a gypsum slurry; a foaming apparatus; and a pump configured to convey foam generated by the foaming apparatus to the mixer, wherein the pump is a positive displacement pump.

This disclosure describes volumetric mobile powder mixer (VMPM) systems and methods for VMPM operation and use. The VMPM is providing with a number of storage compartments (or bins) for liquid or solid ingredients including at least one powder storage bin, a powder transport system, a dust handling system, a solid/liquid mixing system, a cellular foam generator, a product delivery system, and a controller capable of monitoring the delivery and mixing of each of the ingredients, as well as the discharge of the final product. The controller determines if the proper mixture is being discharged by the VMPM and, if not, alerts the VMPM operator. In an automated embodiment, the VMPM controller is also configured to independently control the delivery and mixing of each of the ingredients, as well as the delivery of the final product.

A method of preparing a concrete composition for downhole injection includes utilizing a controller to control a process including circulating process water in a process water supply loop for a predetermined period while monitoring and controlling the temperature and flow rate of the process water, circulating aqueous-based air entrainment solution in an aqueous-based air entrainment solution supply loop for the predetermined period and controlling the flow rate of the aqueous-based air entrainment solution and after the predetermined period of time in which the flow of process water and aqueous-based air entrainment solution have stabilized, simultaneously actuating valves to divert and mix the process water, the aqueous-based air entrainment solution and compressed air to produce an air-entrained foam and mixing the foam with a concrete composition to be deployed downhole.

Manufactures, methods and apparatus are provided through which in some implementations a structural cellular lightweight concrete comprises a concrete mixture that is no more than 65% by volume of the manufacture of structural cellular lightweight concrete, the concrete mixture including concrete conforming to the requirements of ASTM C33; foam that has a density of at least 5 lbs./ft.sup.3, having high stability characteristics, and having a closed cell bubble structure; mix water being potable and free of contamination or deleterious materials; and Portland cement conforming to ASTM C150, the Portland cement being Type I, Type III or White Portland cement, and at least 35% air by volume of the manufacture of structural cellular lightweight concrete.

An apparatus for preparing foam for incorporation into cementitious slurry comprises a conduit having an inlet for receiving a gas feed and a surfactant feed, and an outlet for allowing the exit of foam. The conduit houses a porous plug that provides a partial barrier to fluid flow along the conduit, the plug comprising a plurality of particles that are packed in a regular array and that define a three-dimensional network of pores extending therebetween. The apparatus comprises a resilient component located between the plug and the conduit.

Provided is a gypsum-based board producing apparatus including: a mixer configured to prepare a gypsum slurry; a foaming apparatus; and a pump configured to convey foam generated by the foaming apparatus to the mixer, wherein the pump is a positive displacement pump.

An apparatus for preparing foam for incorporation into cementitious slurry comprises a conduit having an inlet for receiving a gas feed and a surfactant feed, and an outlet for allowing the exit of foam. The conduit houses a porous plug that provides a partial barrier to fluid flow along the conduit, the plug comprising a plurality of particles that are packed in a regular array and that define a three-dimensional network of pores extending therebetween. The apparatus comprises a resilient component located between the plug and the conduit.

Provided is a production process for a nitrogen foamed concrete self-insulating block, comprising the following steps: pre-preparing a foaming liquid filled with nitrogen, pre-preparing a concrete slurry, preparing a foamed concrete slurry, casting moulding, carrying out thermal insulating and demoulding. At the same time, further provided is a foaming device used for the production process for a nitrogen foamed concrete self-insulating block, comprising a foaming agent storage tank, a vacuum foaming tank, a compressed nitrogen pipe, a first transfer pump and a second transfer pump. The block has the advantages of a low heat conductivity coefficient and durability.

A discharge gate is provided for a gypsum slurry mixer, and includes a lower member having an inlet opening configured for receiving the slurry, and an outlet opening configured for delivering the slurry to a dispensing device. An upper member is attached to the lower member, at least one of the upper and lower members having at least one opening for accommodating insertion of an injection port for introducing the foam to the slurry. A cavity is configured for mixing the foam and slurry, and is defined by inner surfaces of the lower member and the upper member.

An apparatus for preparing foam for incorporation into cementitious slurry comprises a conduit having an inlet for receiving a gas feed and a surfactant feed, and an outlet for allowing the exit of foam. The conduit houses a porous plug that provides a partial barrier to fluid flow along the conduit, the plug comprising a plurality of particles that are packed in a regular array and that define a three-dimensional network of pores extending therebetween. The apparatus comprises a resilient component located between the plug and the conduit.